Late last summer I had J&M upper (non-adj) and lower control arms (extreme) installed along with QA1 single adjustable rear shocks. They made a real improvement in traction however the NVH, if you want to call it that, is pretty bad. It is not road noise but more like "clunking". I took it back and was told it is "normal". I need to figure out if it is normal because I really don't like it. If I need to make chnages I will make changes but don't want a repeat. Anyone else have these parts on their GT500's (mine is an '08)?
Suspension Mods & NVH
- Thread starter kens88gt
- Start date
Rolling the windows down helps. 
The upper, by design, transmits suspension and gear harmonics into an area that amplifies them (the rear seat area). I always recommend a rubber bushed arm, ala Roush, at this critical NVH path. If NVH is that much of a concern, I'd sell the upper you have in their now and use the Roush upper.
As much as I'm no fan of the lowers you are using either, I'd start with the upper and then consider changing the lowers second.
As much as I'm no fan of the lowers you are using either, I'd start with the upper and then consider changing the lowers second.
One clunk generator is using an aftermarket UCA with the stock UCA bracket. It's a 14mm bolt in a 16mm hole. (That's true right from the factory). Two solutions are an aftermarket bracket or shims, available from Steeda, that reduce the hole diameter. The last is really a band-aid in my opinion.
Steve
Steve
Thanks for the input. I was told that it is the QA1 shocks that are making the clunk but I can't really tell. I have no problem with increase in NVH, road noise, etc. but the "clunk" was not expected and I really don't like it.
I recently put on BMR adjustable UCA, LCAs and brackets. I thought I could hear/feel clunking from the rear end, so I went under the car and made sure all bolts were torques to spec. I think what I am hearing is the rod ends moving around when the rear end moves.
I have stock rear lower control arms and the stock upper with rear QA1 shocks - no clunk under load or spirited driving. Mine is a 2008 as well.
I decided not to mess with the upper and am just going to a Griggs torque arm instead.
I decided not to mess with the upper and am just going to a Griggs torque arm instead.
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