Wider rear wheels = understeer
#1
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Wider rear wheels = understeer
So unfortunately, just as I thought, going with inch-wider tires in the rear has made my car look very pretty, but it now understeers like an econobox.
I bought those snazzy-looking HP wheels. They seem pretty heavy and right away I could notice that the steering was a lot heavier. That is proably mainly due to the larger tread footprint, though.
On a a tight, twisty road, the front does not want to turn in as quickly - it starts to push. The amazing balance of the car seems to have been lost. I finally confirmed this while entering a long, almost 360 degree freeway on ramp. Front left tire pushed the whole way around.
Not sure if my problem is the newness of the tires, the brand of tires or if I could address this with less pressure in the fronts. But buyer beware - if you want to keep the amazing agility of the car, think twice about a wheel upgrade or at least make sure you hold onto the stockers. I think I'm gonna go look for the factory 17"s from the later cars. Anyone have similar experiences?
I bought those snazzy-looking HP wheels. They seem pretty heavy and right away I could notice that the steering was a lot heavier. That is proably mainly due to the larger tread footprint, though.
On a a tight, twisty road, the front does not want to turn in as quickly - it starts to push. The amazing balance of the car seems to have been lost. I finally confirmed this while entering a long, almost 360 degree freeway on ramp. Front left tire pushed the whole way around.
Not sure if my problem is the newness of the tires, the brand of tires or if I could address this with less pressure in the fronts. But buyer beware - if you want to keep the amazing agility of the car, think twice about a wheel upgrade or at least make sure you hold onto the stockers. I think I'm gonna go look for the factory 17"s from the later cars. Anyone have similar experiences?
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Ok, the tires are:
Front - 225/40Z R18
Rear - 255/35Z R18
Brand - Ventus Sport
Wheel size and offset - arrghh I don't know! Ordered these a while ago. They're pretty conservative - I think 7.5" wide front, 8.5" wide rear. My knowlegable mechanic said they were a good size and offset as they will not rub even with Koni's.
Your constructive thoughts on all that?
Front - 225/40Z R18
Rear - 255/35Z R18
Brand - Ventus Sport
Wheel size and offset - arrghh I don't know! Ordered these a while ago. They're pretty conservative - I think 7.5" wide front, 8.5" wide rear. My knowlegable mechanic said they were a good size and offset as they will not rub even with Koni's.
Your constructive thoughts on all that?
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Well...you are using skinnier wheels than stock up front while going wider at the rear. Of course it's going to plow like a tractor!
Depending on which Ventus tire you are using, you might have also lost traction from the tires on your stock wheels.
There is pretty much no way to salvage the handling with that wheel setup. My advice is to either live with it or sell them and get a proper wheel upgrade.
Depending on which Ventus tire you are using, you might have also lost traction from the tires on your stock wheels.
There is pretty much no way to salvage the handling with that wheel setup. My advice is to either live with it or sell them and get a proper wheel upgrade.
#6
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So I was looking into geting some Volks in 18x9 Front and 18x10 Rear. Should I revert to 18x9 all the way around or just stick with the staggard setup and just match the tire close in size? Like 255 Front and 275 Rear. I want this car to drive like it's on rails.
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#8
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The original poster is having an understeer problem because he has skinnier fronts than stock, although I also suspect slippier tires and driving technique.
#9
FWIW, The "later" factory setup was a 17x8" front w/ 235/45/17, and a 17x8.5" rear w/ 255/40/17. Not alot different than what you've got.
"Ballance" is to some degree a matter of preference, and depends on the rest of your suspension setup. My "street" setup is 9" 255, and 10" 275, and I think it's perfect for that use. I wouldn't want to drive around w/ a 275 front tire on the street, nor would I want to sacrifice rear grip w/ a 255 rear. I think the handling ballance is great.... up until I really push it on SOME corners on SOME tracks... which is why I went for a 9.5" 275 all around for my track wheels.
I've used the street setup on track though, and it's great for 75% of the corners.
"Ballance" is to some degree a matter of preference, and depends on the rest of your suspension setup. My "street" setup is 9" 255, and 10" 275, and I think it's perfect for that use. I wouldn't want to drive around w/ a 275 front tire on the street, nor would I want to sacrifice rear grip w/ a 255 rear. I think the handling ballance is great.... up until I really push it on SOME corners on SOME tracks... which is why I went for a 9.5" 275 all around for my track wheels.
I've used the street setup on track though, and it's great for 75% of the corners.
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Upgrade to better tires.
