>From what i have read about performance headers, the early headers and the
cast iron manifold are equal in perofrmance. In the latest issue of the
"Horn" from the SAOC, Geoffry states that the cast iron is actually better
in performance than the early headers.
Reading David Vizards books, "How to Unleash HP", he discusses various
designs, and the early series headers would fall into the "Bad" catagory.
Any header setup that would be used on an Alpine would have to be custom
made. Using his information, a custom tri-y header for the Alpine should
connect the #1 & #2 cylinder, and the #3 , then collect them further
back. A better design would be just 4 pipes collected into one.
Sports Car Graphics Project Sunbeam car used the stock Alpine headers and
Doanne Spencer thought they were pretty trick. He tried various
modifacations to the exhaust and he outlined where they developed their
power, meaning some of them worked pretty good at low RPMs, but pooped out
above 6000. Others had lots of high end HP, but lost a lot of power in the
lower RPM. Jerry Titus even tells how much horsepower was lost or gained
with each exhaust system. The best configuration they found was a 1 3/4"
pipe, 84" long with the stock headers. This gained 2 HP over all of the
other combos in all of the ranges. This was also confirmed to me independent
of this article by Fritz Lindbeck who uses a 1725, early headers, with the 1
3/4" 84" tailpipe.
All things considered, I am going to make my own tri-y headers when
the time comes. No matter what I do, they still have to be better than the
early series type, and if they are not better, then equal. lou
----- Original Message -----
From: <MrZAG57@aol.com>
To: <servaij@cris.com>; <alpines@autox.team.net>
Sent: Sunday, March 18, 2001 1:03 PM
Subject: Re: Exhaust header theory
> In a message dated 3/18/2001 9:09:32 AM, servaij@cris.com writes:
>
> << If anyone is interested, I found this info that might be helpful to our
> Alpine street racers.
> Jan >>
>
> Hey Jan,
>
> Does anyone offer a competition header for the Alpine engine? I have tried
> several different early series headers on the race car. They each have
been
> modified at the collector "Y" and then use various lengths and diameters
of
> pipe. #1 is a pipe that bends at two 45* angles towards the driver's side
and
> extends to just behind the door and then a 45* with a bologna slice tip.
#2
> pipe leaves the stock "Y" pipe collar but has had a larger diameter pipe
> welded on and this follows the stock layout to the rear of the car and
ends
> in a megaphone extractor. #3 is a pipe that has the larger diameter pipe
> comes back through the "X" frame and then crosses over to the passenger
side
> and exits just infront of the rear wheel in a balogna slice.
>
> My experience with the three variants have been: #1 Sounds Mean and seems
> whimmpy. #2 Sounds Loud as the Hammers of Hell and seems to pull better
below
> 4000 rpms. #3 Sounds OK, but seems to have a flat sensation. It breathes
fine
> at top and doesn't seem to lose anything on bottom.
>
> All of them use the STOCK head pipes themselves though. Reading your
reprint,
> it seems as if the most critical mass of exhaust gas would be that mass
> contained in the individual header pipe before they go from 4 down to 2.
>
> BUT, I am sure I am wrong.
>
> I don't KNOW anything. ( Remember?)
>
> ZAG
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