Too Wide Tires for 1M ?

[HP Autosport]

The 1M can use the widest wheels and tire possible at all four corners, especially in the rear. Staggered setup doesn't mean the car will understeer when setup correctly.

11" wheel with 295 should easily fit in the rear. We are currently running 10.5" with 285 and there is enough space for 11" with a 295 or 305 depend on the offset of the wheel and tire brand.

[HP Autosport]

Originally Posted by guyp

The original 1M Wheels do well on high speed track with Michelin Sport CUP + on OEM size.
I have tried 18x10 with 265-35-r18 square and it drive nicely with R-Compounds.

but My last wheel/Tire setup doesn't do the job overs 140kph. The car move sideways a bit, il Wooble, the stock suspension seems soft with this setup . I feel the car roling more than usual. I don't like the feeling ! i have tried pressures from 29to 40 without succes. help me !

The wheels a Lignt Enkei 18x10 offset 25, the tires are almost new Toyo R888
front: 255-35
rear: 295-30

What could be wrong ?
Thank's

If you are running R-comp or slicks, you will want more spring and damping.

[Advevo]

The more grip you have you need firstly more camber. For road and track don t go much further then 2 degree. Otherwise it s driving very bad on roads.

Standard suspension is certainly not up to the job of semi slicks. I have changed my suspension to JRZ with 18 inch 9.5 J wheels all-round.

Front wheels are 12mm wider then original and rear 10mm wider then original. It feels pretty good.

The toyo tires are very wide tires. 255/35/18 r888 is standing straight on the rim. A pilotsport cup 265/35/18 sits a little bit streched on the rim.

You can better have tires which are little bit streched on the rim that gives more stability.

toyo r888 are very wide tires you should consider go a bit smaller. 295 toyo r888 on 10j is to wide and gives you no stability on the rear end.

[mattm]

Originally Posted by HP Autowerks

The 1M can use the widest wheels and tire possible at all four corners, especially in the rear. Staggered setup doesn't mean the car will understeer when setup correctly.

11" wheel with 295 should easily fit in the rear. We are currently running 10.5" with 285 and there is enough space for 11" with a 295 or 305 depend on the offset of the wheel and tire brand.

HP, think I could wedge a P315/30ZR19 (or even a 325/30ZR19) in the rear on a 10" wheel? In that same vein, a P265/35ZR19 (or P295/35ZR19) on the front 9" wheel? I realize that the larger tires for this is nutz®. I must keep to stock sizes on the wheels as I am going to run SCCA Solo in their stock classing. I can go with up to ±.25" on the offset, so I am looking at changing the offset by 6 mm.

[HP Autosport]

Originally Posted by mattm

HP, think I could wedge a P315/30ZR19 (or even a 325/30ZR19) in the rear on a 10" wheel? In that same vein, a P265/35ZR19 (or P295/35ZR19) on the front 9" wheel? I realize that the larger tires for this is nutz®. I must keep to stock sizes on the wheels as I am going to run SCCA Solo in their stock classing. I can go with up to ±.25" on the offset, so I am looking at changing the offset by 6 mm.

265/35/19 would fit, but will rub on the plastic liner near and at full lock. Lower profile would work if you can find it.

You may be able to get away with a 285 or 295 rear and still have enough support from the wheels. Anything wider than a 295 you should use wider than stock width wheels.

[mattm]

Originally Posted by HP Autowerks

265/35/19 would fit, but will rub on the plastic liner near and at full lock. Lower profile would work if you can find it. You may be able to get away with a 285 or 295 rear and still have enough support from the wheels. Anything wider than a 295 you should use wider than stock width wheels.

Thanks for the feed back. Gotta stick with the OEM sizes for A Stock. I'm looking at Forgestar wheels too. They are relatively light and affordable (a tough combo).

[M3 Adjuster]

Originally Posted by terivera

I am looking for a track wheel setup and I have been told that 18 X10 with 25mm offset should be perfect running 275 X35 all square.

so far... it seems to be a good combo... they do fit..... will know more soon.

[Fundahl]

I found Toyo R888 for stock rims:

265/30ZR19, 9.0-10.0" wheel, 25.4 overall diameter, 10.6" overall width

295/30ZR19, 10.0-11.0" wheel, 26 overall diameter, 11.7" overall width


Would these work well on stock wheels for dry traction? Basically I'm just wondering if they would fit without issue, obviously a great improvement in traction over stock skinny Pilot Sports.

[fourtailpipes]

i cant make a guarantee, but i'm pretty sure you're in the clear.

personally, i'd avoid the increased stagger, but that's another conversation.

[HP Autosport]

Originally Posted by Fundahl

I found Toyo R888 for stock rims:

265/30ZR19, 9.0-10.0" wheel, 25.4 overall diameter, 10.6" overall width

295/30ZR19, 10.0-11.0" wheel, 26 overall diameter, 11.7" overall width


Would these work well on stock wheels for dry traction? Basically I'm just wondering if they would fit without issue, obviously a great improvement in traction over stock skinny Pilot Sports.

