21" camaro SS takeoffs fit c5?
 

Need a sturdy inexpensive 21" wheel for autocross & track day.Found this used set on line.
Fr. 21x8.5 6.25 "bs 38 mm offset 5x120 bolt Tire OD 26.8" SW 9.8" :245/30 ZR21 VENTUS V12
Rr. 21x9.5 6.94 43 5x120 OD 27.5 SW 10.9 275/30 ZR21. My C5 Stock wheels are:
Fr. 17x8.5 6.68 49 5x120 OD 25.6" SW 9.6" 245/45 ZR17
Rr. 18x9.5 7.45 56 5x120 OD 26.7" SW 10.8 275/40 ZR18 If my math is right they should bolt on with a 1/4=1/2" spacer in line with original wheel orientation.
Hub dia on 21" wheel is 66.9,C5 stock is 70.3, I could machine out wheel hub opening 2.4mm to fit.
Next issue is section width and overall Diameter. Car is lifted on aftermarket bolts to clear 28"od x10.5 / 16" Hoosier bias drag slicks so the 27.5"od x10.9 /21" should clear in rear.
Trouble spot is front turning. Front OD is 1.3" taller, Section Width. .2" wider, thus the factory stagger tire spec, !8/17"
Final Question : Before I buy front rims to big, if above numbers work:
Has anyone installed a set of 20" or larger 8.5" or wider frònts on a raised C5 with OD=26.8 &
SW 9.8 and no rub?

I'm not a racer, but I can't see the probability of using any 21" wheel on a C5 to be beneficial. Especially for racing.

:iagree:

21" wheels on a C5 look and ride like crap.

Even if they looked cool how can they be beneficial for any kind of racing ?

Because a 21'' tire will rotate less to cover the same distance as an 18" tire, will use less fuel and take less time.(if you use a 28
'' tall diameter tire it will even be more effective) If you tape neon tube lights to the spokes of the rims at night it will look awsome.:willy:

You make a good point, George. Please forgive me. Clearly I'm an idiot.

Inexpensive track wheels = set of OEM Z06 wheels. They come up for sale all the time in the For Sale forum, and are super light wheels.

IMO a plus 3 tire wheel combo provides better performance.
 

Less rolling resistance, sidewall flex, beter tread contact.
Why else do supercars like Audi A-8, Enzo etc. Spec 20" plus 3-5.
I can buy 4 takeoff 21" with new 275/30 V 12. Lugs tps, valvestems for $1200, {the cost of 3 Hoosier A4or R4 tires only} run them for 100 X as long before worn out, drive to track on them.
Cons: heavier rotating mass, appearance,height,less traction and forward bite than mounting R4 Hoosier on my old 18x9.5/17X8.5 stock 2004 coupe wheels, that look so good on my 85 c-4.
These 21" also bolt on to 4 other chevies I own, fronts have clearance issues, which brings me back to the original question, what size tire is max OD/ SD on a raised C5 Not what you hate or who is stupid.Dissapointed with tenor of some posts.
What tire size and offset 20" wheel are you guys who installed them fit rub free.?

Too big, you will get slow times with those honkers. Besides I don't think that 21" will fit, actually I know it won't.

Peter, wow! 21's on any car do not look or perform well? How does a tire not perform or look well? I have 21's on my Camaro and about to put 21's on another vehicle I just bought. They look awesome and performance is not an issue. With over 750 HP in my Camaro the only issue with tire performance is lack of traction.

Supercars use them because they have 14-15" brake rotors.....

Gene, apples to oranges. OP asked for opinions on 21" on a C5

I stated my opinion. 21" on a C5 - yuk. And the sidewall of a tire on a 21" rim is gonna ride like crap.

On a car designed for a 21" wheel/tire they look better, but, my opinion is that they still look like crap.

As for performance, you said yourself that traction is an issue with the 21" on your camaro. There's not enough sidewall to help your traction issues with the hp level you have. I bet you'd have better luck with a smaller diameter rim.

As for the OP. He clearly understands traction, as he said he's used 28" drag slicks on a 16" wheel. For a road race situation, perhaps a 21" would work ok. If they were significantly better, wouldn't most C5 at the road tracks use them?

Enjoy your weekend all!!!

Right

Wrong. 21s will fit with proper offsets and tire sizing, but are not recommended on an otherwise-stock C5 due to the extremely-short sidewall of tires with the appropriate OD and high unsprung weight of the combo. I had 26" OD front tires (255/40-18) and 27" OD rear tires (295/35-19) mounted on 18x9 fronts and 19x10 rears with no issues on my C5Z06, but I have no experience with lifting and larger OD tires.

Your OD measurement for the fronts is off by an inch, those would be 26.8" tires.

All that said, the amount of lifting and extra weight you are talking about adding would be more detrimental to the performance of the vehicle than any benefits from adding height to the tire.

Might have something to do with the massive flywheel-like 21's. :shrug:

Right, O.D. for a 245/30 zr 21 michelin pilot is 26.8, that would fit front wheel with 1/4 " spacer.

Prepair to not only get spanked at the track but also mocked like crazy.:willy::willy:

Exactly

All in all, you'd still be doing something that will give you nearly no performance benefit but has plenty of downsides. If you want less rolling resistance WITHOUT the negatives of running 21s at the track, run 19-inch rears with a 295 to 305/35-19 (extra inch plus) and 18-inch fronts with a 255 to 275/40-18 (extra inch plus). For fairly lightweight and cost-effective wheel options for this setup, you have OEM C6 and TSW wheels run with a small spacer or the Forgestar options (under $1k for the C6 and around $1500 for the aftermarket)

But my dream of a 21 " Camaro takeoff /c5 swp is dashed because Hangook ventus v 12 fronts not available in 245/30 in N. America
Only in 245/35 ; too tall

and 245/30 only as Michelin pilot Porsche espechiale and no rears that will work, as they cannot be combined with any other tyre.
tx for tryin

In conclusion the largest O.D. Tire that fit a stock height c5 is,,,,,