The Sensible Car - Contains Mazda
Discussion
For various reasons I need a saloon car of some description, mainly as a going to the tip, being able to drive to the airport four up etc. type thing. I didn't really care what as anything white good'ish and boring reliable for a couple of grand would be perfect. I found a few decent looking 320Ds on E-Bay, a very sensible Passat and a half decent 9-3 that looked quite tempting. With sensible hat on I decided that once I was back from Monaco I'd spend Tuesday sorting the sensible car situation out. Tuesday came and I immediately went out and purchased this:
Yep a Prodrive'd RX8..... clearly hitting every target on the boring, white good, reliable and fuel efficient brief.
Even better it was one that was very cheap AND had cold starting problems at no extra cost! Absolute winner all round!
Thanks to some chaps on PH providing a heads up on the usual issues I fitted the biggest battery possible in the battery tray and got hold of the finest Chinese made 2KW "Genuine OEM" starter that e-bay had which completely cured the cold start issues. Cleaning the MAF, changing the crank sensor and giving it the big service including plugs sorted the rest of the niggles it had and I've now completed a few hundred miles with only seven petrol stations visits and an oil top up. Brilliantly it is also returning around 2MPG less than the Porsche does.
It was fairly minging when I took possession of it so it has had a big detail and clean up which has made it look really very presentable, aside from a scuff on the nose and the odd door ding it's grot free and shiny!
It is also a way better drive than any of the other sensible options and rotaries are hilarious engines even at the worst of times. This one goes to just shy of nine and a half thousand RPM and makes a great noise from 7K RPM on wards. The balance is absolutely up there with the best production cars that I have driven, brakes are decent enough, the stability control is a bit of a dick but can be fully turned off and it has 4 seats so in that respect I absolutely nailed one point on the requirements list!
No major plans for it, aside from add Bluetooth support and service it to the book until the engine inevitably runs out of compression. Given how cheap they are to rebuild if it's still in tidy condition by that point it will have a freshen up...... although based on how wrong going and buying a sensible car went I suppose it's quite likely to end up fully Bridgeported and 787B sounding
Yep a Prodrive'd RX8..... clearly hitting every target on the boring, white good, reliable and fuel efficient brief.
Even better it was one that was very cheap AND had cold starting problems at no extra cost! Absolute winner all round!
Thanks to some chaps on PH providing a heads up on the usual issues I fitted the biggest battery possible in the battery tray and got hold of the finest Chinese made 2KW "Genuine OEM" starter that e-bay had which completely cured the cold start issues. Cleaning the MAF, changing the crank sensor and giving it the big service including plugs sorted the rest of the niggles it had and I've now completed a few hundred miles with only seven petrol stations visits and an oil top up. Brilliantly it is also returning around 2MPG less than the Porsche does.
It was fairly minging when I took possession of it so it has had a big detail and clean up which has made it look really very presentable, aside from a scuff on the nose and the odd door ding it's grot free and shiny!
It is also a way better drive than any of the other sensible options and rotaries are hilarious engines even at the worst of times. This one goes to just shy of nine and a half thousand RPM and makes a great noise from 7K RPM on wards. The balance is absolutely up there with the best production cars that I have driven, brakes are decent enough, the stability control is a bit of a dick but can be fully turned off and it has 4 seats so in that respect I absolutely nailed one point on the requirements list!
No major plans for it, aside from add Bluetooth support and service it to the book until the engine inevitably runs out of compression. Given how cheap they are to rebuild if it's still in tidy condition by that point it will have a freshen up...... although based on how wrong going and buying a sensible car went I suppose it's quite likely to end up fully Bridgeported and 787B sounding
Well the sensible car is doing exactly what is says on the tin - being very sensible.
As some of you may have guessed from the thread about my Porsche this is very un-me! So on the basis that A) the car is clearly a good one and B) it did 240 miles on the last tank (mainly through spending a lot of a journey in 50mph average speed road works) and C) it will need an engine rebuild at some point as it takes a little longer than it should to start from hot, I've just ordered all the bits I need to build a 10.5K RPM half bridge ported motor for it....... that should get the MPG down!
