3.6 header system - opinions wanted! - pic

[Craig 930 RS]

VERY short primaries - almost like a 996 header - very different from what I am used to with 3.6 header/exhaust systems.

Does this "make sense"? Any educated guesses?

[Craig 930 RS]

Got pic to load:

[Joe Bob]

They look equal length...does the maker have any dyno time with them?

[Craig 930 RS]

He does. GHL said to the owner of this system that he did use a dyno to test & develop them -

[Joe Bob]

Then what's the problem? Too pricey? Looks like less to rust....

[Craig 930 RS]

No 'problems', Mike.

See my original post which considers the theory of the design -- way different than any other air cooled header I've seen - ULTRA short primaries!

We want to see if this makes any sense before in$talling on a built up beast of a 3.6 -

[Joe Bob]

Well to answer your original question...no, never seen them that short. My 3.6 SC has the classic bag of snakes design header that I may remove one day and put custom heat exchangers back on. This winter has been a bit of a bear even in CA.

If the maker has good dyno numbers,....I don't see any reason to dispute them if he or the dyno operator has a good reputuation....

[poorb0yw]

Definitely goes against conventional N/A header design. Runners look like they belong on a turbo car. I don't see any benefit of going with such insanely short primaries.

The flat collector design looks pretty crappy and archaic. Nothing revolutionary there. In fact, I would say the stock heat exchanger design looks better in this area.

[Elombard]

Not much too them. Are they cheap? (nothing GHL is cheap....). I bet they are loud. Is that one of the reasons why rear engine cars are so loud -there exhaust sustems are so short?

[jluetjen]

They look equal length..

Not to me they don't, the center primary appears to be shorter then the others. That being said, equal length and short may not be worse then equal length and long. Depending on how it's done you can take advantage of the interference principle or the independance principle. A classic interference header design would be a 4-2-1 design on a 4 cylinder engine. An independance design would be the a 4-1 design or the classic early style 911 heat exchangers. Generally the interference design produces better performance in the mid-range (say 3000 RPM +/-) while independance design headers tend to work best in the range closer to peak HP engine speed.

Neither is "better" or "best", but rather a different horses for different courses kind of situation.

[Bill Verburg]

Does this "make sense"? Any educated guesses?

Froma fabrication point of view yes, they are easy to make.

From a performance point of view, no, you want long(~31") primaries in the power ranges a street/track car sees the most

You might as well use tock 993 headers and fan up some mufflers like Mike F. did.

[poorb0yw]

Bill expressed my thoughts exactly. Just more elegantly.

Originally posted by Elombard
Not much too them. Are they cheap? (nothing GHL is cheap....). I bet they are loud. Is that one of the reasons why rear engine cars are so loud -there exhaust sustems are so short?

Hope they are cheap. Thats all of $160 worth of stainless material including the flanges (in the header design). Maybe 5 hours design and build time into the original set. With proper jigs or dimensions I don't see it taking more than 2 hours to fab.

Out of curiosity, whats the asking price?

[Craig 930 RS]

Yeah, Bill & Princeton - I thought the same thing.

A buddy of mine bought these........and I wasn't too high on the design principle. They are spendy units - and built like a tank. You should see 'em in person - they put some serious work into these - thick, multiple, sections, beautifully made.

Just not sure about the design -
BUT they do have short primaries like the 993 units......that had me curious.....

[A Quiet Boom]

Bad idea IMHO.

Believe it or not a 5.8 liter engine is considered tiny in drag racing terms and the lack of torque (more than a 3.6) is ususally "fixed" with long tube equal length headers. Typical drag V8 runs 22-25" primarys, torque rules the street and most tracks of any kind. Headers are a great way of expanding any engines powerband. My old drag 410" V8 made more torque anywhere in the rpm band than a typical 911 motor and I ran 2" primary 23" L headers into 4.5" collectors. Longer primaries can extract torque from a small motor while giving up little in the way of max HP. Add to that that the collector design is seriously lacking and I'd say it's a bad deal. What we need is large tube SSI's or similar. I think those of us in the 911 hobby often get caught up with the idea that we can run "stock location" headers that mate up to conventional exhaust. Find a header with a long primary of decent size and find a muffler that will compliment them. To put my money where my mouth is I own a pair of Bursch headers but will be building my own custom set for my track car.