Exhaust Construction

[Warren]

With a tight budget the self build exhaust is on the cards and I need more info.

I have seen Vince's "how to build headers" and I am happy to have a go but I am lacking detail regarding sidepipe construction. If I am way off in my assumptions then please put me right.

The external bore, it would appear, can be 4 or 5 inch diameter depending on preference and I assume the internal pipe would be 1.5 inch smaller in diameter or should it be more? What effects does this have on performance, for example a 4" side pipe with an internal diameter pipe of 2.5" be at a disadvantage over a 5" pipe with a 3.5" internal and is one harder than the other to bring within decibel reasonable levels.

I am assuming the internal pipe would be straight through and drilled along its length, the packing then sits between the outside of the inner and the inside of the outer. How many holes are we talking about and typical size/frequency?

How many baffles and where do they go? I assume you would sleeve the side pipe join to the exit bend and sleeve again to the collector if going for a single pipe collector. Or use the familiar cone to gather a quad collector? Either way, does the collector reduce again to the inner pipe or simply butt up to the outer, (see my dodgy attached drawing).

How do you combat the movement of the engine, sleeved joint? All suggestions welcome. Equally if there is a book on the subject then point me at it.

Warren

[Warren]

I must say I am suprised at the lack of responses, I thought there were more DIY exhaust builders out there. I did a little shopping around today and a 20 foot length of 4 inch stainless tube (316, the good stuff) retails at £120. 1.5 inch 90 degree bend (316 again) at £5 a time.

I realise that knowledge should have a price but not all builders can afford to shell out the sort of sums required for a 316 stainless sidepipe system and I thought there might be more people that had done it themselves. If you would be happy with 304 the stuff is even cheaper!!!

Those of you that have re-packed an existing system...can you provide any useful knowledge, for example, if you have a 4 inch side pipe, what was the internal bore of the rolled mesh? Did you empty the silencer an botice position of baffles etc.

Any help for us church mice amongst us would be appreciated I am sure. If you are bored with the question and it has been covered in detail before then please point me at the link. Searching the forum has brought up some tit bits, but not the detail I have been looking for.

Cheers
Warren

PS Thanks for the info Dave & Mick

[kdavies3]

Hi Warren, I have a damaged Dax side pipe I can take some measurements from for you but i'm not at home til Thursday.

Kev Davies
Dax, 383ci Chevy Stroker, Tremec TKO
South Wales

[Warren]

Hi Kev

How did you manage that? Are you coming up to Elvington? I am due back down to Milford Haven again soon and will call in if I get chance. Would be really interested in the build of the Dax pipe, particularly internal/external bore sizes.

My welding is not up to the quad collector but I reckon I can manage the rest.

What is it they say, plagiarism is the sincerest form of flatulance....must get that spell checker sorted out!

Cheers
Warren

[nbracken]

Warren, drop Roger Williamson a note at the address below. He may be able to assist you. He is certainly a fabriacator and may help by doing the tricky bits you can't do and advising you on teh rest.

Roger@shinybitz.co.uk <r.williamson1@ntlworld.com>

[Jesus]

Hi Kev,

I do not know if this will help but in the page 51 of the March -April Summit catalogue there are some side pipes at a very low price, brand Patriot, this side exhaust came in 50", 60", 70" and 80", and the price for both side pipes including the installation hardware came from US$ 189.95 to US$ 205.95.

In my opinion for such low price probable do not worth to build it by yourself.

Jesus

[graham]

Warren, I made my own manifolds to quad collector with the custom chrome kit. Then they go through a 2" flexi joint then out into the 3.5 inch single chrome collector. pipes are custom chrome,

The manifolds are time consuming to make but now they're done and work fine. Nice and quiet for the test aswell.

Graham

[kdavies3]

hi Warren, I replaced it as part of a larger insurance claim recently (OOPS).
Yes I'll be at Elivington and on the track too if you want a ride.

Kev Davies
Dax, 383ci Chevy Stroker, Tremec TKO
South Wales

[mjculley]

Would it not be possibe to have a section on the site where plans / sketches etc of common items e.g. exhausts, fuel tanks etc could be posted it seems a shame to re-invent the wheel every time !!

[andyrich]

I made my own manifolds out of 304 stainless. I got custom chrome to supply a 4 inch quad collector with sleves fitted to each pipe, instead of once single conector. All i had to do then was weld up each branch of the manifold in turn up to each pipe of the collector slip a piece of pipe over each branch (acts as a sleve)and it locates into the collector one branch at a time. Its a bit of a pig to remove as u have to do it in sequence but it seals great and have had no problems with it. I also used single flanges to mate up to the engine which i got cut for me by a local firm for £20 using a gasket as a template.
It cuts out the need for trying to group all four brances together and can be fabricated easily by anyone.
As for cost the manifolds were £150 for pipe and bends just a bit of cutting to do. I hired a bottle of agron for a month and used a mig welder with stainless wire. Iv never welded before but with a bit of practice and thought was no problem. Just make sure u cover up as i got some real bad sun burn the first time i tried.
I did all this after the engine and body were fitted but they look great.
Hope this was of some use
andy rich