Scaffolding poles + old VW bits + Rotary engine....
Discussion
+ 2 daft buggers in a shed with a set of hammers and bigger hammers gives.....(sorry if some of this doesn't make sense, straight copy, paste job from elsewhere, if you spot something let me know and I'll go through and fix it!)....this:
It's been done between me and my mate Ed (his car), he originally built up the frame as a cheap car to compete in the local regional championships in, total build cost was around £3k originally, which is fairly cheap as there are some machines in the championships costing between £30-80k+.
The build started before I even knew Ed a fair few years back, cost and time constraints had meant the car had been built around heavily modified VW torsion bar suspension bought in from the states (they use in on their Baja buggies so it's cheap and works reasonably well).
The engine was a bored and stroked 2.1 Beetle unit, on twin 45's, mild camshaft and various modifications to the rockers and heads.
The first time I met him, I gave it the once over and told him the dizzy would give him problems, it wasn't too healthy, and had been mucked about with to stop the engine pinging (given it was original designed as a 1.6 litre unit...)
Anyhow, a phonecall shortly after he attended his first event revealed the dizzy had exploded and scuppered any chance of a finish.
Which resulted in a fair amount of p*ss taking for the next week, and eventually ended up with me getting roped in for years of work on the bloody thing afterword, should have kept quiet
So the last few years we've been working the buggy over between us with upgrades here there and everywhere, ready to enter it in the british championship rather than the few clubman events we've run in on shakedown tests, it's been stripped bare a few times, and work had been seriously slow on it for the previous 6 months because of work commitments (few orders for the 4wd rally cars in his brothers workshops).
Anyway, being a 2wd budget vehicle, the racing should be interesting, there are no weight limits on 2wd vehicles, whereas most 4wd cars are 1200 kilo's plus, so we're half a tonne up already with more to loose yet...
Back to history, the original engine specifications were along these lines:
2.1L VW aircooled engine, build from 1.6 unit.
- 4-1 manifold,
- Carbon/Mica filled PTFE gaskets,
- Dellorto 45's + custom inlet manifold
- Engle 120 camshaft
- Needle roller rockers, high lift 1.4:1 ratio
- Full flow casing with external oil coolers
- Modified cowling with electric fan assist.
- Counterbalanced forged steel crank.
- 3D ignition system (MegaJolt, built it for him after the dizzy problems), I did the ignition mapping DIY.
Along the way the buggy has had several new rear ends, 4 suspension setups, a new front end, 3 different gearboxes/linkages/pedal setups, and 3 different braking setups, I'll go into detail on these at some point.
Now, that may sound excessive and a bit chop and change - but usually they've coincided with a change in the chassis (or an exploding gearbox...) in order to keep the entire chassis working as well as we could within our budget.
The first change came shortly after it's second event, in which there were a few problems, the first was some pretty crap rear pads, they were originally sponsors of the local club series so they had to be used - they were bright green ones
- fell to pieces, and the backing plates then ground into the disc, welded themselves there and then ground away at the hub.
The result of which was some different pads, Mintex 1144's with the backing plates painted green on the rear, Wilwood Poly A's up front - then Hi-spec 4 pots fitted at the rear and some new discs.
The second was the gearbox exploding, this was the original box sourced with the engine so it was to be expected, another box was duly sought, and the engine and rear frame pulled out for fitment, the new box was a five speed version though, which gave us a little more pace as the VW tended to drop off cam, this was later resolved through some careful carb jetting and linkage tweaks, but the shorter gears were welcome at the time.
Of course, the problem with a five speed box is that it's slightly longer, which meant a simple gearbox change meant we had to rejig all the linkages, the cabling, and the entire back end and engine mounts needed moving an inch back.
This in itself mean the driveshafts had to be altered, and new panels formed up out of ally sheet.
So next time you are swearing during a gearbox swap, just remember, it could be worse....
The fun is in getting the engine on the box (yes, that is the right way around), which takes 4-5 goes to get the splines located right, which, when you are holding an engine made from sharp aircooling fins, gets you some funny looks when you've a dozen 'scratch marks' in a pattern down your arms, whoops.
The second box came around 2 events later on, after a final drive turned itself into smeared lump in objection to landing a 6ft drop off a small quarry under full power. Ah well, the joys of cars built out of scrapyard bits
This time we sourced several boxes while we decided what to do with it, the engine was down on power and there was a brand new 3.5 Nissan V6 sat on a crate in the workshop, a Porsche carrera 4wd box was duly acquired by Ed, along with a standard 2wd box.
It was decided to stay 2wd as they're more fun to drive, and it's more fun when you leave the 4wd boys, and it would have taken us about 10 times our budget to do what we wanted properly - unfortunately the next events were fairly soon, and there was no way the 3.5 V6 was going to shoehorn in with the necessary plumbing without a complete new rear end and suspension setup, so in went a 5-speed Renault Master van gearbox, complete with 9" differential, again, this meant new linkages and tweaks to the chassis, along with a spring change due to the different CoG, we finished at 4:30 the morning of the next event....
[i]Now, the problem with concentrating mainly on sorting out the rear, is that, at 5:30am, the morning of the event, after a short nap, you really don't want a whining noise to appear on the shakedown drive before loading it up on the lorry.
You most definately don't want that sound to be whining front wheel bearing, and you definately don't want to be 2 miles from home when it starts getting worse. [/i]
Once a bearing goes on something like this, they don't last long at all under the impact stresses, unlike in a car where it'll whine for 2000 miles, you're lucky to get 2000 yards...
Unfortunately, the smallest of the workshops must be 2010 yards away, because the wheel fell off trundling around the last corner back to it.
In itself that's not a problem, the way the buggy is setup you can post a running stage time with just 3 wheels.........
What IS a problem, is that fabricated steel wheel, meeting a beautiful but rather softer alloy Wilwood '5-star' rally hub.
After turning the 5-star hub into a 1-disc smear, it decided to take a chunk out of the from calipers just for kick before it did it's party trick of wandering off down the lane.
Shiiiittttt.
We've got spare bearings, but no spare hubs, so that's the end of that event already, what fun.
Fortunately, I was driving back up to the workshops at the time, so I just caught Ed running around the corner before a wheel fell off, which gave me a laugh, even if it didn't him.
