Apparently there is some flexing in the rear suspension mounts when pushing the stock Kappas. GM engineers have confirmed this and several aftermarket companies are offering braces to stiffen things up. I know DDM and Kappaphere have offerings. I would like to hear feedback from anyone using these products. Are you seeing improved control while accelerating through turns?
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Apparently there is some flexing in the rear suspension mounts when pushing the stock Kappas. GM engineers have confirmed this and several aftermarket companies are offering braces to stiffen things up. I know DDM and Kappaphere have offerings. I would like to hear feedback from anyone using these products. Are you seeing improved control while accelerating through turns?
I *know* that if your truly want to see a difference in how your car handles then you should order the Rear Suspension Support Crossmember part #25877302 that is used on the Solstice GXP ZOK. This part can be ordered thru gmpartsdirect.com for around $257 plus shipping.
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I *know* that if your truly want to see a difference in how your car handles then you should order the Rear Suspension Support Crossmember part #25877302 that is used on the Solstice GXP ZOK. This part can be ordered thru gmpartsdirect.com for around $257 plus shipping.
From the article I am guessing that the part mentioned is a REPLACEMENT, for the stock crossmember, not a bolt on stiffener? If so, oit is out of my capacity as a mechanic because it would probably lead to the necessity of a 4 wheel alignment after installation. Are there any photos of the part either in or out of a vehicle?
Thanks,
Clif
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Were does this crossmember attach to? I'm hoping its runs from rear bushing to rear bushing of the rear control arm......they are kinda just hanging out there.
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From the article I am guessing that the part mentioned is a REPLACEMENT, for the stock crossmember, not a bolt on stiffener? If so, oit is out of my capacity as a mechanic because it would probably lead to the necessity of a 4 wheel alignment after installation. Are there any photos of the part either in or out of a vehicle?
Thanks,
Clif
Sorry, I could not find a picture. But, according to the article this is a NEW addon. There is no "stock" crossmember currently on anything except the GXP/Redline ... there WILL be in 2009 on the NAs, but not now.
The engineer that pointed me in the direction of the part and the article would have mentioned the need for alignment if it would have been required - of that I am certain.
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Sorry, I could not find a picture. But, according to the article this is a NEW addon. There is no "stock" crossmember currently on anything except the GXP/Redline ... there WILL be in 2009 on the NAs, but not now.
The engineer that pointed me in the direction of the part and the article would have mentioned the need for alignment if it would have been required - of that I am certain.
I see. Do you know if it is a replacement for the crossmember on the GXP/Redline? That is what I meant.
CLif
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I see. Do you know if it is a replacement for the crossmember on the GXP/Redline? That is what I meant.
CLif
It is my understanding (again from reading the article and speaking with an engineer) ... that the crossmember on the GXP/Redline was still 'flexing' on the T2 race Solstice and was replaced with a stronger crossmember.
Therefore ... I would say YES ... it is a replacement for the one currently on the GXP/Redline.
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It is my understanding (again from reading the article and speaking with an engineer) ... that the crossmember on the GXP/Redline was still 'flexing' on the T2 race Solstice and was replaced with a stronger crossmember.
Therefore ... I would say YES ... it is a replacement for the one currently on the GXP/Redline.
Thanks, I thought so. I do not think I want to try this on my back on my garage floor!
Clif
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I changed mine (I installed the Z0K suspension package on my Sol).
It's 6 bolts to swap out plus I think I remember I had to take off a lower control arm. It's not for the non-mechanically inclined but not too difficult either.
The differences in the parts is a 1/4" C-channel that is welded to the standard crossmember and the bushings that attach to the diff are of harder material.
The main difference in the feeling will come from the bushings not from less flex in the crossmember.
Rob beat me to it, but I can add a little more to this.
The Z0K package includes an upgraded crossmember, or more accurately a welded "C" member to a stock crossmember. We had a chance to talk with a couple guys from GM performance when we were down in Florida. I told them about the brace we were developing at the time, figured might as well get some feedback and see what they had to say . We told them about our experience in the Miata community and how we would see some flex in the lower sub-frame on the earlier models that did not have the lower suspension boxed in. Simply adding a bar accross the lower suspension pick-ups in the Miata and boxing in the rear, took care of the problem, and that was the first thing we tested on Randy's Solstice. Then we told them the problem we immediately ran into on the Solstice was that the exhaust was in the way, and if we moved the brace forward or back enough to clear the exhaust, the brace was becoming less and less effective. Also our test car has clearance issues since it is lowered. We struggled with a bunch of different designs trying to support the rear suspension pick-ups on the Solstice/Sky and nothing seemed to work, it would either hit the exhaust or get destroyed by the lowered car.
So after telling all of this to the GM performance guys, we learned a little more about the GXP / Redline brace found on the Z0K package. They tested pencil braces coming up from the lower suspension of the car and it tested well, but they had clearence issues also. Also when they analyzed what was going on back there they found that the crossmember that holds the differential was actually flexing under high cornering loads. So their solution was to make a really trick "C" channel to fit over the rear crossmember. They said in testing that it provided to have the same improvement as the pencil bracing, but was a lot easier for them to install, 1 piece welded to the crossmember and that was it. I talked to them about bracing the rear suspension forward also and asked if they tested that, and they had, and found that there was no measurable improvement going forward.
Hope that sheds some more light on the subject for you guys.
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. We told them about our experience in the Miata community and how we would see some flex in the lower sub-frame on the earlier models that did not have the lower suspension boxed in. Simply adding a bar accross the lower suspension pick-ups in the Miata and boxing in the rear, took care of the problem, and that was the first thing we tested on Randy's Solstice. Then we told them the problem we immediately ran into on the Solstice was that the exhaust was in the way, and if we moved the brace forward or back enough to clear the exhaust, the brace was becoming less and less effective. Also our test car has clearance issues since it is lowered. We struggled with a bunch of different designs trying to support the rear suspension pick-ups on the Solstice/Sky and nothing seemed to work, it would either hit the exhaust or get destroyed by the lowered car. 
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