318is M3 Project or 24v conversion?

[bad_ass_mk4]

So, after a while out of the E30 scene i've finally returned to the fold with a 318is in need of a little love.




I got lucky on eBay and found a H-reg on 149k for very little money.


Now.. I have a bit of a dilema.

I'm going to restore it for use on weekends and trackdays, so i want it to be able to go as well as it looks... I'd love to own an M3 but that isn't going to happen any time soon - so i'd like to make my "poor mans M3" as close to the real thing as possible.


This won't be an M3 replica, more a well restored 318is with as close to the M3's power to weight ratio as possible without it becoming a stripped out trackcar.


I've read enough about the 318is to know that the secret to its comparison lies in its power/weight/handling balance.. Fudge this up and any relation it bares to the M3 is lost. So, what i'm proposing are modifications in this vein ideally while retaining the M42 engine:

A) Find a low mileage M42 (or rebuild my 149k engine) and Supercharge it with the GKD kit, adjust the cam timing, M20 flywheel then install a standalone ecu and have it mapped - This is the most honest route i can think to take while retaining the integrity of the 318is and the M42 engine.


Or (curve ball)


B) I have a E36 325 trackcar that i'm currently selling. Its in really good nick and only has 55k on the clock so the plan was to sell/break that to fund the restoration of the 318is. OR use the E36 and its M50 engine as a quick easy donor for the 318is...

Now, on the face of it this seams the easiest route to take as I already have most of the stuff for the conversion, however i am well aware that I have the iron block M50 and not the lighter weight alloy M52.. so it'll weigh a fair bit. Which compromises the power to weight and will inevitibly effect the handling dynamics of the car, which i really don't want to do as it strays away from what i'm setting out to achieve.

So my question(s) are thus:

- Whats the most reliable power anyone has seen from a supercharged M42 engine?

- Will fitting an M50 blunt the handling of my car as much as i'm imagining or can this be overcome with stiffer dampers and still make for an enjoyable car?

[Quaser]

I would supercharge it and be different - loads of m50'd cars out there now - not many m42 s/c

[MurphyE30]

Would be nice to see a supercharged M42 build.

I will soon have a low mileage M42 engine, box and 4.1 LSD available if you decide to go that route

[bad_ass_mk4]

definitely interested in the LSD.

PM me details please

[MurphyE30]

definitely interested in the LSD.

PM me details please

I'll drop you a pm now

[DanThe]

Appletree on here did a supercharge conversion, check out his build thread for inspiration

[badassyas]

I have a aluminium block with steel liners if you fancy going m52 alloy route. Cheap as chips too!

[bad_ass_mk4]

Any opinions on the driveablility of an M50 engined E30? I already know how the engine feels but do they loose much in the way of nimbleness etc or does the increased grunt offset it enough to make up?

[DanThe]

A 2.5 is a waste of time when there are so many lighter 2.8 engines out there

So, either 2.8 M52 or supercharged 4 pot

Rather than M42 why not start off with a 1.9 M44? You could even stroke it to 2.1 or thereabouts

[jon-m42]

Hi Mate,

Save money and go ahead with the joys of a m52 2.8 in an e30 shell. Thats what I would do.

[satan16v]

Hi Mate,

Save money and go ahead with the joys of a m52 2.8 in an e30 shell. Thats what I would do.

I have to agree with Jon, I supercharged my Mk3 Golf 16v, was a head ache and nothing but problems. Wished I'd left it as it was

At least a 2.8 is tried and tested

[jon-m42]

I drive a m42 myself and as much as i love it for what it is I am clearly aware and accept that it is only a little baby.

It is in no way a fast car and having read up on here it seems big bucks are needed for small power gains. Its better of to start of with more power and add more if need be than to start of with little or no power and then to add.

[bad_ass_mk4]

A 2.5 is a waste of time when there are so many lighter 2.8 engines out there

So, either 2.8 M52 or supercharged 4 pot

Rather than M42 why not start off with a 1.9 M44? You could even stroke it to 2.1 or thereabouts

Ideally i'd stick a 2.8 in as they're around 20-30kgs lighter then the 2.5 if it wasn't for that fact that i already have a perfect 2.5 donor car with chipped ecu sat in my drive.. so seams daft to over look it.

M44 is a nice idea and plenty of lower mileage ones around although from what i'd read they aren't a straight swap - definitely worth looking into for the increased capacity and of course the same SC kit will fit an M44 as an M42 - possibly a move for the future if i SC my M42

I guess at the end of the day its power to weight i'm concerned with.

Any M50 E30 owners out there care to venture their opinions?

[reggid]

m50 swaps are a dime a dozen and you'll want more anyway

[JF008]

I have an 210hp m50 and it leaves me wanting more, although its plenty fun to drive. What kind of power can you achieve with a super charged m42? Turbo'ed M50's look retarded (in a good way)

[fender182]

Theres a M42 stroker kit in the for sale section ATM, at a very good price aswell. 2.1 the engine then bolt a charger on it?

[reggid]

turbo M42 would be better. there was a guy years ago did this in my area and he made ~300hp at the wheels all day long. built you could go for more but it gets expensive when you open engines up

[Demlotcrew]

Turbo.

[bad_ass_mk4]

From what I've researched 200bhp is easily doable with one of the GKD/Mini Supercharger conversions. Maybe more if you mess with the cam timing and get proper management (the 200bhp figure is based on using a rrfpr like the Downing Atlanta kits which isn't really the best solution)

I've also seen a few turbo'd M50's on driftworks that look like a lot of fun although that's a tonne of weight over the front end by the time its all bolted together. I can also see how I'd get bored of an M50 - its great on track in my E36 but day to day the lack of low down torque gets frustrating.. Is the M52 much different in that respect?

I found a thread on r3vlimited about turbo'd M42's yesterday that I'm starting to read through - of the two I'd prefer a turbo over SC as they aren't parasitic... It's just moving away from my original aim for M3 power to weight (and I guess linear power delivery).

I'm sure I'd quickly forget all that when boost kicks in Ya'll!