I've got hold of a cheap used engine from e-bay and the brief spec will be:
- Street ported primary with bridge ported secondary
- Honed and pinned rotor bearings.
- New stationary gear bearings
- Obviously new Apex seals and springs. I've ordered OE Mazda ones and the new Atkins Black Tempered ones with an extra of each that I can put through inspection at work and make a call on what will actually be best.
- New side seals and springs.
- Uprated higher temperature before melting sealing o-rings as this is apparently a common failure mode.
- All the usual seals and gaskets.
- Various Racing Beat bits including an updated thermal pellet and higher pressure oil pressure regulator
- Later spec sump - so between this and the above that should make the oil system fairly R3 like.
- Racing Beat Tubular exhaust manifold
The idea with the half bridge port is that it retains some amount of low RPM behavior whilst still giving a reasonable brap brap idle whilst the bridge ported secondary provides a good increase in delivered air mass. It seems this setup should give around 30bhp additional at the wheels which as it's fairly under powered will help a lot. I'd hope this engine will do 40 - 50K miles between rebuilds, the bridge port setup does hurt apex seal life by all accounts, but as it's doing very low miles compared to the Porsche this isn't too much of a concern - especially as parts are very cheap compared to bits for Porsche engines
The plan is to get this together and then swap it over at a point where I have some spare time so likely to be a couple of months before it's in but I'll post a few pics as it comes together.
As some of you may have guessed from the thread about my Porsche this is very un-me! So on the basis that A) the car is clearly a good one and B) it did 240 miles on the last tank (mainly through spending a lot of a journey in 50mph average speed road works) and C) it will need an engine rebuild at some point as it takes a little longer than it should to start from hot, I've just ordered all the bits I need to build a 10.5K RPM half bridge ported motor for it....... that should get the MPG down!
I've got hold of a cheap used engine from e-bay and the brief spec will be:
- Street ported primary with bridge ported secondary
- Honed and pinned rotor bearings.
- New stationary gear bearings
- Obviously new Apex seals and springs. I've ordered OE Mazda ones and the new Atkins Black Tempered ones with an extra of each that I can put through inspection at work and make a call on what will actually be best.
- New side seals and springs.
- Uprated higher temperature before melting sealing o-rings as this is apparently a common failure mode.
- All the usual seals and gaskets.
- Various Racing Beat bits including an updated thermal pellet and higher pressure oil pressure regulator
- Later spec sump - so between this and the above that should make the oil system fairly R3 like.
- Racing Beat Tubular exhaust manifold
The idea with the half bridge port is that it retains some amount of low RPM behavior whilst still giving a reasonable brap brap idle whilst the bridge ported secondary provides a good increase in delivered air mass. It seems this setup should give around 30bhp additional at the wheels which as it's fairly under powered will help a lot. I'd hope this engine will do 40 - 50K miles between rebuilds, the bridge port setup does hurt apex seal life by all accounts, but as it's doing very low miles compared to the Porsche this isn't too much of a concern - especially as parts are very cheap compared to bits for Porsche engines
The plan is to get this together and then swap it over at a point where I have some spare time so likely to be a couple of months before it's in but I'll post a few pics as it comes together.
Edited by poppopbangbang on Saturday 12th August 22:28
I'll watch this thread with interest.
poppopbangbang said:
- Obviously new Apex seals and springs. I've ordered OE Mazda ones and the new Atkins Black Tempered ones with an extra of each that I can put through inspection at work and make a call on what will actually be best.
How will you inspect them and what are you looking for?Escy said:
How will you inspect them and what are you looking for?
Hardness and therefore compatibility with chrome, any surface details for oil retention, surface finish consistency, taper/machining accuracy and overall sizing. We have a zip scope 250 at work and there isn't a lot you can't see with that 
OP, I love your definition of sensible!
I bought a sensible Mazda back in 2014, but it was a 1996 323f 1.5. Mainly to get the cheap RFL but also because it's a non- intereference engine so no need to worry about the cam-belt!
