Review: GTSPEC rear lateral U and S braces
08-08-2010 | 08:55 AM
#1
Review: GTSPEC rear lateral U and S braces
After finding the GTSPEC 6-pt strut brace and front lower brace to be significant improvements (described here: https://www.rx8club.com/series-i-wheels-tires-brakes-suspension-55/gtspec-6-pt-front-strut-front-lower-brace-review-196104/ ), I recently tried the rear lateral tie brace (S-brace) ( http://www.gtspec.com/product/gtspec...a-rx-8-s-shape ) and the rear tie brace (U-brace) ( http://www.gtspec.com/product/gtspec...a-rx-8-u-shape ). Assuming you have a stock 60 mm pipe diameter on the catback, both install relatively easily since they mount on the nut end of the bolts and don't require removal of any other pieces. The U-brace install is completely trivial. The S-brace can be snaked around the exhaust pipe without dropping the exhaust. It takes a bit of trial and error to find the right trick though. The ability to do this is a plus, but the minus is that it sits lower than it would if shaped more closely to the differential (but would then require dropping the pipe first). On my unmodified suspension with stock tires, the S-brace only gives 4 3/8" (~110 mm) ground clearance. The exhaust pipe is about as low in this area, but has considerable vertical give in the event of a strike, which the S-brace won't have. On both braces, there was a minor but surprising minor lapse in quality control: the inside of the 'cylinders' which serve as the mounting points had not been de-burred before painting. The sharp burrs are a risk to fingers while spinning the nuts on. I took the burrs off with my trusty de-burring tool. Being made of aluminum, the total weight increase is minimal and I didn't bother measuring it. There is only about 7 mm clearance between the 60 mm pipe and the closest part of the S-brace. A 2 1/2" (64mm) pipe should clear, but a 3" pipe (75mm) probably won't without dimpling the pipe.
Results? Much more subtle than with the front braces, and entirely in hard cornering. Near the cornering limit where a bump causes the rear to step out, I think the car digs back in more securely than before. I've run this change about 1000 miles now and don't see much of any difference in other situations. Of the two, the S-brace is doing the work since it provides an additional load path for the suspension links. The U-brace doesn't change any load paths and it bolts to already substantial frame members, so it's hard to see how it would improve much. Is it worth the money? I have my doubts about the U-brace. If you don't already have a rear strut brace or spare tire kit (which serves as a brace) a $100 rear strut brace makes more sense. If you already have that and can live with the clearance issues, the S-brace gives a little something in hard cornering. YMMV.
Results? Much more subtle than with the front braces, and entirely in hard cornering. Near the cornering limit where a bump causes the rear to step out, I think the car digs back in more securely than before. I've run this change about 1000 miles now and don't see much of any difference in other situations. Of the two, the S-brace is doing the work since it provides an additional load path for the suspension links. The U-brace doesn't change any load paths and it bolts to already substantial frame members, so it's hard to see how it would improve much. Is it worth the money? I have my doubts about the U-brace. If you don't already have a rear strut brace or spare tire kit (which serves as a brace) a $100 rear strut brace makes more sense. If you already have that and can live with the clearance issues, the S-brace gives a little something in hard cornering. YMMV.
Last edited by HiFlite999; 08-08-2010 at 09:02 AM.
08-08-2010 | 09:29 AM
#2
After finding the GTSPEC 6-pt strut brace and front lower brace to be significant improvements (described here: https://www.rx8club.com/showthread.php?t=196104 ), I recently tried the rear lateral tie brace (S-brace) ( http://www.gtspec.com/product/gtspec...a-rx-8-s-shape ) and the rear tie brace (U-brace) ( http://www.gtspec.com/product/gtspec...a-rx-8-u-shape ). Assuming you have a stock 60 mm pipe diameter on the catback, both install relatively easily since they mount on the nut end of the bolts and don't require removal of any other pieces. The U-brace install is completely trivial. The S-brace can be snaked around the exhaust pipe without dropping the exhaust. It takes a bit of trial and error to find the right trick though. The ability to do this is a plus, but the minus is that it sits lower than it would if shaped more closely to the differential (but would then require dropping the pipe first). On my unmodified suspension with stock tires, the S-brace only gives 4 3/8" (~110 mm) ground clearance. The exhaust pipe is about as low in this area, but has considerable vertical give in the event of a strike, which the S-brace won't have. On both braces, there was a minor but surprising minor lapse in quality control: the inside of the 'cylinders' which serve as the mounting points had not been de-burred before painting. The sharp burrs are a risk to fingers while spinning the nuts on. I took the burrs off with my trusty de-burring tool. Being made of aluminum, the total weight increase is minimal and I didn't bother measuring it. There is only about 7 mm clearance between the 60 mm pipe and the closest part of the S-brace. A 2 1/2" (64mm) pipe should clear, but a 3" pipe (75mm) probably won't without dimpling the pipe.
Results? Much more subtle than with the front braces, and entirely in hard cornering. Near the cornering limit where a bump causes the rear to step out, I think the car digs back in more securely than before. I've run this change about 1000 miles now and don't see much of any difference in other situations. Of the two, the S-brace is doing the work since it provides an additional load path for the suspension links. The U-brace doesn't change any load paths and it bolts to already substantial frame members, so it's hard to see how it would improve much. Is it worth the money? I have my doubts about the U-brace. If you don't already have a rear strut brace or spare tire kit (which serves as a brace) a $100 rear strut brace makes more sense. If you already have that and can live with the clearance issues, the S-brace gives a little something in hard cornering. YMMV.
Results? Much more subtle than with the front braces, and entirely in hard cornering. Near the cornering limit where a bump causes the rear to step out, I think the car digs back in more securely than before. I've run this change about 1000 miles now and don't see much of any difference in other situations. Of the two, the S-brace is doing the work since it provides an additional load path for the suspension links. The U-brace doesn't change any load paths and it bolts to already substantial frame members, so it's hard to see how it would improve much. Is it worth the money? I have my doubts about the U-brace. If you don't already have a rear strut brace or spare tire kit (which serves as a brace) a $100 rear strut brace makes more sense. If you already have that and can live with the clearance issues, the S-brace gives a little something in hard cornering. YMMV.
08-09-2010 | 07:04 AM
#4
Quite possibly. Also subtle in that pushing the car on the limit is difficult to do on the street without endangering me, other motorists, and my license. And subtle too in comparison to the effect of the front 6-pt braces, which, on an emo-scale, is dramatic.
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