m20b23 with modifications

Fri Dec 02, 2011 8:35 pm

just an idea

if i fitted a m20b23 with the following mods what sort of performance should i achive

M20b23 Engine with 320i Gearbox
3.91 Diff
Motronic 1.3 with remapped ecu
M20b25 Throttle body and inlet manifold
6 Branch and 325i exhaust system

Would you achive around 150bhp?

would it be a pretty decent drive?

Fri Dec 02, 2011 8:48 pm

I thought 323i were already 150bhp?

Fri Dec 02, 2011 8:50 pm

i thought 139 bhp :S

Fri Dec 02, 2011 8:54 pm

i had an old 323i and when i looked for figures the earlier ones had less with the latter ones having 150

it was definitely alot torquier than my 320i due to the longer stroke, longer than a 325i if my memory is correct

Fri Dec 02, 2011 8:56 pm

ah yes, Its come back to me didnt the Y reg ones have less then they fitted a better cam or something

Fri Dec 02, 2011 8:57 pm

Going from E30 Restoration bible, we're both right...

ENGINE: As for pre 1988 320i with LE Jetronic but stroke 77mm. Compression 9.8:1, power 139bhp at 5300rpm and torchue 151 lb/ft at 4000rpm. 1984 onwards models 150bhp at 6000rpm, torque unchanged.

So with the above you mentioned, you should have a pretty nippy little beast on your hands.

Fri Dec 02, 2011 8:58 pm

the modified insurance will be alot cheaper with 150bhp, should get away with the b25 manifold and later engine managment

plus i think they had 3.45 diffs or something so with a 3.91 should be nippy enough

be different and have a 323i badged touring

wonder if 160bhp would be easy to achive then with the above providing i get a decent engine thats had a good service, dissy cap, rotor arm blah blah blah

Fri Dec 02, 2011 9:22 pm

I have a 323i i will be breaking at somepoint in the near future

Is an auto so would have had an easier life and (albeit 10years ago) i have reciepts for a head and bottom end rebuild

Anyone ever done a Motronic 1.3 upgrade on a 323i?

Fri Dec 02, 2011 9:30 pm

Not sure, i recon you could make one pretty decent.

If i was insane i could fit a btb3, high lift cam with the above spec and probably be near 325i performance (160 bhp ish), assuming its still kicking out around 145bhp ish i know people will now say stick a 325i to start with but why not be different

DO they sound like 320i's as you cant beat one of them when there getting tortured

Tue Dec 13, 2011 2:11 pm

Kedge wrote:Anyone ever done a Motronic 1.3 upgrade on a 323i?

Yes,

Can't remember their name but I think they ended up melting a piston due to fueling/timing issues

Tue Dec 13, 2011 2:27 pm

Alex wrote: i know people will now say stick a 325i to start with but why not be different

Because you're spending time, money and effort, adding a lot of 325 bits, producing an engine that'll look like a tuned 325, but still be hard pushed to keep up with a bog standard one.
But it's your time, money and effort!

Fri Dec 16, 2011 4:01 pm

hennared323i wrote:
Kedge wrote:Anyone ever done a Motronic 1.3 upgrade on a 323i?
Yes,

Can't remember their name but I think they ended up melting a piston due to fueling/timing issues

http://www.e30zone.net/modules.php?name ... hlight=323

Thu Dec 22, 2011 9:48 am

i have to agree with Brian, if you are going to fit a different engine you might aswell pick the best one to fit....the starting point is a whole lot better

Tue Jan 03, 2012 11:42 pm

would a 2l m50 not be a far better prospect?

or an m52 from a 323?

trouble is you would be breaking into uncharted territory doing that to a m20b23, which is all well and good but its never cheap.
you can also expect shite fuel consumption for the same power as the 2l m50 or 1.9 m44.