But it was so gutless and boring that after 6 months I bought a BMW 325ti Compact to replace it - maybe I should have tried an RX8?!
I bought a sensible Mazda back in 2014, but it was a 1996 323f 1.5. Mainly to get the cheap RFL but also because it's a non- intereference engine so no need to worry about the cam-belt!
But it was so gutless and boring that after 6 months I bought a BMW 325ti Compact to replace it - maybe I should have tried an RX8?!
Hi Poppop,
I enjoy reading about your Porsche exploits and the 95-02 F1 tech thread.
I have an RX-8 which I've got carried away sorting niggles with! My contribution to this thread is what I've read about the Atkins seals. Rotary Revs have stopped using them - they've come across many failures - info snippet here: https://www.rx8ownersclub.co.uk/forum/viewtopic.ph...
However, I would be very interested to hear what you find under the zip scope - it might offer some explanation. Goopy seals appear to be the favoured ones for FI applications - although they are more prone to wearing the housings apparently.
Thread boomarked
I enjoy reading about your Porsche exploits and the 95-02 F1 tech thread.
I have an RX-8 which I've got carried away sorting niggles with! My contribution to this thread is what I've read about the Atkins seals. Rotary Revs have stopped using them - they've come across many failures - info snippet here: https://www.rx8ownersclub.co.uk/forum/viewtopic.ph...
However, I would be very interested to hear what you find under the zip scope - it might offer some explanation. Goopy seals appear to be the favoured ones for FI applications - although they are more prone to wearing the housings apparently.
Thread boomarked
So firstly seals. The Mazda seals are quite clearly made with some kind of Magic, there is some sort of surface hardening tech used that I've not seen before and is probably proprietary to Mazda/the seal producer. The tip of the seal is hardened but with a uniformity that I don't think you could achieve with any other process. Hence there is no run in or break in process required as the seal is good to go from 0KM.
The Atkins seals are by comparison somewhat simpler and are made from a material which work hardens in use to create the hard surface at the tip of the seal and the tip is larger than the Mazda seal. They have a sacrificial friction reducing surface I guess to reduce wear and avoid pick up whilst the tip work hardens. As such a correct running in procedure and oil choice would be critical in getting good life from them as if you use the sacrificial coating up before the work hardening has occurred the seal life would be massively short. To this end I suspect some of the issues experienced with these have been due to too gentle a running in process.
Dimensions wise both seals are produced to very tight tolerances - I have one rotors worth of each here and the tolerances across Mazda and Atkins seals are extremely tight.
I'm going to use the Atkins seals as the larger tip is likely to last better with a bridgeport and I'm confident I can run the engine in sufficiently quickly to create a work hardened surface. If you're building a none bridgeport engine though the Mazda seals would be the sensible choice as you can't get it wrong with these!
The Atkins seals are by comparison somewhat simpler and are made from a material which work hardens in use to create the hard surface at the tip of the seal and the tip is larger than the Mazda seal. They have a sacrificial friction reducing surface I guess to reduce wear and avoid pick up whilst the tip work hardens. As such a correct running in procedure and oil choice would be critical in getting good life from them as if you use the sacrificial coating up before the work hardening has occurred the seal life would be massively short. To this end I suspect some of the issues experienced with these have been due to too gentle a running in process.
Dimensions wise both seals are produced to very tight tolerances - I have one rotors worth of each here and the tolerances across Mazda and Atkins seals are extremely tight.
I'm going to use the Atkins seals as the larger tip is likely to last better with a bridgeport and I'm confident I can run the engine in sufficiently quickly to create a work hardened surface. If you're building a none bridgeport engine though the Mazda seals would be the sensible choice as you can't get it wrong with these!
As for the car, well the old motor is out:
New one should be going in next week if the time is available.
It's had a good once over, brakes were on the wear limits so new ones have gone on. Nothing special but it was never that lacking in brakes anyway and the increase in thickness of friction material will likely solve the long pedal when hot issue as there was not a lot left!
Suspension is good and aside from a bit of surface corrosion on the damper bodies there is nothing wrong with it so I'm quite happy leaving it on there. Prodrive did a good job with it and as it's NLA as replacement parts it would be silly to change it.
