325i - cheap bhp gains??

[325ikid]

Hi guys,

Just joined today and site looks great I have not long purchased a 2 door 325i on 120k superb can & engine, has been looked after and doesnt seem to have lost much horsepower over the years - pulls really well and I am over the moon with it after owning a few sierras, but i was wondering how to get more power out of it without spending £thousands??

Its got spax coilovers all round and a few exterior mods but engine is standard.

Can anyone give me tuning advice??
would be very greatfull
Thanks

[Speedtouch]

Welcome to the Zone I can supply a chip for £35 posted - PM sent.

[octanejunkie]

If you buy the chip, a six branch manifold will release a couple more. Stay away from council cone filters though.

[Rav335uk]

I can recommend the chip

[steve_k]

chip, 6 branch manifold, free flow exhaust, induction kit (of your choice), new cam, full service, the list is endless.

[octanejunkie]

Throttle cable adjustment. I found out the other day that my throttle wasn't opening all the way as the cable was too slack!

[oomz1975]

A good service will release a few ponies.

[djk]

A good service will release a few ponies.

+1

Make it run right, then fit a noisy zaust so it sounds fast!

[e30topless]

BTB, a spiky cam, and a good service, forget the intake and a chip they won't help at all

[drewjak]

, forget the intake and a chip they won't help at all

seems an odd sugestion seen as 99% of cars benefit from both mods, so why not with an e30??

[pukar]

Throttle cable adjustment. I found out the other day that my throttle wasn't opening all the way as the cable was too slack!

+1...mine was only slightly slack, its the first thing i did on my car and its free!! no bhp gains though

[zaust]

Also good and free, is to bypass the hot water from circulating round the Throttle body.

[Simon13]

there are no easy cheap mods on the 2.5. They won't mkae extra bhps without £££. Chips are a waste of time and just overfuel the top end and raise the rev limiter and lose you power

[Brianmoooore]

The best power releasing mod to make to a 325i is a good, full service, going over everything and making sure all is working exactly as intended. Very few gains can be made on a 325i engine that's running properly already.
The difference between your Sierra and a BMW couldn't be greater - the Ford was designed by accountants, using the absolute cheapest materials they could get away with, while the BMW was designed by engineers. No doubt the accountants kept an eye on what they were up to, but the engineers made the final decisions.
The standard 'chip' in the 325i ECU was programmed to make sure the car performed acceptably under all sorts of barometric and temperature conditions, and on fuels that are somewhat dubious when compared to UK fuels. There are gains to be made by fitting as reprogrammed chip, such as the 'zone chip' from A-tech (Ant on here), or one from Speedtouch, but don't expect the gains to be massive. Steer well clear of anyone who claims 10 bhp+ from just a chip!
BMW know how to design components, and every part of the inlet and exhaust systems are well up to the job on a standard engine, even the exhaust manifold. A well designed aftermarket long branch manifold will increase top end power by shifting things further up the graph, but the standard manifold is good - it was designed for a wider torque band.

[Banjo1981]

Throttle cable adjustment. I found out the other day that my throttle wasn't opening all the way as the cable was too slack!

+1...mine was only slightly slack, its the first thing i did on my car and its free!! no bhp gains though

Taking the throttle body apart and giving everything a proper cleaning will also help, no gains as such but not having to move crusty springs will make it more responsive,

[polsta]

Throttle cable adjustment. I found out the other day that my throttle wasn't opening all the way as the cable was too slack!

how can a novice check this

[HairyScreech]

best bang per buck after getting it running right is to build a cheep 2.8 stroker. a £600 cheep build using good used parts will give you more gain than any bolt on. plus when you do stick bolt ons on you will get even more out of them.

although that does assume you can build it yourself.

[bss325i]

FACT!!!

The best bhp per £££ gain available for the M20B25 is the BTB2 or BTB3 6 branch manifold.

On a healty M20B25 engine, gains of 15bhp and 20+lbft is what you will get!

They are approx £650 when a group buy is done.

