m30b35 vs s52b32.....really

[slammin.e28]

I are serious. emkay four is serious binzness

[Bearmw]

If having to adjust valves is a major impediment then I guess I'M old school. Not that I wouldn't also enjoy a more modern motor but more likely an M54 or V8 if I ever go that route. I am expecting to basically finish my m30 vert mechanicals this spring. I am going ms3x and sequential ignition and a 3.46 diff. I hope to get the car corner weighted, dyno tuned, and take it to the drag strip for ha ha's. Will post my results. I already liked the torque band a lot with 3.25 rear, factory manifolds, and a less than optimal WAR tune.

A lot of the decision comes down to your willingness to wait out good deals on parts and your willingness to at least baseline whatever combo you decide upon.

[TheTacoMan]

Alot of people look just at the peak horse power and peak torque. The m30 makes alot more toque earlier


M30s torque is considerably better. However you will need to consider the weights of both.
That said the dual over head cams is much more modern and is a better engine, but is it more fun ?
For the price Im not sure.

[SubDad]

Way to change my suspension fixing plans!

I will cheerfully help you do whatever swap you end up doing if we can come to an agreement over my getting all the parts from your M20B25; engine (how bad is it? What's this turbo-talk?), transmission?, computer, wiring, rad, random little clips yada yada..
I've got an M20B20 that's fun but gutless, I've got a garage we can work in, I've got tools and I live in Ottawa.
Not only that, but we've actually met. (Hi! Still got those head-rests?)

[Mr. Burns]

I will cheerfully help you do whatever swap you end up doing if we can come to an agreement over my getting all the parts from your M20B25; engine (how bad is it? What's this turbo-talk?), transmission?, computer, wiring, rad, random little clips yada yada..
I've got an M20B20 that's fun but gutless, I've got a garage we can work in, I've got tools and I live in Ottawa.
Not only that, but we've actually met. (Hi! Still got those head-rests?)

ha absolutely!

engine isn't bad whatsoever, doesn't burn a drop of oil, has a new goetze head gasket, metric blue head bolts all maintenance up to date, t-belt water pump etc etc.

I had it boosted for a short while and quickly threw in the towel after I wrestled with endless tuning issues...yank it all off, got new oil pan and sold the whole ordeal

Headrests are here with your name on them!(well not literally, that would be tacky)

[LowR3V'in]

How much does a complete s52 go for these days?

[Massimo]

torque you say why not m70 it

[SubDad]

How much does a complete s52 go for these days?

Dunno. Got me a line on a local M20B25! Yeah! Instant 50% horsepower boost.

Mr. Burns, may I call you tomorrow? Or PM me.

[Mr. Burns]

Gimme a shout anytime
I'm at the cottage for the weekend at Tremblant, but should be back for Sunday early afternoon

[SubDad]

OK, great, call you Sunday.
Now, um, R3V, could you please keep giving Mr. Burns advice and encouragement to change out his M20B25 so I can have it?

But, is it really a good idea to put massive torque in a vert?

[lukeADE335i]

What is so fun about driving a car that falls on its face above 5500 RPM's.

The M30B35 certainly doesn't fall on its face after 5500 RPMs - particularly when lugging around 300kg less than it does in the e32 / e34 (maybe the low comp B34 from the e28 does? Never driven one).

I have just swapped out my 3.73 diff in the e30 to a 3.46 to tame it down a bit so I don't bounce it off the limiter so easily on hard launches.

As for the difficulty of the swap - the M30 is straight forward, but does need quite a collection of parts. If you're using a B35, there's not really any need to bash the firewall back by an inch - I pushed mine back maybe 5mm at most to get the engine in P3.

[F34R]

What is so fun about driving a car that falls on its face above 5500 RPM's.

I think of you as a swell fellow, but this is wrong^ The M30b35 does not stop pulling till it is bouncing the limiter. It will smoke the tires from first to 3rd with ease and I ran down an m52 swap like it was a joke. I know the s52 will pull away...but it is not as much fun. That grunt from the m30 is just bliss! You cannot beat the punch it gives.

Not to toes: Let's be serious, the m30 is not crazy heavy over a dressed m20. Remove PS, Ac and you're in the same ballpark with 100+hp and GOBS of downlow bruteforce.

I love the m30, I would rather it over an s52 anyday. IMO the only step up is the s54 for all around weight and power gain. I am sure many will disagree with me, but who cares? anything is better than an m42!

[Bmwdayz]

I love M30 torque but they do fall on there face after 5500. Also I had a e30 m52 and raced my friend with a e30 M30 and beat him. So I guess it all comes down to how the car is set up. Exhaust, chip, gearing. Either way I've driven both and I vote s52. And When I'm not ripping around I get great gas mileage which the M30 isn't capable of.

[lukeADE335i]

I'd say gearing played a fair role in your M52 vs M30 drag.

Too true on the fuel economy front though - can't argue with that one :)

[mbonder]

Here's my take after having driven both (currently own an s50 car)

M30: The M30 car is going to be more fun as a cruiser if you are shifting in the first half of the rev range as the torque curve is very linear and begins very early in the rev range. I really loved the m30 from a stop light or in passing situations on the highway.

Gas mileage was poor though if you were constantly pushing it even in those lower ranges.

The engine definitely gives you that "pushed into you seat" feel though from a standstill. I really didn't see the need push it past 5.5k rpms.

S50/s52: This car is more fun if you like winding out the gears, as the 24v motor will breathe better in the upper half of the rev range. Many people who track their cars choose this engine as it suits that application better. On the street I really don't wind out the gears that much except maybe on the highway.

Fuel economy is better, even if you a stomping it (although not by much when you are into the pedal).

An added benefit of the newer engine is that it was found in the e36, which BMW built a billion examples of. The aftermarket support will never die for these cars so the bolt ons as well as larger upgrades like superchargers and turbochargers are always there as long as you have the cash. If you think more power will be needed in the future, I would go this route.

In the end, pick the engine that suits your driving style as that's what's going to make you truly happy when you get into the car. Don't do it based on budget (although everyone has their limits), don't do it based on what others would do, don't do it based on 12v vs 24v. Do it for you as you'll be driving the car!