Official M50 Manifold Swap Thread

[turbodefrost]

K so i finally got it all installed the otherday, didn't throw any codes, idle's fine, everything seems ok... only thing is it seems slower now... I raced a modded 325is and before the install we were dead even, after, he walked away from me easily. There were a few differences, but i don't think they were enough for him to walk me especially if I'm supposed to be faster now: before we had the same amount of gas, this time he had 1/2 tank, and i was almost full. before we were alone, this time i had a passenger. before i had no spare tire in the trunk, this time i did. before he was running on 17" kosei's, now he's on 15" bottlecaps.

I read somewhere that it takes some time for your ECU to get used to everything, but I still can't see how I got so much slower! anyone care to evaluate?

[LuvMy328is]

K so i finally got it all installed the otherday, didn't throw any codes, idle's fine, everything seems ok... only thing is it seems slower now... I raced a modded 325is and before the install we were dead even, after, he walked away from me easily. There were a few differences, but i don't think they were enough for him to walk me especially if I'm supposed to be faster now: before we had the same amount of gas, this time he had 1/2 tank, and i was almost full. before we were alone, this time i had a passenger. before i had no spare tire in the trunk, this time i did. before he was running on 17" kosei's, now he's on 15" bottlecaps.

I read somewhere that it takes some time for your ECU to get used to everything, but I still can't see how I got so much slower! anyone care to evaluate?

The car will take a few days to adjust, it should get stronger. The important thing to to remember as mentioned in my first post, you will lose midrange Tq with out M50 specific software. You should notice the car is much stronger over 5000rpm. Once you get your DME flash, you will have a 7000ish rpm redline. You do need to drive the car a bit differently i.e. keep the revs up. If you plan on getting M3 cams wait for your DME upgrade. If not, get a shark injector or AA software flash, that should help a bunch. If your sig is accurate, it's time to get a free flow or cold air intake
~Phil

[turbodefrost]

The car will take a few days to adjust, it should get stronger. The important thing to to remember as mentioned in my first post, you will lose midrange Tq with out M50 specific software. You should notice the car is much stronger over 5000rpm. Once you get your DME flash, you will have a 7000ish rpm redline. You do need to drive the car a bit differently i.e. keep the revs up. If you plan on getting M3 cams wait for your DME upgrade. If not, get a shark injector or AA software flash, that should help a bunch. If your sig is accurate, it's time to get a free flow or cold air intake
~Phil

ok thanks, maybe we'll run again in a few days to see if there's a difference. I will be getting S52 cams eventually so i'll be waiting until then to get any kind of software. And yes I really need to get CAI I think it will make a BIG difference!

[Fr1D4y]

This has probably been asked before, so feel free to link me to the answer.

Im interested in doing this conversion to my M52 328, as it looks fairly easy in all honesty, and should give good power gains. As part of my university studies in motorsport, I learnt about engine aerodynamics, i.e. the way the the air charge moves through the engine, and the basics are that the smoother it flows, the better. This is why people get their ports and intake manifolds polished.

I was looking at the first pic in the first post of this thread (the one comparing the runner internal diameter size differences) and I started to think about how the air would see this huge increase in runner diameter just before it flowed into the intake ports. Ive been told that the M52 engine'd E36 328's (like mine) were restricted quite heavily to meet with German emmision regulations, and a smaller intake manifold was used to stifle the air flow into the engine.

So my question is, does this smaller M52 intake manifold's internal runner diameter, match up to the M52 engines intake ports for each cylinder?

If it doesnt, then OK, fitting an M50 manifold would hopefully remove this restriction, converting the M52 engine back to the way it was originally designed prior to being restricted, and allow a nice smooth flowing air charge to enter the cylinders, as the port size and shape would now exactly match the runner size and shape.

If it does match up as stock (which is more likely to be the case tbh), then surely by fitting an M50 manifold with larger runner diameters, you would be introducing an instant diameter change when the larger runner meets the smaller port, leading to pretty horendous air flow through the engine as the air hits this sharp edge where the larger runner meets the smaller port.

So basically, has anyone who has done this mod noticed which intake manifolds internal runner diameters, actually match up correctly with their cylinders port diameters?

