Another rim/tire question
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Joined: Nov 2008
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Another rim/tire question
I have a 1986 Corvette (z51 package). I believe the current size is 245/55/9.5 with a 38mm offset.
I have found some rims that I like, but I fear they may "stick out".
The specs are the following:
17x10 with a +20 offset.
18x11 with a +20 offset.
In both cases I would like to run a 305 or 315 tire...
I have found some rims that I like, but I fear they may "stick out".
The specs are the following:
17x10 with a +20 offset.
18x11 with a +20 offset.
In both cases I would like to run a 305 or 315 tire...
Le Mans Master
Joined: Jun 2009
Posts: 6,528
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From: South Dakota
The '86 Z51 had:
16" x 9.5" with 38 offset wheels on all four corners with 255/50/16 tires.
Compared to the stock wheels the 17x10 with a 20 offset would be
(-6.35+18) or 11.65 mm (0.459") further outboard on the inside edge of the rim.
(6.35+18) or 24.35 mm (0.959") further outboard on the outside edge of the rim.
(0.5" wider wheel is 12.7mm wider or 6.35 mm per side) (18mm difference in offset to the stock wheel)
The 18" x 11" compared to the 17" x 10" would be 1/2" further inboard than the 10" on the inside edge and 1/2" further outboard on the outside edge.
Good luck.
16" x 9.5" with 38 offset wheels on all four corners with 255/50/16 tires.
Compared to the stock wheels the 17x10 with a 20 offset would be
(-6.35+18) or 11.65 mm (0.459") further outboard on the inside edge of the rim.
(6.35+18) or 24.35 mm (0.959") further outboard on the outside edge of the rim.
(0.5" wider wheel is 12.7mm wider or 6.35 mm per side) (18mm difference in offset to the stock wheel)
The 18" x 11" compared to the 17" x 10" would be 1/2" further inboard than the 10" on the inside edge and 1/2" further outboard on the outside edge.
Good luck.
Team Owner
Joined: Sep 2003
Posts: 25,394
Likes: 2,741
Your 10" wheel @ 20 would stick out 24mm+ further than what you have now and you would gain just less than 1/2" (12mm)inner clearance.
I didn't do tires and I don't see either being good choices but you didn't mention profile either.
Your 11" wheel @ 20 would stick out 37mm+ further than what you have now and you would lose 1mm+ inside.
I don't use the wheel comparison calculator on the CF but it does real well and it's very close to what I did. You can compare your own and there's an option to add tire sizes but I'd use the same tire when calculating just because I don't know how it does tires, if at all. I can do tires and wheels as an assembly but it's difficult.
I always compare every one to the one that's a "known" rather than against one another.
Try the calculator yourself and play with it and if you've got questions just post back and try to confirm your suspicions. NONE of these calculators should be considered "gospel" but they're a good "toy"!
http://forums.corvetteforum.com/tire_rim_calculator.php
I didn't do tires and I don't see either being good choices but you didn't mention profile either.
Your 11" wheel @ 20 would stick out 37mm+ further than what you have now and you would lose 1mm+ inside.
I don't use the wheel comparison calculator on the CF but it does real well and it's very close to what I did. You can compare your own and there's an option to add tire sizes but I'd use the same tire when calculating just because I don't know how it does tires, if at all. I can do tires and wheels as an assembly but it's difficult.
I always compare every one to the one that's a "known" rather than against one another.
Try the calculator yourself and play with it and if you've got questions just post back and try to confirm your suspicions. NONE of these calculators should be considered "gospel" but they're a good "toy"!
http://forums.corvetteforum.com/tire_rim_calculator.php
Last edited by WVZR-1; Apr 23, 2014 at 07:05 PM.
