wheel offset issue
Thread Starter
Racer
Joined: Feb 2007
Posts: 313
Likes: 0
wheel offset issue
For use at the drag strip I am planning on using a C5 Z06 wheel. It is an 18 x 10.5 inch with a +55mm offset. The stock wheel , as you know, is a 19 inch wheel with a +65mm offset. The tire I am planning on using is a Nitto NT 05R P285/40R 18. The wheel diameter of the 18 inch Nitto is almost identical to the 19 inch stock PS2 tire.
What problems will I have with the offset difference? If any can it be fixed with a 10MM wheel spacer? How complex a job is it to use a wheel spacer/ Are new studs required? Is the spacer permanent? If so that would make my offset +75mm with the PS2’s.
What about any other issues you guys might know from experience.
I want to be able to take off the Stock PS2’s and put these tires on and run at the strip. Then take them off afterwards and back on the street with the PS2’s.
What problems will I have with the offset difference? If any can it be fixed with a 10MM wheel spacer? How complex a job is it to use a wheel spacer/ Are new studs required? Is the spacer permanent? If so that would make my offset +75mm with the PS2’s.
What about any other issues you guys might know from experience.
I want to be able to take off the Stock PS2’s and put these tires on and run at the strip. Then take them off afterwards and back on the street with the PS2’s.
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
No personal experience and not an expert, just passing on what I've seen here. Hope it helps. 
I put links to 2 other threads in this one:
http://forums.corvetteforum.com/c6-t...n-base-c6.html
I put links to 2 other threads in this one:
http://forums.corvetteforum.com/c6-t...n-base-c6.html
Race Director
Joined: Mar 2011
Posts: 13,262
Likes: 3,150
From: SW Florida
2021 C6 of the Year Finalist - Modified
Also, are you sure that your stock C6 2006+ Z06 rear wheel has a +65mm offset? ... I can tell you, if it's OEM, it is a 19" x 12" with a 59mm offset (same as the 2010-2011 Grand Sport)
Lets say the offsets I just gave you are correct. If you remove the your stock 12" C6 Z06 wheel and replace it with the 10.5" C5 Z06 wheel, the C5 wheel's inner edge will move inward 20mm (0.8").
The outer edge of the wheel will move inward 18mm (0.7").
Calculator: http://www.1010tires.com/wheeloffsetcalculator.asp
.
Last edited by Turbo6TA; Apr 12, 2011 at 01:55 PM.
Thread Starter
Racer
Joined: Feb 2007
Posts: 313
Likes: 0
Are you sure that C5 Z06 rear wheel that you want to use at the drag strip has a +55mm offset? ... From what I have read, if it's OEM, it is a 18" x 10.5" with a 58mm offset.
Also, are you sure that your stock C6 2006+ Z06 rear wheel has a +65mm offset? ... I can tell you, if it's OEM, it is a 19" x 12" with a 59mm offset (same as the 2010-2011 Grand Sport)
Lets say the offsets I just gave you are correct. If you remove the your stock 12" C6 Z06 wheel and replace it with the 10.5" C5 Z06 wheel, the C5 wheel's inner edge will move inward 20mm (0.8").
The outer edge of the wheel will move inward 18mm (0.7").
Calculator: http://www.1010tires.com/wheeloffsetcalculator.asp
.
Also, are you sure that your stock C6 2006+ Z06 rear wheel has a +65mm offset? ... I can tell you, if it's OEM, it is a 19" x 12" with a 59mm offset (same as the 2010-2011 Grand Sport)
Lets say the offsets I just gave you are correct. If you remove the your stock 12" C6 Z06 wheel and replace it with the 10.5" C5 Z06 wheel, the C5 wheel's inner edge will move inward 20mm (0.8").
The outer edge of the wheel will move inward 18mm (0.7").
Calculator: http://www.1010tires.com/wheeloffsetcalculator.asp
.
Then the question is will the stock wheel studs work fine if I shim 8 mm? Are they long enough?
Drifting
Joined: Nov 2005
Posts: 1,745
Likes: 35
From: Turlock CA
you are correct they are offset of +58mm. I have a C6 ( not Z06) and i thought the offset was +65mm. It seesm from what I am reading that using a C5 Z06 18 inch rim on the rear of my C6 will work but i may need an 8-10 mm shim.
