Best way forward - new engine, or tune current?

[off_again]

Ok, newbie here so go lightly - I am reading lots and trying to catch up as much as possible, but I certainly dont know everything....

Got a 325i at the moment and the engine is good and strong even though its got 180k on the clock. But lets be honest, its gotta be down on power. Its being run as the wifes car for the moment until we get our kitchen done - but after that its mine.... all mine....

So, interested in the options for the engine. Given a 2.5 engine with such a high mileage, is it better to rip it out and get something else put in or say overhaul it back to a good standard and tune it up? I am not looking for mega-power or anything, but I would like around 200BHP (more is better obviously). From what I understand, a good 2.5 should be close to 160ish and some sensible mods will take this to 190ish.

But, would it be easier to just say sod it and get an M50 or similar? Is it even worth thinking about turbo / supercharging an overhauled high miler like this?

Lots of questions and and too many options. Just looking for advice really. Oh, and the budget should stretch to a couple of grand so no need to scrimp but silly money need not be spent - as I have to sort out the suspension and wheels too....

[Hyperion]

Hi mate, welcome to the Zone.
Ok, lets see, you have quite a few options to go here.
The popular ones are:
1) M30B35 Conversion - taking the engine out of a 535i and putting that in, should give 210hp.
2) M20B27 Conversion - which is upping the capacity of the engine to 2.7 ltr, this wont give you 200hp but it makes quite a difference to how the the car drives, quite a nice conversion and you keep your current engine.
3) M50 Conversion - This is another good idea, zone member Stevetigger did a conversion recently and it came out quite good.
http://www.e30zone.co.uk/modules.php?na ... highlight=
4) TURBO - this is the way to go if you want to go really really really really fast , we have a section for this to do your head in.
5) Supercharging - This is an idea i am thinking about, i like the idea of it. Just like the turbo, but it might work out a bit more expensive.
Thats about it from me.
So pick a route 2,4,5 keep the same engine, or 1,3 swap time

[M5pilot]

Welcome to the Zone.

You'd be surprused by BMW engines. Jonb had a 200k 325i and that made stock power on a dyno day.

The best way is to go for a different engine altogether like the M52 2.8 from the E36 328i. I doubt you'll get this done in your budget though consiering the manifold will cost a load of money.

The more likely solution is to get a MAF conversion (Nads325i took his off the other day and it made quite a big difference - £500), 6 Branch manifold, Big Bore throttle Body, good suspension kit and an Exhaust.

This lot will hit £2000 and give you a much better car with a fair bit more poke.

Sal

[Simon13]

Welcome to the Zone.

You'd be surprused by BMW engines. Jonb had a 200k 325i and that made stock power on a dyno day.

The best way is to go for a different engine altogether like the M52 2.8 from the E36 328i. I doubt you'll get this done in your budget though consiering the manifold will cost a load of money.

The more likely solution is to get a MAF conversion (Nads325i took his off the other day and it made quite a big difference - £500), 6 Branch manifold, Big Bore throttle Body, good suspension kit and an Exhaust.

This lot will hit £2000 and give you a much better car with a fair bit more poke.

Sal

and then it won't be able to stop still so budget even more for suitable brakes. Or overhaul your stock setup

[M5pilot]

Brembo/BMW discs,

Ferodo/Mintex/Pagid pads are all rated by different people on here.

Renew brake fluid and fit braided hoses and your sorted in that region.

[off_again]

Cool, thanks for the feedback. Looks like best go for a rebuild and some generous modifications while I am at it.

Quick question on exhausts though - mine is looking in fair condition (if a little rattly). So, is it best to hang on and splash on a full system with new headers / downpipes etc as well as the centre section / backbox or just do it in sections when required? Is there any benefit for a full system or can they be sorted in sections? Exhausts are not my strong point.....

[Simon13]

if it's on the original bmw system, keep it! U won't find an after market exhuast which is better, louder yes but not more perfromance. Saying that exhausts bar the header/manifolds don't make alot of difference on M20's

[Ant]

My policy:

If it aint broke, dont fix it

I have had an M20 B25 stripped to all its components @ the request of the owner.

Mill had 327K on it but FSH , internals were mint save for some oil staining on the mains and big end, no scoring to the crank, no ovalling of the bore on the thrust side of the throw, cross hatch from the honing still easily visible

Before embarking on a full strip down, get the compression tested and a dyno plot, see what you have 1st dude.

Then based on the above make the informed decision