The next event was the final one we attended before taking it back in the workshop for a rethink, a local club event where you can just turn up and drive, all went well that morning, bar getting the lorry stuck in the staging area and having to tow it out.
The engine was running a little rough, but then, it's been due some new piston rings and probably some new shells for a while, but we couldn't see the point of spending money on the VW engine, it does the job but when it goes bang, well, there was that V6 waiting in the workshop....
This probably annoyed the poor overworked veedub, after being originally designed as a 1.6 with about 40 horsepower, for some greasemonkey to pull it apart, subject it to a bore out of existing holes, put in holes that shouldn't be there, push the output to 120bhp and then run it at 5000rpm, solid mounted to a buggy driven by a pair of nutters with suicidal tendancies, well, perhaps it had every right to to be a bit ****ed off and spit a shell that day....
The competition in the 2wd class included an RS200 look-a-like, and a similar machine to ours but with a long-travel double wishbone front end, 1.6 turbo engine with ~190bhp (More like around 120 when it got going tbh!), but it had a pretty poor frame compared to ours.
We were quite happy after the first run, setting a time 12 seconds faster than him (7 mile stage), which got us some mutterings about his power steering failing and his engine overheating.
What we didn't tell him was we'd had to stop for 30 seconds at the bottom of the hill as the carbs flooded the engine because of bouncing floats, and we'd noted better lines that should pick up another 10 seconds...well, no point rubbing it in is there, that's what the next lap is for....
Especially when you'd lost time yourself as the VW had thrown a belt and you'd lost PAS and overheated the engine yourself.
After rigging a new belting system up, we were ready to go out for the second stage, with a better idea of the course allowing Ed to pick up the pace on the corners and avoid the ripples on the exit to get the power down, we worked out at 43 seconds up from our last time around after two thirds of the way around the course, on par with the 4wd guys running there, but we were loosing power, the engine was starting to blow a little smoke, but we had to finish the stage to get back to service area anyway, so full throttle it is.
Out of the marshland they called a corner halfway around the course, the car simply would not slog it's way out of the mud, struggling to pull second gear where normally we would have been in the top of third, onto the next straight, top of 5th at ~80mph over ripples - imagine speedbumps 2 feet apart at 80mph - and the engine spun a shell, the shock and friction as it attempted to weld to the crank dropped the engine revs massively and with a locked rear axle and the back end already snaking as it was putting the power down over the ripples, the car immediately spun several times, we ended up travelling backwards at around 60-70mph, downhill on wet grass toward a stone wall.
Now, we weren't too concerned about the buggy as we know how strong it is - the entire frame is T45 tubing, it would have made a mess but be fixable - but we knew for a fact that there were spectators behind the wall and the buggy would flatten it like a bowling ball hitting smarties tubes, or go over the top.
With Ed hard on the footbrake and attempting to bring the front end back around with the steering, I hung onto the left hand fiddle brake and between us we managed to slew the buggy around to a stop away from the wall.
Some good natured cursing ensued in the fight to restart the engine, which luckily hadn't welded itself solid, and once it fired into a nice, uneven beat with lashings of rattles, we limped the remainder of the stage in first gear, and announced our retirement to the marshalls.
We posted an 8m40s stage time.
Which amusingly was still faster than a third of the competitors...so the car had a bit of potential against the local club racers.
Ooops:
The diagnosis was terminal, we went home and hatched plans, coming to the conclusion that the 3.5 V6 was just too big for the current chassis and we may as well start from scratch with it - as we could use it as a stressed member for a double wishbone front and rear.
Given the buggy was meant to be a low-budget challenge, this was wiped off the list and an RX-8 renesis engine accidentally made it's way into the workshop.
Quick rundown on the chassis before I go into the Renesis conversion:
Chassis-
- Mixture of 2-3" T45 steel tubing, mandrel bent and welded, weight is a touch over 750 kilos. You can quite happily lift the front with one person and walk around with the car.
- Rear setup are 4 gas pressure monotubes, consisting of 2 Bilstein dampers, 2 Fox adjustable coilovers, all remote res. nitrogen charged, giving around 14 inches of rear suspension travel, these act on a rear torsion bar setup with heavily braced arms, again, made from T45 tube, the bars are rising rate and there's a secondary assist bar which comes into play after 10" of travel.
- Front setup is now 2 Fox coilovers aiding a rising rate twin torsion bar front end adapted from the VW setup, approximately 12" of travel up front.
- Brakes are a mixture of small 2 pot Wilwoods up front and Hispec 4 pots on the back, linked with braided hoses to 2 AP master cylinders on a balance bar with a homemade pedal box, it also sports a hydraulic handbrake/fiddle brake setup to brake individual wheels for turning the front end in quicker (or donuts).
Solid discs (less weight) all around matched with the uprated pads.
- Wheels were our own steels - 15x6J, made by by Ed, weighing in at 5.8kilos, fitted with 215/75 Bridgestone MS's.
It's absolutely hilarious to drive, but not exactly the most sophisticated or good-looking car in the world I'll admit :lmao
Phillip said:
It's been done between me and my mate Ed (his car), he originally built up the frame as a cheap car to compete in the local regional championships in, total build cost was around £3k originally, which is fairly cheap as there are some machines in the championships costing between £30-80k+.
The build started before I even knew Ed a fair few years back, cost and time constraints had meant the car had been built around heavily modified VW torsion bar suspension bought in from the states (they use in on their Baja buggies so it's cheap and works reasonably well).
The engine was a bored and stroked 2.1 Beetle unit, on twin 45's, mild camshaft and various modifications to the rockers and heads.
The first time I met him, I gave it the once over and told him the dizzy would give him problems, it wasn't too healthy, and had been mucked about with to stop the engine pinging (given it was original designed as a 1.6 litre unit...)
Anyhow, a phonecall shortly after he attended his first event revealed the dizzy had exploded and scuppered any chance of a finish.
Which resulted in a fair amount of p*ss taking for the next week, and eventually ended up with me getting roped in for years of work on the bloody thing afterword, should have kept quiet
So the last few years we've been working the buggy over between us with upgrades here there and everywhere, ready to enter it in the british championship rather than the few clubman events we've run in on shakedown tests, it's been stripped bare a few times, and work had been seriously slow on it for the previous 6 months because of work commitments (few orders for the 4wd rally cars in his brothers workshops).
