I just installed RT cats on my car today and now the mid pipe is rubbing the M brace. (my setp up is RT cats and Nismo catback). I know people had this problem with crawford cats * Nismo and they had to shim the M brace. This needs to be taken care of ASAP i.e. today or tomorrow because I have to drive to oklahoma tomorrow. Should I shim the M brace or do something else? How do i shim the brace? What size washer? etc. Thanks for the quick help guys!

 

Are u refering to what I call the W Brace that is at the rear to mid area of the car ???? If so --shimit for at least the time being and ur guess is as good as mine as far as shims ---Improvise----U CANT go to a machine shop today, so go to the Hardware store and get some washers ---- And if u just cant do it , then leave it out till u get back to Ok or Tx---I ran with out mine for a couple 1000 miles with no ill affect

 

screw shims, this is all you need.

 

Excuse me but isn't this brace welded in place? Are you certain that this is a simple bolt-on brace?

 

It is a bolt on piece. I have the same problem. RT HF's and Japtrix Y/B.

A little crowbar and bending and you'll be alright. No need to go nuts and its not ghetto rigging it by bending it, not all exhaust is going to fit exactly as planned.

 

I used 1/8" thick washers on mine (Nismo exhaust, Crawford headers & cats) - worked perfect & eliminated the slight rub/vibration.

 

My X pipe was hitting it prety badly too. I used several washers. about half an inch made it better.

 

Yep.. used washers under the 4 M-brace bolts to make about 1/4-inch gap, to prevent the exhaust from vibrating against the brace (which is attached to the chassis). Crawford high-flow cats and stillen exhaust here.

 

I took off that V looking brace thats towards the back in your pic. How important is that?

 

I have R/t cats and a Nismo Y-Pipe and mine rubbed. Performance Nissan sent spacers when I ordered my exhaust parts. No need to bend.

 

Thanks for the clarification.

 

The M-brace is a major rear chassis support. Not optional. Put it back.

 

So we were on the same page do you have a different pic of the m brace? Thanks for the help

 

The first time I had this I put heat wrap around the exhaust about a year or so ago. I was going to do the washer thing but I forgot all about it until I just read this post. Might get around to doing that in the next week.

 

 

Yup ok. Thanks again man. I better put that thing back on.

 

Just a little update for yall.

Got up early this morning and jacked the car up and put her on stands. I removed the 4 bolts and checked for washer sizes. I then went to the store and bought 24 3/8 washers. I got back, scotch taped the washers together (to make it easier to handle when sticking them inbetween the brace and the pans) I poked a hole in the scotch tape to allow to bolt to pass through. I used 6 washers for each bolt. Tightened the bolts back on (it took around 240 inch lbs to get them off so just to be sure i tightened them back down to that). Jacked her back down and it worked great. Only took an hour and a half or so including going to the hardware store. Thanks for the help guys!

 

Just looking at the pic again and I must say. Thats a clean undercarriage. Also wanted to say thanks for sharing the thread.

 

I just installed my crawford hfc's and have some vibration coming from the driver side at the low rpms coming out of first gear from a dead stop. Other than than that the rest of the gears and and higher speeds it sounds great. I mad sure to give the shield on shield area plenty off clearance. So i am now wondering if it could be the m brace. I just went under the car and dont see how it can be rubbing there. From the pic in this thread, can someone point out exactly where this vibration is taking place? Thanks folks.