Autocross z28 setup on 1le

[mcynet]

OK my thought is to get more rubber on the road to help with autocross lap times in my F Street class.

I have been looking at copying what was done on the z28, but i have some questions.

Z28 runs
Front - 22873225 - (19x11 11mm os) (GM says the shipping weight is 25.88 pounds) - $795.00
Rear - 22873227 - (19x11.5 26mm os) (GM says the shipping weight is 26.32 pounds) - $795.00

All Tires 4 305/30/19 pzero trafao

All that = 1.3g turning..... THAT IS WHAT I WANT

the 1le rims are 20X10 23mm offset Front and 20X11 43mm offset in the Rear.

What Im wanting to run is a 19 X 10.5 inch rim, mainly because I cant find it the other sizes. and a Handkook Ventus R-S3 305/30/19 Tire.

Also, the rims Im finding are 27mm offset. and bolt pattern 5x120

Now for the questions...

1) Will what I have listed work? (10.5X19 with the handkook)

2) What are acceptable ranges for the offset front and rear on a 19 inch rim? if I'm using the 305/30/19

3) Without modification to the suspension can I fit the tires and wheels on my car?

4) Does anyone have a lead on where to buy 19 X 11 rims that will work... Better

5) what the hell is the offset, and why is it important? please explain it to me in layman terms

Thanks for the help in advance, I'm not a very mechanical car guy I just do research till I understand and I'm trying to fix my problems I had on the track

[Orange Crush 1LE]

A great source of knowledge and lightweight forged wheels is CCW. I run 315/30-18s on 18 x 11s front and 18 x 12s rear, I'm not positive what my offset is. My 18s don't quite tuck under the fenders, so they're fine at the track but not a good choice for street. I plan on adding Z/28 like fender flares to remedy this. You need to modify the front suspension arm for clearance to run 18s. The clearance is so tight that if the wheel weights are all the way towards the inside, the suspension arms will knock them off, LOL. The 18s are a reaaaallllllyyyy tight fit, 19s would be easier. So bottom line, I think you're headed in the right direction.

CCW can set you up with the correct offsets.

There are other choices as well as the Trofeos, I love Nitto NT-01s. Not sure what comes in a 305/30-19 though.

[Cuda7050]

For what its worth, F street rules don't allow you to put wider wheels on. You can probably get away with it locally, but at bigger events a protest might happen. Otherwise, to be legal you will get bumped to a higher class.

[mcynet]

I thought in F Street you could put on wheels that came on standard models of the car like the z28, or zl1 like i said im new to this so I could be wrong.

[Cuda7050]

I don't believe you can swamp parts from one model to another unless you swap every part over to create the alternate model. The change in model must be complete, not just cherry picking parts. Also the model must have been produced the year of your car. For instance, I would love to convert my SS to a 1LE, which wouldn't be to hard, but 1LE's were not produced in 2012, so I can't legally do it in FS.

They're others with more experience that may prove me incorrect, but I have been studying the rules pretty closely and reviewing several SCCA forums to educate myself.

[Novie LE]

Originally Posted by mcynet

OK my thought is to get more rubber on the road to help with autocross lap times in my F Street class.

I have been looking at copying what was done on the z28, but i have some questions.

Z28 runs
Front - 22873225 - (19x11 11mm os) (GM says the shipping weight is 25.88 pounds) - $795.00
Rear - 22873227 - (19x11.5 26mm os) (GM says the shipping weight is 26.32 pounds) - $795.00

All Tires 4 305/30/19 pzero trafao

All that = 1.3g turning..... THAT IS WHAT I WANT

the 1le rims are 20X10 23mm offset Front and 20X11 43mm offset in the Rear.

What Im wanting to run is a 19 X 10.5 inch rim, mainly because I cant find it the other sizes. and a Handkook Ventus R-S3 305/30/19 Tire.

Also, the rims Im finding are 27mm offset. and bolt pattern 5x120

Now for the questions...

1) Will what I have listed work? (10.5X19 with the handkook)

2) What are acceptable ranges for the offset front and rear on a 19 inch rim? if I'm using the 305/30/19

3) Without modification to the suspension can I fit the tires and wheels on my car?