[BraveUlysses]

The M52 manifold runners don't match up, and you call tell that from the first pic because of the gasket spacing is identical on both M50 and M52 manifolds.

[E36M3E]

Even the M/S52 engines are based on the M50 platform. Theyare M50 intake ports.

BTW...been asked 50 times at least.

E

[Fr1D4y]

If that is the case, then I am genuinely shocked that a company reknowned for developing the worlds most refined straight 6 engines, would allow cars to roll off the production lines with stock intake flow characteristics like this, hence my question.

Needless to say, I will be swapping manifolds pronto.

Cheers for the info

p.s.
Anyone know if they did the same thing to the exhaust manifold as well?

[Fr1D4y]

Sorry to double post.

I was wondering if anyone has ever managed to fit a euro-spec s50 inlet manifold (the one with the individual TB's) to an M52 328 engine?

[LuvMy328is]

Sorry to double post.

I was wondering if anyone has ever managed to fit a euro-spec s50 inlet manifold (the one with the individual TB's) to an M52 328 engine?

I don't believe so. BUT at one time I think BMP had a conversion system that used the 6 ITB setup.
~Phil

[SergeK]

Even the M/S52 engines are based on the M50 platform. Theyare M50 intake ports.

BTW...been asked 50 times at least.

E

I gotta say one thing about this man right here. Eric is a great seller! His Kit was put together extremely well and his customer service is unreal. I emailed him a few weeks ago because i was in a bind. I previously installed the M50 mani a few months ago. Lately i noticed my car wouldnt idle and noticed my crank case hose was torn to shreds. I ripped the manifold off and found another vacuum line unplugged and couldnt figure out where it goes.. I emailed Eric and within 20 minutes, he calls me and help me out.

Simply Stellar customer service, support, and an awesome product altogether. If he had stickers, id pastem up and down on my car and tattoo his name on my ass!

[TIMSGT]

subscribed

[jehuflores]

This thread is gold!!! Awesome work ~Phil!

** subscribed

[McDani3coupe]

+1 for the sticky and rename!!!

[LuvMy328is]

Refer to my manifold picture. Notice the "Pinwheel" on the front? That easily determines it is the M50 manifold a.k.a OBD1 manifold.
~phil

[wopperjr]

As stated before does this swap benefit auto tranny 328's or severely cut down the power compared to stock? I'm thinking about a manual swap in the future, but have neither the time or money to do this as of now, and all my engine mods were going to come first. So...?

[LuvMy328is]

I'm certain the improvements will be noticed. There was just a 328is auto dyno'd in the Dyno thread a few days ago. Doing the 5spd swap should put about 5-10% more of the crank power to the ground though. I will try to find that dyno.
~Phil

EDIT:

Member: TCarlisle
New dyno on 10/12/2007 with the following mods:

Build Date: 4/97
Mods: Conforti CAI, Conforti Shark (S52 cam/M50 Manifold specific), Borla Cat Back, S52 Cams, M50 manifold, Fan Delete, ASC Delete, UUC Pulleys
Dyno Type: Dynojet, STD Corrected
Dyno Conditions: About 75 deg F
Gear Dynoed: 3 (Auto)
Peak HP: 203
Peak Torque: 182
Air/fuel: 13.5 - 14:1

Three dyno runs were performed, and results were consistent. 1st run was 201, 2nd run was 202, and last run was 203hp.

So basically, adding an M50 manifold and specific software and FDM and ASC delete and pulleys added 10hp to the wheels. Assuming 20% drivetrain loss (higher due to auto) the engine is putting out about 253hp at the crank (with 182K miles on the odometer). That is about 64hp over stock, for an increase of 34%.

I did the ASC delete by putting a rubber sewage pipe in place of the ASC and the stock boot, not the Samco boot. It works, but it is pretty soft and I do wonder if at high RPM when large volumes of air is being sucked in, if that soft rubber "sucks in" a little and maybe even oscillates thus disrupting the air flow. I will replace with a Samco boot, but am not dropping cash on another dyno run just to find out.

Injectors are orginal. I probably have a little bit of power to be gained just by having them professionally serviced and bring the spray volume and pattern back to what it should be. I am sure after 182K miles the injectors are a little "tired" and thus are losing me a few HP. I will do this in the spring, but again probably not worth another dyno run.

