Discussion
I have a MK3 MX5, and have had the geo set up by WIM and Eibachs fitted at the same time. Subsequently I have had the Eibach uprated anti roll bars fitted, and on the road the car is a delight, but you have to be going too fast to really push it beyond it limits, which is fare enough on the public road.
I did a trackday last weekend, and hoped to enjoy some neutral to oversteering action, only to find the cars pretty well set up to understeer, slightly progressing to neutral...all very safe etc, but hardly exiting, and not how I thought MX5`s behaved? When asked by WIM about how I would like the car to feel etc, I specifically asked for neutral to oversteer if poss.
Is this just a trait of MK3`s, given their extra level of sophisitcation, or am I going to have to go further with the set up to alter the characterisitcs? The car is fitted with Michelin Pilots, aswell which I am sure could be better.
I did a trackday last weekend, and hoped to enjoy some neutral to oversteering action, only to find the cars pretty well set up to understeer, slightly progressing to neutral...all very safe etc, but hardly exiting, and not how I thought MX5`s behaved? When asked by WIM about how I would like the car to feel etc, I specifically asked for neutral to oversteer if poss.
Is this just a trait of MK3`s, given their extra level of sophisitcation, or am I going to have to go further with the set up to alter the characterisitcs? The car is fitted with Michelin Pilots, aswell which I am sure could be better.
trackerjack said:
If youlet a little air out of the rear tyres and put a bit more in the front you may find that this is all it takes.
Then a tad bit of toe in to persuade the front in.
Then a tad bit of toe in to persuade the front in.
That sounds backwards to me - try the opposite of those ones!
It may also be partly down to driving style.
Thanks...I did try letting a bit of air out of the fronts, it made a smidgen of difference. I did have the tyres inflated to 30 psi, where the standard setting is 25psi. The car is set up with 15" wheels and relatively tall sidewalls, so I was a bit reluctant to drop the pressure too much, plus you loose a bit of feel/taughtness.
The embarrasing thing was, was that I struggled to keep up with a Cooper S (Supercharged) around the faster bends...he just seemed to have more grip and was able to pull round a corner, but the MX5 was clearly quicker than everything other than a Striker in the tighter corners. I know some better tyres would probably increase cornering speeds, but that is not necessarily more fun.
The embarrasing thing was, was that I struggled to keep up with a Cooper S (Supercharged) around the faster bends...he just seemed to have more grip and was able to pull round a corner, but the MX5 was clearly quicker than everything other than a Striker in the tighter corners. I know some better tyres would probably increase cornering speeds, but that is not necessarily more fun.
As above, you need to soften the front and/or stiffen the back.
I reckon though that it's the stiffer ARBs that have caused the understeer rather than geo setup. What made you think it needed stiffer ARBs?
Also, what's your driving style on track? Personally I prefer the slow-in/fast-out method i.e. brake late into the corner, hold the throttle to the apex then accelerate out. If you lift off the throttle at any point in the bend you are likely to get understeer.
p.s. don't underestimate the Cooper S - they have masses of grip and inspire lots of confidence so I'm not surprised you had trouble keeping with it in high-speed bends.
I reckon though that it's the stiffer ARBs that have caused the understeer rather than geo setup. What made you think it needed stiffer ARBs?
Also, what's your driving style on track? Personally I prefer the slow-in/fast-out method i.e. brake late into the corner, hold the throttle to the apex then accelerate out. If you lift off the throttle at any point in the bend you are likely to get understeer.
p.s. don't underestimate the Cooper S - they have masses of grip and inspire lots of confidence so I'm not surprised you had trouble keeping with it in high-speed bends.
i've found that these cars are pretty sensitive to driving style and can be made to understeer or oversteer just by where you send the weight distribution, before you start investigating tyre pressures and ARB / damper settings. having said that, at low speeds where there isn't much weight transfer they do have a tendency for understeer especially if you come in fast and just pile on steering. a little trail braking helps 
at higher speeds tho, i found my car was fairly neutral through corners and could be manipulated into a little oversteer just with the throttle (and not mashing it or clutch kicking, i'm not talking drifting oversteer)
at higher speeds tho, i found my car was fairly neutral through corners and could be manipulated into a little oversteer just with the throttle (and not mashing it or clutch kicking, i'm not talking drifting oversteer)Basically I love the go kart style of driving, whereby you can put the thing into a drift almost before you enter the corner, and power through etc. I think if you sat with me you`d find I am pretty committed all the way through.
I wanted the uprated roll bars because with the standard set up the car rolled too much for my liking. I agree the uprated roll bars will be a lot to do with it, and when I saw them, I was a bit dubious about fitting the front bar. I think I shoud have left the front and just done the rear..the standard rear is made from coat hanger wire!
Years ago I drove a MK1, and it was a ball...every corner you came to it drifted through in very balanced way...so I guess that is what I am aiming for.
In most other respects the car is superb and very well engineered.
Also, I guess some of you guys know your stuff...short of fitting a supercharger, what can be done to get more oomph out of the engine? The engine is basically a Durated which can be tweaked on 2.0ltr Fiesta`s for instance to give an easy 200hp...does Mazda`s ECU prevent such modifications?