The airbox has had a low loss filter in it and the exhaust is now minus a silencer and a cat so those two should help a little with breathing. It's also had a larger capacity aluminum radiator as this seemed wise as the cooling system is marginal on the standard engine (wankels aren't the most thermally efficient things!).
The clutch had plenty of life left in it but the release bearing was rough so I've changed that and the gearbox and diff has had fresh oil.
Just got to pop the new motor in now!
New one should be going in next week if the time is available.
It's had a good once over, brakes were on the wear limits so new ones have gone on. Nothing special but it was never that lacking in brakes anyway and the increase in thickness of friction material will likely solve the long pedal when hot issue as there was not a lot left!
Suspension is good and aside from a bit of surface corrosion on the damper bodies there is nothing wrong with it so I'm quite happy leaving it on there. Prodrive did a good job with it and as it's NLA as replacement parts it would be silly to change it.
The airbox has had a low loss filter in it and the exhaust is now minus a silencer and a cat so those two should help a little with breathing. It's also had a larger capacity aluminum radiator as this seemed wise as the cooling system is marginal on the standard engine (wankels aren't the most thermally efficient things!).
The clutch had plenty of life left in it but the release bearing was rough so I've changed that and the gearbox and diff has had fresh oil.
Just got to pop the new motor in now!
Looks tidy in there poppop.
Two things of note whilst you're there in case you didn't already know. Make sure you've got the foam bits on the radiator so the air does go through the rad - people have noted that cooling is compromised with the foam missing.
Check your oil cooler hoses under the wheel arch liner - a rather common weak point on these. I built up some new hoses using AN10 hose.
I assume you're not gonna bother with the SAI? - you can code that out of the PCM with mazdaedit, or iirc there's a hooky copy of mazda wds floating about that can do that too - you can turn off the CEL for various DTC's too with them too.
Two things of note whilst you're there in case you didn't already know. Make sure you've got the foam bits on the radiator so the air does go through the rad - people have noted that cooling is compromised with the foam missing.
Check your oil cooler hoses under the wheel arch liner - a rather common weak point on these. I built up some new hoses using AN10 hose.
I assume you're not gonna bother with the SAI? - you can code that out of the PCM with mazdaedit, or iirc there's a hooky copy of mazda wds floating about that can do that too - you can turn off the CEL for various DTC's too with them too.
zippyonline said:
Looks tidy in there poppop.
Two things of note whilst you're there in case you didn't already know. Make sure you've got the foam bits on the radiator so the air does go through the rad - people have noted that cooling is compromised with the foam missing.
Check your oil cooler hoses under the wheel arch liner - a rather common weak point on these. I built up some new hoses using AN10 hose.
I assume you're not gonna bother with the SAI? - you can code that out of the PCM with mazdaedit, or iirc there's a hooky copy of mazda wds floating about that can do that too - you can turn off the CEL for various DTC's too with them too.
It had hoses two years ago so these are in fine fettle - the car has full history at the same Mazda dealer from new and doesn't appear to have wanted for anything. There are a couple of £3K invoices in there for cats, coils, hoses etc. Two things of note whilst you're there in case you didn't already know. Make sure you've got the foam bits on the radiator so the air does go through the rad - people have noted that cooling is compromised with the foam missing.
Check your oil cooler hoses under the wheel arch liner - a rather common weak point on these. I built up some new hoses using AN10 hose.
I assume you're not gonna bother with the SAI? - you can code that out of the PCM with mazdaedit, or iirc there's a hooky copy of mazda wds floating about that can do that too - you can turn off the CEL for various DTC's too with them too.
Foam bits present and correct on the rad along with the gaps taped, it's quite a race car rad setup with it canted at 45 degrees in the nose so it will be sensitive to ducting, as are the oil coolers which have really nice ducts on the front of them. Credit to Mazda really as it's quite none road car in it's design.
I was going to leave the SAI in place to be honest as it doesn't weigh a lot and there doesn't seem to be a performance disadvantage from leaving it in place? Or is there and I've missed something?
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