Anyway, being a 2wd budget vehicle, the racing should be interesting, there are no weight limits on 2wd vehicles, whereas most 4wd cars are 1200 kilo's plus, so we're half a tonne up already with more to loose yet...
Back to history, the original engine specifications were along these lines:
2.1L VW aircooled engine, build from 1.6 unit.
- 4-1 manifold,
- Carbon/Mica filled PTFE gaskets,
- Dellorto 45's + custom inlet manifold
- Engle 120 camshaft
- Needle roller rockers, high lift 1.4:1 ratio
- Full flow casing with external oil coolers
- Modified cowling with electric fan assist.
- Counterbalanced forged steel crank.
- 3D ignition system (MegaJolt, built it for him after the dizzy problems), I did the ignition mapping DIY.
Along the way the buggy has had several new rear ends, 4 suspension setups, a new front end, 3 different gearboxes/linkages/pedal setups, and 3 different braking setups, I'll go into detail on these at some point.
Now, that may sound excessive and a bit chop and change - but usually they've coincided with a change in the chassis (or an exploding gearbox...) in order to keep the entire chassis working as well as we could within our budget.
The first change came shortly after it's second event, in which there were a few problems, the first was some pretty crap rear pads, they were originally sponsors of the local club series so they had to be used - they were bright green ones
- fell to pieces, and the backing plates then ground into the disc, welded themselves there and then ground away at the hub.The result of which was some different pads, Mintex 1144's with the backing plates painted green on the rear, Wilwood Poly A's up front - then Hi-spec 4 pots fitted at the rear and some new discs.
The second was the gearbox exploding, this was the original box sourced with the engine so it was to be expected, another box was duly sought, and the engine and rear frame pulled out for fitment, the new box was a five speed version though, which gave us a little more pace as the VW tended to drop off cam, this was later resolved through some careful carb jetting and linkage tweaks, but the shorter gears were welcome at the time.
Of course, the problem with a five speed box is that it's slightly longer, which meant a simple gearbox change meant we had to rejig all the linkages, the cabling, and the entire back end and engine mounts needed moving an inch back.
This in itself mean the driveshafts had to be altered, and new panels formed up out of ally sheet.
So next time you are swearing during a gearbox swap, just remember, it could be worse....
The fun is in getting the engine on the box (yes, that is the right way around), which takes 4-5 goes to get the splines located right, which, when you are holding an engine made from sharp aircooling fins, gets you some funny looks when you've a dozen 'scratch marks' in a pattern down your arms, whoops.
The second box came around 2 events later on, after a final drive turned itself into smeared lump in objection to landing a 6ft drop off a small quarry under full power. Ah well, the joys of cars built out of scrapyard bits
This time we sourced several boxes while we decided what to do with it, the engine was down on power and there was a brand new 3.5 Nissan V6 sat on a crate in the workshop, a Porsche carrera 4wd box was duly acquired by Ed, along with a standard 2wd box.
It was decided to stay 2wd as they're more fun to drive, and it's more fun when you leave the 4wd boys, and it would have taken us about 10 times our budget to do what we wanted properly - unfortunately the next events were fairly soon, and there was no way the 3.5 V6 was going to shoehorn in with the necessary plumbing without a complete new rear end and suspension setup, so in went a 5-speed Renault Master van gearbox, complete with 9" differential, again, this meant new linkages and tweaks to the chassis, along with a spring change due to the different CoG, we finished at 4:30 the morning of the next event....
[i]Now, the problem with concentrating mainly on sorting out the rear, is that, at 5:30am, the morning of the event, after a short nap, you really don't want a whining noise to appear on the shakedown drive before loading it up on the lorry.
You most definately don't want that sound to be whining front wheel bearing, and you definately don't want to be 2 miles from home when it starts getting worse. [/i]
Once a bearing goes on something like this, they don't last long at all under the impact stresses, unlike in a car where it'll whine for 2000 miles, you're lucky to get 2000 yards...
Unfortunately, the smallest of the workshops must be 2010 yards away, because the wheel fell off trundling around the last corner back to it.
In itself that's not a problem, the way the buggy is setup you can post a running stage time with just 3 wheels.........
What IS a problem, is that fabricated steel wheel, meeting a beautiful but rather softer alloy Wilwood '5-star' rally hub.
After turning the 5-star hub into a 1-disc smear, it decided to take a chunk out of the from calipers just for kick before it did it's party trick of wandering off down the lane.
Shiiiittttt.
We've got spare bearings, but no spare hubs, so that's the end of that event already, what fun.
Fortunately, I was driving back up to the workshops at the time, so I just caught Ed running around the corner before a wheel fell off, which gave me a laugh, even if it didn't him.
The next event was the final one we attended before taking it back in the workshop for a rethink, a local club event where you can just turn up and drive, all went well that morning, bar getting the lorry stuck in the staging area and having to tow it out.
The engine was running a little rough, but then, it's been due some new piston rings and probably some new shells for a while, but we couldn't see the point of spending money on the VW engine, it does the job but when it goes bang, well, there was that V6 waiting in the workshop....
This probably annoyed the poor overworked veedub, after being originally designed as a 1.6 with about 40 horsepower, for some greasemonkey to pull it apart, subject it to a bore out of existing holes, put in holes that shouldn't be there, push the output to 120bhp and then run it at 5000rpm, solid mounted to a buggy driven by a pair of nutters with suicidal tendancies, well, perhaps it had every right to to be a bit ****ed off and spit a shell that day....
The competition in the 2wd class included an RS200 look-a-like, and a similar machine to ours but with a long-travel double wishbone front end, 1.6 turbo engine with ~190bhp (More like around 120 when it got going tbh!), but it had a pretty poor frame compared to ours.
We were quite happy after the first run, setting a time 12 seconds faster than him (7 mile stage), which got us some mutterings about his power steering failing and his engine overheating.
What we didn't tell him was we'd had to stop for 30 seconds at the bottom of the hill as the carbs flooded the engine because of bouncing floats, and we'd noted better lines that should pick up another 10 seconds...well, no point rubbing it in is there, that's what the next lap is for....
Especially when you'd lost time yourself as the VW had thrown a belt and you'd lost PAS and overheated the engine yourself.
