Just wondering if anyone has any info / experience with this system. I am interested but remember reading somewhere a while ago that it did not fit properly.

Thanks

Seann

 

I read on their site that this was intended only for the twurbo and other high pressure Minis.

 

3" for a I4?????

Christ, thats too big.

 

it should be great on tced cars

 

We've seen this big before, if I remember correctly it works pretty good. Superchargers change the rules

Nik

 

3" is great for performance. But in most cases it will be LOUD. That is probably why they are recommending TC cars to use it. But, if your hearing has gone bad already from fast cars, fast women, and rock music, you won't mind the extra dbs .

-Brian

 

I would think they are recommending it for TC cars because the TC creates some backpressure in the exhaust system since it is powered by the exhaust. That and the extra air being forced out. Superchargers don't create backpressure, obviously. I don't know the specific engineering, but I know that without enough backpressure engines can actually make less power than with some backpressure.

 

Today class we shall learn about turbochargers and how lack of back pressure quickens spool up.

 

That too.

 

Cool science lessons fellas.....but can anyone answer the questions I posted?
What is the quality and fitment of this exhaust? Anyone?

Seann

 

That statement is untrue.

 

"I know that without enough backpressure engines can actually make less power than with some backpressure."

That statement is untrue.

 

I remember reading that somewhere, but I could remember wrong.

According to this link, that statement does hold some validity.

http://www.warnertechnology.com/Cars/backpressure.shtml

 

The link references 944s. Ask any PCA-CRer, if you want to be competitive on the track with one you best have a Stahl system!

 

That is refering to a N/A motor.

-Brian

 

...and it's wrong.

 

My original statement was meant as a broad statement, not specific to MINIs.

 

Can you explain why? I'm just trying to figure things out.

 

I was under the impression back pressure in the header was good for torque on N/A cars. Is this wrong? Can you point me to a place that will explain why? I am curious as well.

-Brian

 

Basically what I've found out from a short Google search is that you want to size the exhaust so that it doesn't lose too much heat as the air travels out, with the reasoning being that cold air is denser and harder to move than hot air. That being said, you don't want the exhaust to be too restrictive. There's a happy medium in there somewhere, supposedly.

 

You do not have to take my word for it. My suggestion is to read Internal Combustion Engine Fundamentals by John Heywood. Everything you thought you like to know or even try is most likely presented in The Book.

 

I don't think my library has a copy of it.

 

Wow, pricey book. Time to find a library

 

I keep linking folks to this thread on NAM and no one has told me it's full if &hit yet.....

 

"Some self-proclaimed engine gurus claim too large of an exhaust tube on a car can cause problems; engines need a certain amount of backpressure to run correctly. Although the statement about not running too large of a tube is correct, the assumption about engines needing backpressure is not. A vehicle needs the lowest backpressure possible to produce the maximum power by keeping pumping losses low. Too big of an exhaust pipe causes power loss, especially in low-end torque, because a big pipe has less exhaust stream velocity than a smaller pipe."

That's basically what I've been reading elsewhere.