Horsepower

hplug

hplug

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I am building a motor for my 72. I have a 3.5 available as well as the stock 3.0 but I have been contemplating a S54 out of an E46 M3 which is stock at 333 horsepower. If I went this route I would mate a 6 speed and thing I have figured out how I can use the stock speedo.

My big question is car the E9 handle this power, everyone has heard the horror stories of too much power. I dont mind some bracing like strut towers and a cross on the undercarriage but I do not want anything inside the car that would effect the look of originality i.e. roll bars etc. What do you guys think?
 
I have an S38 in my car and I'm not the only one. I would recommend going up that far in HP only if you do a full strip-down renovation and add chassis strength through various methods (for example, I have tubbed out my trunk and added stringers as well as stringers under the seats, etc. - you can see most of this on other threads). Coupeking's website has some information. If you don't do this you will be likely to experience chassis flex and (probably sooner if not later) start tearing things apart.

The S54 could be used (I looked into it) but is a lot more work than the S38 or similar motors for not much more if any power.

With a 6-speed you will have console issues, probably more than the folks like me who have a 5-speed but maybe not. Also, you might have an issue with trans fitment under the car.

They do make electromechanical conversion equipment to take the reading from newer transmissions and convert them to run a mechanical speedometer. I had one that I never actually used since I went with a 265 Getrag instead, but it's possible.

Another point is that while the sideloader diff can handle maybe 400HP, that's in well-sorted original form. I killed my 3.45LSD and was fortunate to have another diff already far along in the build process.
 
Yeah, the general opinion is that the S54 is much more of a headache than the S38 for not a lot more performance. The S38 is still no walk in the park compared to a later M30B35, which is pretty drop-in.
 
Educate a total n00b here. I thought the 3.0 BMW engines were pretty much the same across the years as far as transmissions, mounting points, etc. Not unlike small block Chevy's. The only big difference would be in the induction and exhaust systems but the base engine and head is basically the same.

So are there major hardware (mounting points, actual engine size)differences in the basic configuration between say, the M30B35 and the S38?
 
Bwana said:
Educate a total n00b here. I thought the 3.0 BMW engines were pretty much the same across the years as far as transmissions, mounting points, etc. Not unlike small block Chevy's. The only big difference would be in the induction and exhaust systems but the base engine and head is basically the same.

So are there major hardware (mounting points, actual engine size)differences in the basic configuration between say, the M30B35 and the S38?
Click to expand...

It seems like it depends on whom you ask, but my project required special motor mounts (basically, the "motor-side" of the S38 mount grafted on to the "body-side" of an E9 mount, so not that difficult). The real issues are around things like brake boosters, intake issues, battery location, etc. - the entirety of the engine with accessories takes up more volume.

I've heard of folks who had to hammer the firewall but I didn't have that issue.
 
hplug said:
I have been contemplating a S54 out of an E46 M3 which is stock at 333 horsepower. If I went this route I would mate a 6 speed
Click to expand...

Seems to me that the more power you have, the fewer transmission speeds you need. Big GM V8's got along fine with 2-speed Powerglides.

Multi (e.g., 5+) speed transmissions are only necessary when your engine has a narrow torque band - like with a small-displacement engine.
 
The Powerglide was the default GM auto tranny until the mid 60's. You got it behing everything from the 2.5L four cylinder in the Nova , the 2.3L Corvair six, even the 2.3L Vega.
 
Here is a link to a youtube video of someone who has done this conversion:

http://www.youtube.com/watch?v=6aW8zxClvW4

Here is the title if the link doesn't work: 1972 BMW 3.0 CS WITH A 1997 M3 MOTOR.wmv

On the s38 conversion; I was seriously considering this myself, then decided to do a hybrid (s38 intake mated to a M30B35 block). Ultimately I ditched that project because it was over the head of the shop I was using to make it work. I settled on the tried and tested M30B35, MSII, 320i intake runners, etc. done by Coupeking and Don Lawrence. I remember visiting Coupeking's shop and seeing a verona coupe with an s38 conversion that looked impossibly sweet. Erik; however, said he prefers the M30B35 as it is more suited to the coupe's GT nature, can make similar power with some fettling, and has lower operational costs.

I've driven an s38 before. It was in a 1984 745i (special for South Africa) and it was a blast to drive. But that car was a tank compared to the coupe and could handle all that power. I've also driven a coupe with the M30B35 setup (LaJolla Independent) and have to say that the hp/torque combo were just about perfect for that car. Maybe a slightly hotter cam to make it just a little livelier off the line would have been a decent upgrade, but other than that, it was awesome for the kind of mostly laid back driving I do.

If you like/need something a bit more rev happy, then definitely go the s38/s54 route, but I wouldn't think you would need a roll cage unless you routinely autocross or bump the redline when you drive. How often do you get to wring the engine's neck so-to-speak? If the engine is more for show, and I am not knocking you if it is, then I think the bracing you mentioned would be sufficient.
 
Ive done probably the closest thing to an S54 in a cs , I put one in my e12 racer. It was not easy and it was ton more work than I expected.
the e12 and e9 will have many of the same things to over come

#1 the exhaust from the s54 runs right into the steering linkage
#2 the intake /airbox will hit the brake master and booster
on the e9 it will be worse because the base where the booster bolts to, sits further out in the engine bay
#3 elctronics ,
A) ews , either you will spend at least 1500 to reprogram it out of stock ecu or spend thousands more on stand alone
B) electric throttles , I kept them , and have DBW in my car, still working those bugs out

4) oil pan, the s54 has a dual sump with dual pickups, you most likely need to convert it to a single front sump with single pickup no mater what subframe you end up with
5) this is all before motor mounts, trans, trans mount , drive shaft, chassis reinforcements , etc
6) mine was put into a full racecar so there will be a lot more work to "civilize "it for street use, like ac, idle control, etc


A customer asked me how much I would charge to do this to a CS , in all seriousness , I said 40 k at least .

here is a link to the build thread I did

http://forums.bimmerforums.com/forum/showthread.php?t=1546476

Im starting a new project, where Im building a CSL Racer, My original idea was to use the s54 , I have changed my mind and going with an s38b36

The S54 is a really cool motor, They will turn some serious RPM, The power this thing makes with only 3.2 L is crazy. You can programn where the cams come on and really dial in your power curve to hit where you want. was it worth it , yeah it was, but Im not doing that much work again , no matter how cool it would be to have an S54 powered e9 ( unless some want to pay me to do it!)

lastly here is a video from a couple weeks of ago enjoying the fruits of all that work

http://youtu.be/LM5Tq5ZiWNY?hd=1
 
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