10% quicker, opinions please
Discussion
Original question below but this is what I meant to ask:
I am a reasonably experienced sprint / hillclimb driver with many class-winning results and class records. I am not particularly experienced with this car. My previous competition cars have either already been modified to the limit allowed or competed unmodified and therefore I have little experience of the impact of modifications on lap times.
Do you think that replacing rubbish tyres with 1b tyres on appropriate wheels, increasing power to weight ratio from 119 bhp per tonne to 180 and replacing the very tired dampers and springs with racing ones would improve my lap time by 10%?
Original for trail:
I competed in a sprint at Snetterton 100 in my mk1 Golf GTI 1600. My car is virtually standard and my plan was to run it in the up to 1600 standard class AEMC championship.
However, though I’d driven the circuit before, this was my first AEMC sprint and the result got me thinking.
I was 6 seconds per lap off the winning car in the up to 2000cc road going class (ie bigger engines than mine and more modifications) which was an S2000. The lap took me 60 seconds so if I could go 10% faster I'd be close to a giant-killing performance! There were 6 cars in that class and I was quicker than the last one (Puma) and very nearly as quick as the second to last one (an MX5).
My car is not only “standard” but not even a good standard. The dampers are tired, the tyres are the mix of Chinese and Polish it came with and the engine is 100k old (though in a good state of tune).
It seems reasonable to that some semi slick tyres, uprated springs and dampers plus, say, 50% more power has got add up to 10% quicker laps.
Then I think "there's no way my little Golf could lap as fast as an S2000".
Then I think about weight. My car is 840kg and the S2000 (not much weight loss allowed) is 1250kg. Currently my car might have 110bhp (probably a less) and the S2000 at least 240bhp. So even I tuned my engine to 150bhp, he’d have 200bhp per tonne to my 178. But light weight pays off all over the circuit…
Experts – is it possible? Comk1 Golf could a 150bhp mk1 Golf take the fight to an S2000, assuming similar qualities of tyre, damper, driver etc.
Ps, if you want to see how soft the suspension is see here:
http://www.youtube.com/watch?v=KUDCVy_-IWQ
Which will also demonstrate that there is room for improvement in the driver!
I am a reasonably experienced sprint / hillclimb driver with many class-winning results and class records. I am not particularly experienced with this car. My previous competition cars have either already been modified to the limit allowed or competed unmodified and therefore I have little experience of the impact of modifications on lap times.
Do you think that replacing rubbish tyres with 1b tyres on appropriate wheels, increasing power to weight ratio from 119 bhp per tonne to 180 and replacing the very tired dampers and springs with racing ones would improve my lap time by 10%?
Original for trail:
I competed in a sprint at Snetterton 100 in my mk1 Golf GTI 1600. My car is virtually standard and my plan was to run it in the up to 1600 standard class AEMC championship.
However, though I’d driven the circuit before, this was my first AEMC sprint and the result got me thinking.
I was 6 seconds per lap off the winning car in the up to 2000cc road going class (ie bigger engines than mine and more modifications) which was an S2000. The lap took me 60 seconds so if I could go 10% faster I'd be close to a giant-killing performance! There were 6 cars in that class and I was quicker than the last one (Puma) and very nearly as quick as the second to last one (an MX5).
My car is not only “standard” but not even a good standard. The dampers are tired, the tyres are the mix of Chinese and Polish it came with and the engine is 100k old (though in a good state of tune).
It seems reasonable to that some semi slick tyres, uprated springs and dampers plus, say, 50% more power has got add up to 10% quicker laps.
Then I think "there's no way my little Golf could lap as fast as an S2000".
Then I think about weight. My car is 840kg and the S2000 (not much weight loss allowed) is 1250kg. Currently my car might have 110bhp (probably a less) and the S2000 at least 240bhp. So even I tuned my engine to 150bhp, he’d have 200bhp per tonne to my 178. But light weight pays off all over the circuit…
Experts – is it possible? Comk1 Golf could a 150bhp mk1 Golf take the fight to an S2000, assuming similar qualities of tyre, damper, driver etc.
Ps, if you want to see how soft the suspension is see here:
http://www.youtube.com/watch?v=KUDCVy_-IWQ
Which will also demonstrate that there is room for improvement in the driver!
Edited by Shoestringracer on Wednesday 4th June 19:28
You're assuming that the S2000 driver is never going to improve either, maybe it was their first ever race, maybe they had a bad day, maybe they had mechanical issues preventing them going faster, maybe they don't know the track...
Any of the above could see them being significantly faster at the next outing.
My advice is enjoy it and don't get too crazy with money.
