What size wheels and tires fit under the AWR bodywork? Backspacing? Offset? I know EP cars run slicks, but I'd also be curious about DOT-R sizes.

Alternatively, Trent, how much rubber at you fitting to put down your 400rwhp?

Please and thank you.

glen

PS- AWR hasn't returned my email asking this question..

 

not sure what everyone else is running but heres my setup. 15x10 diamond wheels with 6" back space all four corners, running 1/4 spacers all way around. (measurements were off just a tad) im using the 275-35-15 R6's. the 10 wide fronts dont tuck well behing the front bumper as i would like them too but i havent made myself a new one just yet. im putting down 425hp with total weight at 2550lbs with me, and the tires seem to be holding up well with great grip.

hope that helps some.

heres what they look like on my car

 

Do you have some larger pictures I could look at? The body work seems like a huge benefit for fitting rubber. Sounds like 5.75" for 10in wide is the magic. How's suspension clearance? Which suspension are you running? (Here's hoping you say GC 2.5" coil-overs...)

How's life in ST1 with the FC Turbo?

 

im just running the ksport inverted monotube coilovers revalved for my spring rates. but ya 2.5" springs though. everything clears suspension just fine. had to use the 1/4 spacers in front to clear the calipers, i just spaced the rears too to keep track even.

sorry i dont have any bigger pics.

and its almost like a never ending battle to try to develop a car unless you gots lots of money (which i dont lol) but the challenge is the fun part for me

 

rob81gsl, so the Diamonds don't clear the stock calipers? I was just measuring my car to get a set for rains. It did look like it was going to be close right at the caliper piston bumps. After looking at them I was going to go with 1/2" spacers but if 1/4" works I'd feel a little better even with 1/2"ARP studs.

Which style did you get, I have to live with 15x7's and 9.5 slicks.

 

ya it was the bump that was my issue. the 1/4 spacer took care of it with the 6" backspace. its close as hell but has never hit.

 

Cool thanks. I have 3.5" backspace with 7" wide rims on the rears and that puts me .2" under the max allowed in EP. It looks like I'm going to order a pair for the front with 4" BS and work with my suspension and spacers to get the track I want.

For gkmccready, If the body is designed for EP it has to cover a 9.5" wide slick on a 7" wide rim with 3.5" BS. That get you to the max track, with the max rim width and biggest slick you can buy for a 7" rim. The tire itself ends up being about 10.5" wide when mounted but they are looking at contact patch. Hope that helps give you an idea of how far the fenders stick out from stock besides just saying its 2" wider. That way you can play with BS on whatever size rim you get and stuff a big tire between the fender and spring.

 

i am positive that the 16x10 0 offset Diamonds need a 5mm spacer to clear the front calipers

 

Yea, they use the same centers on all the offsets and just weld them in in a different spot so the offset doesn't matter to clear the caliper. Its just how the center is shaped.

When you bringing that car to my area Wilson? I want to get a closer look at it.

 

I'm running Enkei RPF1's 17x8 in front and 17x9 in the rear. ( I think both are in the 35 offset range) I run Yokohama A005 Slicks, 235/40/17 up front, 255/40/17 out back. Car sticks well. I have 25 mm wider frnders up front and the rears are rolled and stretched a little. Future plans may involve doing silly widebody things and going to a 18x10 front and 18x12.5 rear rim with 275/40/17 up front and a 315/35/17 slick in the rear. I've run steel wheels in the past and the center is too shallow, I had to run a 15 mm spacer for clearance. I'm debating a DTM style cheap wheel flare option. Here's a rough rendering of what I'm thinking:
Underneath is a shot in action from last year with the 17" yokohama rubber and Enkei's

-Trent

 

what offset are those diamond stars on your car rob? I need a set of track wheels that look flush with my widebody. My current street wheels (enkei rpf1's) 17x10 +18 still have like an inch or so inwards in the rear.

thanks, Mikal

 

He covered it already, see below.

 

Thanks to everybody for responding. I think there's enough info here for me to figure out what will fit. I was concerned about getting enough tire under the car.

 

X2 Dimondracingwheels 16x10 0 offset Works On all 4 corners but do need the spacer up front!

 

Okay, waking this thread up again. Sorry.

Stock TurboII 16x7 +40 wheels. 5.625" backspacing. 2.375" frontspacing. 225/50r16 tires. EP fibreglass bodywork. Tire rubs the spring, but the car can still be rolled, so it's not an extreme rub.

Rear fenders seem to add about 3" room to the outboard size. Front fenders seem to add about 2".