After rigging a new belting system up, we were ready to go out for the second stage, with a better idea of the course allowing Ed to pick up the pace on the corners and avoid the ripples on the exit to get the power down, we worked out at 43 seconds up from our last time around after two thirds of the way around the course, on par with the 4wd guys running there, but we were loosing power, the engine was starting to blow a little smoke, but we had to finish the stage to get back to service area anyway, so full throttle it is.
Out of the marshland they called a corner halfway around the course, the car simply would not slog it's way out of the mud, struggling to pull second gear where normally we would have been in the top of third, onto the next straight, top of 5th at ~80mph over ripples - imagine speedbumps 2 feet apart at 80mph - and the engine spun a shell, the shock and friction as it attempted to weld to the crank dropped the engine revs massively and with a locked rear axle and the back end already snaking as it was putting the power down over the ripples, the car immediately spun several times, we ended up travelling backwards at around 60-70mph, downhill on wet grass toward a stone wall.
Now, we weren't too concerned about the buggy as we know how strong it is - the entire frame is T45 tubing, it would have made a mess but be fixable - but we knew for a fact that there were spectators behind the wall and the buggy would flatten it like a bowling ball hitting smarties tubes, or go over the top.
With Ed hard on the footbrake and attempting to bring the front end back around with the steering, I hung onto the left hand fiddle brake and between us we managed to slew the buggy around to a stop away from the wall.
Some good natured cursing ensued in the fight to restart the engine, which luckily hadn't welded itself solid, and once it fired into a nice, uneven beat with lashings of rattles, we limped the remainder of the stage in first gear, and announced our retirement to the marshalls.
We posted an 8m40s stage time.
Which amusingly was still faster than a third of the competitors...so the car had a bit of potential against the local club racers.
Ooops:
The diagnosis was terminal, we went home and hatched plans, coming to the conclusion that the 3.5 V6 was just too big for the current chassis and we may as well start from scratch with it - as we could use it as a stressed member for a double wishbone front and rear.
Given the buggy was meant to be a low-budget challenge, this was wiped off the list and an RX-8 renesis engine accidentally made it's way into the workshop.
Quick rundown on the chassis before I go into the Renesis conversion:
Chassis-
- Mixture of 2-3" T45 steel tubing, mandrel bent and welded, weight is a touch over 750 kilos. You can quite happily lift the front with one person and walk around with the car.
- Rear setup are 4 gas pressure monotubes, consisting of 2 Bilstein dampers, 2 Fox adjustable coilovers, all remote res. nitrogen charged, giving around 14 inches of rear suspension travel, these act on a rear torsion bar setup with heavily braced arms, again, made from T45 tube, the bars are rising rate and there's a secondary assist bar which comes into play after 10" of travel.
- Front setup is now 2 Fox coilovers aiding a rising rate twin torsion bar front end adapted from the VW setup, approximately 12" of travel up front.
- Brakes are a mixture of small 2 pot Wilwoods up front and Hispec 4 pots on the back, linked with braided hoses to 2 AP master cylinders on a balance bar with a homemade pedal box, it also sports a hydraulic handbrake/fiddle brake setup to brake individual wheels for turning the front end in quicker (or donuts).
Solid discs (less weight) all around matched with the uprated pads.
- Wheels were our own steels - 15x6J, made by by Ed, weighing in at 5.8kilos, fitted with 215/75 Bridgestone MS's.
It's absolutely hilarious to drive, but not exactly the most sophisticated or good-looking car in the world I'll admit :lmao
Edited by PhillipM on Sunday 23 May 11:49
Edited by PhillipM on Friday 22 April 11:53
Phillip said:
Right, job number one was to mock up and adapter plate to get the RX-8 engine onto the VW gearbox, as well as machine a new flywheel with a counterbalance weight to fit a smaller clutch, as the the Mazda unit is too large for the bellhousing.
So, a decent 2800lb pressure plate, plus an AP cerametallic 3-puck clutch plate, with the centre cut out and a VW one pressed in, made it's way onto the engine:
Which lets us bolt the engine on for mock-up of the ancillaries and hoses, before taking it back off and machining the various brackets and fixtures out of ally to keep the weight down - it's easier to mock-up in steel as you can just whack the MIG on it to tack something in place - but it's a hell of a weight penalty when you add up the amount of brackets and adaptors on a car, so all the final versions will be ally where they can be.
And a couple of hours work to get the exhaust manifold sorted out - unequal length manifold as the centre port is siamesed on these, like an a-series, so the centre branch meets at a different length to the others to keep it from causing problems with pulse tuning.
As you can see, still not touched the plumbing!
We've kept the standard intake manifold on this engine, as although it's quite large, it's an extremely good design, with several variable intake ports on it, replacing it with throttle bodies would result in a marginal top end gain for the cost of a huge amount of midrange.
We had massive problems with a fooked microtech ECU we were supplied, which isn't fun when the only bloke who maps them is several hours trip away and really couldn't be arsed to do our car anyway - we took 4 trips over there and the car ran like a bag of s*it even after switching to DTA instead, bearing in mind this guy is a rotary specialist we got led up a lot of blind alleys with regard to the fuel system - one trip to our normal DTA mapper and the car now flies. Hmm.
That set us back month and a large sum of money we didn't really have to spend.
A month or so later on and the car had the rest of the exhaust made up, a new crank trigger wheel on for the DTA to read (they're a right pain to make up!), most of the plumbing in, and the loom stripped out for wiring to begin, hence the big pile of old wiring on the floor:
A new rear bonnet to keep it all dry:
And we finally got the thing running after about 6 months work, there were still a few jobs left to do on it, and a lot to tidy up, including another trip to the dyno having a flat spot sorted out and the top end mapped to account for getting the final variable inlet stage working - the rev. limiter is at 9600rpm...
Hopefully, we should soon be back to this:
We'll run this car for a year or two to prove the drivetrain, then sell it and make a new car with the RX8 engine (well, the new 1.6L version, when it arrives) in the middle where it should be, multi-link wishbones and a body with at least some kind of nod to aero
Some more to come yet...
So, a decent 2800lb pressure plate, plus an AP cerametallic 3-puck clutch plate, with the centre cut out and a VW one pressed in, made it's way onto the engine:
Which lets us bolt the engine on for mock-up of the ancillaries and hoses, before taking it back off and machining the various brackets and fixtures out of ally to keep the weight down - it's easier to mock-up in steel as you can just whack the MIG on it to tack something in place - but it's a hell of a weight penalty when you add up the amount of brackets and adaptors on a car, so all the final versions will be ally where they can be.