Learn proper technique and lighten the car then go for tyres and power then suspension...just beware sticky tyres can kill engines if you're hoofing it.
Any of the above could see them being significantly faster at the next outing.
My advice is enjoy it and don't get too crazy with money.
Learn proper technique and lighten the car then go for tyres and power then suspension...just beware sticky tyres can kill engines if you're hoofing it.
tuffer said:
Instruction, weight removal, modifications, in that order but I stand to be corrected.
Thanks for reply. Instruction a good idea, but I have been doing it for a while, with some success so I don't think it would bridge the gap. Not allowed much weight reduction at all. Which is actually an advantage for me as modern cars can't remove heavy electric motors etc and I don't have any to remove.
Shoestringracer said:
The dampers are tired, the tyres are the mix of Chinese and Polish it came with and the engine is 100k old (though in a good state of tune).
I think that's part of the answer. You won't make up 6 secs but decent tyres will make a big difference I'd have thought. Are you allowed List 1B tyres (eg Yoko A048 or Toyo 888)?Right, my fault – I don’t think I asked the question right so people are answering different questions. What I meant to say was:
“I am a reasonably experienced sprint / hillclimb driver with many class-winning results and class records. I am not particularly experienced with this car. My previous competition cars have either already been modified to the limit allowed or competed unmodified and therefore I have little experience of the impact of modifications on lap times.
Do you think that replacing rubbish tyres with 1b tyres on appropriate wheels, increasing power to weight ratio from 119 bhp per tonne to 180 and replacing the very tired dampers and springs with racing ones would improve my lap time by 10%?”
edit - got 1a and 1b mixed-up
“I am a reasonably experienced sprint / hillclimb driver with many class-winning results and class records. I am not particularly experienced with this car. My previous competition cars have either already been modified to the limit allowed or competed unmodified and therefore I have little experience of the impact of modifications on lap times.
Do you think that replacing rubbish tyres with 1b tyres on appropriate wheels, increasing power to weight ratio from 119 bhp per tonne to 180 and replacing the very tired dampers and springs with racing ones would improve my lap time by 10%?”
edit - got 1a and 1b mixed-up
Edited by Shoestringracer on Wednesday 4th June 15:48
Edited by Shoestringracer on Wednesday 4th June 15:51
As standard the suspension is far too soft for track driving, the amount of roll means that the camber relative to the track goes positive at the extremities of roll:
The rear axle will always be a limiting factor, having no camber compensation. Therefore, limiting roll, either by higher spring rates or more roll stiffness would be my first modification, even before stickier tyres. Normally tyres would be one of the first changes but I feel that the Mk1 Golf is a special case due to the excessive roll as standard. You can see from the above image that both inside tyres are barely contributing to lateral grip at all!
Not perfect, but better
Another problem with the rear axle is that it can deform under heavy cornering, changing the rear toe. This would be exaggerated with sticky tyres. It's therefore common the brace it.
Also note the custom ARB. As far as I'm aware, adjustable ARBs are not available off the shelf for the Mk1, so it would be a custom job as above.
The rear axle will always be a limiting factor, having no camber compensation. Therefore, limiting roll, either by higher spring rates or more roll stiffness would be my first modification, even before stickier tyres. Normally tyres would be one of the first changes but I feel that the Mk1 Golf is a special case due to the excessive roll as standard. You can see from the above image that both inside tyres are barely contributing to lateral grip at all!
Not perfect, but better
Another problem with the rear axle is that it can deform under heavy cornering, changing the rear toe. This would be exaggerated with sticky tyres. It's therefore common the brace it.
Also note the custom ARB. As far as I'm aware, adjustable ARBs are not available off the shelf for the Mk1, so it would be a custom job as above.
Edited by JoeMk1 on Wednesday 4th June 16:11
Edited by JoeMk1 on Wednesday 4th June 16:23
Decent grippy tyres, uprated brakes, as good a quality damper setup as you can afford and engine mods along the lines you've suggested would make for a very competitive car. I would recommend undertaking them in the above order, and one at a time so that you can gauge their effectiveness.
There's always going to be 'the guy to beat' in the class, if you're fortunate sometimes its you, but often its not. Prepare the car to the level you can afford or are willing to go to, and drive it to the best of your abilities. The rest, as they say, is in the lap of the gods.
There's always going to be 'the guy to beat' in the class, if you're fortunate sometimes its you, but often its not. Prepare the car to the level you can afford or are willing to go to, and drive it to the best of your abilities. The rest, as they say, is in the lap of the gods.
And, in sprinting, there's always the cars ability to get off the line to take into account. I would imagine that the rear drive S2000 will always have an advantage in this area.
