Autox and tire discussion

[SGOS252382]

Originally Posted by Todd in Vancouver

Great idea for a thread.

With all the discussion on tires thought I'd throw another subject in here. AutoX really gets going next month locally so I'm off to Drivers Training in a week to brush up on my driving skills. Fact is my ZL is more capable then my driving skills are so all the horse power and tire in the world isn't going to make me any faster until I get better at driving. Just something to think about as we all head into racing season before everyone spends more cash on the cars it might be a better investment in yourselves.

Yes and no, - driver skill is extremely important, but so are your tires. Crappy tires will ruin your day at the track.

You've already got some good street tires on your ZL.

I've seen guys show up at the track with crappy hard rubber and their car handles like crap. Next trip to the track they throw on a set of Michelins and they look like a completely different driver going around the track.

[NJ Drive]

Originally Posted by WarWolfX0

...with the 305/30/19...
Also theses tire would drop the car 1.25" from stock

The car would be 0.625" lower using a 1.25" reduction of overall tire diameter.

[WarWolfX0]

No my numbers are correct I already divided the number in half.
The diameter of the 305/30/19 tires are 26.2", stock are 28.7"
26.2"-28.7"=2.5"
That is a 2.5" overall decrease in diameter
2.5"\2=1.25"
A 9% decrease in speed compared to the tach
The tires is really a "26.3" but the math say .2
25.4 is the metric conversion rate to inch
(((245*45%)/25.4)*2)+20"= 28.68" or 28.66" for the rear
(((305*30%)/25.4)*2)+19"= 26.20"

Compared to Michelin 295/35/20 which is 28.1"
(28.1"-28.7")/2=.3"
That is a .3" drop
Compare that to my balding stock tires i have no drop.

I also found tire that will fit my front 9" wide 255/40/20
There is only a .1" overall difference between the 2 tires

A better 19" tire size that work be closer to stock height would be the 285/40/19 that is 28" in diameter. (9.5-11" rim)

Another viable option for my 9/10" wheels would be 245/45/20 and 315/35/20 those are dead on. Just, I don't know if the Michelin 315 would fit a 10" wheel since they recommend a 10.5-12.5" rim.

[NJ Drive]

Got ya.

I understand the math... I thought you were loosely saying that a reduction of overall diameter meant an equal drop in ride height.

[WarWolfX0]

I have been doing the math for a few day I a really just wanted to post it some place. I even have a excel file that has all the Michelin tires sizes grouped by rim then ordered by circumference. It even has thread width and percentage from stock. I have gone tire mad.

[So Cal Camaro]

When you run the 26.2" OD tires, be prepared for how low your Camaro will sit added to any other drop you may already have, but it will drive like a slot car...

[Norm Peterson]

Originally Posted by WarWolfX0

Another viable option for my 9/10" wheels would be 245/45/20 and 315/35/20 those are dead on. Just, I don't know if the Michelin 315 would fit a 10" wheel since they recommend a 10.5-12.5" rim.

Wait a moment - you only have 9's/10's on your 1LE for more than just temporary all-season or winter tire fitment?


Norm

[JDP Motorsports]

I'm running the Michelin PSS 295/35R20 in the front and the 315/35R20 in the rear. The tires work very well and I am pleased with the overall performance. I have had issues with the outer edge pealing and chunking which frankly sucks after 1 event... I will be going to a 19x10 F and 19x11 R with BFG Rivals in the very near future.

Kind regards,

Jordan Priestley
888.308.6007

[Retro69]

Originally Posted by JDP Motorsports

I'm running the Michelin PSS 295/35R20 in the front and the 315/35R20 in the rear. The tires work very well and I am pleased with the overall performance. I have had issues with the outer edge pealing and chunking which frankly sucks after 1 event... I will be going to a 19x10 F and 19x11 R with BFG Rivals in the very near future.

Kind regards,

Jordan Priestley
888.308.6007

I've been looking into a smaller diameter wheel to open up more tire options. Last time I checked tirerack.com I didn't see Rivals in 19", only 18s and they are like two inches shorter than the 20's.

You have any idea on what wheels you're considering yet?

[WarWolfX0]

Originally Posted by Norm Peterson

Wait a moment - you only have 9's/10's on your 1LE for more than just temporary all-season or winter tire fitment?


Norm

Technically it is a 2010 SS with the 1LE track package and a 3.91 rear gear, with TSW rims (stock 8/9 are my winter tires), and the zl1 short throw shifter. At the time they didn't think that the 10" rim would fit the front. Also the 1LE didn't exist when I got the rims.

[WarWolfX0]

Originally Posted by JDP Motorsports

I'm running the Michelin PSS 295/35R20 in the front and the 315/35R20 in the rear. The tires work very well and I am pleased with the overall performance. I have had issues with the outer edge pealing and chunking which frankly sucks after 1 event... I will be going to a 19x10 F and 19x11 R with BFG Rivals in the very near future.

Kind regards,

Jordan Priestley
888.308.6007

Ya I only see 2 19" tires in there lineup, unless they are releasing a new size that is not on the site the largest you can go is 285/35ZR19, which will fit both 10/11 rims fine.

[Bryan1LE]

Hey Jordan, what camber are you running if you don't mind me asking? I'm currently trying to decide on wheel size and PSS or Rival. I noticed the chunking on your fronts when I met you at OUSCI last year, but forgot to ask about it. And congrats on the strong run at Laguna!

[So Cal Camaro]

Originally Posted by JDP Motorsports

I'm running the Michelin PSS 295/35R20 in the front and the 315/35R20 in the rear. The tires work very well and I am pleased with the overall performance. I have had issues with the outer edge pealing and chunking which frankly sucks after 1 event... I will be going to a 19x10 F and 19x11 R with BFG Rivals in the very near future.

Kind regards,

Jordan Priestley
888.308.6007

The edges on the PSS are an issue, mine wear out that side too fast...but from what I have seen on cars, the Rival's aren't any better...in fact given the weight of our Camaro's, none of the tires I have tried fair well on the outer edges, oddly except the NT-05's which usually wear the center stripe too fast, even at lower pressure....

[Norm Peterson]

Originally Posted by WarWolfX0

Technically it is a 2010 SS with the 1LE track package and a 3.91 rear gear, with TSW rims (stock 8/9 are my winter tires), and the zl1 short throw shifter. At the time they didn't think that the 10" rim would fit the front. Also the 1LE didn't exist when I got the rims.

OK, makes sense now. I'm finding out for myself that the wider you want to go with the wheels, the tougher it gets. The first inch wider is a no-brainer, the next half inch fairly easy, and from there it's a lot tougher.

(I can't think of a better use for your stock wheels than winter duty once you've upgraded for the other three seasons )


Norm