Here's the post

[E36M3E]

I gotta say one thing about this man right here. Eric is a great seller! His Kit was put together extremely well and his customer service is unreal. I emailed him a few weeks ago because i was in a bind. I previously installed the M50 mani a few months ago. Lately i noticed my car wouldnt idle and noticed my crank case hose was torn to shreds. I ripped the manifold off and found another vacuum line unplugged and couldnt figure out where it goes.. I emailed Eric and within 20 minutes, he calls me and help me out.

Simply Stellar customer service, support, and an awesome product altogether. If he had stickers, id pastem up and down on my car and tattoo his name on my ass!

Thx for the kind words. I'm gonna get my stickers made and call my tattoo guy!!

Eric

[jehuflores]

Thx for the kind words. I'm gonna get my stickers made and call my tattoo guy!!

Eric

There you go, when I read that comment I wondered when "Eric" would comment on it, lol.

[E36M3E]

Refer to my manifold picture. Notice the "Pinwheel" on the front? That easily determines it is the M50 manifold a.k.a OBD1 manifold.
~phil

careful though. there are M50 manifolds out there that have the pinwheel but are from a different model and have a different sized connector for the ICV in the back.

these manifolds can be drilled or you can use the earlier model part...I think it might be from the 525 as well. I just drill them.

Eric

[LuvMy328is]

careful though. there are M50 manifolds out there that have the pinwheel but are from a different model and have a different sized connector for the ICV in the back.

these manifolds can be drilled or you can use the earlier model part...I think it might be from the 525 as well. I just drill them.

Eric

Ok, according to Real OEM the Part# 11611735727 (INTAKE MANIFOLD) was found on the following vehicles:

E34: Details on E34
E34 525i SEDAN
E34 525i TOURING

E36: Details on E36
E36 325i SEDAN
E36 325i CONVERTIBLE
E36 325is COUPE
E36 M3 COUPE

So I guess the sure fire way is to reference that P/N

~Phil

[E36M3E]

Ok, according to Real OEM the Part# 11611735727 (INTAKE MANIFOLD) was found on the following vehicles:

E34: Details on E34
E34 525i SEDAN
E34 525i TOURING

E36: Details on E36
E36 325i SEDAN
E36 325i CONVERTIBLE
E36 325is COUPE
E36 M3 COUPE

So I guess the sure fire way is to reference that P/N

~Phil

yes and manifold part numbers ending in ...728 and ...730 (IIRC) are good as well. and PN 1161720612 is good too but it looks just like the offending manifold off of the model with the smaller ICV connector hole...but it has the bigger hole.

but even if you get the one with the smaller hole, can't remember the PN, you can still drill it or use the other connector.

Eric

[LuvMy328is]

Good info, moving it to the top of the thread

[AMDdude]

ok thanks, maybe we'll run again in a few days to see if there's a difference. I will be getting S52 cams eventually so i'll be waiting until then to get any kind of software. And yes I really need to get CAI I think it will make a BIG difference!

Hey, how is your car doing now? Did it get better? I'm thinking of also doing this swap, great thread!

[TIMSGT]

Just had my M50 mani installed by Eric (E36M3E). It only took about 13 hours and when he was done the car started right up and the idle smoothed out in under a minute. If there is any loss of low end torque I cant really tell, BUT from 3.5rpm on the car is noticeably more alive. With the pedal burried into the floor the engine noise is magnificent and the the needle seems to jump right to redline.

In addition to the cool noise it makes and the performance gains, and dispite the fact that I've been driving my car pretty hard lately, the M50 mani seems to have given me much better gas mileage. My last tank took me 410 miles with just under a gallon left.

This mod is a MUST for M/S52 owners. Forget about clear corners and tint for now and go get a M50 manifold and install kit at m50manifold.com. Eric is extremely knowledgeable and has great craftsmanship. This one is a no brainer, increase performance and save gas, two things that don't usually go together.


Special Note:
It didn't extactly take Eric 13 hours to install my manifold, in the middle of the install he was called into work unexpectedly for the day. The actual time it took was more like 3 hours.

[TIMSGT]

how do we get this thread parked?