And a couple of hours work to get the exhaust manifold sorted out - unequal length manifold as the centre port is siamesed on these, like an a-series, so the centre branch meets at a different length to the others to keep it from causing problems with pulse tuning.
As you can see, still not touched the plumbing!
We've kept the standard intake manifold on this engine, as although it's quite large, it's an extremely good design, with several variable intake ports on it, replacing it with throttle bodies would result in a marginal top end gain for the cost of a huge amount of midrange.
We had massive problems with a fooked microtech ECU we were supplied, which isn't fun when the only bloke who maps them is several hours trip away and really couldn't be arsed to do our car anyway - we took 4 trips over there and the car ran like a bag of s*it even after switching to DTA instead, bearing in mind this guy is a rotary specialist we got led up a lot of blind alleys with regard to the fuel system - one trip to our normal DTA mapper and the car now flies. Hmm.
That set us back month and a large sum of money we didn't really have to spend.
A month or so later on and the car had the rest of the exhaust made up, a new crank trigger wheel on for the DTA to read (they're a right pain to make up!), most of the plumbing in, and the loom stripped out for wiring to begin, hence the big pile of old wiring on the floor:
A new rear bonnet to keep it all dry:
And we finally got the thing running after about 6 months work, there were still a few jobs left to do on it, and a lot to tidy up, including another trip to the dyno having a flat spot sorted out and the top end mapped to account for getting the final variable inlet stage working - the rev. limiter is at 9600rpm...
Hopefully, we should soon be back to this:
We'll run this car for a year or two to prove the drivetrain, then sell it and make a new car with the RX8 engine (well, the new 1.6L version, when it arrives) in the middle where it should be, multi-link wishbones and a body with at least some kind of nod to aero
Some more to come yet...
Edited by PhillipM on Sunday 23 May 11:49
Yep, more to read yet - I hope that's a big cup of coffee your sat with
Phillip said:
A little more work squeezed in over the past few weeks - made the doors (as doors or nets are now compulsary), with tubular ally frames and thermoformed polycarb over the top, new front bulkhead made to clear the new brake cylinders.
There's a pair of new front calipers on the way as the old ones are too far gone now to be worth refurbishing (they are 30 years old....), plus new pads.
I'll be machining some new discs up for it this week as the old ones have warped very badly from the sticking front calipers (they're about 3mm out )
After that a quick strip down of the front suspension to replace some worn beam bearings and then it's finally ready to roll.
New discs for it I've had made up from some CGI iron plate:
Ideally the rear needs to go vented now we have 260-odd bhp, but they'll do for now until we've got some pennies spare, as always it's gone over budget!
After fitting new calipers/pads/discs and building the scoop for the rear bonnet, along with finishing off the meshing, and rebuilding the front suspension, we went off to Newstead last weekend to finally compete.
Unfortunately the going was so sandy/boggy that we were running for miles at full throttle, which resulted in the fuel boiling in the injector rail from the buildup of heat in the engine bay.
Which means this week we're lifting the rear scoop upwards and forwards into cleaner air, meshing the rear panel by the exhaust manifold, and wrapping the fuel rail to keep it insulated.
We'll probably double skin the exhaust too as that's where most of the heat-soak is coming from - rotaries run silly exhaust temperatures, the outer two headers get cherry red, butthe shared center runner glows orange right up to the collector!
Back end as it stands after a wash - going to add some mesh, bring the scoop up and above the roof:
There's a pair of new front calipers on the way as the old ones are too far gone now to be worth refurbishing (they are 30 years old....), plus new pads.
I'll be machining some new discs up for it this week as the old ones have warped very badly from the sticking front calipers (they're about 3mm out
)After that a quick strip down of the front suspension to replace some worn beam bearings and then it's finally ready to roll.
New discs for it I've had made up from some CGI iron plate:
Ideally the rear needs to go vented now we have 260-odd bhp, but they'll do for now until we've got some pennies spare, as always it's gone over budget!
After fitting new calipers/pads/discs and building the scoop for the rear bonnet, along with finishing off the meshing, and rebuilding the front suspension, we went off to Newstead last weekend to finally compete.
Unfortunately the going was so sandy/boggy that we were running for miles at full throttle, which resulted in the fuel boiling in the injector rail from the buildup of heat in the engine bay.
Which means this week we're lifting the rear scoop upwards and forwards into cleaner air, meshing the rear panel by the exhaust manifold, and wrapping the fuel rail to keep it insulated.
We'll probably double skin the exhaust too as that's where most of the heat-soak is coming from - rotaries run silly exhaust temperatures, the outer two headers get cherry red, butthe shared center runner glows orange right up to the collector!
Back end as it stands after a wash - going to add some mesh, bring the scoop up and above the roof:
Edited by PhillipM on Sunday 23 May 11:49
Still going
Which was hilarious, and highlighted a few issues with breathers and bits, so was worth going!
But a few days later...
We sourced a new box thanks to a very nice bloke over on the PPC forums, problem was, it had stripped the splines on one of the driveshafts from the shock too, and they are custom-made jobbies, quite a cost....
Fix that, make some changes to better bearings in the 'box and finally, off to Radnor for another race:
Some photo's from that event:
And it even finished at the next event at crickhowell too, again, 1st in class:
More to come, we haven't finished breaking it yet
Phillip said:
This is one for all you polishing fanatics, how to clean the underside of your car the lazy way:
That's a mere 100+ kilos of mud, gravel and sheep s*it you can see washing away under the car....
After that we set to work again, air intake has been shifted around to the side and ducted forward to a scoop, the bottom rear panel by the headers has been meshed to allow some airflow over them, and the entire exhaust has gone off to be ceramic coated, there larger meshed area around the rear to let some more air out and some ceramic blanket around the fuel lines to stop them picking up so much heat from the engine bay
Just got to work out how to sort the roof scoop out and we'll be motoring again
A week later....That's a mere 100+ kilos of mud, gravel and sheep s*it you can see washing away under the car....
