Wheel Offset Question With GT350 Brakes

[XCRN]

I am trying to plan for the future here when I pickup a set of new wheels that are available in both regular S550 offset and GT350 offset, but what complicates my decision right now is I want to in the future get the GT350 brakes. I am starting with a base GT. The rear offset is such a small difference I am not too worried about that, the front however change a lot from the GT at 19x10 +35 offset and the GT350 at 19x11 +24. So given my future goals which set do I need, the GT or GT350 set? It seems as if the GT350 brakes do move the mounting face, but I did not think by that much, is the huge change in front offset more of the fender widend?

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[NightmareMoon]

I thinks the wider fenders on the 350 more than anything else. Its a little tricky to stuff 11" wide wheels in the front on a GT (but it can be done). Much more reasonable to put a 10" wide ET35 wheel up front on our cars.

 

[XCRN]

I thinks the wider fenders on the 350 more than anything else. Its a little tricky to stuff 11" wide wheels in the front on a GT (but it can be done). Much more reasonable to put a 10" wide ET35 wheel up front on our cars.

So the GT offset will not change wheel location too far with the GT350 brakes?

 

[D Bergstrom]

I have done a lot of research adding the GT350R brake kit to my GT. From what I have found, the front brakes do not add any width to the car, so you use a S550 offset wheel for the front. The GT350R rear knuckle ends up adding about a 1/4" to each side in the rear, so you can use a GT350 offset for the rear. It also seems the GT350 and GT350R brakes are the same, just the R comes with the red calipers.

I feel the front GT350 offset is more a factor of the wheel width. A 10" wide, 35mm offset front wheel has a backspace of 6.88", while the oem GT350 front wheels with a 10.5" width, 30 mm offset has a backspace of 6.93". So the inside of the wheel is pretty much in the same place, just the extra 0.5" width of the wheel is on the outside, hence the reason for the wider fenders on the GT350. I believe the R has less offset on it wheels, probably to add a little width to it.

LMR has a install video of the GT350R brake kit, good video, and I believe it discusses wheel offsets in it also, should check it out.

Doug

 

[XCRN]

I have done a lot of research adding the GT350R brake kit to my GT. From what I have found, the front brakes do not add any width to the car, so you use a S550 offset wheel for the front. The GT350R rear knuckle ends up adding about a 1/4" to each side in the rear, so you can use a GT350 offset for the rear. It also seems the GT350 and GT350R brakes are the same, just the R comes with the red calipers.

I feel the front GT350 offset is more a factor of the wheel width. A 10" wide, 35mm offset front wheel has a backspace of 6.88", while the oem GT350 front wheels with a 10.5" width, 30 mm offset has a backspace of 6.93". So the inside of the wheel is pretty much in the same place, just the extra 0.5" width of the wheel is on the outside, hence the reason for the wider fenders on the GT350. I believe the R has less offset on it wheels, probably to add a little width to it.

LMR has a install video of the GT350R brake kit, good video, and I believe it discusses wheel offsets in it also, should check it out.

Doug

I really appreciate the info Doug! The rear seems easy to get by with a small spacer. and there is probably a lot less variable with that such as fender design. I really doubt they would pay for the tooling to make larger fenders on the main body. So I will plan on going with the GT set and stick with it after brakes. Just add any small spacers as needed.

 

[D Bergstrom]

I really appreciate the info Doug! The rear seems easy to get by with a small spacer. and there is probably a lot less variable with that such as fender design. I really doubt they would pay for the tooling to make larger fenders on the main body. So I will plan on going with the GT set and stick with it after brakes. Just add any small spacers as needed.

A spacer won't help in the rear. GT350 wheels have more offset, so it helps with the extra width on the rear knuckle, tucking the wheel closer to the suspension. Say you have a 19x11, 50 mm offset wheel on the rear of your mustang now. If you add the GT350R brake kit, that same wheel will now be a 1/4" further out towards the fender, so effectively making the rear offset of that 19x11 wheel closer to 43 mm. A GT350 rear wheel has a 56 to 60 mm offset, so the extra 1/4" is offset by the extra offset. You might still be ok using the 50 mm offset wheel with the GT350R brakes, just something to look out for.

Doug

 

[DekiDoo]

A spacer won't help in the rear. GT350 wheels have more offset, so it helps with the extra width on the rear knuckle, tucking the wheel closer to the suspension. Say you have a 19x11, 50 mm offset wheel on the rear of your mustang now. If you add the GT350R brake kit, that same wheel will now be a 1/4" further out towards the fender, so effectively making the rear offset of that 19x11 wheel closer to 43 mm. A GT350 rear wheel has a 56 to 60 mm offset, so the extra 1/4" is offset by the extra offset. You might still be ok using the 50 mm offset wheel with the GT350R brakes, just something to look out for.

Doug

I'm so lost. I'm picking up a set of gt350 rear brakes and knuckles, and I know my PP wheels won't work, but I'm totally confused about how a spacer won't help the wheel clear the caliper.

 

[D Bergstrom]

I'm so lost. I'm picking up a set of gt350 rear brakes and knuckles, and I know my PP wheels won't work, but I'm totally confused about how a spacer won't help the wheel clear the caliper.

I will clarify. I meant in relation to offset, a spacer is not needed. Again, the rear GT350 brakes add width to the rear of the S550, so a spacer is just going to have the wheel stick out even further. I guess if you can find a wheel with a large enough inside diameter to work with GT350 brakes, and the spokes won't clear, then yes, a spacer will help, just have to watch how far that spacer will make the wheel stick out. I prefer not to have the wheels sticking way out, not a big fan of "poke", just doesn't look right to me, prefer to still have my wheels tucked in some, so I would not run a spacer with the GT350 brakes. Just a matter of preference.

Doug

 

[DekiDoo]

I will clarify. I meant in relation to offset, a spacer is not needed. Again, the rear GT350 brakes add width to the rear of the S550, so a spacer is just going to have the wheel stick out even further. I guess if you can find a wheel with a large enough inside diameter to work with GT350 brakes, and the spokes won't clear, then yes, a spacer will help, just have to watch how far that spacer will make the wheel stick out. I prefer not to have the wheels sticking way out, not a big fan of "poke", just doesn't look right to me, prefer to still have my wheels tucked in some, so I would not run a spacer with the GT350 brakes. Just a matter of preference.

Doug

Thank you for clarifying that, I appreciate it and it makes sense.

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