litch

I suppose my calculations were off, not surprising. I'm not looking for ultra efficiency, just the best I can get with easily accessible tubing and parts. My plans may Change (I'm 19), so that may be exactly what I want. Is there a way you can give me a number comparison between 1st, 2nd, and 3rd wave? Leon, what you wrote was good stuff, easy to understand. I'm just having trouble applying it to my goals, I suppose. R3VO, the exhaust manifold is going to be custom, and I'd like to make it top mount so I can easily access the turbo.

Oh, ok. I assumed that a longer runner would produce stronger waves, at a lower rpm. I can't remember where it was calculated, but something I read said it would be a first order harmonic (I can't remember what it's actually called) at around 4500 rpm. So, essentially there would be no benefit in such a thing, besides making room. I would assume that using itb's would eliminate the lag problem then?

Recently I've been thinking of a way to move the intake manifold so I can make room for a large turbo. My father suggested having the intake manifold make a wide 180 degree turn, and go over the top of the valve cover to the other side of the engine. I measured it out, and it seems like there would be clearance, but I'm not too sure on the specifications of things. The runners would end up being 26" inches long or so, not to mention making a large bend, but considering there are oem manifolds that are similar, I can't imagine it would be absolutely terrible. Can somebody explain to me what sort of effect a manifold like this would have, and how a bend in a runner would affect resonant waves? I think I have a basic grasp, but I'm not an engineer by any means.

Alright, this isn't really something I wanted to ask, but I will anyway. I'm converting to a turbo setup, and lacking a manifold, so in the spirit of diy I'm going to make one that hopefully makes getting to the turbo easier. To help me come up with some ideas of how to make it work, I'd like you to post some pictures of custom turbo manifolds you have, or have made for an L-series motor. Also, any advice, such as runner diameter, length, or tricks that you use would be appreciated. Thanks in advance.

So what, and where exactly can I get a device that bleeds boost? Im confused as to exactly what you are referring to.

We have a seat/guide machine. All the seats were cut and valves ground. They all tested good under vacuum. I've checked around the headgasket and didn't see anything.

I went out and tried that. Its only under load that it feels gutless, by the way, as if it bogs really bad as it starts going into positive pressure.

Smoothing out the short turn radius, and polishing the casting and the injector transition into the runner. It just seems the car is gutless with bad throttle response. I know I screwed up somewhere, just not sure where.

I wasn't quite sure where to put this, so do what you will with it. Anyway, I have an l28et with a p90a head. I blew a head gasket, and decided to do some minor port work while I had the head off. After putting it back together, it seems that the car does ok until 2000 rpm or so, and then it gets pretty gutless until about 4500. I read later that the ecu cannot compensate for head work and such. Could this be causing my problem? And help is appreciated.