After that we set to work again, air intake has been shifted around to the side and ducted forward to a scoop, the bottom rear panel by the headers has been meshed to allow some airflow over them, and the entire exhaust has gone off to be ceramic coated, there larger meshed area around the rear to let some more air out and some ceramic blanket around the fuel lines to stop them picking up so much heat from the engine bay
Just got to work out how to sort the roof scoop out and we'll be motoring again
Phillip said:
The buggy now has nice ally roof scoop and rejigged hinges, plus an air intake scoop to take air from the high pressure area at the top of the windscreen, the exhaust collector and manifold has gained a couple more heatshields and there's been a few alterations to the panels for the engine air intake and cooling around the exhaust manifold.
We've cut down the rear bulkhead to the 'V' in the rear cross and then panelled that up to the roof to give a large airbox for the radiator to draw from and to remove the restriction the rear rollover hoop would cause with the new roof scoop.
And then we headed to Oulton Park for a drift day in lieu of having somewhere to test:We've cut down the rear bulkhead to the 'V' in the rear cross and then panelled that up to the roof to give a large airbox for the radiator to draw from and to remove the restriction the rear rollover hoop would cause with the new roof scoop.
Phillip said:
But a few days later...
Phillip said:
Had a synchro failure on 3rd gear a couple of days before the first event 
So, engine out, shafts off, radiators out, loom out, gearbox out, new box in...
So, with that done, off to another event, nothing else can go wrong now, surely?!So, engine out, shafts off, radiators out, loom out, gearbox out, new box in...
Phillip said:
Made it to Waterbeach this weekend for a bit of fun, unfortunately with a sporadic engine cut out problem which I suspect is the alternator given the battery voltage is dropping.
That and the melted alternator terminal...
Got a few good runs in though and shook the revised front suspension down - spent last week realigning it, new springs, alter the dampers and changed the bumpstops and torsion bar rates, the front is about spot on now, in fact we went over 2 foot by 2 foot square trenches without being able to feel it through the car, so that's working well.
The rear is on the soft side so we're just waiting for some new springs now, it's fine whilst in the forests or along most of the bumpy stuff, but it slams the rear skid plate onto the floor on the bigger jumps, always knew it wanted harder rear springs but now we know how much to go with, so the suspension is finally working at last.
Still wants the dampers altering a bit but that's a winter job.
She still runs a bit too warm even with the new scoop, so the exhaust manifold is coming off to be given an internal and external ceramic powdercoat, as it's the heat building up around the engine causing problems rather than the water/oil temp, it was damned warm weather though, which didn't help - 21* and blue skies, better than rain but wasn't helping the engine!
Ended up having to shortshift and leave it in third in the tight stuff and letting it haul itself out to keep the exhaust temperatures down (and whoever says rotaries have no torque wants to come and sit in this thing, when it pulls itself from axle deep, out of soil full of clay, in a forest, at 2krpm in 3rd...)
Other than that she's doing well at last, it might actually do a full event next month!
Got to try and sort a bit more silencing though, 105db driveby and 104 static where everyone else was 104 static and ~90db driveby....whooops
Broken as normal:
Sorted, fix those and it should all be peachy...no?That and the melted alternator terminal...
Got a few good runs in though and shook the revised front suspension down - spent last week realigning it, new springs, alter the dampers and changed the bumpstops and torsion bar rates, the front is about spot on now, in fact we went over 2 foot by 2 foot square trenches without being able to feel it through the car, so that's working well.
The rear is on the soft side so we're just waiting for some new springs now, it's fine whilst in the forests or along most of the bumpy stuff, but it slams the rear skid plate onto the floor on the bigger jumps, always knew it wanted harder rear springs but now we know how much to go with, so the suspension is finally working at last.
Still wants the dampers altering a bit but that's a winter job.
She still runs a bit too warm even with the new scoop, so the exhaust manifold is coming off to be given an internal and external ceramic powdercoat, as it's the heat building up around the engine causing problems rather than the water/oil temp, it was damned warm weather though, which didn't help - 21* and blue skies, better than rain but wasn't helping the engine!
Ended up having to shortshift and leave it in third in the tight stuff and letting it haul itself out to keep the exhaust temperatures down (and whoever says rotaries have no torque wants to come and sit in this thing, when it pulls itself from axle deep, out of soil full of clay, in a forest, at 2krpm in 3rd...)
Other than that she's doing well at last, it might actually do a full event next month!
Got to try and sort a bit more silencing though, 105db driveby and 104 static where everyone else was 104 static and ~90db driveby....whooops
Broken as normal:
NotAHappyChappy said:
Well, we've finally sorted the brakes, solved the cooling problems, and fitted a new alternator to sort out the electrical gremlins.
Took it for a nice 10 mile test run with nothing but a very slightly slipping clutch.
Back in the workshop, adjust the clutch, back down to the test track, perfect, no slipping.
2 minutes down the track, into 4th gear, BANG.
No drive :angry:
Maybe not then, I'm beginning to think the car was cursed....Took it for a nice 10 mile test run with nothing but a very slightly slipping clutch.
Back in the workshop, adjust the clutch, back down to the test track, perfect, no slipping.
2 minutes down the track, into 4th gear, BANG.
No drive :angry:
We sourced a new box thanks to a very nice bloke over on the PPC forums, problem was, it had stripped the splines on one of the driveshafts from the shock too, and they are custom-made jobbies, quite a cost....
Fix that, make some changes to better bearings in the 'box and finally, off to Radnor for another race:
MoreHappyThanUsualPhillipM said:
Well, good news and bad, nothing broke, and for the first time since it's inception, the car has actually finished an event
Bad news was it's still getting hot enough at full chat that you have to back off a little bit - bigger oil cooler should sort it as it's oil temp not water that's the problem now.
Good news is the event was a lot of fast, very steep, full throttle uphill slogs in 26*c ambient temperatures, so it'll only get better from here!
Even better news is it's got a shiny trophy with 1st in class engraved to it's name.
It finished! And it didn't explode in a shower of gearbox internals! Bad news was it's still getting hot enough at full chat that you have to back off a little bit - bigger oil cooler should sort it as it's oil temp not water that's the problem now.
Good news is the event was a lot of fast, very steep, full throttle uphill slogs in 26*c ambient temperatures, so it'll only get better from here!
Even better news is it's got a shiny trophy with 1st in class engraved to it's name.
