I know that Javad is putting out a lot of power through the 3B intake manifold, but I also know it has to be a restriction. In the light of scaling down the budget on my 4KQ 20V project, I would like to know if doing something about the intake is worth the while.

To start, my desired output will be adjusted to about 400. This will allow me to use the manifold and turbo I am getting from James--thereby saving about $1300 off the bat compared to what a manifold and turbo would have cost new.

At 400 HP, is the 3B intake a significant enough restriction to be worth addressing? I have considered using 16V intake runners that I could cut to the desired length and weld onto a plenum. I could also just build the whole manifold from scratch using stainless or mild steel and some injector seats. If I were to go this route, does anybody know where I can get velocity stacks? Or are those not worth the money?

The turbo will be a 3ldz, and from what I am told, 400HP would have it breathing pretty hard. Is it worth doing something about the intake manifold in order to make thr work easier for the turbo?

i don't think that changing the IM is necessarily going to affect the way the the turbo performs in that sense. it may provide more flow, but if the turbo's out of it's range, then the IM won't affect it.

I'm very confident that at "only" 400 crank HP, the 3B is no restriction at all, even now at almost 500 wheel HP (closer to 600 crank), its posing very little restriction, but I'd love to test it.

The easiest way to improve it would be to drill out the allen bosses that run through the plenum and weld up the holes, I'd love to test this mod soon.

Intake mods like the ones talked of above have been done to cars on the S2Forum (S2forum.com). Although I am sure there are some benefits, one fanatical modder changed his Exhaust manifold (Header?) and said it was the best mod he ever carried out. He said ' although the car was always fast it never really felt it..... now it is mad'.
Chris

Good idear! For a long time, I have been considering sawing off the plenum of the 3B and making a tubular plenum with a front-facing TB. That, along with cleaning up the allen bosses, should be just fine.

Derek,

I agree that if the turbo is out of its range there is nothing I can do to change that. What I was getting at was that by eliminating intake manifold restrictions, I could allow more boost to "reach" the intake by easing a bottleneck--eliminating backpressure between the compressor and the IM. I wanted the turbo to be able to reach its full limit instead of being stopped short of its limit due to restriction.

I just can't let myself dump the kind of money into this 4KQ that I had once planned, so I want to look for every little affordable trick I can do. I believe that, at 400HP, I can built a nice, low-stress, 2.6L 20V that should make excellent long-term power. I know that at that power level, the Eurovan parts are by no means necessary. But it's a street engine, so displacement would be nice. Plus, I'd like to see what the big bottom end will do to the torque and the shape of the horsepower curve. It should make a much more usable street engine, I think.