How large of an exhaust is too large for a differential T-Brace?

[SLOASFK]

A friend of mine did a lot of work on my FD yesterday, including installing a differential brace and a bumper gaurd.

After starting the car for the first time, I noticed a bad rattling coming from the rear of the car. I assumed this was the tip rubbing against the bumper gaurd, but after closer inspection, I noticed that the tip doesn't get anywhere near the gaurd. Then I started to think about Rich Farrell and the fact that he had to ditch his T-brace when he went with the 4" exhaust because it wouldn't fit. My cat-back is 3.75" ID, and though the brace fit with no problems I'm wondering if the vibrations of the exhaust are causing it to rattle against the brace.

Does anyone have any experience with the old style HKS Super Dragger, or any other 3.75" ID cat-backs while running a T-brace? Any help is greatly appreciated.

On another note, my diff mounts are blown out and the car had a nasty clunking in the rear when reversing. Since installing the T-brace, that clunking is completely gone, so I'd like to not have to remove it until after I get my new busings installed.

Thanks,

Brian

[McVicker]

I had a similar problem when I was using my JIC exhaust. The flange was rubbing against the brace, we had to notch it out with a sawzaw. You could get under the car and take a look, if it's rubbing it you will see.

-Dan

[AnthonyNYC]

I'm running the larger Greddy off road setup, I had the same issue but had the shop Speedtek in Long Island weld additional mounts to the area that was touching. I also used 2 large hose clamps and attached a thick piece of silicone hose in that area in the event it ever touched again.

[Fendamonky]

I'm running a 4" exhaust with the Banzai diff brace and I've not noticed anything. Slightly of the subject, I know, but it could be something to consider.