Some photo's from that event:
And it even finished at the next event at crickhowell too, again, 1st in class:
More to come, we haven't finished breaking it yet
Edited by PhillipM on Sunday 23 May 11:50
And this is what happens when you don't have a decent navigator
We'd missed too many events building the car to win the 2 wheel drive championship - the nearest competitor just had to turn up and get a point for starting to beat us at this one - whereas we had to come first to beat him if he didn't turn up. There was a chance as he'd blown his engine at the last event, but someone lent him one so he could win, ah well, always next year eh?
Pictures from there:
So, moving onto some winter work:
http://www.youtube.com/watch?v=kj6jiFTUHxg
Or three:
http://www.youtube.com/watch?v=N6oVAWLKCpg
http://www.youtube.com/watch?v=IOLZIJv01C0
And we headed to Sidbury, event was pretty rough, we had an alternator fail and put us out of the running, and there was a nasty accident so not the best weekend out:
Look, it's clean!
Maybe not:
We had a bit of trouble with the clutch again too, so a new alternator with better quality bearings and a larger pulley to reduce the load on it was fitted, and we swapped the flywheel as we suspected some high spots on it were the cause of the clutch problems.
Course, we made it lighter too - couple of kilos....
Which gave us 1st in class at Waterbeach last month, plus 9th overall - it would have been 8th but the throttle cable snapped about 200 yards from the finish line - can't be having things going too well now can we?
That's it for now!
Phillip said:
Well, a few weeks back, Ed put it into a tree at Minehead whilst I was laid up with flu!
Anyway, he bent both front beam tubes, a shock tower, made a 2D wheel out of a 3D one, broke the steering ram/mountings and bent a fair few tubes.
We've been debating just chopping the front off and sticking a double wishbone setup on there not ideal for the car, but we've already got the bits to hand (from building other cars), and it should be better than the trailing arm setup.
However, after chipping the bent tubing out, a bit of ingenuity with a jig allowed us to get the beam tubes under pressure in the right places, and that and a gas axe resulted in straight tubing again, with the front end welded back on, the bent tubes were chopped out, the frame jigged back up and new ones welded in, new suspension bushes, bearings, straightened the trailing arms out, made a new control valve for the steering and made some new wheels up and she was good enough to go.
Cheap and cheerful wins again!
And all that work resulted in....another shiny 1st trophy....
Just about managed to cobble it all back together by 3pm on Saturday, loaded up, drove down, ended up kipping in the car as we needed a boat rather than a tent, course was rough as anything, bouncing off the skidpan most of the time, as there were area's where they'd been testing tank suspension out or something.
p*ssed it down most of the day so was far too slippy for a 2wd car really, but still managed 1st in class + lap times were good enough for 8th overall.
Lots of broken cars due to the ruts though - rough as hell.
So everything aches today, but ah well.
We had a bit of trouble with a seal on the PAS pump giving up, and a car in front putting the boot down whilst sideways on a muddy patch just as we were overtaking, putting about an inch of muck on the screen and blowing the wiper motor
But apart from those and the battery giving up and making us late for our last run, the car itself is alive and well again, with no problems
Walters Arena in 2 weeks now that the WRC boys have finished using it, gravel tracks!
Hmmm, everything seems to be going suspicously well with the car, can't have that now can we?Anyway, he bent both front beam tubes, a shock tower, made a 2D wheel out of a 3D one, broke the steering ram/mountings and bent a fair few tubes.
We've been debating just chopping the front off and sticking a double wishbone setup on there not ideal for the car, but we've already got the bits to hand (from building other cars), and it should be better than the trailing arm setup.
However, after chipping the bent tubing out, a bit of ingenuity with a jig allowed us to get the beam tubes under pressure in the right places, and that and a gas axe resulted in straight tubing again, with the front end welded back on, the bent tubes were chopped out, the frame jigged back up and new ones welded in, new suspension bushes, bearings, straightened the trailing arms out, made a new control valve for the steering and made some new wheels up and she was good enough to go.
Cheap and cheerful wins again!
And all that work resulted in....another shiny 1st trophy....
Just about managed to cobble it all back together by 3pm on Saturday, loaded up, drove down, ended up kipping in the car as we needed a boat rather than a tent, course was rough as anything, bouncing off the skidpan most of the time, as there were area's where they'd been testing tank suspension out or something.
p*ssed it down most of the day so was far too slippy for a 2wd car really, but still managed 1st in class + lap times were good enough for 8th overall.
Lots of broken cars due to the ruts though - rough as hell.
So everything aches today, but ah well.
We had a bit of trouble with a seal on the PAS pump giving up, and a car in front putting the boot down whilst sideways on a muddy patch just as we were overtaking, putting about an inch of muck on the screen and blowing the wiper motor
But apart from those and the battery giving up and making us late for our last run, the car itself is alive and well again, with no problems
Walters Arena in 2 weeks now that the WRC boys have finished using it, gravel tracks!
Phillip after Sweetlamb event said:
Unfortunately, despite being the fastest 2wd on the course, we got two punctures, both on the rear axle, that left us stranded at the far side of the course 
By the time we'd been back to service and rolled two wheels and a jack through the woods for 4 miles, we couldn't complete enough runs to finish the event. Bah.
The car had been spinning the wheels on the rims somewhat early on in the day, which probably helped towards them getting thrown off the rim by the rocks.
We do have some 16x8J steelies in the making to fit over the winter though, which will let us step up to more aggressive tyres with 8 ply Kevlar sidewalls instead of the 3 ply nylons we are currently having to run, should sort that out.
By the time we'd been back to service and rolled two wheels and a jack through the woods for 4 miles, we couldn't complete enough runs to finish the event. Bah.
The car had been spinning the wheels on the rims somewhat early on in the day, which probably helped towards them getting thrown off the rim by the rocks.
We do have some 16x8J steelies in the making to fit over the winter though, which will let us step up to more aggressive tyres with 8 ply Kevlar sidewalls instead of the 3 ply nylons we are currently having to run, should sort that out.
We'd missed too many events building the car to win the 2 wheel drive championship - the nearest competitor just had to turn up and get a point for starting to beat us at this one - whereas we had to come first to beat him if he didn't turn up. There was a chance as he'd blown his engine at the last event, but someone lent him one so he could win, ah well, always next year eh?
Pictures from there:
So, moving onto some winter work:
Phillip said:
3 weekends to get it back together before the first event and it currently looks like this:
Hmm, tiny little bit of work left then?
