exhaust?

[4runner_RV6]

Hey got a quick questions.I'm adding a new 2.5inch exhaust to my 4runner rv6 efi 3litre petrol and wondering if i should add a high flow cat to the 2.5inch exhaust or should i just keep the original cat and not worry about a high flow?would the high flow cat make a diff in power? thats what i'm mainly after more power and a better sound. If anyone has any sugestions that would be great.


Thanks ;D

[Fenring]

When I was into V8's etc the trick wa to put the muffler etc as far back as possible in the system. I have also heard that cat's can be all clogged and restrictive after a few years. Might pay to have it inspected when the old pipe comes off. (Have also seen them with the guts cut out so they just flow straight thru as well. ;D )

some people rip the guts out of the cat...... just don't get caught :-\

[350rangie]

If you can afford the high flow cat its worth doing. less restriction in the exhaust. You may not notice a huge difference in a standard motor but it will sound better.

[Twisty]

ON my first V6 4runner I had a 2.5" exhaust system installed with a 2.5" high flow cat, and it sounded awesome!! and made a decent improvement.

The first system I had on my current 4Runner was Hurricane Extractors, twin 2" until after the transfer case, no cat, 2.5" straight throuigh muffler then 3" tip. This was the best I've had as far as performance goes, but it was bloody loud! My mate bought this system off me and added a small resontor near the end, which didn't hurt perforamce, but quitened down heaps.

I then put on a 3" mandrel system with 3" High Flow cat and Straight though muffler put on with the old exhuast manifold back on (I was going to turbo the V6). This was the best it has ever sounded, and it performed excellent too, but I can't compare it to the other exhuast performance wise as I was running engine management as well. I will be using this exhuast with the V8, but with an extra 3" cat.

Have you got extractors on? or are you going to put them on? If you don't have extractors, and you not keen on spending the $330 for them, I would remove the crossover pipe that wraps around the back of the V6 and then have separte pipe for each bank (2") until after the transfer case. (you will get a big gain from doing this, the crossover pipe is very restrictive). Then go into 2.5" pipe with highflow cat and straight though muffler. It wont be much dearer to run the dual pipes at the start, just a bit of work to get the existing crossover pipe out.

[Nemesis]

3" on a 3L :o Man talk about overkill! Didn't you lose a heap of bottom end power from that?
When I was going to mod my XR8 I was in two minds whether to go single 3" as i thought i might lose backpressure, and that was on a 5L bent eight lol.

Who makes the extractors again?

[Twisty]

Hurricane make the extractors....Bout $330 a pair, shop around as I've seen them for up to $500.

I went 3" since I was going to be putting a turbo on, and with turbo's the biggest exhaust you can fit will be the best.

It didn't seem to loose torque with running just the 3" exhaust on the V6, I think the std. restrcitive manifold was still providing enogh back pressure. But I was running engine management, so this probably helped as well, as the fuel and timing would have been tuned to suit.

[4runner_RV6]

Have you got extractors on? or are you going to put them on?



Thanks for all your feed back its been great. Just to your question twisty. Na i probably won't be getting extractors until i can afford a turbo for it which will prob be a while...lol..Its easier to do it that way isn't it? when you say cross overs they are just before the cat? i don't know much about engines and so fourth yet still learning :). the 2.5" exhaust and the cat are being done professionally but at not a bad price $415aud for both.

This is my first 4wd and really only just started going out bush to so you prob see a bit more of me in here ;D

Thanks for all your help again

[Twisty]

Thats not too bad a price.....I would get a quote to run a twin system for before the cat as well, as described below.

At the moment the drivers side exhuast manifold runs around the back of the motor and has a head on with the passengers side exhuast manifold. Then all the exhuast gases exit from the middle of the passenger side exhuast manifold.

This setup if very restrictive, and wouldn't cost much to fix, and will probably give you almost as much power gain as fitting extractrors.

Remove the pipe that wraps around the back of the motor, run a 2" pipe off the drivers side manifold down past the gearbox into a y piece then into your new cat. Do the same from the passenger side exhuast manifold and you'll be set.

I will get some pics tonight of what I'm talking about so you can see what I mean. Its deffinetly worth doing.

[4runner_RV6]

cool cheers that will be great ;D

[Twisty]

Ok, heres some pics of my old V6 (3VZE) that is sitting on the garage floor now the V8 has gone in ;D make it easy to explain how poor the std. exhuast manifold is on V6 4Runners.

This is look at the rear of the V6, the bit that is closest to the firewall. You can see the drivers side (right) comes around the back of the motor then straight into the passenger side manifold (left).
http://www.4wdlinks.com.au/albums/album49/acb.sized.jpg

It the all exits from the bottom of the passenger side manifold, which you can kinda see in this pic. (the bump on the lower bit of the manifold.
http://www.4wdlinks.com.au/albums/album49/acc.sized.jpg

[Twisty]

And then do this....
http://www.4wdlinks.com.au/albums/album49/acd.sized.jpg

http://www.4wdlinks.com.au/albums/album49/ace.sized.jpg

It might cost a little bit more but it will give a big improvement. And will be a lot cheaper than installing extractors.

Whatever you do, it WILL sound ballsy afterwards, a mate of mine has a 2.5 inch system on his V6 4 Runner, and it sounds great :D

[4runner_RV6]

awesome thanks for that twisty ;D

Just another quick question for u twisty, did you have any probs with getting a mod cert for your 33inch tyres? or you have no mod cert? ;)

[stocksofar]

Twisty, how easy do you think that its gunan be to remove and blank off that crossover pipe while the donks still in place? Sounds like a drama and a half to me, still if its worth doing its worth doing right eh. What are you planning to do with the old donk?
Was yoru exhaust guy local Twisty? Local as in Venom or up the coast?


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quote author=twisty_toy94 link=board=5;threadid=6133;start=0#msg101684 date=1103237891]
And then do this....

[4runner_RV6]

Had the exhaust added today ;D sounds great and goes a bit better to.
You should have seen the old cat, all rusty and a metal plate was welded on to get cover some holes and to get it past road worthy, cheap pricks.....lol

[4runner_RV6]

oh yeah for the extractors he wants to charge me $1300 for them because he doesn't want to do them....lol
He just finished a set for a guy at arb and says if he ever has to do them on a 4runner again he will charge shivloads...lol

[Nemesis]

All that info dave, you legend ;)

I might do that twin system, save some $ over the extractors.

[Twisty]

It's not too bad to get the crossover pipe out, if you have bodylift it's a piece of cake, if you don't just unbolt the gearbox cross member and lower the cross member down letting the motor pivot backwards on the mounts. You'll then be able to get it out pretty easy. But bodylift is the way to go. Once you have the cross over pipe out just get a flange laser cut by someone which can be bolted onto the end of the manifold to blank it off. While welding the cast iron can be done, a lot of people wont do it.

The extractors aren't too bad to install, took me a day to get mine in. It's easiest if you remove all the studs and replace them with bolts, as the drivers side is a very tight fit.

All my exhaust work gets done at Red Roo (Carline) in Nambour. The guy (Scott) is a champ and used to own TJM on the Sunshine Coast, so he gives a decent discount for fellow 4x4ers.

My 33's aren't approved, and you can't get them approved in QLD. It sucks up here for all modifications, except engine swaps.

[4runner_RV6]

Bummer that sucks about the tyres, i have to do everything by the book :( because of the insurance, oh well still goes well :)

Thanks for the info ;D

[Twisty]

Hey Nem? you ended up doing this mod didn't you??