325i M20B25 Performance Modifications?

[Z2TT]

Hello.

New member here and first time with a E30.

I want to mod my 325i 1990 to get some more power, I'm not really keen on going down high comp + aftermarket cams route but more so improving upon the factory setup.

From what I take it some people reported upto 15hp gain with a Chip and same with headers.

Will a specific Chip have to be made to suit header upgrade or will the off the shelf ones still have good power and no ill effects when combining with headers.

I'm in Australia so I have a RHD, is there any Bolt on RHD Headers over from England that I can buy as there is only one option here in my country :

http://www.motorsportsdownunder.com/catalog/i5.html

http://www.motorsportsdownunder.com/sit ... 5i%20325is


I have done research on Chips and everybody is a bit divided, from what I read nobody likes the Dinan chips at all which seem to be discontinued. Some people say they had good result with JimC Chip while others said hardly at all.

Is there any other alternatives for Chips? I'm not really keen on the Miller MAF + Chip as I don't want to tune it from scratch.

I intend to keep the factory 325i Exhaust.

I had looked for a Supercharger kit but none seem available, there was a company in Germany but have not received a reply.

I'd appreciate any pointers.

Thanks

[Grrrmachine]

Anything's possible with enough time and money, but no, you will not get 15+ hp just from a chip. You might get 15hp with a big-bore throttle body, MAF conversion, six-branch exhaust manifold and THEN a custom chip tuned to your motor, but without messing around with cams and compression ratios and reporting the head, you will not get an M20 up to 190hp.

This is why people go for the easier and cheaper M52 swap.

[hongkongfuey]

Why not go cam? Is there a reason you don't want to go this route?

[Speedtouch]

Welcome to the Zone!

PM sent.

[Z2TT]

I like the factory like Idle and drivability of the car which is why I didn't want to go cam.

Never having done and dynoed any of this stuff I can only go by what the Chip manufacturers websites say "15hp"

The M52 Idea came to my mind but having driven e36 328i before, it seems a lot of work for a small bit of power I was thinking more so M30 Conversion.

From what I take it from you guys comments it seems the M20B25 is very well optimized in it's tuning from factory?

[Speedtouch]

The problem with the standard program is it's designed to operate on all grades of fuel, all over the world, so it contains lots of bits of program that for the most part, are never needed, and serve only to hinder the overall running.

The program can be optimised for your particular engine or region, which greatly improves the driveability, making for smoother throttle response for instance, and usually gains a few ponies and a 2-3mpg fuel consumption improvement.

There are noticeable gains to be had on the standard M20 engines with a simple chip change.

[Brianmoooore]

The power an engine produces is closely related to its performance as an air pump. The more air it pumps through, then the more power it produces, as long as fuelling and spark timing is matched to the amount of air. A 'chip', on a normally aspirated spark ignition engine, can't do anything for airflow, and as Speedtouch says, just tidies up the fuelling and spark timing
The three ways to improve the amount of air pumped are to make it 'breathe' better, more cubic capacity, and increased revs. The latter soon runs into problems, as if the 'breathing' isn't increased, it just sucks harder without actually moving more air.
With the standard cam, everything else was pretty much optimised by BMW to produce an efficient (for the time), powerful engine with a good spread of torque.
You say you've driven an E36 328i, but I can assure you that engine is much more effective when fitted to a lighter E30, and don't forget that the 328 is restricted by its inlet manifold in standard form. There's getting on for twice the standard increase over a M20 easily available if a M50B25 inlet manifold is fitted.