Outer Limits 4x4 Board

A mate is about to start building the exhaust for the V8 in the FJ40. Motor is a Holden 5.0L EFI (304). Running stock manifolds, then twin 2" into single 3" with a 3" cat and muffler. All mandrel bent stainless steel.

I'd like the sound to be similar to my old lexus V8 4runner (Deep growl, no bark, loud when into it, not too bad when not). It had twin 2.5" into twin 3" cats into single 3" with a straight through barrel type muffler.
http://www.youtube.com/watch?v=X5xzY-ljyGY" onclick="window.open(this.href);return false;
http://www.youtube.com/watch?v=3nMGfRFDt7M" onclick="window.open(this.href);return false;

The muffler my mate is trying to get me to run is offset as it goes through (i think this may be too quiet). He thinks a straight through one like I had on the 4runner is going to be too loud due to the exhaust length being much shorter, and having a single cat which is smaller and better flowing compared to the old school type 3" ones I ran on the runner.

I should add, my mate is no exhaust guru, just likes tig welding, free beer, and FJ40s. He has mostly done ones for deisels.

Heres a pic of the cat/muffler.



Anyone with experience or advice with what that have ran on the 5.0l V8's would be much appreciated.

Videos would be great too.

id run the center to offset straight through fiber packed muffler, still loud enough to be noticed but you can also putt around without it being over the top and it will help keep the back pressure there more then the center to center straight through.

You wont get a lexus noise from the 5.0, nothing sounds quite like a Lexus, but you already know that.

It shouldn't be too hard to subdue especially on stock manifolds but they develop a natural bark at 3000 plus rpm.

You will learn to like it

Cheers for the replys.....got the 2" side of the exhaust done last night. Plan is to finish it off till the cat for now and worry about the rest later. Might be something else in the works now that will effect the rest of the exhaust.

Evil! wrote:id run the center to offset straight through fiber packed muffler, still loud enough to be noticed but you can also putt around without it being over the top and it will help keep the back pressure there more then the center to center straight through.

why would you want to keep backpressure?

440 BB wrote:

Evil! wrote:id run the center to offset straight through fiber packed muffler, still loud enough to be noticed but you can also putt around without it being over the top and it will help keep the back pressure there more then the center to center straight through.

why would you want to keep backpressure?

Back pressure is torque

backpressure is a power and torque restrictor, an exhaust can be too big but thats to do with the gasses cooling too quickly and becoming a restriction

I ran a 2 3/4" with mine, I did a bit of research when I go mine done, and they all recommended this size. Also hear that stainless isn't that great of an option on 4wd, something about cracking often and a few other reason's I can't remember. But I figure it would be easier to patch a Mild Steel exhaust rather than trying to Tig under the car.

But this is only what I have heard from a little bit of enquiry and I do suffer from male syndrome. So feel free to educate me on it.

my bb chev is 2 x 2 1/2 into a 3" with a striaght through muffler with a slight off set. finishes in front of the rear diff so about as long as a shorty.
I grabbed a stainless muffler as the shop had one there and it was only $10 more than a standard one. Here is a vid from the beerwah skids, excuse the clutch melting when we grabbed 3rd a few times and the rear locker breaking. was a fun day though..!!

http://www.youtube.com/watch?v=0HHRhE0A ... plpp_video" onclick="window.open(this.href);return false;

440 BB wrote:backpressure is a power and torque restrictor, an exhaust can be too big but thats to do with the gasses cooling too quickly and becoming a restriction

I have seen dyno figures to the contrary, XA falcon with a 351 ran with full exhuast then pulled the exhuast off and ran with it straight from the extractors. Same dyno, same day, same operator, less power with exhaust removed.

yes too much back pressure can be detrimental to making power and torque but too little can have the same affect

loosecanon wrote:I ran a 2 3/4" with mine, I did a bit of research when I go mine done, and they all recommended this size. Also hear that stainless isn't that great of an option on 4wd, something about cracking often and a few other reason's I can't remember. But I figure it would be easier to patch a Mild Steel exhaust rather than trying to Tig under the car.

But this is only what I have heard from a little bit of enquiry and I do suffer from male syndrome. So feel free to educate me on it.

I have heard some similar stories about about stainless too, but this is just being done in the shed at home for cost of materials, so happy to give stainless a run.

I had a mandrel bent steel exhaust on the 4runner with the lexus V8 and it had rusted out within 2 years so wasnt getting that again. Am guessing because the bends didnt have the aluminiumised coating.

purplebus wrote:my bb chev is 2 x 2 1/2 into a 3" with a striaght through muffler with a slight off set. finishes in front of the rear diff so about as long as a shorty.
I grabbed a stainless muffler as the shop had one there and it was only $10 more than a standard one. Here is a vid from the beerwah skids, excuse the clutch melting when we grabbed 3rd a few times and the rear locker breaking. was a fun day though..!!

http://www.youtube.com/watch?v=0HHRhE0A ... plpp_video" onclick="window.open(this.href);return false;

Haha, nice work Shane. Sounds about pefect for what I'm after. Thanks.