I wanted the uprated roll bars because with the standard set up the car rolled too much for my liking. I agree the uprated roll bars will be a lot to do with it, and when I saw them, I was a bit dubious about fitting the front bar. I think I shoud have left the front and just done the rear..the standard rear is made from coat hanger wire!
Years ago I drove a MK1, and it was a ball...every corner you came to it drifted through in very balanced way...so I guess that is what I am aiming for.
In most other respects the car is superb and very well engineered.
Also, I guess some of you guys know your stuff...short of fitting a supercharger, what can be done to get more oomph out of the engine? The engine is basically a Durated which can be tweaked on 2.0ltr Fiesta`s for instance to give an easy 200hp...does Mazda`s ECU prevent such modifications?
I do think that the Front ARB is probably part of the cause.
Also the 'lob it in and powerslide round' method is perhaps not best suited to the car in its current guise.
Ref the engine - I wondered this. There was that company linked short while ago who had done the MX5 GT engine - they reckon they can get 275bhp.
I know that FM in the states have now 'cracked' the factory ECU and when you buy a 'charger you post your ECU to them for them to modify it.
I've no idea how similar the ECU is to the Ford parts.
Part of me thinks that if some MK3 owners managed to get 'in' with the Ford enthusiasts that are familiar with the engine and do some further research there must be some knowledge that can transfer over.
Also the 'lob it in and powerslide round' method is perhaps not best suited to the car in its current guise.
Ref the engine - I wondered this. There was that company linked short while ago who had done the MX5 GT engine - they reckon they can get 275bhp.
I know that FM in the states have now 'cracked' the factory ECU and when you buy a 'charger you post your ECU to them for them to modify it.
I've no idea how similar the ECU is to the Ford parts.
Part of me thinks that if some MK3 owners managed to get 'in' with the Ford enthusiasts that are familiar with the engine and do some further research there must be some knowledge that can transfer over.
i don't think there's anything wrong with fitting uprated ARB's - obviously there will be differences between teh mk1 and mk3 but i think especially on track they do improve things. the big advantage is that from increased roll stiffness you get faster response for transients which is better for corner entry / exit and direction changes. are your ARB's adjustable? on mine, i have several holes in the arms allowing you to basically change the lever length and soften or harden the bar. i ask as a big role of ARB's is to tune the proportion of weight transfer that you get at each axle. when i first fitted mine with the uprated spring and damper combo i already had on, i felt it did induce more understeer so i backed off the front bar to the outermost hole in order to soften up the front, and got a pretty nice balance back.
the ride does suffer as a result over bumpy pot-holed a-roads where you've got one wheel hitting a bump but suspension is always going to be a compromise if you're asking it to do different things and i like the bars
the ride does suffer as a result over bumpy pot-holed a-roads where you've got one wheel hitting a bump but suspension is always going to be a compromise if you're asking it to do different things and i like the bars
CTE said:
Unfortunately the front is not adjustable, but you are right, the responsivness to direction changing is excellent and noticeably better than standard.
so i'm guessing the rear is not adjustable either then, as stiffening that would also help. if not, then the only other option is really adjustable dampers... or just more track time / driver training in order to learn how to get the most out the car. i always remember that top gear episode where clarkson drove the s2 elise and hated it as it just understeered all the time as it had skinny front tyres. but then they got that gavin guy to drive it, who develops all the ride and handling at lotus, and just from throttle / steering control he was hanging it out at will round every corner. (not that i'm comparing you to the ham fisted clarkson idiot!!
)On my mk3 I had whiteline adjustable arb's. You could make the back hang out like a mk2 escort if you stiffened the back and softened the front. Ultimately, while they did eliminate roll they ruined the ride. I didn't really notice until I took them off to sell the car and for that week before the car sold I enjoyed the roll. It certainly communicated the on set of oversteer better. I also had a kansai strutbrace on that car and that made a difference to how the car behaved( understeered a lot less). I fitted the strutbrace to my mk3.5 for a while but it made no difference so I took it off and sold it!
The whiteline bars were solid. Reckon they must've added about 10kg!
The whiteline bars were solid. Reckon they must've added about 10kg!
On my mk3 I had whiteline adjustable arb's. You could make the back hang out like a mk2 escort if you stiffened the back and softened the front. Ultimately, while they did eliminate roll they ruined the ride. I didn't really notice until I took them off to sell the car and for that week before the car sold I enjoyed the roll. It certainly communicated the on set of oversteer better. I also had a kansai strutbrace on that car and that made a difference to how the car behaved( understeered a lot less). I fitted the strutbrace to my mk3.5 for a while but it made no difference so I took it off and sold it!
The whiteline bars were solid. Reckon they must've added about 10kg!
The whiteline bars were solid. Reckon they must've added about 10kg!
Paddy_N_Murphy said:
What is Understeer ?
joking aside, I said to a colleague / mx5 doubter the other day I can not honestly recall understeer ever - road driver only, non of this track hero stuff from me[
Yep I have done so many track days and seen so many MX5's spin and can honestly say I have never seen one understeer.joking aside, I said to a colleague / mx5 doubter the other day I can not honestly recall understeer ever - road driver only, non of this track hero stuff from me[
Understeer = going through hedge forwards. Oversteer = going through hedge backwards.
Gassing Station | Mazda MX5/Roadster/Miata | Top of Page | What's New | My Stuff