Then the question is will the stock wheel studs work fine if I shim 8 mm? Are they long enough?
Then the question is will the stock wheel studs work fine if I shim 8 mm? Are they long enough?
What is normally done to run drag tires is to widen a 18x8.5 front wheel by 2-2.5 inches which will fit very well. A search will find many threads on this.
You can also take a 17" wheel and widen it (Weldcraft is one shop) in the same way. I run 17x9.5" + 2" wheels on the rear of mine -- all under the fenders. This may give you a better selection of tires.
Last edited by dbratten; Apr 12, 2011 at 09:12 PM. Reason: added info
Thread Starter
Racer
Joined: Feb 2007
Posts: 313
Likes: 0
details
The 18x10.5 wheel will stick out an inch more than the OEM 19x10" wheel that you now have. There is no problem with clearance to the inside. You will not want to move it out more with spacers.
What is normally done to run drag tires is to widen a 18x8.5 front wheel by 2-2.5 inches which will fit very well. A search will find many threads on this.
You can also take a 17" wheel and widen it (Weldcraft is one shop) in the same way. I run 17x9.5" + 2" wheels on the rear of mine -- all under the fenders. This may give you a better selection of tires.
What is normally done to run drag tires is to widen a 18x8.5 front wheel by 2-2.5 inches which will fit very well. A search will find many threads on this.
You can also take a 17" wheel and widen it (Weldcraft is one shop) in the same way. I run 17x9.5" + 2" wheels on the rear of mine -- all under the fenders. This may give you a better selection of tires.
What advantage do I have having special rims made? I realy want to avoid spending a lot of $$ since this is not a regular thing.
Last edited by youout; Apr 12, 2011 at 09:29 PM.
Race Director
Joined: Mar 2005
Posts: 11,549
Likes: 27
From: Southampton NJ
Thanks this kind of detail is very helpful. I have found Nitto NT05R that are 285/40R 18 which work well on a 10.5 rim. I do feel that I have an inch width to work with but was not sure how much flex the tires goes through at the start. so i think this tire and rim combo should work. I race about once or twice per month
What advantage do I have having special rims made? I realy want to avoid spending a lot of $$ since this is not a regular thing.
What advantage do I have having special rims made? I realy want to avoid spending a lot of $$ since this is not a regular thing.
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Drifting
Joined: Nov 2005
Posts: 1,745
Likes: 35
From: Turlock CA
Thanks this kind of detail is very helpful. I have found Nitto NT05R that are 285/40R 18 which work well on a 10.5 rim. I do feel that I have an inch width to work with but was not sure how much flex the tires goes through at the start. so i think this tire and rim combo should work. I race about once or twice per month
What advantage do I have having special rims made? I realy want to avoid spending a lot of $$ since this is not a regular thing.
What advantage do I have having special rims made? I realy want to avoid spending a lot of $$ since this is not a regular thing.
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
The base c5 18" rim works fine, even fits a 305 tire perfectly. I've used it on the road course.
A better choice is a c5 front or a c5z front with 275/40/17's, they are shorter tires and give you more gearing off the line.
However, if you have an automatic, you need to keep your tire size close to stock or you'll run into shifting and redline issues.
A better choice is a c5 front or a c5z front with 275/40/17's, they are shorter tires and give you more gearing off the line.
However, if you have an automatic, you need to keep your tire size close to stock or you'll run into shifting and redline issues.
Race Director
Joined: Sep 2007
Posts: 16,557
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From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
regarding the tire size. A MT or Hoosier DR will easily hold 500HP. However, the only problem I'd see would be when running a 2.73 gear and needing to shift to 4th with not much space left at the end. According to the OP's profile, he's a 3.15 gear, so the 4th gear shift would only be a problem with larger tires, not smaller ones.
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
regarding the tire size. A MT or Hoosier DR will easily hold 500HP. However, the only problem I'd see would be when running a 2.73 gear and needing to shift to 4th with not much space left at the end. According to the OP's profile, he's a 3.15 gear, so the 4th gear shift would only be a problem with larger tires, not smaller ones.