BC

I have played around quite a bit with the newer versions of EAP (Engine Analyzer Pro). I have many of the most realistic info in the engine parameters inputs as possible, with the help of Louie and Todd.

With the stock configuration of the hard parts of the long block, and changing some cam info, as well as the intake and exhaust info, I have found a few things:

1) The intake manifold is very difficult to give the computer the proper info - garbage in, garbage out with this sort of thing, so I have been very careful to at least err on the side of caution.

2) Retarding or advancing the cams makes quite a bit of difference on the exhaust system needs/requirements in the software - meaning you can see very large increases in combustion pressures and total degrees of heat depending on those advance/retard numbers on the cam - and this makes differences in what you will see with the output from different exhaust characteristics.

3) Connected to that, when you are forcing huge amounts of air mass through this engine, (as I am sure with any other) - the exhaust parameters can greatly change the peak and overall power numbers. It may seem obvious, but what I see is that a very short 2" ID exhaust (seems almost impossible to fit) manifold/header assembly would be the least restrictive - AND it makes little difference on toque numbers below 4500 and above 2500.

For this reason, I have thought recently about making exhaust headers that would be based on the total footprint of the normal S4 exhaust manifold - meaning VERY short, but with larger piping.

4) The intake manifold's parameters affect the power numbers in the power band obviously, but in a contrast to the exhaust - the intake greatly affects the numbers below 4500 when you are off-course so-to-speak.


This all said, I am talking about an engine that is seeing 28psi of peak boost from a centrifugal SC. Adding a turbo as Todd has done changes... about everything.

BC

I start so many threads that just... Go nowhere.

KenRudd

Add pictures. For those of us that get confused by big words.

hacker-pschorr

In the early days of Todd playing with EAP with the red car he talked about doing this. I cannot remember why he decided to not go that route.

BC

Because the normal headers are essentially that already, though smaller.

hacker-pschorr

I know, he was planning on a set that would have looked almost identical to the stock ones, just everything increased by X amount.

I was pushing him to develop a set knowing they would fit my car with different flanges

BC

Because its a smallish project, and much less work that trying to fit a larger set of long-tube headers, I may try this. I acquired an S4 manifold set, and may try and jig something up in thick steal to see if I can make something.