Justin@VMP
May 5th, 2009, 12:01 PM
Over a year ago I sent a set of stock wheels off to be widened by 2", from 9.5" to 11.5", with the intention of putting MT 345s on once they became available.
http://vmptuning.com/GT500/wheels/wheeloutside.jpg
http://vmptuning.com/GT500/wheels/wheelinside.jpg
I waited and waited for MT to come out with the 345/34/18 and they kept having production delays.
So I just ordered some of the 305/35/18 which are 26.4", slightly shorter than the stock 27" tires, which gives me a little better gear ratio and puts me right where I want to be when going through the traps with my power level and 3.73s.
In retrospect I'm glad I did not get the 345s, as they would have been a tad tall for my current power level and 3.73s gears, and they would have bulged at least 1/2" on either side of my rim, which may have caused me to rub without running spacers.
To fit the 11.5" wheels without spacers I knew I was going to have to do some slight mods to the wheel wells. It ended up not being anything too major.
First, I removed the bump stop bracket by cutting the 9 spot welds that hold it on, using a 1/4" spot weld cutter. This is where having a right angle drill is nice, as the spot welds above the spring perch are hard to get to with the axle in the way. I tore up a few cutters.
http://vmptuning.com/GT500/wheels/cutting%20spot%20welds.jpg
http://vmptuning.com/GT500/wheels/bump%20bracket%20removed.jpg
After a little spray on rubber undercoating and some black spraypaint:
http://vmptuning.com/GT500/wheels/ready%20for%20rim.jpg
Test fitting:
http://vmptuning.com/GT500/wheels/rim%20mount%20only.jpg
The bottom shock mount needs to be moved inboard slightly, you can do this by cutting the metal spacer at the bottom, moving it to the other side, and adding a washer to take up the material that was removed by your cut out wheel (about 1/8"):
http://vmptuning.com/GT500/wheels/shock%20mount.jpg
The covers/boots for the stock shocks had to be removed.
http://vmptuning.com/GT500/wheels/stock%209.5%20weight.jpg
http://vmptuning.com/GT500/wheels/wide%2011.5%20weight.jpg
12" is the max rim width recommended by MT for these tires, so with an 11.5" rim the tire sidewall does not bulge at all:
http://vmptuning.com/GT500/wheels/305tire%20back.jpg
http://vmptuning.com/GT500/wheels/305%20tire%20front.jpg
http://vmptuning.com/GT500/wheels/305tire%20width.jpg
I did not want to run spacers and change the wheel offset, because that would just throw more crap onto the fenders. Though I may end up adding an 1/8" spacer on one side for a little bit more clearance. The rim is very close to the shock rod, if you go up a driveway just the right way at an angle, where one side is compressed, and the other extended, it will sometimes rub. Otherwise I have not had any problems, but I would not road race the car with a welded wheel or with something this tight. There is just enough room to get your fingers between the fenderwell and the tire if you stick your hand back there.
If I did it all over again, and knew I was not going to run 345s, I may go with an 11" or 11.25" wheel, just because it would give a little more clearance.
I may look at running something other than the MT 305 when these wear out, M&H has some DRs out now, and I'm sure other manufacturers will come out with them too.
I also run a watts link to try and keep the axle centered.
http://vmptuning.com/GT500/wheels/wheeloutside.jpg
http://vmptuning.com/GT500/wheels/wheelinside.jpg
I waited and waited for MT to come out with the 345/34/18 and they kept having production delays.
So I just ordered some of the 305/35/18 which are 26.4", slightly shorter than the stock 27" tires, which gives me a little better gear ratio and puts me right where I want to be when going through the traps with my power level and 3.73s.
In retrospect I'm glad I did not get the 345s, as they would have been a tad tall for my current power level and 3.73s gears, and they would have bulged at least 1/2" on either side of my rim, which may have caused me to rub without running spacers.
To fit the 11.5" wheels without spacers I knew I was going to have to do some slight mods to the wheel wells. It ended up not being anything too major.
First, I removed the bump stop bracket by cutting the 9 spot welds that hold it on, using a 1/4" spot weld cutter. This is where having a right angle drill is nice, as the spot welds above the spring perch are hard to get to with the axle in the way. I tore up a few cutters.
http://vmptuning.com/GT500/wheels/cutting%20spot%20welds.jpg
http://vmptuning.com/GT500/wheels/bump%20bracket%20removed.jpg
After a little spray on rubber undercoating and some black spraypaint:
http://vmptuning.com/GT500/wheels/ready%20for%20rim.jpg
Test fitting:
http://vmptuning.com/GT500/wheels/rim%20mount%20only.jpg
The bottom shock mount needs to be moved inboard slightly, you can do this by cutting the metal spacer at the bottom, moving it to the other side, and adding a washer to take up the material that was removed by your cut out wheel (about 1/8"):
http://vmptuning.com/GT500/wheels/shock%20mount.jpg
The covers/boots for the stock shocks had to be removed.
http://vmptuning.com/GT500/wheels/stock%209.5%20weight.jpg
http://vmptuning.com/GT500/wheels/wide%2011.5%20weight.jpg
12" is the max rim width recommended by MT for these tires, so with an 11.5" rim the tire sidewall does not bulge at all:
http://vmptuning.com/GT500/wheels/305tire%20back.jpg
http://vmptuning.com/GT500/wheels/305%20tire%20front.jpg
http://vmptuning.com/GT500/wheels/305tire%20width.jpg
I did not want to run spacers and change the wheel offset, because that would just throw more crap onto the fenders. Though I may end up adding an 1/8" spacer on one side for a little bit more clearance. The rim is very close to the shock rod, if you go up a driveway just the right way at an angle, where one side is compressed, and the other extended, it will sometimes rub. Otherwise I have not had any problems, but I would not road race the car with a welded wheel or with something this tight. There is just enough room to get your fingers between the fenderwell and the tire if you stick your hand back there.
If I did it all over again, and knew I was not going to run 345s, I may go with an 11" or 11.25" wheel, just because it would give a little more clearance.
I may look at running something other than the MT 305 when these wear out, M&H has some DRs out now, and I'm sure other manufacturers will come out with them too.
I also run a watts link to try and keep the axle centered.