You guys have great rims that you pay good money for why not put some of the best rubber you can find on them? I wouldn't put any brand on my car that not heavily involved in racing. I have stock rims with Goodyear f1's, my car only gets out of hand when I want it too. Even in wet conditions I can hit it pretty hard. Like Rynberg said the staggered width is what it is and without a really adjustable suspension and tuner it would be tough to work out, but a good set top of line tire would up the limits.
You guys have great rims that you pay good money for why not put some of the best rubber you can find on them? I wouldn't put any brand on my car that not heavily involved in racing. I have stock rims with Goodyear f1's, my car only gets out of hand when I want it too. Even in wet conditions I can hit it pretty hard. Like Rynberg said the staggered width is what it is and without a really adjustable suspension and tuner it would be tough to work out, but a good set top of line tire would up the limits.
#12
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i have a extreme staggered setup... but didnt go cheap on the tires.. the understeer is noticeable but not too bad.. i think the tires being michelin piolet sports helped but the sizes didnt.. also, my wheels are really light forged 2 peice wheels.. did u ever wonder why those HP wheels cost $750 for the set?? and multipeice wheels like volks, hre's, work's ect... cost WAY more...
btw, my sized are:
235/35/18 in the front and
285/30/19 in the back.. but i have no more tire spin
btw, my sized are:
235/35/18 in the front and
285/30/19 in the back.. but i have no more tire spin
#14
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I think anyone that is changing wheels/tires needs to CAREFULLY examine everything they can before doing so. MAZDA spent a fortune on R&D to make the FD an extremely nimble and well-balanced sports car, heck there is even a disclaimer in the owners manual about using any TIRE other than what came out as stock! To me, this shows that the balance of the car is easily affected by poor/improper wheel/tire choices. One should be very careful, in my opinion, before undertaking a major change.
There is a wealth of information available in the various sections of the forum, especially the suspension/wheels/tires, that has good stuff from people that have already "been there/done that".
There is a wealth of information available in the various sections of the forum, especially the suspension/wheels/tires, that has good stuff from people that have already "been there/done that".
#15
sammy d,
for what it's worth, i ran 225/40 and 285/35 A048 on TE37s 8.5f/9.5r. i had great turn in, and never plowed. perhaps try changing your driving style a bit
for what it's worth, i ran 225/40 and 285/35 A048 on TE37s 8.5f/9.5r. i had great turn in, and never plowed. perhaps try changing your driving style a bit
Last edited by omochi; 04-08-06 at 10:14 AM.
#16
Old and grumpy
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And to the original poster, I know it's been said already but you just made a couple bad decisions when it came time to put wheels your car. Put the stock wheels back on with some GOOD rubber until you can find some wheels you like that will let you run proper sized upgraded tires.
Last edited by cabaynes; 04-08-06 at 10:51 AM.
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Originally Posted by neit_jnf
just drop a stiffer rear swaybar in there
#18
Originally Posted by SammyD
My knowlegable mechanic said they were a good size and offset as they will not rub even with Koni's.
Originally Posted by neit_jnf
just drop a stiffer rear swaybar in there
Oh and FYI, in 99% of situations, understeer is safer. It'll keep ya alive
~Ramy
#22
Rotor Head Extreme
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Reading this thread is confusing me. If the original posters staggered set-up was so bad, why does Pettit run 225/40/18 front by 285/30/18 rear on the Banzai 20b? I believe this is the combination David Hayes is running with his car but only with wider 335/30/18 in the rear. He said the handling felt great and didn't notice any front push.
#24
T-von, the original poster had problems b/c he was running 7.5" wide rims in the front on crappy tires!
Many ppl on this forum who are avid road course goers run staggard setups. Few run 255s all around, although I believe that's what the RE JGTC car runs (255s or 285s all around, I forget which one).
Set up correctly (correct widths, weights, tires, and alignment settings), a staggard setup can be better given that you're making a lot more power than stock (wider contact patch in the rear). Combos like 225s/255s, 255s/275s, 245s/285s, and 285s/315s are among the popular/recommended one...from what I've come across at least.
~Ramy
Many ppl on this forum who are avid road course goers run staggard setups. Few run 255s all around, although I believe that's what the RE JGTC car runs (255s or 285s all around, I forget which one).
Set up correctly (correct widths, weights, tires, and alignment settings), a staggard setup can be better given that you're making a lot more power than stock (wider contact patch in the rear). Combos like 225s/255s, 255s/275s, 245s/285s, and 285s/315s are among the popular/recommended one...from what I've come across at least.
~Ramy
#25
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if your rims are only 7.5 and 8.5 that kinda of big tires for that width i would go 215 40 in the front and 235 or 245 35 in the rear that might help since you might be getting tread flex.
Last edited by seanfd3s; 04-08-06 at 07:06 PM.