wrenchtech

Time for a new exhaust system. Is there anything to be gained from work done on the exhaust from the crossover pipe to the tail pipe? I'm new to the 3vze motor, but I've heard that you have to spend about $4000 to get a 25 hp bump So probably just as good to have the corner muffler shop replace it with a stock tube size, right? -- Matt

91diesel

I'd either go with headers (what I did) or I've heard of people getting a muffler shop to fab up a dual down pipe set up from both heads that mix below the motor. Either way you will gain a much better flow and reduced heat on the HGs.

wrenchtech

I think headers are more than I want to invest in this motor, but the dual downpipe might be worth a try. The motor has got 180k miles on the clock and had a recent HG replacement. I think I should prepare for a 5vzfe (3.4 V6) motor swap instead of sinking money into this motor. -- Matt

Jay351

If you are planning the 5vzfe swap, don't bother with the 3.0 mods. Save up your money.

If you DO want to upgrade the exhaust, a custom x-over and 2 1/4" exhaust will free up some power. Perhaps around 5 rwhp.

wrenchtech

I am interested in learning more about the custom cross-over. Any write-ups to be found on that subject? It strikes me that it would be kind of like collectors on a header, i.e., the length of the pipes may matter, in that they would probably be optimum if they were equal length. Also the diameter would need to be right too. -- Matt

wrenchtech

I am completely new to the 3.0 motor, so I'd like to try a few low cost mods just to get some experience with it. A guy over on 4x4wire Toyota forum is building a revised crossover exhaust for his 3.0 truck right now. So far this is a low buck project for him. Since I need a new exhaust for my 4runner anyway I think I should give it a try.

As far as the main exhaust diameter goes, I'm running a 2 1/4" system on my 22RE pickup and I'm very happy with that. Is 2 1/4 a good size for the 3.0 or would 2 1/2 be better? Low and mid range torque are more important than power than top end, maybe 2 1/4 gives a needed level of back pressure to keep the low end power. -- Matt

Jay351

The 3vze comes stock with a 2 1/8" exhaust pipe size. I have found that a 2 1/4" exhaust is about as big as you want to go on the 3vze before you start to lose low end power (which this engine needs).

2 1/2" is just too big

krb90

Yeah...that would be me. I've had some other things to deal with the past week or so, but I've got the piece made and I'm now waiting on my heads to get back from the machine shop. I'll put up pics here too when I can. Lots of stuff in a mess right now (truck, me, other people, etc). But it's basically cutting the drivers side flange off the stock crossover back a few inches, and turning it down to the exhaust pipe instead of how it turns horizontal into the manifold. About a 16" or so pipe. Staying with stock exhaust the rest of the way....this is going on a 2wd, no lift, so it should work no matter what your setup is. But I will say that it would be hard to do without removing alot of the top end to get to anything. Wish me luck, and hopefully this weekend I'll be putting it together.

Greg_Canada

I have stock downpipe that necks up to 2.5" right before the o2 sensor and a full 2.5" exhaust from cat back and i have great low end torque and it pulls fine up top. i can accelerate from 1000 rpm no problem... but it cruises great above 1500rpm.... i'd tell anyone to do it...