We developed our mini after starting out in sprinting and the single biggest performance enhancement came from changing tyres (in our case to slicks, specifically uncut wets which are the softest compound available) followed by a new engine with a significant power hike.
Always good to have someone to chase though
We developed our mini after starting out in sprinting and the single biggest performance enhancement came from changing tyres (in our case to slicks, specifically uncut wets which are the softest compound available) followed by a new engine with a significant power hike.
Always good to have someone to chase though
We run a couple of cars in our southern Sprint championship, a 1600cc Eunos and a 1600cc 205 Gti. Have to run on list 1a tyres and pretty much no modifications apart from safety items. We run up a against Saxo VTS and 106 Gti, Mk1 MR2, etc. and the last champion had a Honda Civic VTS, around 45bhp more than the opposition but quite heavier than the 106. He was consistently fastest but beatable. Weight was the enemy. There will not be huge gains to be had other than making sure your car is in the best possible fettle you can. What our class really needs to win is an early 1600cc Civic Type R, that would clean up.
Not sure on your regs but by the sound of it you want to go into a modified production class, which to be blunt is some serious chequebook racing and you may find yourself in a money pit. Just be warned, I am not sure if this is the route you are taking you may spend a LoT of money and not win, so you throw more money at it... I would be tempted if you gave a tidy solid MK1 Gti Golf to sell it on and find something a bit more suitable. Although saying that, everyone love a cool fast Golf!
Not sure on your regs but by the sound of it you want to go into a modified production class, which to be blunt is some serious chequebook racing and you may find yourself in a money pit. Just be warned, I am not sure if this is the route you are taking you may spend a LoT of money and not win, so you throw more money at it... I would be tempted if you gave a tidy solid MK1 Gti Golf to sell it on and find something a bit more suitable. Although saying that, everyone love a cool fast Golf!
Hello! I am the owner of said S2000 at Snetterton. I've been sprinting it for a few years and it has had a fair bit of development, but mainly in the suspension. Engine is stock apart from filter and exhaust so probably has more like 220bhp (Honda were being a bit optimistic when they quoted 237).
For what it's worth I was beaten by a modified mk1 Golf in the wet at Combe last year, but having said that I don't really know Combe. I reckon if you modified your golf you could beat me at the slower venues but I'd still win at the faster ones like Goodwood where top speed is everything. To put it into context I get beaten by the modified Minis at the twistier shorter venues, and we're about even at places like North Weald.
For what it's worth I was beaten by a modified mk1 Golf in the wet at Combe last year, but having said that I don't really know Combe. I reckon if you modified your golf you could beat me at the slower venues but I'd still win at the faster ones like Goodwood where top speed is everything. To put it into context I get beaten by the modified Minis at the twistier shorter venues, and we're about even at places like North Weald.
Hello! Thanks for all the replies. I guess this one above is as near as we will get to a definitive answer. Interesting too as most of my experience has been in a one make series so the cars had similar strengths and weaknesses at the same venues so it hadn’t really occurred to me that it might vary from one place to another. I guess then that an all-rounder car, that does pretty well at all venues, might do less well in a championship than one that gets lots of wins and lots of low places.
I really enjoy trying to work out what the right combination of car, class and championship might be. I do recon that, in the under 2 litre road going an '80s hot hatch might be the sweet spot between older cars, which tend to be very light but have smallish, pushrod engines and modern cars with their large and powerful multivalve engines but heavy (but stiffer) bodies.
Things like 205s and mk1 Golfs are fairly light like an old car (800 and something kilos) but have overhead cams and five-bearing cranks. There is a guy down in Cornwall who can build a 190bhp 1800cc 8valve Golf engine which would fit within the road going rules and give over 220bhp / tonne. I assume you could do something similar with a 1.9 205. You'd have to spend a lot on the engine to get a similar power to weight ratio from a Clio or recent Civic Type R because they are quite a lot heavier and S2000s are heavier still. Plus you'd be dealing with the extra weight everywhere else round the circuit.
Of course, as pointed out by another poster, FWD might be a limiting factor, especially once you get into the high levels of power, though low weight should help reduce inertia...
One of my favourite avenues for exploration is an X1/9 turbo. Light (<800kg?), RWD and mid- engined and, according to the internet, the Punto GT with essentially the same engine can make well over 200bhp. Not exactly the same engine though so you’d need to use the X1/9 block and head, which, apparently aren’t as strong as the Punto ones. I was interested to see that someone else has had the same idea one was entered for the B19 sprint last month. I was looking forward to a chat with the owner but it was withdrawn.
