L.A. Performance exaust set-up

[Eurolook71]

I just got a chance to really check out the LA-PERF website and was impressed with their j-tubes and header setup. Both are 1.75" which would be fine for a mild 1911 (right?). My only question is, can any turbo muffler bolt up to the header?? Thanks for any help.

[danielzink]

y only question is, can any turbo muffler bolt up to the header?

I'm using Lee's Jtube and header setup. I got one of Aircooled.net's Turbo muffler's. I had to cut the flange off the muffler where it bolts to the collector and spin it around and re-weld it. It fits fine now.

You can see some pics at: 65 GL bug down near the bottom of the page.

Dan

[kdanie]

1.75" primary pipes are very large for a 1911cc engine unless it is a high rpm screamer that makes 200hp. 1.5" primarys will support up to 150hp and give much better driveability. Primary dia. and length are the most critical elements of a header design, closely followed by collector dia. and length. Every VW header I have seen has too short of collector for optimum power.

Primary dia. is based on hp level of the engine, primary length dictates the rpm the header is tuned for. This is from 2 custom header builders that have been in business for 40+ years each and thousands of dyno tests.

ken

[Wally]

Ken,
What do you use yourself ?
Thanks,
Walter

[kdanie]

My engine is a mild 2.0L-125hp or so. I built a 1.5" header with 42" primary length and 2.25" collector to focus the power band from 3500-5000pm and still pull to the 6200 rpm redline.

Primary tube size is all about keeping the velocity up without causing restriction of flow....use the smallest tubes necessary to get the job done or you sacrafice performance.

I've been sucking up header design knowlege from every source I can find for the past 2 years and have managed to learn a lot but still thirst for more. I don't profess to be a header whiz but I have learned some amazing things from several people with a lot of design/fabrication/dyno time. I realized I made several mistakes in my youth when it comes to header choice and left signifiacant amounts of HP on the table because of those choices. Ed Henneman and Jerr Stahl have both been in business over 40 years designing/building/testing custom competition headers and are suprisingly free and open with information on what really works.

For comparison, with the 1.75" primary tubes Eurolook71 mentioned, a v8 engine would need to make about 450hp to take advantage of primarys that big. Whak that engine in half and you've got a 225hp 4 cyl.... not a bunch of those cruising the streets.

I have been compiling all the information from books, magazine articles, phone conversations (Ed loves to talk!) and websites into one place. I would like to write an article for a magazine to publish on header design and a second on header construction with some dyno testing thrown in.

Sorry for the long response but I truely love the science/art of header design,
ken

[Wally]

Thanks for the long reply: the more info the better for most of us!
But you must then like BAS his really stainless steal equal length header with 39mm inner diameter and all mandrel bent! Not a weld in there: you surely must appriciate that ? After all, 1,5" is about 38mm... After that the BAS is about 2" for damper circuit.
BTW I like the pictures of the type 4 headers very much of the site you gave us, bit I'am not too keen on the damper set-up I saw in the type 3 square: it was sticking out a lot!
Thanks,
Walter

[kdanie]

Walter,

I do like the BAS headers. They seem to be well designed and fabricated. I like the stub pipes used on the larger header. Stub pipes are the only way to go on a type 4, they add to the cost but make fitment and sealing easier. I don't know of anyone that imports BAS headers to the U.S. though.
ken

[vujade]

European Motorworks is a BAS distributor.

I know they sell the BAS 911 Kits, so Im they have the exhausts too.