View Full Version : Has anyone ran dual exhaust and how did it work?

January 27th, 2009, 12:24
I saw online someone had duals on their 90 something XJ and it sounded and looked awesome. Do many people do this because i have not seen this to many times? Anyone have any thoughts?

The Box
January 27th, 2009, 13:43
Mine had dual exhaust when I bought it. It was louder but maybe due to the muffler. I've see a couple that looked alright, but the tips that were on mine looked like they belonged on some suped up honda. Depending on your setup, I could see space becomeing an issue. I ended up changing the muffler and running a single pipe. It really just comes down to your preference I guess.

January 27th, 2009, 13:49
the sound has a lot to do with length, diameter and bends of the tube, plus the muffler/cats used. True duals are tricky, you'll have to get a dual-outlet header. I don't know offhand who (if anyone) makes one for the 1990 motors. Some people just split the pipe and run two sections from the single downpipe, so this isn't a true dual exhaust. There are a lot of things to consider.

At any rate, if you want to keep the engine power, you'll need to run smaller pipes if you run duals. The 4.0 motor doesn't have enough airflow to run dual 2.25" or 3" pipes so you'll actually lose power and torque if you run dual large pipes. If you're just looking for looks and sound, go right ahead otherwise you'll have to do some math depending on if you're running true duals or splitting the stock exhaust.

January 27th, 2009, 14:37
I don't know offhand who (if anyone) makes one for the 1990 motors.

http://www.cliffordperformance.net/Merchant2/graphics/00000001/57-2015%20300.jpg (http://www.cliffordperformance.net/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=57-2015&Category_Code=J258) 57-2015 "6=8 HEADERS" Jeep Headers 1987-2005 w/ 242 cid (4.0L). Includes Smog Fittings. (http://www.cliffordperformance.net/Merchant2/merchant.mvc?Screen=PROD&Store_Code=CP&Product_Code=57-2015&Category_Code=J258)
Code: 57-2015
Price: $359.00
Quantity in Basket: none

Clifford Performance^^

January 27th, 2009, 14:47
I thought the Renix system was a little different, I guess not... I figured Clifford would have something, but didn't feel like searching, thanks! ;)

January 27th, 2009, 14:53

January 27th, 2009, 15:32
waste of time and money.

January 27th, 2009, 15:52
if budget was unlimited, I'd go for it.
As it is... 2.5" from the header on back will flow more than all but the gnarliest 4.0-based engines could need.
If you decide to go dual, I won't knock it... but wolfpackjeeper is totally right from a bang-for-buck standpoint.

January 27th, 2009, 16:58
on the other hand, a nice dual exhaust setup will heat up the gas tank twice as fast. Or in half the time depending on how you look at it...

January 27th, 2009, 18:04
waste of time and money.

Deadman 94 xj
January 27th, 2009, 18:07


January 27th, 2009, 18:15
waste of time and money.
unless it was going to be for a top end supercharged drag race motor. For what most of us use a 4.0 for a good old single is more then fine.

Deadman 94 xj
January 27th, 2009, 18:17
Not to mention more crap to make noise and get dented up.

January 27th, 2009, 19:07
Can you do it? Yes. Is it worth the money and effort? No. Spend the money on a quality manifold, mandrel bent pipe from manifold to cat and onto a quality muffler, you'll be more than happy.

January 28th, 2009, 06:27
i have actually done one on an xj and it was not easy - some teenage kid wanted it despite being an inline 6 and not a v-6 ... routing the exhaust tubing stinks and it really suffers off road because the drivers side is so exposed and this was a simple cat back! the xj is a compact suv and there is little to no room even under the vehicle... it sounded ok though - flowmaster dual outlet 2 1/4 pipes

January 28th, 2009, 07:06
duals on an inline motor... lame..