My math says an 18x9.5 with 5.25" backspacing is 5.25" frontspacing which adds 3/8" inboard clearance and 2.875" to the outside. So that's about perfect for the rear, but nowhere close for the front. Could probably go with 5.5" backspacing and get rid of the rub which would still put me 2.625" outboard -- don't think the EP fenders add that much clearance up front.

18x9, 5.5" bs, 4.5" fs, 2.125" increase over stock while improving inboard clearance 1/8". That seems like the max for the front to me. The rear seems like it could tolerate an 18x10, 5.5" bs, 5.5" fs, 3.125" increase over stock.

Do folks running the EP (15x7, 3.5" bs, 9.5" slick) and/or running the 10in wide wheels have them sticking out of the front fenders? I'm guessing the answer is yes?

Thanks!

 

Bueller?

 

I'm not familiar with the term "front spacing"... I assume you mean the distance from the mounting face to the outside lip of the wheel. And if that's the case you might need to check your math. As 5.5" bs + 4.5" fs creates a 10" wide wheel, not 9".
Hate for you to order wheels only to be off by a full inch.

 

That's an artifact of how wheel manufacturers measure wheel width. The count where the tire sits between the lips and not the distance to the outside edges. If you measure the stock 16x7 wheels you'll find they measure "wider" than 7" if you try to measure the full outside to outside width.

 

So then the bs/ fs numbers are to the outside edge of the wheel lip?
That makes sense. :thumbsup

 

Yup. Because bs/fs are for fitment to the chassis while the wheel width is for fitment of the tire.

Appreciate you looking out for me, though! Wouldn't be the first time I'd measured twice, cut once, and then had to buy new materials. :-)

 

25 mm offset

 

Trent, I just picked up some 17x8 Forgelines with a 35mm offset. Based on your experience, would they fit under stock fenders with a 235x40x17 Toyo 888 on them?

Eric

 

With which wheel width?

From measuring from the current 16x7 TurboII wheels on the car... no room inboard in the front, about 2" outboard. In the rear there's an inch or so inboard, and maybe 2.5" outboard. Seems like a 10" wheel would fit the back, but a 9" wheel would be pushing it in the front if you wanted to keep it inside the fenders. And this is assuming you size tire width to wheel width and don't have over-hang.

The 15x7 to fit the 9.5" EP slick (10.4" wide) with 3.5" backspacing (0 offset) effectively moved the wheel 1.58"/40mm outboard to clear the strut. So if I could keep the section width within the wheel width it seems like a 10" wide wheel would be equivalent. And both seem like they'd stick outside the fenders in the front.

My head hurts... rob81gsl, those 15x10 with 5.75" backspacing and 275mm tires just don't seem to match my math and yet you've got them in there and working...

 

Can anybody see a flaw in this logic?

16x7 +40 225/50r16 Slight inside rub, 9.2" section width
16x7 +40 205/55r16 Stock, 8.4" section width
15x7 +0 23x9.5x15 EP Slicks, 10.7" section width, wheel 1.57" further out

Compared to 225s the EP slicks add 1.5" to the section width (0.75" inside, 0.75" outside), but move the wheel out by 1.57", which gives the inside clearance necessary... effectively adding 0.82" of inner clearance. Looking at the 205s, EP slicks add 2.3" to section width (1.15" in & out) so you still gain 0.42" of inner clearance.

Groovy.

15x10 +0 275/35r18, 10.8" section width, wheel center line is same, but add 1.5" inside and outside while moving the wheel 1.57" out. Should give really close to the same clearance as the EP slicks, right? 10.7" vs 10.8" section and the wheel size is lost in the tire section width discussion?

18x10 +0 285/30r18, 11.5" section width. That's 0.8" wider than the EP slick, so 0.4" more inside & outside. Looking at the 205s the EP slicks gained 0.42" of clearance, and this would take back that clearance leaving me... with stock clearance? Yes? Even with a bunch of static negative camber this seems like it should work.

Can somebody double check my math, please? I'm also wondering if part of the clearance fun is that an EP slick is only 22.8" tall while my 225/50r16 is about 24.8" ... the 225s rub on the spring, but if they were shorter the top would miss the spring & perch...

Of course, I've ignored fender clearance now... but if my math seems right the 285s would stick out 0.4" further outboard than the EP slicks which is probably something that can be worked with? Or just run the cheater 255/35r18 Hoosiers with 10.3" tread and 10.8" section... lose 0.6" tread width, but gain 0.8" in section width to work with. And both the 255 and 285 work on 18x10 so a front/rear set up is easily workable...

Yes, I really am still looking in to this. I got keen on the 15x10s but needing the spacers and looking at available rubber I'm not so convinced now...