M50 vs. S50

[elevationHIGH]

Forgive me if this has been a post, I've been searching but havent found info to satisfy what I've been questioning.

My question: What are the major differences between the 2 engines? I've read numerous posts and articles about the S50 being an upgraded version of the M50, and if so I was wondering if it was cost effective to self upgrade the engine to ///M status or just purchase a S50 engine with appropriate componets to upgrade my '95 325?

Also, I was in need of a car for college, and was unable to find a manual, yeah i know, So is it in my best interest to upgrade right away or can it sustain the engine's power?

ANY info would be appriecited. Thank you in advance.

[Truman325i]

before engine work , swap a manual in not to hard ( done it myself , im 18 and kinda scrawny).

Also the s50 has better number for reasons , such as intake manifold , cams , more displacement.

Cheaper to swap engines if you have the means and dedication , otherwise search for stroker kits at www.zionsvilleauto

[BCM M3]

Actually, the intake manifolds are identical on the M50 and the S50. The main difference between the 2 engines is the displacement and the cams, although there are some other more subtle differences as well. That said, by the time you max out the M50 in mods (while remaining naturally aspirated), you will just barely be making close to stock S50 power. If you want M3 power without forced induction, the best way to do it is to just start with an S50 or S52.

As a former owner of an auto 325ic, I can definitely say that the single best thing you could do is swap for a manual. I don't think the lousy automatic could take S50 power levels for very long anyway.

I think the best option is probably just to hold on to the car for a few years, then upgrade to an M3. If that idea doesn't appeal, go ahead and mod the 325, but start with the tranny.

[Furious]

Actually, the intake manifolds are identical on the M50 and the S50. The main difference between the 2 engines is the displacement and the cams, although there are some other more subtle differences as well. That said, by the time you max out the M50 in mods (while remaining naturally aspirated), you will just barely be making close to stock S50 power. If you want M3 power without forced induction, the best way to do it is to just start with an S50 or S52.

As a former owner of an auto 325ic, I can definitely say that the single best thing you could do is swap for a manual. I don't think the lousy automatic could take S50 power levels for very long anyway.

I think the best option is probably just to hold on to the car for a few years, then upgrade to an M3. If that idea doesn't appeal, go ahead and mod the 325, but start with the tranny.

yes i agree, i have done the M50 to s50 upgrade myself, that was a choice of my own. however in your situation i would just as stated in the quote save up and trade in for an actual M3 that is manual, it will cost you less to just trade in than do all the nessecary upgrades to be at M level.

[elevationHIGH]

awesome thx for the info.

[elevationHIGH]

Is there a way to fortify the autp trannyto withhold the power at all?

[beatniks325]

Is there a way to fortify the autp trannyto withhold the power at all?

sure you could build a cage around the gas pedal....;)

[tomt30273]

Is there a way to fortify the autp trannyto withhold the power at all?

Well, according to GM, it's called a 4L30. GM designation, not BMW. They say the 30 means it will handle up to 300 ft/lbs of torque. I'm pretty sure the E36 M3 doesn't have 300 ft/lbs on tap. Whether this is true or not, don't know. Just repeating what I read.

[tomt30273]

Okay, found it in the manual. The 95' 325 uses the A4S 310 R. "A" is for auto (duh). The "4" is for the number of gears. "S" denotes it has overdrive. The "310" is the amount of torque the input shaft can take. "R" is the place of manufacture, in this case, Strasbourg, France.

I know the S50 makes 240 hp and 225 ft/lbs of torque. The transmission should handle the S50 power quite well, unless you really get into modding, FI or so.

[Furious]

good info , where did you find it? link?

[elevationHIGH]

Very helpful. Thank you again.

[tomt30273]

good info , where did you find it? link?

I found it in the "general information and maintenance" section of my "Chilton" manual. I found hp figures in the Bentley, but no torque numbers. It's probably in there somewhere, but I find the Bentley to be hard to naviagte through and find "some" things easily. Still a great manual, all in all.

[tomt30273]

I still think you would be better off, performance wise, with the S50+tranny swap. But if you can't afford both, at least you could enjoy one until the money is saved up.

[uber e36]

Okay, found it in the manual. The 95' 325 uses the A4S 310 R. "A" is for auto (duh). The "4" is for the number of gears. "S" denotes it has overdrive. The "310" is the amount of torque the input shaft can take. "R" is the place of manufacture, in this case, Strasbourg, France.

I know the S50 makes 240 hp and 225 ft/lbs of torque. The transmission should handle the S50 power quite well, unless you really get into modding, FI or so.

This is what the bentley says:

318 - Getrag S5D 200G (92-95)
318 - Getrag S5D 250G (96-98)
323/5 - Getrag S5D 250G
328 - ZF S5D 320Z
M3 - ZF S5D 310Z (95)
M3 - ZF S5D 320Z

So I'm not sure where you got that info for the 325 Tranny handling 300 tq?

[tomt30273]

This is what the bentley says:

318 - Getrag S5D 200G (92-95)
318 - Getrag S5D 250G (96-98)
323/5 - Getrag S5D 250G
328 - ZF S5D 320Z
M3 - ZF S5D 310Z (95)
M3 - ZF S5D 320Z

So I'm not sure where you got that info for the 325 Tranny handling 300 tq?

Those are the figures for the manual tranny. And if you'll read two posts up you will see where I posted where I found them.

[Bimmer14PA]

Keep the m50+ different tranny+FI(TURBO)..:)

[TboneM3]

Or a stroker M50 with cams and such can make a little more than stock S50.
If smogging isn't important to you and you want to swap go obd1 S52.

[elevationHIGH]

Anyone know a good company to stroke the m50?

[Furious]

i just realized that tom your TomCtx. haha no wonder the info is good.. thanks. ill have to bother you on the other forum for the complete list so i can post it up

[jiggynites]

thats some funny stuff the auto 325 tranny can handle more torque than the manual.. good to know

[elevationHIGH]

more specifically to stroke the 2.5 out to 3.0L? Any companies?

[elevationHIGH]

Sorry, that question seems confusing. .

I was wondering ifany companies made a stroker kit for the M50 to make it into a 3.0 liter? I've searched and only found a kit to stroke to 2.8?

Any thought?

[beatniks325]

there is a 2.9L stroker kit

[elevationHIGH]

there is a 2.9L stroker kit

Where might I find this?