Those may work, but the only way to find out is to get them on the wheels, put them on the car and go out for a spin.

[Fundahl]

Originally Posted by HP Autowerks

Those may work, but the only way to find out is to get them on the wheels, put them on the car and go out for a spin.

Expensive test.

[Fundahl]

Originally Posted by fourtailpipes

i cant make a guarantee, but i'm pretty sure you're in the clear.

personally, i'd avoid the increased stagger, but that's another conversation.

I can live with a little extra "push" to be able to accelerate harder without breaking into a drift.

Or is there another reason? I'll probably go Ground Control camber plates as I want to keep stock suspension and wheels but maximize cornering and acceleration ability.

Has anyone bought the "Race" version and messed with Caster? I'm still not exactly sure the effect of that calibration.

[fourtailpipes]

Originally Posted by Fundahl

I can live with a little extra "push" to be able to accelerate harder without breaking into a drift.

Or is there another reason? I'll probably go Ground Control camber plates as I want to keep stock suspension and wheels but maximize cornering and acceleration ability.

Has anyone bought the "Race" version and messed with Caster? I'm still not exactly sure the effect of that calibration.

since they're track tires, i'm imagining you using them on the track, in which case, an increased stagger is the last thing i'd want. if you're using them on the street, i'd be a little more understanding of the increased stagger (though still generally opposed), but they wont last long. i used to really like the PSC as a daily tire, but that's an expensive game to play.

caster is an adjustment perpendicular to camber, which tilts the strut forward or backward. this is essentially a camber multiplier (can serve to increase or decrease wheel tilt as steering angle increases). speaking broadly, if lateral traction is your goal, these cars like a lot of camber AND caster, but for a mostly stock car like yours, you could add some camber, but should probably leave caster alone. if you're interested in learning more, grassroots motorsport has a great article on basic alignment theory that will get you to first base.

FYI, you may find that the increased mechanical grip you're likely to get out of the R888 (assuming you get them hot enough) increases your sensation of sloppiness in the suspension. generally, you want to stiffen springs, damper settings, and swaybars when adding significant mechanical grip.

[Fundahl]

Originally Posted by fourtailpipes

since they're track tires, i'm imagining you using them on the track, in which case, an increased stagger is the last thing i'd want. if you're using them on the street, i'd be a little more understanding of the increased stagger (though still generally opposed), but they wont last long. i used to really like the PSC as a daily tire, but that's an expensive game to play.

caster is an adjustment perpendicular to camber, which tilts the strut forward or backward. this is essentially a camber multiplier (can serve to increase or decrease wheel tilt as steering angle increases). speaking broadly, if lateral traction is your goal, these cars like a lot of camber AND caster, but for a mostly stock car like yours, you could add some camber, but should probably leave caster alone. if you're interested in learning more, grassroots motorsport has a great article on basic alignment theory that will get you to first base.

FYI, you may find that the increased mechanical grip you're likely to get out of the R888 (assuming you get them hot enough) increases your sensation of sloppiness in the suspension. generally, you want to stiffen springs, damper settings, and swaybars when adding significant mechanical grip.

Understood. Stickier tires definitely show the softness of the stock stuff. Basically I'll have two set's of stock rims, one with R or A compound tires (depending if I'm autoX or roadcourse) and then a set with my street tires.

I plan on AD08s or PSS's for street tires. I think I'll try to get around -2.0 camber in the front with the Ground Control plates with the 260/30R19 and see how that feels.

Thanks for the info!

[nachob]

Originally Posted by Pete_vB

So the front offset is actually 38 vs 31 stock, so you took out 7mm of scrub, likely putting you close to zero or actually negative scrub radius. You don't want negative scrub, you want to stay somewhat positive to preserve stability and steering feel. Try adding a 5-7mm or 1/4" spacer up front and see if that helps.

Also, if I understand it right you don't have issues with high speed balance mid-corner, more straight-line stability?

Pete and Dan Parker, I need your help!

I have my 1M but I have always wanted a set of BBS RG-Rs. I love the forged lighter wheel with truly classic BBS styling and a lip.

They make a 19x10 ET 25 rear, the same as stock so no problem there but for the front they only have a 19x8.5 ET30 and 19x10 ET20.

I don't want to go narrower but I also don't want the wheel sticking out past the fender where it might rub, throw more crap on the side of the car and worst yet, affect handling by altering the scrub radius. Also, it would look weird because the rears would be stock inset and the fronts sticking out. I don't like spacers.

So that leaves me with 19x8.5 ET30. That is only 1 mm difference so the centerline of the contact patch should be almost identical to stock but now I wonder how the handling would be affected by having a 1/2" narrower wheel supporting the 245 width tire. 8.5" is fine for 245 width but I assume there was a reason BMW went with a 9" for competition package wheels.

What do both of you think? Will it be much squishier since the sidewall is more vertical?

I also think aesthetically it will be inset another 5mm from the edge of the fender. If I did add add a 5mm spacer for aesthetics, do you feel the change in scrub radius will be affected?

I am mostly on the road but don't want to negatively impact handling since the car can already be a handful.

Thank you gentlemen.