E30 Zone

what is the downsides of bigbore exhaust on a bmw e30

small cats/rodents could crawl inside at night to sleep and be roasted/gassed to death when you start it up?

Well you'd look and sound like a complete prat.

And motorway journeys would be an assault on your hearing.

My scorpian is loverly for the first mile, then its tiresome and tedious.

doe's it increase fuel compsumtion?

low velocity exhaust ( low backpressure ) cause very bad low rpm driving
while it helps at higher rpms, although a stock 325i exhaust is very capable.

scotttollan wrote:doe's it increase fuel compsumtion?

Might do but more likely it won't really do anything. Apart from make you look like a corsa kid and a chav. And make your ears bleed.

Youve got a proper engine with the correct quota off pots....leave it standard.

where can i get the stock twin pipe exhaust from and how much are they?

thanks

Dustbin FTW!

lol

no honest were can i get one and how much does it cost?

Stick a post up in the parts wanted section, someone might have one.

Strange as it may seem, BMW sell them! Cheaper alternative is OEM stuff from GSF or ECP.

what ID is the stock dual from catback on m20b25? What about an Alpina?

I have a dual 2.25" from the BTB back but its too large and a bit annoying/drony at low rpms below 1750rpm or so. I have been looking at getting something that suits the BTB secondaries a little closer perhaps dual 2" with something besides the hotdog resonators which don't seem to do much for quieting. I wish the exhaust people didn't throw out my entire (from head back) good condition exhaust what a waste

Alpina 2.7 system is "big bore" 50mm piping is internally different silencers and is about the only M20 performance that will gain power. Sounds sh!t hot too, like a standard system with big balls, really meaty

Standard 2.5 system is very good, these have 44mm bore piping

So in answer to question yes there is but they are £1300

apart from mine it's not a alpina it's just says bmw