m30b35 vs. m50b25

[Wh33lhop]

M30 also won't bolt up to an M20 trans, so you can't swap motors without swapping transmissions with an M30.

That was a deal breaker for me, as I had to carry the motor and hardware around in my trunk till I could swap it. :p

[Jean]

B35 over non vanos m50 anyday of the week (and even vanos m50 unless you upgrade cam(s) on it) .. it's just plain faster, more hp/more torque, simpler, it's a fricking work horse of an engine. BMW used it for what 20+ years in 5, 6, 7 series cars. They don't have any more cooling issues than m20 or m50.

It's cheaper to rebuild a b35 than it is a dohc engine...

If I was going to do it again it would be a b35 OR m52+, non of the m50 nonsense.

[weaksauce]

m30b35 > m50 NV

m50 vanos or Obd1 M52, both with m3 cams and tune > m30b35

so a tuned and modded m52 huh?
what about a cam for the m30. whats that cost $300?
tune? how about a chip for the m30.oopppss theres another $100 for a used chip.


so chip and cams for the m30 $400-$500
tune and cams for the M50 $1000 min (schricks and a tune)

my .02

[LowR3V'in]

^You should use new rockers for a new cam if you're
thinking about that.

The m50 would be pretty good as a daily for the mileage
and no valve adjustments. Better yet find a vanos motor.
Non-vanos is like a chip+headers upgrade on a m20. :P

[Jb325is]

so a tuned and modded m52 huh?
what about a cam for the m30. whats that cost $300?
tune? how about a chip for the m30.oopppss theres another $100 for a used chip.


so chip and cams for the m30 $400-$500
tune and cams for the M50 $1000 min (schricks and a tune)

my .02

I think the point was you'll definitely get more gains doing that to an m50 than you would with an m30. You have to spend big bucks on the m30 to get any power out of it N/A

[rThor432]

Do you think a m30 would be cheaper to rebuild because they both need head gaskets

M30's are extremely easy to rebuild. I can almost say that I enjoy working on M10's, M20's, and M30's on engine stands thanks to their simplicity. It's like putting together Legos.

When I said fabrication was necessary, I of course was referring to the engine mounts as some have mentioned. I thought that also, depending on the engine position, you would have to modify the driveshaft to work with the G265 trans. A stock M3 driveshaft should work, and maybe even E24 and E28 driveshafts work. I haven't done that research.. M30 isn't in the cards for me for a looong time if ever.

[weaksauce]

I think the point was you'll definitely get more gains doing that to an m50 than you would with an m30. You have to spend big bucks on the m30 to get any power out of it N/A

i spend big bucks on my s52 trying to make it fast NA and it worked sort of.
i did a 3 angle valve job, schrick cams, m50 manifold, 3.5 hfm, 24 lbs injectors and the eurosport software. all that to get to 230 RWHP
all that cost about $3k

i wonder what it will cost me to get to 230RWHP in the M30B35 i am building?


the chip for a 95 m50 gives 22 hp advertised thru turner
http://www.turnermotorsport.com/html...UCT_ID=413-325
the chip for a 91 m30 gives 43 hp advertised thru turner
http://www.turnermotorsport.com/html...DUCT_ID=E34535
not trying to be a dick, just speaking of my past experiances.

[Jb325is]

i spend big bucks on my s52 trying to make it fast NA and it worked sort of.
i did a 3 angle valve job, schrick cams, m50 manifold, 3.5 hfm, 24 lbs injectors and the eurosport software. all that to get to 230 RWHP
all that cost about $3k

i wonder what it will cost me to get to 230RWHP in the M30B35 i am building?


the chip for a 95 m50 gives 22 hp advertised thru turner
http://www.turnermotorsport.com/html...UCT_ID=413-325
the chip for a 91 m30 gives 43 hp advertised thru turner
http://www.turnermotorsport.com/html...DUCT_ID=E34535
not trying to be a dick, just speaking of my past experiances.

That seems really low on your s52. I've personally seen countless s5x's making over 230whp with just bolt ons and stock cams.

When a manufacturer posts gains like the ones you've posted for the chips, that isn't peak horsepower. Do you really think if your m30 made 175whp on the dyno you could throw a chip in it and it would put down 218whp? No way. Those gains are WAY under the curve, you might get 43 hp somewhere, but it won't be peak horsepower

I am speaking from experience also btw, my m30 is a b35 with euro bore, 10.5:1 compression, heavily ported head with 290 cam, long tube stahls etc.. and it refuses to make over 200 whp with the stock ecu. I'm very close to installing my megasquirt setup but even then I'll be lucky to break 225whp.

A friend of mine has a similar motor, but with stock bore and a 3.8 crank (we think) that makes 229whp with autotronic full standalone ($1.5k-2k ecu).

My point is, it costs a TON of money make any power out of normally aspirated m30, you'd be better off going with a TCD stage I to make an easy 300whp

[LowR3V'in]

cam, high compression, and headers w/ stock ecu?
Don't be surprised. ;)



I like these dynos.
Owner: Martin Bacon – e34 (m30b35) stock dyno



Owner: gary242 – b35 with Schrick 284 cam and Paul LaDue headers

[Jb325is]

Wow those are very high.. My graph is somewhere on bimmerforums, I'll see if I can find it. It's pretty obvious my car is falling on its face well before it should be making peak power with the 290.. But I'm trying not to get my hopes up on much bigger power with the megasquirt, we'll see though

[msinger]

since you want a bigger motor, obviously the m30, m50 is actually lighter than the m30 (not by too much mind you) as far as i know its the s50 that is the heaviest

[rThor432]

as far as i know its the s50 that is the heaviest

Well, the Euro version might be heavier than the M30. I'm assuming you are talking about the real [Euro] S50 here.

[weaksauce]

s52s that can make about 250 NA on a ambitious dyno. 230 is more real world.
i personally like the power under the peak in my motors, so having 238 hp at 7200 rpm is cool and all, but you have to beat the hell out of the car to use it all.
i'm hoping this m30 swap is going to feel more like what i look for in a motor.

a few of my favorite cars i've owned
91 750iL
97 540i
98 C5 vette
05 dodge cummins HO

so i guess I'm a torque junky

[rThor432]

you have to beat the hell out of the car to use it all.

Not really, S52's have a good bit of torque really. But I guess this thread is about M50B25's..

[619E30]

I just want the best swap for the buck