The current wheels I have on my Supra are 18's & they are 8.5 in the front, & 10 inch in the rear & I run 275 in the rear. HP came in at 350 last time it was on the dyno
Thought Im looking into having the rears widened cause I like them so much but they didnt come in a larger size, like a 10 or a 10.5 like i wanted.

If that's 350rwhp, then that's at least 28.7% more hp than stock (350rwhp /.85 = 411.76hp vs 320hp oem spec - please feel free to double-check my math). This means that your rear rims should have been about that much wider than stock...which is already about a 12" wide rim (11.5" would be fine, since that's the max that fits under the oem fenders). That'd be about 315mm-width rubber.

You can't run oem width rear rims and oem width rear rubber unless you're running oem rwhp. I know a guy that tried to run his stock rims at BPU on a MINT/PRISTINE <20K miles '98 Mkiv Supra, and within hours he ended up smashing it sideways into a big rock in a ditch. That's just ONE example of many. Every single component on the ENTIRE MKIV SUPRA TURBO has been spec'd and designed by Toyota to work together by highly qualified automotive engineers with decades of training and experience. You just can't go bumping up the hp and expect nothing else NEEDS to change. When you go BPU or beyond, one of the things that NEEDS to change is the rear rim+tire width. In turn, when that changes, the front rim width and front tire width must change together. It's like a symphony - you can't go replacing a violin with an amplified electric guitar and expect Beethoven's 5th to still sound right.

If the rims you think you "want" don't come in the right size, then don't buy them. It's that simple. There are LOTS of companies making LOTS of styles of rims that do come in 11.5"+ widths. Please let me know if you need help finding what you're looking for.

After you figure out how wide the rubber is that you need to run on the rear, then you can pick the front rim width and the front rubber width in proportion.

Ok, lets say I decide to go with the 11 inch rear wheel, what size should the front be? Would I then run something in the 300's for a rear tire?

Thanks

Cody

I used the tire calculator on discount tire site to help me determine the size tires I wanted. I wanted to say close to the factory spec diameter. I will also tell you the speedo change with the tire tire compared to what's spec. This will help you with picking a tire size that's close to spec. Hope this helps. Here's the link: http://www.discounttire.com/dtcs/infoTireMath.dos

http://www.discounttire.com/dtcs/infoTireMath.dos (Tire Calculator Link)

That calculator doesn't help calculate traction (i.e. width) - only diameter/circumference.

1) 11.5" width rims fit under the (trimmed) rear fenders just fine, and 315-width rubber is fairly common. Why would you go down to 11"?
2) Oem specs are 8" front and 9.5" rear. That's 84%. 84% of 11.5" is 9.68" (close enough to 9.5"). So 9.5" width fronts match 11.5" width rears.

Check this out:
http://mkiv.com/techarticles/parts/o...ned/index.html
...this was my first rim upgrade. I ran 9.5" oem rear rims in the front, and 11.5" widened oem rear rims in the back.

I dont want to have to trim my fenders, or roll them if thats the same thing,

if I can stick with an 11 and not have to roll my fenders thats what i am after,

If you don't mind me asking, why don't you want to trim the rear inner fender lips on your Supra?

I've done this mod on at least a dozen Supras. It's easy, the results look fantastic (i.e. practically invisible unless you know what you're looking for), it's just as strong (really!) and (of course) you can fit 315 rubber inside afterwards.

I also had the fenders rolled on my Supra (this is before I started doing the inner lip trimming), and the results were not nearly as good. Although 315s did fit afterwards, the process put so much stress on the fender that the fender panels got slightly bent. As you would expect, this really bugged me...so I eventually got it corrected. I'm just telling you about this so you know that 1) I really do have a lot of experience with this, and 2) rolling and trimming are VERY different procedures. Please let me know if you want any more info on trimming and I can tell you step-by-step how to do it easily and effectively with no need for experimentation or figuring things out on the fly.

hey,
 

what's the proper off set for a supra, these are what i'm looking at,
does positive offset mean they will stick out?

cody

Size
19x8.5 Front, 19x10 Rear

Bolt Pattern
5X114.3mm

Offset
20mm Front , 25mm Rear

Lip Size:
2.5" Front, 3" Rear

Color:
Chrome

Hub Bore Size:
73.1 mm

Quantity:
4 Wheels

Condition:
Brand New