Sounds like our competition has stepped it up this year - there's a two new 2wd buggies arriving, both built with about 10 times our budget, so we'll be doing well if we win any!
One's a spaceframe with a fibreglass shell over it to look like a car, similar to the construction of the 4wd cars, but with a civic type-r engine, sequential gearbox, bypass shocks all around, limited slip diff, and long travel double wishbones, all brand new parts - not scrapyard monkies like us - similar power and weight to us, but should have lots more traction and grip, and should be much more aerodynamical, so faster on the high speed tracks.
The other is a little single-seater buggy, clothed in carbon fibre/fibreglass, with a 1400 Kawasaki bike engine in the back, sequential box with the quaiffe back end and diff, should be a good 150 kilos lighter than us and that too is on long arm double wishbones, bypass shocks.
Bugger!
Having had problems with the brakes overheating, and in the case of the Poly-A pads - eating discs at about 1mm per event, and a set of pads every other event - we had some Carbotech XP8's custom made for it - far better bite, they don't fade, and the pad and disc wear has dropped to about 0.1mm per event - just slightly better then!
A week later:Hmm, tiny little bit of work left then?
Sounds like our competition has stepped it up this year - there's a two new 2wd buggies arriving, both built with about 10 times our budget, so we'll be doing well if we win any!
One's a spaceframe with a fibreglass shell over it to look like a car, similar to the construction of the 4wd cars, but with a civic type-r engine, sequential gearbox, bypass shocks all around, limited slip diff, and long travel double wishbones, all brand new parts - not scrapyard monkies like us - similar power and weight to us, but should have lots more traction and grip, and should be much more aerodynamical, so faster on the high speed tracks.
The other is a little single-seater buggy, clothed in carbon fibre/fibreglass, with a 1400 Kawasaki bike engine in the back, sequential box with the quaiffe back end and diff, should be a good 150 kilos lighter than us and that too is on long arm double wishbones, bypass shocks.
Bugger!
Having had problems with the brakes overheating, and in the case of the Poly-A pads - eating discs at about 1mm per event, and a set of pads every other event - we had some Carbotech XP8's custom made for it - far better bite, they don't fade, and the pad and disc wear has dropped to about 0.1mm per event - just slightly better then!
Phillip said:
Nearly there!
Another week...Phillip said:
Slightly wider new wheels
And a pic in the sunshine!
And even a video!And a pic in the sunshine!
http://www.youtube.com/watch?v=kj6jiFTUHxg
Or three:
http://www.youtube.com/watch?v=N6oVAWLKCpg
http://www.youtube.com/watch?v=IOLZIJv01C0
And we headed to Sidbury, event was pretty rough, we had an alternator fail and put us out of the running, and there was a nasty accident so not the best weekend out:
Look, it's clean!
Maybe not:
We had a bit of trouble with the clutch again too, so a new alternator with better quality bearings and a larger pulley to reduce the load on it was fitted, and we swapped the flywheel as we suspected some high spots on it were the cause of the clutch problems.
Course, we made it lighter too - couple of kilos....
Which gave us 1st in class at Waterbeach last month, plus 9th overall - it would have been 8th but the throttle cable snapped about 200 yards from the finish line - can't be having things going too well now can we?
That's it for now!
Edited by PhillipM on Sunday 23 May 12:15
Well, bar this weekends work which was:
I'm thinking of running a rota on the next bit to break
Phillip said:
Bit more work on this now since the last race, stripped down and revalved the rear Fox dampers as the oil was knackered and the old bilstiens on there have lost some damping.
They're not revalvable though - sealed units - so I've altered the shims and pistons in the Fox's instead, as they're cooler running anyway.
Should have a bit more traction over the rough stuff and be a lot better landing and taking off over jumps, hopefully.
Stripped the rear calipers down and rebuilt those as they were sticking a bit, had all the nuts and bolts off the drivetrain and suspension and renewed the locktite as it tends to soften up after a few events.
Front upright has had a couple of new bearings again and a sleeve on the shaft to take it up to the next size bearing - see if we can get them to last longer than a season!
Also sorted out the number board by taking off the top where it looks bloody ugly and putting some proper stickers (thanks to Adam!) on the side of some Carbon/Kevlar panels on the side of the car.
Tweaked the airbox to get another litre of capacity in there just for a touch easier breathing for the engine, and sneaked a bigger filter in so it doesn't get clogged up as fast with the dust and mud.
Other than that, just routine maintaince - oils/filters/water/grease bushes/regass dampers.
And ready for the next race next weekend - novelty being ready this early for us!
And if you've got this far, well done They're not revalvable though - sealed units - so I've altered the shims and pistons in the Fox's instead, as they're cooler running anyway.
Should have a bit more traction over the rough stuff and be a lot better landing and taking off over jumps, hopefully.
Stripped the rear calipers down and rebuilt those as they were sticking a bit, had all the nuts and bolts off the drivetrain and suspension and renewed the locktite as it tends to soften up after a few events.
Front upright has had a couple of new bearings again and a sleeve on the shaft to take it up to the next size bearing - see if we can get them to last longer than a season!
Also sorted out the number board by taking off the top where it looks bloody ugly and putting some proper stickers (thanks to Adam!) on the side of some Carbon/Kevlar panels on the side of the car.
Tweaked the airbox to get another litre of capacity in there just for a touch easier breathing for the engine, and sneaked a bigger filter in so it doesn't get clogged up as fast with the dust and mud.
Other than that, just routine maintaince - oils/filters/water/grease bushes/regass dampers.
And ready for the next race next weekend - novelty being ready this early for us!
I'm thinking of running a rota on the next bit to break
Edited by PhillipM on Sunday 23 May 12:27
from me too, love the home brew work you've all put into it and the way you tell the stories is grand.Chalk up a pair of first in class trophies
Car riding much better with the revalving on the rear dampers, but we had major issues with heat buildup boiling fuel in the rail - lots of misfires when the car got hot - we've had it before but thought we'd cured it with lagging - but now the car is riding better we're on full throttle harder and longer....
Full writeup later, I'm cream crackered!
Car riding much better with the revalving on the rear dampers, but we had major issues with heat buildup boiling fuel in the rail - lots of misfires when the car got hot - we've had it before but thought we'd cured it with lagging - but now the car is riding better we're on full throttle harder and longer....
Full writeup later, I'm cream crackered!
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