4) Does anyone have a lead on where to buy 19 X 11 rims that will work... Better

5) what the hell is the offset, and why is it important? please explain it to me in layman terms

Thanks for the help in advance, I'm not a very mechanical car guy I just do research till I understand and I'm trying to fix my problems I had on the track

You cannot change rim width and remain in F-Street. Contact Forgestar and speak to them about your goals. Personally I am looking into coping the 20 in setup except in a 19in diamater. I am in the process of looking to see if a 305 will fit in the front without rubbing, just have not actually done anything about it yet.

Offset is very important, the higher the number the more the wheel is "pushed" towards the inside of the car, the lower then number the more it is pushed to the outside of the car. When trying to fit bigger tires or wheels you can and will rub on the inside suspension or outside fenders if the offset is wrong.

[mcynet]

Well I do have the 2014 so I'm good on the year, same as the z28. THE RULES ARE VERY CONFUSING... I think my factory rim width is allowed to be modified by 1 inch, but it is not necessary because factory my car came with 11" rims on the rear, I would just be adding them to the front which came with 10" if I square the setup to 11" all the way around I think I'm good. I wish we had an scca official to answer. I believe the 305 will easily fit on the rear 11" without issues. Zl1 has the same rims and factory 305 on the rear.The real question is the front 305 and what size rim and offset I need to get it on the car.

I should probably take a rear zl1 wheel and try it, but I want to drop to 19s,. Also is anyone using the handkooks and how are they on the track?

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[Novie LE]

Originally Posted by mcynet

Well I do have the 2014 so I'm good on the year, same as the z28. THE RULES ARE VERY CONFUSING... I think my factory rim width is allowed to be modified by 1 inch, but it is not necessary because factory my car came with 11" rims on the rear, I would just be adding them to the front which came with 10" if I square the setup to 11" all the way around I think I'm good. I wish we had an scca official to answer. I believe the 305 will easily fit on the rear 11" without issues. Zl1 has the same rims and factory 305 on the rear.The real question is the front 305 and what size rim and offset I need to get it on the car.

I should probably take a rear zl1 wheel and try it, but I want to drop to 19s,. Also is anyone using the handkooks and how are they on the track?

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Download the scca rule book for claification. After reading the pdf a couple weeks ago it states that wheel DIAMETER can be changed +/- 1in, not wheel width. If aftermarket wheels are going to be used, the widths must stay identical and the offsets must be within 5mm of factory equipment. Your car did not come with z28 wheels, so you cannot use whatever wheel chevy decided to put on whatever camaro.

As for the rear zl1 wheel, you already have that on your 1le. If you are talking about taking the actual wheel and running it in the front, it most likely will not work because the offset going to make it rub on the susension, not the mention it will also break the rules when it comes to offset and width. As far as the rs-3, I plan on autoxing this weekend with a different club, a very well known driver will be there with his 1le running rs-3 on factory wheels. Im sure he will share his findings.

[mcynet]

I thought there was a section that said I could change parts between models of the same year. If not can I get a 305 on a 10" rim?

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[Scott@Bjorn3D]

Have you thought of keeping your rims to be safe and move to a 295. I know folks have said the Michelin Pilot Sports in that size run close to 300 vs others 295's.

[mcynet]

Yes I have, but I wanted a separate set with autocross tires so I can swap them out. I figured if I did that I might as well get the additional handling benefits of lowering the car with the 19" rims.

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[Novie LE]

Originally Posted by mcynet

I thought there was a section that said I could change parts between models of the same year. If not can I get a 305 on a 10" rim?

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You are not allowed to pick and choose what you want to change. PLus the parts you are talking about are from a car that will not be ranked in F-Street (z/28). If they rank the z/28 it will probabaly be A-Street? Maybe somehwere else, however the fact that comes with r-comps from the factory might mean you need to run a different tire to match the 200TW rating, which in that case makes the z/28 useless lol

Can you fit 305's on a 10 inch rim, sure. How will that affect turn in with a slight buldge...don't know till I try it.

[Fraxum]

This may help:

http://www.camaro5.com/forums/showthread.php?t=201546

Sux to be you has been through many combinations.

[SVThis]

Keep in mind also when you change wheels for street class the offset has to be plus or minus 7mm vs stock