[ScottZ95ZR1]

Originally Posted by Don in VT

Hi All,

Just got back from the shop, where I work, with great news. My Tech, Adam, installed a Summit Racing narrow X pipe on my wife's 90 ZR1 and the loud droning that was real bad is gone. Not just reduced but gone. No change to the mufflers is planned until they need to be replaced.

Since sound is a tricky subject so I'll describe my wife's system as the results we got may not be the same as any other owner will get.

1990 ZR1
Std exhaust headers/manifolds
Std Cats in place
2 1/2" st st pipe to Summit Racing Narrow 2 1/2" X pipe (not stainless steel)
X pipe back to mufflers is 2 1/2" st.st.
Mufflers are older Flowmasters with dual tips.

Prior to install of the x pipe the exhaust was "true dual".

What a difference with the X pipe.

My Tech, Adam Rainville, has the touch with Vettes as he really likes to work on them. He did a great job.

Regards

Don in VT

Glad Adam got you fixed up and you're happy with it!

Originally Posted by XfireZ51

Scott,

Yes it did and that was 2 years ago. I since have made a small modificaton to the system removing a constriction at the drivers side header collector which I have also documented on the registry. At the time, the B&B I had removed was a 3Gen with resonator, no Xpipe. I recently took the car to the dyno again and did a little tweaking. The first run was almost identical to the first run I did with the MF 2 years ago. However, after playing with the tune, I was able to take the motor from 383rwhp/347rwtq to 395rwhp/357rwtq. So that tells me the system doesn't have the restrictions it was hypothesized to have. And it looks good while solving the reosnance issue to boot. That's why I would recommend that you give it a look.

I do remember you posted regarding the header constriction and will revisit that thread - thanks Dom.