[bss325i]

The best power releasing mod to make to a 325i is a good, full service, going over everything and making sure all is working exactly as intended. Very few gains can be made on a 325i engine that's running properly already.
The difference between your Sierra and a BMW couldn't be greater - the Ford was designed by accountants, using the absolute cheapest materials they could get away with, while the BMW was designed by engineers. No doubt the accountants kept an eye on what they were up to, but the engineers made the final decisions.
The standard 'chip' in the 325i ECU was programmed to make sure the car performed acceptably under all sorts of barometric and temperature conditions, and on fuels that are somewhat dubious when compared to UK fuels. There are gains to be made by fitting as reprogrammed chip, such as the 'zone chip' from A-tech (Ant on here), or one from Speedtouch, but don't expect the gains to be massive. Steer well clear of anyone who claims 10 bhp+ from just a chip!
BMW know how to design components, and every part of the inlet and exhaust systems are well up to the job on a standard engine, even the exhaust manifold. A well designed aftermarket long branch manifold will increase top end power by shifting things further up the graph, but the standard manifold is good - it was designed for a wider torque band.

I could pick out a few factual errors in your post but ill prob get banned or something!

[325ikid]

Hi guys,

Thanks a bunch for all the responses! have given it a nice service using some castrol and k&n oil and air bits (pannel filter) and also gave the throttle a good clean. I will have a look at the throttle cable when I get chance too.

Dont really want to chip it or anything just personal preferance, would like a 6 branch so if anyones planning a group buy count me in

Would also like to cam it but have heared rumours that an uprated cam will kill it? and also an m3 cam is the way forward?? what do the boffins say about camming these engines?

I am not as such a novice but have always messed with engines that are like LEGO! (ford) and as much as id love to build a stroker it sounds abit out of my depths!

Thanks again for all the helpfull responses! :thumbs:

[djk]

Hi guys,

Thanks a bunch for all the responses! have given it a nice service using some castrol and k&n oil and air bits (pannel filter) and also gave the throttle a good clean. I will have a look at the throttle cable when I get chance too.

Dont really want to chip it or anything just personal preferance, would like a 6 branch so if anyones planning a group buy count me in

Would also like to cam it but have heared rumours that an uprated cam will kill it? and also an m3 cam is the way forward?? what do the boffins say about camming these engines?

I am not as such a novice but have always messed with engines that are like LEGO! (ford) and as much as id love to build a stroker it sounds abit out of my depths!

Thanks again for all the helpfull responses! :thumbs:

M3 is a 4-pot, no cam compatibility. A lot of people say a lightened flywheel makes a big difference.

[bss325i]

Hi guys,

Thanks a bunch for all the responses! have given it a nice service using some castrol and k&n oil and air bits (pannel filter) and also gave the throttle a good clean. I will have a look at the throttle cable when I get chance too.

Dont really want to chip it or anything just personal preferance, would like a 6 branch so if anyones planning a group buy count me in

Would also like to cam it but have heared rumours that an uprated cam will kill it? and also an m3 cam is the way forward?? what do the boffins say about camming these engines?

I am not as such a novice but have always messed with engines that are like LEGO! (ford) and as much as id love to build a stroker it sounds abit out of my depths!

Thanks again for all the helpfull responses! :thumbs:

The M20 is a simple engine to work on so a stroker isnt that hard to build. If your comfortable with a pinto engine then you'll be ok with an M20.

[Morat]

Wasn't 285/285 the recommended maximum duration road cam? I think that shrick have changed the way that they describe their cams since then though....

[HairyScreech]

for a normal road car id would say you dont want to be running more than a 290 ish cam. things get a bit leary when you get into the 300s .

[Dezzy]

Everything I have ever read seems but back up most of what has already been posted. BMW air box, exhaust and ecu are about the best you will find anywhere for the M20.

Just make it the best running M20 you can and as Barry says (he should know his B25 is about the fittest out there). Btb or other quality 6 branch and oem exhaust is about the best you can do.