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Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 12:11 am
by Andy325i
What exhausts (S/S of course) gives the best gains powerwise for the M20B25?
Does anyone know if milltek make one for the above? (can't see it on their website)
Is this a good price?
http://cgi.ebay.co.uk/SCORPION-Full-Sys ... dZViewItem
Many thanks
Andy
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 12:18 am
by Ant
Oe is "the best" thers a few HP to be gained from the zaust but TBH I'd prefer a good fitting item over anything else.
The tonal quality of stainless is a little tinnier( is that a word ?? ) than the OE mild but still
how loud would you want it ?
Scorpion fit great , as does the sebring , avoid the Mongoose, it fits terrible
Evolve have a few options listed on their site, might be worth a browse...
Re E34 bits
Posted: Sat Oct 27, 2007 12:25 am
by elebub
Andy325i
PM'd you re E34 bits
Andy
Re: Re E34 bits
Posted: Sat Oct 27, 2007 8:55 am
by aceraf
That's a good price, but it's not a complete system though is it? I thought the scorpion full system had the opion of downpipe aswell, so that would be a complete system!
Also, does de-catting these car's make much impact on performance??? I've had past experience of cars responding very well to de-cats (obviously a friendly MOT station would be required).
Re: Re E34 bits
Posted: Sat Oct 27, 2007 10:57 am
by Brianmoooore
aceraf wrote:Also, does de-catting these car's make much impact on performance??? I've had past experience of cars responding very well to de-cats (obviously a friendly MOT station would be required).
I think the main improvement is in fuel consumption rather than power. Can't be many UK 325s that are required to have cats.
Re: Re E34 bits
Posted: Sat Oct 27, 2007 11:07 am
by wildeian
I have an Ernst Sports exhaust on my Touring.
It's nice and subtle around town, but has a nice roar when you floor it!

Re: Re E34 bits
Posted: Sat Oct 27, 2007 12:01 pm
by aceraf
Brianmoooore wrote:aceraf wrote:Also, does de-catting these car's make much impact on performance??? I've had past experience of cars responding very well to de-cats (obviously a friendly MOT station would be required).
I think the main improvement is in fuel consumption rather than power. Can't be many UK 325s that are required to have cats.
Mine is a 1988, can i get away with it?
Re: Re E34 bits
Posted: Sat Oct 27, 2007 12:06 pm
by StuBeeDoo
aceraf wrote:Mine is a 1988, can i get away with it?
Has it definitely got a cat then??
Re: Re E34 bits
Posted: Sat Oct 27, 2007 12:09 pm
by aceraf
StuBeeDoo wrote:aceraf wrote:Mine is a 1988, can i get away with it?
Has it definitely got a cat then??

never checked!
will check and report back
Re: Re E34 bits
Posted: Sat Oct 27, 2007 12:20 pm
by StuBeeDoo
aceraf wrote:StuBeeDoo wrote:aceraf wrote:Mine is a 1988, can i get away with it?
Has it definitely got a cat then??

never checked!
will check and report back
TBH, I'd be very surprised on a 1988 UK spec. car.
Re: Re E34 bits
Posted: Sat Oct 27, 2007 1:31 pm
by AlpineAde
The difference in power between a 325i with a cat and one without is 1 bhp.
At least that is what it says in my owners manual.
Re: Re E34 bits
Posted: Sat Oct 27, 2007 1:47 pm
by Brianmoooore
Aceraf - Your car is cat prepared, but highly unlikely to have one if it's a UK car.
Feel under the front battery tray for a socket that's clipped to the underside. If there's a plug connected into this with a wire going on, then you have a lambda sensor, and should have a cat.
Just a blanking cap, and you don't have a cat.
Re: Re E34 bits
Posted: Sat Oct 27, 2007 2:36 pm
by aceraf
Brianmoooore wrote:Aceraf - Your car is cat prepared, but highly unlikely to have one if it's a UK car.
Feel under the front battery tray for a socket that's clipped to the underside. If there's a plug connected into this with a wire going on, then you have a lambda sensor, and should have a cat.
Just a blanking cap, and you don't have a cat.
thanks, will have a look.
Posted: Sat Oct 27, 2007 7:33 pm
by BMracing
Any vehicle before September 1992 (up to and including J plate) does not legally require a cat, even if it has one fitted.
Re:
Posted: Sat Oct 27, 2007 7:36 pm
by aceraf
Any vehicle before September 1992 (up to and including J plate) does not legally require a cat, even if it has one fitted.
Thought it was something like that.
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 8:11 pm
by Andy325i
Ant wrote:Oe is "the best" thers a few HP to be gained from the zaust but TBH I'd prefer a good fitting item over anything else.
The tonal quality of stainless is a little tinnier( is that a word ?? ) than the OE mild but still
how loud would you want it ?
Thanx for the input Ant, the current exhaust is a Jetex system (non S/S) and has been on there about 14 years and getting very due for replacement

I really don't want to go back to O.E. for longitivity reasons.
As for noise , I had a scorpion half system on my old 325i and had the center box removed when it started to rattle. This was virtually the same on idle as before, but got nice and throaty when given a good amount of right foot, without being ott
Andy
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 9:19 pm
by Brianmoooore
The life of an OE E30 exhaust system is normally around 14 years or so. There are plenty of E30s around still with the exhaust they left the factory with!
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 9:28 pm
by Andy325i
Good point, but I wouldn't have a case if I went back to the dealer after 3 or 4 years if there was a problem and I imagine it would be simular in cost to a S/S system and iirc most have a lifetime guaranty

If I have anything to do with it I will still have the car in 14 years
Andy
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 9:31 pm
by Cabrio
some good stainless items are available and should last even longer and look better if include with manifold etc....E30 centre have a great system...not cheap but depends if plan to keep car etc
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 9:34 pm
by Brianmoooore
You'll probably find that the 'lifetime warranty' requires annual inspections to be made (at your expense), and has so many get out clauses as to be worthless.
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 9:38 pm
by aceraf
be careful what grade os SS it is aswell...i've had zausts done in the past that use the lowest grade SS they can get away with!
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 10:27 pm
by Cabrio
Best grade is T304 thats what E30Centre have on theres and no checks required and no charges to check if asked for...so just need to compare prices etc...if made correctly and not silly money cant understand concerns really
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 10:29 pm
by Andy325i
Cheers

What is this E30 center you talk of?
Andy
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 10:31 pm
by Cabrio
They are in Wolverhampton just off J9 M6...specialise in all things E30...break them and build race cars...owners are brothers and close friends of Nigel Moseley
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 10:33 pm
by Andy325i
and they build S/S from scrach I am guessing?
Do you have any contact details for them?
Many thanks
Andy
Re: Best exhaust for M20B25 1992?
Posted: Sat Oct 27, 2007 10:36 pm
by Cabrio
They have them manufactured yes...they have agreed the deal with me but if want other stuff will be happy to forward you details...sure they are listed on hear by other people...send me pm