Working on installing MBRP 4" exhaust system. Anyone who has installed a 3" round down pipe care to lend a tip on getting it between the firewall and the transmission? The opening is approximately 3/4" less than than the 3" round pipe. What's the best method of installation here, cut the flange on the firewall or try to bend it with a 2X4 until it squeezes through? Any other ideas? I will be attacking the rest of it in the morning.

I found the best way to remove the old exhaust was to sawzall it in many pieces and toss it outside. I started to take it off in one piece but getting the connectors out of the rubber supports was taking too long. When I cut out the cat, it was over half plugged...I though I had a serious flow restriction.

Thanks in advance for any help...

 

Ya got to cut and bend back the pinch seam.....
http://www.drivetrain.com/downpipeinstinstr.html
This link shows how with a couple pics

 

Just make sure you get enough clearance I didn't and sometimes when I drop the hammer and make a turn the dp hits the firewall .Makes a nasty little noise I will have to fix it soon.

Dave

 

I second 1996pwrstrk.Go a little bigger than not quite enough.I've had mine off three times now cause after awhile it will start rubbing in one little spot and it makes a terrible sound.

 

I made the clearance as large as I could with out cutting out the fire wall entirely. I bent the flange as tight as I could get it to the firewall the whole length. Even with this removed the down pipe is wedged between the firewall and the transmission. Only got a short test drive, I noticed a lot more noise in the cab at idle. Deep tone, not bad but much louder. Driving down the road it is not as bad. The noise is transfered directly through the fire wall. Can definitely hear the turbo whine more. Lots more boost, at least 25% and the tires want to spin if it is at all slick when I step on it. Don't know how I could have gotten any more room without removing the fire wall though. I'll have to drive it more and see how it works.

 

If you need more room, try changing out the cab bushings and going with polyurethane. If you are still on the original bushings, they are bound to be worn out and sagging.

Max