For the record, I bought the Golf because I wanted to do a few local sprints and a few local classic rallies so I needed a car that qualified for both. Since then I've remembered that I want to do well and maybe I should have got the right car for one and not do the other. For the sprints I was going to compete in the standard class, like Furyblade Lee talks about above, and I think it would be competitive as it has similar power to weight ratio as the others.
Cheers
Chris
I really enjoy trying to work out what the right combination of car, class and championship might be. I do recon that, in the under 2 litre road going an '80s hot hatch might be the sweet spot between older cars, which tend to be very light but have smallish, pushrod engines and modern cars with their large and powerful multivalve engines but heavy (but stiffer) bodies.
Things like 205s and mk1 Golfs are fairly light like an old car (800 and something kilos) but have overhead cams and five-bearing cranks. There is a guy down in Cornwall who can build a 190bhp 1800cc 8valve Golf engine which would fit within the road going rules and give over 220bhp / tonne. I assume you could do something similar with a 1.9 205. You'd have to spend a lot on the engine to get a similar power to weight ratio from a Clio or recent Civic Type R because they are quite a lot heavier and S2000s are heavier still. Plus you'd be dealing with the extra weight everywhere else round the circuit.
Of course, as pointed out by another poster, FWD might be a limiting factor, especially once you get into the high levels of power, though low weight should help reduce inertia...
One of my favourite avenues for exploration is an X1/9 turbo. Light (<800kg?), RWD and mid- engined and, according to the internet, the Punto GT with essentially the same engine can make well over 200bhp. Not exactly the same engine though so you’d need to use the X1/9 block and head, which, apparently aren’t as strong as the Punto ones. I was interested to see that someone else has had the same idea one was entered for the B19 sprint last month. I was looking forward to a chat with the owner but it was withdrawn.
For the record, I bought the Golf because I wanted to do a few local sprints and a few local classic rallies so I needed a car that qualified for both. Since then I've remembered that I want to do well and maybe I should have got the right car for one and not do the other. For the sprints I was going to compete in the standard class, like Furyblade Lee talks about above, and I think it would be competitive as it has similar power to weight ratio as the others.
Cheers
Chris
In the TVR championship we are handicapped by 2.5% for using B list tyres. If your existing a list tyres are poor the change should make at least a total of 3.5%. Weight loss makes a big difference but I am unable to quantify that. 10% faster as a target is an awful lot. You could just buy and S2000. It would probably be the cheaper option and you would see who is the better driver in the same machinery.
Some time ago I started sprinting in my Alfa 145 road car in the standard road class and had some success but often came up against a guy with a S2000 that I only beat once or twice. I competed a lot at Goodwood so I have a reasonable amount of data there. My best lap time in the Alfa was a 107.67, the S2000 a 99.7. After a few seasons I decided to go into Modified production with a Fiat Uno Turbo. I would imagine that standard it would have been similar to the Alfa.
I spent a decent amount of money on the Uno; engine, brakes, tyres, etc although it remained road legal. The best I managed in that was a 97.49. So yes it can be done but if you want to modify your car you could buy something properly quick for what you would need to spend e.g. something like a formula ford which would be vastly superior and designed for the job not to mention a sheer pleasure to work on compared to a road car!
Note that the X1/9's are surprisingly lardy I think as they tried to beef it up for some American crash regs so check the weight if you want to go down that path!
I spent a decent amount of money on the Uno; engine, brakes, tyres, etc although it remained road legal. The best I managed in that was a 97.49. So yes it can be done but if you want to modify your car you could buy something properly quick for what you would need to spend e.g. something like a formula ford which would be vastly superior and designed for the job not to mention a sheer pleasure to work on compared to a road car!
Note that the X1/9's are surprisingly lardy I think as they tried to beef it up for some American crash regs so check the weight if you want to go down that path!
Shoestringracer said:
tuffer said:
Instruction, weight removal, modifications, in that order but I stand to be corrected.
Thanks for reply. Instruction a good idea, but I have been doing it for a while, with some success so I don't think it would bridge the gap. Not allowed much weight reduction at all. Which is actually an advantage for me as modern cars can't remove heavy electric motors etc and I don't have any to remove.
Instruction instruction instruction! You have been doing it for while - with some success. With instruction you may have had more success!!
I've raced for 25 years. I'm always open to instruction when it comes to finding time. And I'm a holder of a MSA ARDS instructors licence since 2000.
A day with a good instructor will gain you more time, for less money than more engineering on the car - unless there is something fundamentally obvious with the car that can be fixed for £100 - and I doubt that's the case!
Gassing Station | UK Club Motorsport | Top of Page | What's New | My Stuff