E30 Zone

whats the best keep it as a 2 pipe system or make it 2 into 1 ifso what bore size and with mid box in or straight through no box

i would stick with bm's design and make it 2 pipe personally..

Buy an Eisenmann. Your life will be better with it.

anyone

I don't have a highly modified 2.7 like you, I just have a fairly standard 2.3, so a bigger exhaust might be better for you but here is what I have anyway:

It's a 6 branch with two pipes (unkown size but smaller than 2 1/2 inch) back until about where the gear lever is (maybe just a little further back) and then it goes into a single 2 1/2 inch pipe and just after that there is one of those cylinder looking inline muffler things I think. Then there is another bigger muffler at the back. It is all mandrel bent.

http://www.members.westnet.com.au/astondg/Exhaust1.jpg

The red arrow is where 2 pipes become 1 and the blue arrow is the small cylinder muffler thing.

It is as close to a race type exhaust as I would want to go on a road car I think. It can drone a little bit at constant throttle but I don't find it bad. I am very happy with it. It has a fairly deep note, especially at idle. I can't compare it to a two pipe system, except the standard one and I am happy with this over standard.

Aston

Think the standard system makes it a 6-2 BUT with a crossover which is apparently very important for making torque. The cross happens in the first box if that's any help?

i have a 6 branch which with a crossover but im not suro which is the best with centre box or not or 2 or 1 pipe system

well if u need a cross over for torque then surely u need a 2 pipe system mate.

I know the bore size on a 318iS exhaust flows more than the 325i system. So if the 318is had a 2 pipe system with the same bore size as a 325 system it would of been restrictive for it.

So i'm now thinking 3 to 1 times 2 fromt the manifold x pipe flange and 2 pipes into front of the centre box, then after the centre box a big single pipe to the back box and a 7inch tail pipe tight?

I can't say how much power I gained (or even lost) with my exhaust because I got the 4.1 LSD put on at the same time so that made a bigger difference. I don't think I lost any torque though, it doesn't pull any worse any where (from idle to the redline).

Aston

i had a new system made up from 2.5" stainless steel, there wasnt enough ground clearance to make a single big bore system, especially at the rear axle, so had to go for a slightly smaller bore but keeping the original 2 pipe design, i had the mid box removed and have just one large silencer at the rear,my downpipe from the manifold is a single 3" pipe connected to a y -piece at the bulkhead , but thats only because im running a from a turbo, its loud but its a deep rumble,not like a boy racer exhaust!! cost me Ԛ£430 to have it made at an exhaust specialist, but i think it was worth it

fuzzy wrote:i had a new system made up from 2.5" stainless steel, there wasnt enough ground clearance to make a single big bore system, especially at the rear axle, so had to go for a slightly smaller bore but keeping the original 2 pipe design

I didn't think about that. My car isn't much lower than standard so it has enough clearance for 2.5" although the exhaust does scrape sometimes, I have to take it easy in car parks and stuff.

Aston

That blue thingmo is a hotdog.

I'm thinking BTB into 2 slim cats (need them in Aus or the Pigs bend you over) along into Eisenmann centre and back box. If thats too loud I'll be slipping some hotdogs in behind the cats.

I'm aiming to build a similar donk to Player...will be interesting...