Who cares? We don't need to answer this question. You and your buddy above are making the assertion that wider tires = slower car around a racetrack. Prove it.

 

I'm pretty sure my amateur driving ability wouldn't make a great test bed for proving this.

For a company as large and well known as JUN, I'd imagine they would use 275's or 285's if they needed to.

No need to get all upset over my simple question.

 

Maybe sponsorship / agreement with a tire mfgr for a certain "brand" or model of tire that only comes in that width in the (approx) proper OD? Just a thought. Or maybe they like making t3h smoke and showing off more than winning real races (the kind that don't come on DVDs with kanji and have names like "Battle JDM 2006 XL extreme edition").

Then again, I know little about JUN other than that I can't afford and thus probably don't need anything they sell, and that at one point they had a Super Lemon (sounds like my Ford tow-vehicle?) that was fast :P

 

Absolutely, depending on your wheel's offset. There is still more room, and I also have stock suspension.

 

A 1" spacer? E-gad. 275 is too large for an 8" wheel, and I'm sure is making your times suffer versus a properly-sized 245 or 255 on the 8".

 

Well . . . the 275 r-compound tires are still new & was used for the 1st time recently. Even so, I ran faster times than one Z06. I can't wait when the tires have been properly heat cycled so I can run even faster times. So much for being slow.

 

no need to get aggressive here. Like i said, i SUGGEST, im here for knowledge too. I went with 285 before on the track too with the same setting and on the back straight and front straight i DID lose alot of speed. I wasnt able to achieve a faster time, ( cold be the weather) on a race track ( not drag )

There is no perfect setting for every track and every car has a different setting and such. There's always a need for a balance. I was just suggesting that wider isnt ALWAYS better.

 

I was just trying to say wider isnt always better around a racetrack. Are you trying to say wider tires = faster car around the racetrack?

 

almost always. "rolling resistance" vs corner exit speed would be how I look at things. at the end of the day it's all internet bench racing 'til you "prove it" yourself, the topic is rather dead / moot at this point

 

Simply strapping widder tires won't make the car any faster. Widder tire will push the car's limit farther. You the driver is what will make the car faster. And that only happens if the driver is able to take advantage of the wider thread by carrying more speed into the corner.

This is not a critique of your driving skill. it's a simple reality that we each must face, humbly, when driving on a race track.

As for "each car being different", we're pretty much all driving the same car.

 

well put

 

This is what I said:

Every race sanctioning body specifies a maximum rim width in the majority of their road race classes as one way of equalizing performance. In the SCCA Production category many cars are limited to 7" wide wheels. Goodyear and Hoosier both developed cantalievered slicks that fit on the 7" wide wheels but actually give up to 9" of tread width. These slicks are the freaks of the road racing tire world, but they work and are a way to run a wider tire while staying within the rules.

A wider tire was so important in that category of racing that Goodyear and Hoosier spend a buttload of money engineering a tire that gives up to 2" more width. Goodyear and Hoosier both think wider is better in the race tire world.

 

Wider-is-better certainly worked for our 2005 Track that Carter piloted to a very close 2nd place in BS at the 2006 Solo Nationals.We had 285/30/18 710's on the 8" fronts and 8.5" rears.We first used 245's but could not dial out the understeer until we went to the 285's.

 

We use 285 x 18" Kumho 710 on 9" fronts and 10" rears. Last year we used a smaller tire because we were required to use a narrow 8.5" wheel. the Kumho 710 tires this year are the same compound as last year so the tire is a constant. Our car is definitely faster this year due to wider tires. The driver is the same and the car is basically the same. One thing you need to consider on a road course is that the "Z" car is a momentum car. It doesn't have the torque that a V-8 Camaro has but it will corner a little faster, therefore momentum. When driving a Z the speed will be basically in your learning how to be fast smooth. I always advocate making the car handle before you spend or waste money on more engine. If you want response when you push down the fast pedal buy a corvette.

 

285s on an 8" wheel? 255 is the recommended max on an 8" wheel, but I'm listening...

 

+1...kinda wish I kept my miata to learn how to drive and handle the track, then step up to something w/ more power.

 

First, you criticize me (above post) for mounting 275s on an 8" rim. Then, someone else mounted an even wider tire (285s) on an 8" rim (below post). Both of us obviously have used our setups on an autocross course or the track, and have not had any issues. I'm just wondering since you're posting advise here -- have you even tracked your Z? What are you basing your comments from -- experience? Or, just reading information on the Internet and/or this forum? I'm listening . . .

 

Z-U-Later brings up a good point.It is often helpful to the reader,for posters to qualify their suggestions/opinions by stating were the info comes from....experience,testing,results etc.

 

One thing people sometimes forget is that racers do strange things with their cars to meet a set of rules. Ideally a 285 width tire should be mounted on a 10" to 10.5" wide rim, but when the rules say the max rim width is 8", you and your buddies spend hours getting a 285 to fit where is doesn't belong.

 

Just do whatever you are comfortable with, I am perfectly happy with my 235/40/17 setup.