manifold advice? - Page 2

HiImBrian · 11-26-2007

Quote:

Originally Posted by ecoli

You want a big manifold or a big turbo? Bigger and longer runners make spoolup worse.

I meant big ports sorry.

**JET** · 11-26-2007

Yep, you want the smallest manifold available to help spoolup.

**Shane@DBPerformance** · 11-26-2007

Big ports/runners usually equal more lag. Most of the weld-el manifolds out there have bigger inner diameter runners than the outer diameter of the manifold that I had on my car when it 700whp. I have seen some Honda eBay turbo manifolds lately that have runners that are much bigger than the weld-el manifolds, they look like they were made to support 2000whp, but are normally found on 250whp cars. In general, anything before the turbo or after the turbo that is bigger will give less lag, like bigger downpipe/exhaust and bigger air intake pipe and filter. While anything made bigger in the loop from the turbo back to the turbo, will give more lag, like FMIC, intake manifold, ported head, aftermarket intake manifold, etc(except for displacement). I have seen 1000RPM quicker spool on a car from going from a fancy longer runner topmount turbo manifold top to a non-equal length shorties manifold and topend power wasn't any different.

HiImBrian · 11-26-2007

So shane, are you saying that smaller ports would increase spool up???

**JET** · 11-26-2007

Quote:

Originally Posted by Mr.98GSX

So shane, are you saying that smaller ports would increase spool up???

What "ports" are you referring to? I think you mean runners in the exhaust manifold. Smaller runners will spool a turbo quicker, larger runners will take longer to spool. Just like Shane said, increasing the size of anything between the compressor housing and turbine housing will increase lag.

HiImBrian · 11-27-2007

Yea sorry, runners is what I meant. So if bigger runners adds lag why do people ever upgrade manis if it just makes their turbo more laggy? Last time I checked laggy turbos suck teh balls. I read that other guys thread about a 1g mani with his 14b and that made some sense.

What I got from it was basically, you want an exhaust mani thats big enough to keep up with the turbo up top, and small enough to spool up down low.

**JET** · 11-27-2007

Yes, you are right. A stock runner sized manifold is going to create a restriction on a large turbo. FWIW, I am running a ported 2g manifold on my car.

HiImBrian · 11-27-2007

Fwiw=?

**JET** · 11-27-2007

Quote:

Originally Posted by Mr.98GSX

Fwiw=?

For What It's Worth. Basically I made 450 whp at 25 psi on mine, if you are not planning on making more power than that, then I wouldn't worry about upgrading past a 2g manifold. If you are planning on going to a full garrett, then that is a different story.

**Kracka** · 11-27-2007

Get a ported EVOIII exhaust manifold. It won't crack and they are available for decent prices.

**Shane@DBPerformance** · 11-27-2007

Most people goto upgraded manifolds because they want to mount a non-mitsu turbo, or they want to be blingin, or they want to run an external wastegate, or they want to try to get more topend power. Pretty much in that order. If it wasn't for the power of bling without regard for spoolup or cracking then DNP wouldn't still be in business.

HiImBrian · 11-27-2007

kracka i like the EvoIIIs but is the design really that much better than the 2gs? Or I guess, whats the main difference? The big thing I like is I'm running an evoIII head with a lightly ported intake mani to match the head and if I could get an evoIII exhaust mani and have that perfect match all the way through I think that'd be best. My only thing is whats the main diff between the 2g and evoIII mani?

And thanks shane, I love how you always chime into my simple threads and actually explain how and why something is. Hell I'll admit I thought a shorter, yet bigger runner would increase spool up because there would be no restriction. But I totally disregarded the fact that force is what really spins the turbine. The sad thing is, I know a ton of people that would think to get a tubular because year they are ballin and they just look more efficient. Thanks guys

And we all know it takes more force to scew a 5 year old than it does to scew a porn star right. haha just kidding...

..but seriously LOL

HiImBrian · 11-27-2007

^Sweet thanks. That really helps. I think I'm going to keep an eye out for an evoIII mani just to keep everything equal throughout. I remember reading something about this a while back that it's good to keep everything the same size. If mitsu made it that way to start out with it was probably for a good reson.

**JET** · 11-27-2007

I think the only difference between a 2g and EvoIII manifold is that the evo III already has a 7cm opening for the turbo, the rest is the same. If the 2g one is ported, then it should be the same.