M50B25 boosting questions.

[clutterbucker]

I have a few options on how to boost this up:

1. rebuild engine to stock specs, with a very slight overbore to smooth out the walls, add turbocharger

2. rebuild engine with lower compression, add turbocharger

Now, taking price and reliability first and foremost into consideration, which of these two would you pick? And with your choice of 1 or 2, what size turbo would you use?

My thoughts: GT28 turbo, stock spec engine (10.5:1 comp), low boost. Turbo kit for $3500ish. Around 285bhp.

My preference would be a low spooling point, and a reliable car with some power.

Your thoughts?

[nando]

taking price and reliability first

N/A S52 swap. forget the turbo crap if you want reliability..

[matt]

That's BS.

There are turbo kits and tuners out there who can provide reliabilty and driveabilty as stock. But this is probably not possible on a DIY basis without a lot of trial and error. Trial and error is not reliable.

[nando]

taking price and reliability first

sure, but that's not what he's talking about.

besides, ~280hp isn't that big of a deal, you could spend that same money on an S52 swap and mods and have the same power with a lot more reliability than any turbo.

[clutterbucker]

I just figured that a pre-made turbo kit from some known and trusted retailer would be relatively reliable and problem free.

[matt]

Who's selling those for $3500?

[Good & Tight]

Stock rebuild with low boost will be very reliable. Now if you plan on boosting more than 10psi that's a different story.

[clutterbucker]

No, it will be around 6-7psi.

http://www.turbo-kits.com/325_turbo_kits.html <<they sell them

The kit I'd be buying would be around $4500 though. ($3350 + $950 for fuel and injector upgrades)

This E34 M50 525 5spd is the shit, minus the boring to drive because of the "it's so slow" factor.

it's faster than my ex-girlfriend's cobalt, but that's not saying much. mad boring.

edit: Thanks good&tight, I'll rebuild stock and go from there. You're the only one that actually answered my question.
If anyone knows from experience and wants to become my guide in this undertaking, I would be way more than appreciative.

[nando]

ah, this is the engine that's already in your E34? I thought you were talking about swapping an M50 into your E30 and turboing that. what you are talking about makes more sense..

[clutterbucker]

right, sorry I didn't clarify.

I think I have my answer now.

[808BMW]

My dad has a 97 528i (E39) is the shit, feels way faster than my 89 325i, I've been thinking about a turbo for it

[PeaveyBassist]

e39 528i is not fast haha

Will

[clutterbucker]

Definately not faster than your 325i. Maybe more torquey, but definately not faster.

A turbocharger would work wonders for that car, minus (I assume) the obstacle of OBDII.

[clutterbucker]

I was just thinking:

I have a spare VANOS M50, and mine is non-vanos. What if I were to rebuild the VANOS M50 I have, and insert S50 cams and a chip (along with the proper ECU and wiring harness).

Would that be stupid?

[DrMcDave]

mls gasket
head studs
TCD turbo kit

good for 300whp or so and sub 13 1/4 miles in most cases. They seem to be very reliable.

I am looking to do the above. i have the head studs and am in the process of rebuilding my head. slap the mls on there and your good to go.