EvergreenToy

I want dual exhaust on my 4runner, but I've heard complications can arise. What I want to know is, can it be done? A catback split would be fine, I'm really after the look and the sound. Any part ideas? Install tips?

Jay351

Yes it can be done, anything can...

Problems can arise like you mentioned. Clearance is tight for a dual exhaust. And the 3vze hates big pipes... I would go to something like a dual 2" or smaller pipe diameter....

Matt16

If its look you're after, why not just have a dummy exhaust pipe coming out the back and a good muffler on the "real" exhaust. That would be a whole lot simpler, but I really haven't payed attention to what sounds good on Toyota trucks. IMO you need big displacement to sound good on a truck (thus Toyota's don't sound "good" to me.) Sound preference is very subjective.

Tubbyfatty

This has been brought up in the past. Earlier last week i believe. Just search for "exhaust suggestions" or something along those lines. But basically you cant go true dual because you dont have enough flow. Search.

RobD

Massive waste of money. The 3.0 needs scavanging from the exhaust. Basically, without enough back pressure, you won't get a good enough fuel/air charge. Anything above 2.25" pipe will cause you to lose power.

sa51

agreed, i bought my 4 cylinder with dual flowmasters and no cat on it, it ran and sounded like crap. i replaced it with a downey system and a hi flow cat and it still sounds like a civic, but not nearly as bad.
ive been looking into flowmaster's hushpower series and i think i'm going to replace it with that and a 2 inch pipe instead of 2.5

EvergreenToy

Alright, good stuff. My cousin's taco has duals on it, i don't think theyre true duals though, sounds pretty good, and provides decent power, but then again he has the 3.4L six, which may make a big difference. So if I decided to just go single, while diameter should i go for?

EvergreenToy

Just browsing around and found a dynomax cat back single as well as a Thorley system, also found a 50 series muffler. Opinions welcome.

mastacox

I would highly recommend the Flowmaster 50 Series SUV. On my old '92 4Runner I had a 2.5" header-back exhaust with 2.5" Catco high flow cat and 2.5" in-out 50 series muffler. It sounded great, and was a good match for the 3.slow turd IMO.

jason724

Did you have a FIPIK on it too?

mastacox

Nah, I just had the stock intake.

Jay351

2.25" Pipe diameter. NO bigger. The 3vze is pretty small, and its stock 21/8" pipe is almost perfect. Since 2.25" is easy to find and will provide a little bump in power WITHOUT losing low end power like a 2.5" pipe will..

P.s Don't buy a K&N fipk.

Search ISR mod and make one yourself for under $20.

mastacox

Pipe sizing is a fuzzy subject, but I'll tell you right now 2.5" is a very common aftermarket exhaust size used on the 3.Slow (most aftermarket headers have a 2.5" collector). I didn't experience any of the dreaded power loss you're describing, perhaps you could point us to a set of dyno sheets that verifies what you're claiming?

x2 on that, FIPK's are crap.

jason724

What about an S&B intake, I've heard they're much better than the K&N ones... http://www.sbfilters.com/products/pr...number=75-9006

The only reason I've kind of leaned away from the ISR mod is that I'm not really big into DIY projects because my 4Runner is my only means of transportation, so I can't afford to have it off the road for very long. I'm also kind of hesitant because of all the sensors and such.... Unless there's an easy way to leave all the sock tubing and just by pass the ISR thing. Sorry for the thread hi-jack. (I'll start a new thread)

Don't go for a dual exhaust, it'd be a huge hassle only for a loss in performance... And it'd be a PITA to do it yourself because you'd have to bend the pipes around the spare tire..

tman12345

how bout you split it after the muffler into duels?

thedude42

yea i have seen a 4 runner on here a green one a 3rd gen that has duels

i believe that if you run a 1 in 2 out duel pipes it should work fine just split them after the cat keep 2in or 2.25 in pipe till the crome tip!

Jay351

It's true, thats a very common size. But take a peek at the more high end exhausts. They are all 2.25". 2.5" for the 3vze is pretty damn big, most small v8's come with 2.5" pipes...
I don't have any hard numbers, but from what people on both sides have told me, 2.5" piping caused a loss in low end power, but a gain in top end (make sence eh?). 2.25" is the most you want to go to keep a little extra low end power....



Actually, the isr mod only requires a few hours down time (tops!).

Go to the exhaust shop, get a 3" diameter exhaust pipe (about 13") bent in the middle with 46 degree bend.

Remove your stock intake and mock up the new pipe. Remove and reinstall the stock intake so your truck is usable while you make the pipe.

Drill two holes and attach some brass fittings (for the two crankcase vents you must plumb in).

Get two 3" rubber hose peices (about 3" long) and 4 band clamps.

Install. Add some paint to make it look more factory

If you do it this way, you only spend about 30 mins removing the intake, mocking up the new pipe then re-installing the old intake.

Then your truck is fully functionable untill your ISR pipe is ready to install..
Its not like you wreck the stock stuff, its all reversable (very easily!).

I will show you a picture of mine once cardomain is back up...

HupDogDaddy

I have the Jardine cat back exhaust with downey headers. It's not a dual system but it actually sounds decent. But it did add 200 HP so I'm good with it

Yotas&Jellos

200hp?

Is that a typo?

HupDogDaddy

200 extra HP is easy with the 3.0