M50 with mods or stock S50?

[ParsedOut]

I've been lurking here for quite a while and finally registered to hopefully get some info i haven't found by searching or reading existing posts.

i have a budget of about $6k for motor work. this car will be my daily and i would like ~250hp and yet still very reliable. here are the options i can see...

keep the M20 with a turbo
keep the M20 and "stroke it" :twisted: (maybe not quite 250hp?)
swap M50 and drop a few grand on some nice upgrades and maybe freshen motor
swap S50 and leave stock

i realize the easy answer is just get the S50, but with that option i'd be stretching my budget thin and i would really like be able to spend some money on replacing gaskets, valve job, etc to really get a fresh motor and not have to worry about it other than routine maintance. where as with the M50 i could afford to do all that work and along with some motor work to get the HP up there.

the second question is, how much work would have to be done to the M20 and M50 to get up to the 250hp mark?

BTW, i'm not a mechanical n00b. i've been addicted to watercooled VW for years and have done several motor swaps, standalone EFI work, etc. so i have a pretty good idea of what i'm getting into, it's just a matter of the specifics i need some clarification with.

[Jarvis]

The most reliable + easiest way to get 250hp in an E30 is a chipped S50.

Although with your budget, you could get the TCD Stage 2 M20 turbo kit to get ~290 rear wheel hp (350bhp).

A 2.9L non-vanos M50 stroker could be done for your budget, and that would provide ~240whp (280bhp).

An OBDII M52B28 (possibly aluminum block if you can find it) would get similar results to the 2.9L stroker, with S52 cams, tuning, and a few bolt on's.

[ParsedOut]

i dont' know if i'm just being paranoid about the reliablity of these motors, but if i can get the M50 pretty much rebuilt with a stroker kit for the same $$ as a questionable condition S50 and get equal if not more HP then it kind of seems like a no brainer. am i missing something, or would the M50 motor work cost more than i'm anticipating?

[Addissimo]

6k for just the motor, or the entire motor swap?

If 6k for just the motor- get an s52 and go standalone. You can easily do that for 6k, stick with the getrag 260, and get a 3.46 gear set in back, i bet you'll love it.

Pick up an s52 for about $3500
m50 intake manifold $50-150
e34 oil pan $200
Standalone EFI $1500
brake booster (ix) $250
535i mounts $60
$5660

you still have room left over for a nice clutch.

If you tune it well you're looking around 310hp maybe a bit more.

Or you could just go for a 2.8 with stand alone and twin turbos- you'll be fast enough.

And no, I'm not talking straight bullshit- this is all plausable, you just have to know where to look and what you're doing.

-Addis

edit: by the time you rebuild an m50 with a stroker kit, I'm pretty sure you'll be balls deep into the motor.

edit2: is the us spec s52 double vanos? I dont think so... but i cant remember for sure. If so, expect to pay more like 4k for a motec efi system. lol

[erik325i]

edit2: is the us spec s52 double vanos? I dont think so... but i cant remember for sure. If so, expect to pay more like 4k for a motec efi system. lol

No, I believe the s52 is single VANOS, OBD2

[ParsedOut]

6k for the entire swap. so it seems that with all the little odds and ends that add up pretty quick, i'd be looking at a stock S50 swap unless i can find a smokin deal... i've also had quite a bit of experience with Megasquirt, so that's an option too, but i'd rather not run that on my daily driver, i did that for 2 years on my latest VW and it was a nightmare.

*edit, somewhat off topic, what is the final word on keep the Getrag 260 with these M50/S50 swaps. does it torque the tranny mounts enough that modifying the crossmember is really a necessity?

[erik325i]

I recommend the s50, because that's what I'm planning on doing.

About the Getrag 260 tranny, it can be used, but it will be 10 degrees off. This is why you have to modify the shift linkage, and make a custom tranny bracket. I am going to try to use my 260 tranny with my swap.

[Addissimo]

you do need to modify the cross member for prefection, with a combination of tranny mounts, you can make it "good enough"

[erik325i]

you do need to modify the cross member for prefection, with a combination of tranny mounts, you can make it "good enough"

Which mounts?

[Addissimo]

I believe I heard that using the e21 mount and a normal e30 mount make things close to perfect.

-Addis

[ParsedOut]

hmm, do the pistons and rods on an M50 need to be dropped in from the top or can that go in from the bottom? my reasoning is, that if the rods and pistons can be pushed in from the bottom the motor can be stroked pretty easily without going too deep in the motor. it seems that basically an S50 crank with S50/S52 rods with machined pistons is all that is really necessary to get 2.9l (i think, maybe 2.8) but if the head has to come off for the pistons to go in, then i might as well have the block bored out to accept the S50 pistons as well and end up with a fully rebuilt (minus headwork, fuck that i'm not getting that deep into it yet) bottom end which essentially is an S50 for close to what one would spend on a questionable history used S50. am i looney in assuming this? i know machine work isn't cheap, but really it would just be a matter of disassembly and reassembly with new gaskets, seals and different internals (crank, rods, pistons).

oh yeah, and i'm sure i'm not the first one to think of this, but regarding the getrag 260 tranny issue, how hard would it be to rig up the E36 tranny bracket, looks about right... mounting points look quite a bit different though. :|

E36



E30

[Stu]

I use a Getrag 260 trans...for mounts, I use an M10 engine mount on the driver side and a 635csi solid tranny mount on the other. The trans bracket needed to be cut/welded to accomodate this.

[erik325i]

I use a Getrag 260 trans...for mounts, I use an M10 engine mount on the driver side and a 635csi solid tranny mount on the other. The trans bracket needed to be cut/welded to accomodate this.

Do you have any pics of this setup?

[ParsedOut]

bump this back up. i finally sold my 98 jetta so i'm thinking this project will take place around feburary when we get moved up to Portland and settled. i'll try and find a nice body 89+ 325 with a blown motor or maybe a restored salvage e30 m3 and sell the s14. but the motor choice is still just itching at my brain.

M50 stock $3k 190hp
M50 rebuilt stroker $6k 240hp
S50 stock $6k 240hp
S52 with megasquirt $6k 280hp ???

seems like for the $$$ and peice of mind a rebuilt M50 stroked with factory parts looks like the winner but with a lot more work. i really want to keep the oem fuel management and just maybe get a chip to handle the mods, standalone is just too hardcore for a daily driver IMO.

[erik325i]

M50 stock $3k 190hp
M50 rebuilt stroker $6k 240hp
S50 stock $6k 240hp
S52 with megasquirt $6k 280hp ???

If you say an s50 install is $6k, what makes you think you can do an s52 with megasquirt for the same price?