Giving my 320i more ooomph?

Post Sun Sep 17, 2017 9:44 pm

Hi, looking to improve the performance of my 320i Auto Cabriolet.
I have the chance to get a 325i engine cheap, but it needs a rebuild. How much would it cost approx if I did it myself?
The other option is to change the throttle body on my 320i
for either a 325i one or a 64mm bored out one off eBay.
I would probably get a chip as well.

Any thoughts? Please don't say sell it and buy a 325i!
I already have one!

Post Sun Sep 17, 2017 9:52 pm

go the 325i route.
instant 170 hp.
new cambelt, gaskets, headbolts, waterpump, head skim, coolant and oil would be 300.

2 weekends work, happy to help as we are local to each other

Post Sun Sep 17, 2017 10:13 pm

mark_i wrote:go the 325i route.
instant 170 hp.
new cambelt, gaskets, headbolts, waterpump, head skim, coolant and oil would be 300.

2 weekends work, happy to help as we are local to each other

You'll be lucky to find many standard m20b25 engines putting out much more than 150bhp. If you want power, put an M52 in.

Post Sun Sep 17, 2017 11:41 pm

Don't waste your time and money trying to get any more from a b20. A throttle body and chip won't make any discernible difference to anything other than your wallet. Either accept it for what it is, a nice steady cruiser (and an auto at that) or go the displacement route.

Post Mon Sep 18, 2017 10:14 am

Cloggy Saint wrote:Don't waste your time and money trying to get any more from a b20. A throttle body and chip won't make any discernible difference to anything other than your wallet. Either accept it for what it is, a nice steady cruiser (and an auto at that) or go the displacement route.

100% agree with this.

Topblag wrote: You'll be lucky to find many standard m20b25 engines putting out much more than 150bhp. If you want power, put an M52 in.

Agree with the second bit, disagree with the first. There's no reason why, in my experience, that the average M20B25 shouldn't put out the power it left the factory with after a good service, or even slightly more, since friction losses will be less.

Post Mon Sep 18, 2017 10:43 am

A e30 and a m20 go together like rod hull and emu.

Post Mon Sep 18, 2017 12:44 pm

a mild chip in my cabby gave it more mid range grunt- nothing to set a lap time on but defo an improvement on the oem.

Post Mon Sep 18, 2017 1:09 pm

When I had a b20 I added a mild chip and TB from a b25 and noticed no improvement at all.