Help with rear wheel/tire sizing
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Help with rear wheel/tire sizing
I know there's a million threads on this already, and the more I read, the more i get confused....
Anyone that has already done this with a similar setup, please chime in with a definite answer if possible:
1978 with offset trailing arms, NO rear sway bar, and a shortened (cut) rear fiberglass leaf spring;
What is the widest wheel size and/or tire size I can get on there. I have no problem going to a 16" or 17" wheel if necessary. I do not want to go outside the fenders more than the stock setup and would rather put all the extra tire and wheel on the inside. Also if possible, I prefer to stay as close to the stock overall diameter of a 27" tire as possible....hope I'm not asking the impossible here!
Anyone that has already done this with a similar setup, please chime in with a definite answer if possible:
1978 with offset trailing arms, NO rear sway bar, and a shortened (cut) rear fiberglass leaf spring;
What is the widest wheel size and/or tire size I can get on there. I have no problem going to a 16" or 17" wheel if necessary. I do not want to go outside the fenders more than the stock setup and would rather put all the extra tire and wheel on the inside. Also if possible, I prefer to stay as close to the stock overall diameter of a 27" tire as possible....hope I'm not asking the impossible here!
Last edited by Tony Rags; Jul 12, 2012 at 10:10 PM.
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
I know there's a million threads on this already, and the more I read, the more i get confused....
Anyone that has already done this with a similar setup, please chime in with a definite answer if possible:
1978 with offset trailing arms, NO rear sway bar, and a shortened (cut) rear fiberglass leaf spring;
What is the widest wheel size and/or tire size I can get on there. I have no problem going to a 16" or 17" wheel if necessary. I do not want to go outside the fenders more than the stock setup and would rather put all the extra tire and wheel on the inside. Also if possible, I prefer to stay as close to the stock overall diameter of a 27" tire as possible....hope I'm not asking the impossible here!
Anyone that has already done this with a similar setup, please chime in with a definite answer if possible:
1978 with offset trailing arms, NO rear sway bar, and a shortened (cut) rear fiberglass leaf spring;
What is the widest wheel size and/or tire size I can get on there. I have no problem going to a 16" or 17" wheel if necessary. I do not want to go outside the fenders more than the stock setup and would rather put all the extra tire and wheel on the inside. Also if possible, I prefer to stay as close to the stock overall diameter of a 27" tire as possible....hope I'm not asking the impossible here!
I like the tires I have now and they helped a lot with reducing oversteer. They are not real high performance tires however, so 17s are probably in the future. A 275/45/17 would be about 26.75", not sure if anyone makes one though.
I'm full of information.
Burning Brakes
Joined: Feb 2011
Posts: 849
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From: Woodland California
I'm running SLP 17" rims with 245/45/17 Kumos.
They are a tight fit, in the back, in the inside, but I do like the look.
I do wish they were 18" rims though, better inside clearance.
I know that 245/55/17 is real close to stock tire height.
I don't have a picture of it with the front wheels straight.
It would show the wheel spacing better.
These tires are about 1/2" shorted than stock.
Ralph
They are a tight fit, in the back, in the inside, but I do like the look.
I do wish they were 18" rims though, better inside clearance.
I know that 245/55/17 is real close to stock tire height.
I don't have a picture of it with the front wheels straight.
It would show the wheel spacing better.
These tires are about 1/2" shorted than stock.
Ralph
Burning Brakes
Joined: Feb 2012
Posts: 925
Likes: 7
I'm running SLP 17" rims with 245/45/17 Kumos.
They are a tight fit, in the back, in the inside, but I do like the look.
I do wish they were 18" rims though, better inside clearance.
I know that 245/55/17 is real close to stock tire height.
I don't have a picture of it with the front wheels straight.
It would show the wheel spacing better.
These tires are about 1/2" shorted than stock.
Ralph
They are a tight fit, in the back, in the inside, but I do like the look.
I do wish they were 18" rims though, better inside clearance.
I know that 245/55/17 is real close to stock tire height.
I don't have a picture of it with the front wheels straight.
It would show the wheel spacing better.
These tires are about 1/2" shorted than stock.
Ralph
Unless I'm doing my math wrong, the 245/55/17s are about 27.6" tall, 245/45/17 are 25.7". Not sure what's stock height on your car.
I was looking at 17" tires, BFG G Force Sport Comp 2 are $153 for 255/45/17 and $175 for 275/40/17. 275/40/18 are $219. Not bad money for a significantly better tire than the Radial T/As I'm running now.
I know 18" rims at the back clear the spring and all, but I'm on the fence about the looks. Big wheel and not much sidewall seems a little out of place on an old bomb. Maybe I need to get used to seeing it. 18s and 19s sure don't look bad on a C6. Maybe a mix of 17 on the front and 18 on the back.
Last edited by Super6; Jul 13, 2012 at 03:37 PM. Reason: Correct typo on tire height.
Racer
Joined: Jul 2009
Posts: 338
Likes: 9
From: South Bend IN
NCM Sinkhole Donor
I am running 18x9.5's with 5.5bs on standard trailing arms with a sway bar. I did put a 1/8" spacer in to give a little more clearance for the sway bar. The only other thing I had to do was move the parking brake cable bracket to the top of the trailing arm. I am running 275/40/18, which come out the 26.7 inches. This is a good website to help you figure sizes http://www.miata.net/garage/tirecalc.html
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
The problem with offset trailing arms is the tire will hit the frame before it hits the trailing arm thereby not giving you much of an advantage.
To get good rubber these days you have to go to at least a 17in wheel and even then the tires sizes are diminishing. A 245/45/17 is only 25.7" not 26.7".
I have 255/45/17's on the front of mine '80 which are 26" tall and 285/40/18's on the back which are stock 27" tall. These tires are ZR rated and they call them Ultra High Performance. There are now even higher performance tires out there to take you safely to 200mph these are the W and Y series tires and if the y is in brackets as in (99Y) at the end the tires are safe in excess of 200mph.
The BF Goodrich Radial TA we all had at one time or another
is good for about 110 -120mph IIRC correctly and is outdated as some cars coming off the showroom floor now can go that speed in 3rd gear.
To get good rubber these days you have to go to at least a 17in wheel and even then the tires sizes are diminishing. A 245/45/17 is only 25.7" not 26.7".
I have 255/45/17's on the front of mine '80 which are 26" tall and 285/40/18's on the back which are stock 27" tall. These tires are ZR rated and they call them Ultra High Performance. There are now even higher performance tires out there to take you safely to 200mph these are the W and Y series tires and if the y is in brackets as in (99Y) at the end the tires are safe in excess of 200mph.
The BF Goodrich Radial TA we all had at one time or another
is good for about 110 -120mph IIRC correctly and is outdated as some cars coming off the showroom floor now can go that speed in 3rd gear.
Last edited by MotorHead; Jul 13, 2012 at 08:37 AM.
