MelloYellow

Anyone ever experience any rubbing issues with 285's up front?
I'm considering 285/40-17"s.

Thanks,

Brad @ MMS

Mike,

Can you e-mail me or call me, because I can't get throught to you with the number I have.

Thanks

Vinzvette

Since being on here a couple of years and talking to numerous vette owners locally 275 is the largest that Ive heard of. :cool:

Shinobi'sZ

I have 285/30's on 18 X 10.5" on my fronts with no problems. The biggest I ran on my stock rims were 255/40 BFG KD's on the front. Keep in mind Mellow that unless you are just wanting to say that you have 285's up front...on a stock rim..... the best contact patch is stock and the largest without losing performance is the 255's I referred too. Otherwise the tires just crown and loose stability and contact. This is just my advice for performance. I had to struggle with this when I was considering purchasing 295's for my stock rear rims.....285's would perform better on a 9.5" rim just like 255's will on a 8.5" rim. But I don't know what size rims you have either. :cheers:


[Modified by Shinobi's97, 4:14 PM 10/19/2001]

MelloYellow

Thanks guys. Brad I sent you my new phone#.

Shinobi, I'm looking at 10" up front and 12"-12.5" out back.
Just wanted to make sure I don't have to change anything up front for those tires. Gonna widen my stock rims here local by a reputable National shop. Plan to run Pilots @ 285/40-17 & 345/35-18's. ETA is like... Jan-February.

$200/wheel to widen the stock HiPol's. 345's on a 12.5" would be SICK!!
:D

EuG

Mello,
ElDiablo has 285/30/18 on 10.5 CCW wheels on the front.

As far as widening stock rims, as I e-mailed you, it won’t work. To much backspacing :(

Shinobi'sZ

Sounds cool Mello and I am not knocking you mods at all when I say this.....but do you think that you will gain that much difference running 345's vs 335's in the rear, versus the fact that you are going to have to tub the rear to fit 12" wide rims. I mean it is a personal preference. I am asking because I really struggled with tubbing my car (I mean it is not like you are ruining it or anything) but just if I would really gain over the 335's and not tubbing. :cheers:

EuG

Shinobi's97,
You have to tub for 335s also (if you don’t’ want them to stick out)
And you should really put 335 on at least 12” rim.

I know a few people run ‘em on 11.5” rim and it works ok, but it’s not recommended.

BTW: If anybody is interested I got a video of ElDiablo’s car. He runs 335s on 11.5 CCW rims out back. No tubbing.
http://www.corvettegarage.com/users/...s/ElDiablo.avi
( DiVX codec required to view)

vetterdstr

I also have the 285/30/18's up front with 10" wheels. They went on just fine except for one thing. We had to take a file and shave off just a hair of material so the wheel didnt come in contact with the upper A arm when the wheel was fully turned to the left. Other than that one thing... this T&W setup I now have is the Best Ever!! :)

vetterdstr :chevy


[Modified by vetterdstr, 8:50 PM 10/19/2001]

MelloYellow

Heya,

The reason I'm focusing on the 345's is the ratio on that tire is 35. It'll give me more sidewall and should improve my traction a LOT over the 30 ratio 335's. I'd really like to find a 345/35 solution.

EuG

The solution is VERY expensive. :(
You need GTR body kit :yesnod:, then some 12.5-13” rims and tires :eek:

Snowman runs 345s….

MelloYellow

Ya. :(

Hmm, there are a couple peeps that tubbed and fit 345/35's here.

My new goal is to find some magical way to crunch 10.5-11" in without tubbing. LOL. Numbers don't seem to be working, but.. maybe... Since these guys are fitting 11.5" w/o tubbing, I should be able to fit at least 10.5" with stock offset I hope. Dunno how much tubbing may buy me. Doesn't look good tho with this offset. Maybe the wheel guy has some tricks...

Shinobi'sZ

FYI, 345/35 is quite a bit taller of a tire..therefore you will have taller gears,,you are effecting gear ratio's as well. If you are running 3:73's it might not be so bad,,,,but I suspect it would effect your 1/4's and your dyno numbers. :cheers:

Also the guy (John) who manufactures the CCWheel is the one that advised me that the 335 is fine and he recommends them on a 11.5" wheel. The tire sticks out 1/8-1/4" its at the point where you have to get eye level with the car and really look for it.....otherwise I don't think most would notice. I am also running a 10.5" wheel on the front with a 285/30 there is plenty of room for a 285/35. John told me that the 285/30's sidewall is different and therefore it handles different when cornering. A 345 definetly needs a 12" rim. Do your measuring for Sidewall Height the bigger you go the taller your gears. I went with a 335/30 because it is about a 1/2" shorter sidewall, that means my gear ratios are shorter and I am getting more torque with them. Of course if you have an ARE 432 Cid, you don't have to worry too much about not having enough torque! :D


[Modified by Shinobi's97, 11:07 PM 10/19/2001]

MelloYellow

Do you know the offset & backspacing #'s CCW is using for the 11.5/335 without tubbing? How much clearance is left inside with that fit?

Thx,


[Modified by MelloYellow, 12:12 AM 10/20/2001]

Shinobi'sZ

You have between 1/4-1/2 inch between the inside of your tire and wheel well at the top depending on your camber. I measured and observed it many times when I installed my poly urethane bushig kit. Like I said the thing you have to look out for is the bottom transverse leaf spring....they are not all centered exactly from the factory. I had my car to low and actually scratched the inside of my rim........this was do to having positive camber..when you jack the car up and let it down it does not settle right away. My ride height now is 26" in the rear and all is fine.....John was cool enough to fix my rim for me for just shipping it to him..I was little embarrassed after doing all my suspension mods myself......needless to say I ground the rear spring mounting plate (not really necessary, but just in case it gets close going over a SEVERE bump or something). I think most of all it had to do with my Camber settings because I had to tear down all the control arms (upper and lower) to install the poly kit. :cool:

JWSchmidt3

I have Yokohama AVS-Sports 275/40-17 and when new, they slightly rubbed when cut in all the way. I'm lowered about an inch. Yoko's run a little bigger though then most tires, so a Goodyear or Michelin 285 might fit (in a 17" wheel) but I wouldn't risk it. :cheers:

Shinobi'sZ

I just calculated the differences between a 335/30 18 and a 345/35 18. The difference is +.39 width and +.80 height. Here is the link if you want to do it yourself. http://www.c5-corvette.com/home.htm

The calculation between a 275/40 18 and a 345/35 18 is +.2.76 width and +.42 height. You are making your gear ratio's higher.

The calculation between a 275/40 18 and a 335/30 18 is +2.36 width and -.37 height. You are lowering your gear ratio.

I hope this helps in making your determination about how your mod effects your car in all aspects of performance.
:cheers:

vetterdstr

Here is a link to a site that give great information about comparing 2 tire sizes. http://www.miata.net/garage/tirecalc.html

The tire/gear site I used to use has gone off line... :cry

vetterdstr :smash:


[Modified by vetterdstr, 7:02 AM 10/20/2001]

MelloYellow

Thanks everbody. I'll keep it on the safe side and use 275's if I can up front. My main question is how much can I add to a stock rim without changing the offset before I start hitting the rear spring plates or control arms? Can I go ANY past 8.75" backspacing?

I believe M. Hefner tried making some 11"s out of stock wheels but ran into problems. I'm not sure if he tried tubbing or not.

Maybe 10.5-10.8 would fit widening a stock rear rim? That's the question...


[Modified by MelloYellow, 11:45 AM 10/21/2001]