Keeping the exhaust from hitting the cross brace.

[jtzako]

My resonator is hitting the cross brace under the car since I added new Cats. So far I havent found a way to prevent this. I tried putting washers in between the brace and the car to give it an extra 1/4 inch but that wasnt enough apparently. I also tried a brace that is about 1/3 the width of the stock brace and it reduces the instances of impact but it still does hit when I hit bumps in the road.

I'm looking for another solution. I noticed there are 2 bolts above the exhaust, one on each side of the resonator, that bolt into the chassis. I could use them, perhaps, to put in some sort of exhaust hanger in this section of the car to keep the resonator off the brace.

Here are the issues:

1) The resonator gets hot enough to melt/burn rubber. Perhaps too hot for normal hanger hardware.

2) Vibration/noise isolation. If I dont have some sort of 'soft' isolation of the hanger from the chassis it will vibrate the chassis quite a bit and cause more noise in the car.

Anyone have an idea what I could do here? Is there a type of hanger hardware I could use to fashion a hanger for this that can withstand the heat?

[Cam 427]

If the cats are clamped on, you might try loosening the clamps and repositioning the exhaust up away from the brace.

[jtzako]

Originally Posted by Cam 427

If the cats are clamped on, you might try loosening the clamps and repositioning the exhaust up away from the brace.

They are clamped to the exhaust, but there is no way to reposition them any farther. I've tried pushing them as far together as possible to keep the exhaust up higher but even with that they still hit the brace.

[JS]

Check out my post, I fixed mine and nooooooooo more rattles

[Ivan @ Southwest Speed]

Something isn't lined up correctly.

Take a look at everything as you work your way back. Pay attention to small things that will affect larger changes downstream.

We've had to do washers and install different tunnel braces all together on many different applications. Even the 2.5" systems.

Keep at it and let us know what you find!
Ivan

[jtzako]

I'm not really sure what else to check. The Cats are solidly bolted to the manifolds. No way to adjust that as far as I can tell. I have pushed the cat pipe and exhaust pipe as close together as I can get them and clamped them tight. There is still about 3/4 inch gap there (under the clamp) but I cant seem to get them any closer. There is no more adjustment anywhere along the way.

These Cats flex a LOT more than stock due to the different type of flex pipe on them vs stock. I suspect that is why they allow the exhaust to move enough to hit the brace.

[JS]

Punch into the search engine and use my sig.
I fixed it and it will never rattle again.

[jtzako]

Originally Posted by JS

Punch into the search engine and use my sig.
I fixed it and it will never rattle again.

I have seen that one thanks... However it isnt the rear of my exhaust hitting, it is closer to the front/middle. There already is a good hangar in the rear section. Also, I dont want anything I cant easily remove.

What I think I am going to do is get a generic exhaust hangar and make a slide mod to it so it can use the existing bolt holes above the resonator. With that I can 'hang' the resonator up a bit and keep it off the brace. The Rubber part should isolate the noise/vibration from the car. I may use some header/exhaust wrap to cover the strap part to keep the heat from being an issue for the rubber part.

[JS]

So was mine, the bolt holes are there and once u weld the brackets to the pipe like I did u can hang on the ehxuast and it wont move...The rubber bushings give it just enough flex to work perfectly...Look in Summit for the brackets and just do it, mine is perfect and I've gone over countless bumps in the last week

[jtzako]

I made myself an exhaust hanger that works to keep my resonator off the cross brace. I used 2 exhaust hangers from Jegs and metal strap material. I wrapped the metal strap with header wrap so it would help isolate some heat and vibration and hopefully not let the rubber part of the hangers melt from the heat of the resonator.

The whole thing bolts to the car using 2 chassis bolts that already exist just above the resonator.

I had to do some modification of the exhaust hanger to make it work for this but it seems to do well so far. The initial drive I took indicates the resonator no longer hits the cross brace and there is only minor 'noise' getting into the passenger compartment from adding the extra brace.

[Hicompression]

JBA does not make a "flex" style midpipe like Solo does, yet JBA claims their "rigid" midpipes fit both the LS3 and the L99. Maybe it would have been better to have bought the LS3 midpipe and used it. It certainly wouldn't have had the flex the L99 midpipes have.

[jtzako]

Originally Posted by Hicompression

JBA does not make a "flex" style midpipe like Solo does, yet JBA claims their "rigid" midpipes fit both the LS3 and the L99. Maybe it would have been better to have bought the LS3 midpipe and used it. It certainly wouldn't have had the flex the L99 midpipes have.

I was wondering about that also. What is the point of the flex pipe exactly? The stock 'flex' pipe is quite rigid. I doubt it moves much, if any compared to these on the Solo cats.

[Hicompression]

Originally Posted by jtzako

I was wondering about that also. What is the point of the flex pipe exactly? The stock 'flex' pipe is quite rigid. I doubt it moves much, if any compared to these on the Solo cats.

To tell you the truth, I'm not quite sure why GM put the flex pipe on the L99 midpipes. Maybe someone else knows?...

[tjbusa]

http://www.bartonindustries.com/BUY-Tunnel-Brace.html