Half The Cylinders, Twice The Fun: The M5-Powered 836CSL

[Echo31]

http://www.speedhunters.com/2020/02/...owered-836csl/

Thoughts?

[jclausen]

Interesting

[Belgiumbarry]

it stays a "heavy" car…. and will miss torque out of that 6 cilinder S38..... i had a M5 like that , only comes alive above 4000 rpm… better for track , not road.

[WildKarrde]

it stays a "heavy" car…. and will miss torque out of that 6 cilinder S38..... i had a M5 like that , only comes alive above 4000 rpm… better for track , not road.

He actually got the weight down to 3500lb, which is a pretty respectable achievement! I'm sure that engine absolutely sings in that car.

I've always wondered if anybody had ever tried to put an M30 in the E31, looks like this guy took it up one notch! I'm sure from a performance perspective it wasn't worth what it cost him to build this car, but it is a truly gorgeous specimen.

[shogun]

Have seen that car on some meetings here in Japan and also on a drift course, he likes drifting
My wrenching buddy made some videos years ago when he drove with him on a drift course and 2 videos also show the engine running with hood open
drift course https://www.youtube.com/playlist?lis...R51wTjGErD4c5P
engine running
https://www.youtube.com/watch?v=0bNb6oHg1_w
https://www.youtube.com/watch?v=vB21e41SweY

Ebisu Circuit – The Home Of Drifting https://driftinjapan.com/ebisu-circu...e-of-drifting/

[m6bigdog]

I'd stay away from the S38 motor.
I have a 1991 M5 with S38B36 (owned since new) sitting along side my 1997 850 M73B54 (owned since 2004) in the garage.
The S38B36 (high RPM HP motor) has the engine sounds to die for, however the M73B54 (torque monster) is King for cruising.
With that, more V12 have been put into E34 chassis than L6's have been put into the E31 and for good reasons!!
The S38, L6 engine (extremely limited production 12,200 cars 1998-1996) will cost you more than any other motor you could put into an E31 and it only has 315 Hp and 265 lb-ft of torque.
The S62B50 V8 from the E39, M5 with 394 HP & 369 lb-ft of torque would show much more power and be a less expensive motor swap.
Personal experience: I have chased all kinds of cars on the mountain roads of California and while the M5 may scream like a banshee at 7k RPMs as you row through the gears the 850 with the 5.4L V12 and 5-speed auto is faster despite the extra weight.

[TedBobo]

Interesting....

[Hyper]

... the M73B54 (torque monster) is King...

This is completely supported by the math.
The B36's 266 ft-lbs vs 3500 is equivalent to the 4.4 V8 vs 4100 lbs, which is to say not very impressive.
On the other hand, which would you rather toss into a corner, 4100 or 3500 lbs.

[m6bigdog]

This is completely supported by the math.
The B36's 266 ft-lbs vs 3500 is equivalent to the 4.4 V8 vs 4100 lbs, which is to say not very impressive.
On the other hand, which would you rather toss into a corner, 4100 or 3500 lbs.

Hyper, vehicle weight is a single component if road performance; not the end-all-be-all.
Suspension geometry, roll stiffness and tire patch/compound can be a more significant contribution.
If chassis weight was the determining factor then the lightest vehicle would always be faster and more agile.
I also love chasing down the assumed performance cars on mountain roads with my Tesla P85D which weighs 4900 lbs.
Oh, the Tesla's advantage is all wheel drive and 690 lb-ft of torque.
So the Tesla may not be the fasted going through the turn but exiting, you better be prepared for a whole new experience.
That is, if you can get the passenger to let go of your neck and stop screaming.
The Tesla is first car I have owned that REQUIRES that you change lanes before you hit the throttle when passing. Yep, several close calls with the instant acceleration!!

[e31bev]

I'd stay away from the S38 motor.
I have a 1991 M5 with S38B36 (owned since new) sitting along side my 1997 850 M73B54 (owned since 2004) in the garage.
The S38B36 (high RPM HP motor) has the engine sounds to die for, however the M73B54 (torque monster) is King for cruising.
With that, more V12 have been put into E34 chassis than L6's have been put into the E31 and for good reasons!!
The S38, L6 engine (extremely limited production 12,200 cars 1998-1996) will cost you more than any other motor you could put into an E31 and it only has 315 Hp and 265 lb-ft of torque.
The S62B50 V8 from the E39, M5 with 394 HP & 369 lb-ft of torque would show much more power and be a less expensive motor swap.
Personal experience: I have chased all kinds of cars on the mountain roads of California and while the M5 may scream like a banshee at 7k RPMs as you row through the gears the 850 with the 5.4L V12 and 5-speed auto is faster despite the extra weight.

I would love to put in the s62 on my 840 but too bad I live in California
Do you know how difficult is the swap and perhaps the potential to get it bar'd in cali?

[Fatandre]

I have been considering a s85 swap

[8eights]

Thought you already have a S/70

Force induct it.

[Brandon J]

Had the S38 3.6 and with the right modifications, it screams. The mid to upper end torque issue are mainly solved by using 3.8 cam gears which move the torque band lower, a good performance chip (since gas has improved), and the right gearing to a 3.91. An M5 wagon is not far off the weight of an e31 M70 and if this person reduced weight lower than a stock e34 M5, then I am sure it screams. Plus, the S38 is really a race->street engine that has solid lifters, sodium-filled valves, beautiful stainless steel headers from factory, and can take the beating. Mine dyno'd at around 272 wheel HP on a Mustang dyno (those typically measure lower), which equates to ~330hp at the engine. I had a 4.5k rpm operating range between 3000-7500, so most of the time I never changed past 3rd gear during spirited driving.

Performance chips are where a lot of the power comes with this old engine and Dinan, which only tunes above 4k rpm, is one of the worst tunes for the S38. Powerchip and Landzer are really good since they log real-world time/data. I confirmed with safe A/F in my dyno runs with both chips. Not only looking at peak numbers, the area under the curve (AUC) for torque/HP filled out real nice in every rpm giving very usable power even in part-throttle. Heck, still I daily drove my e34 S38 during winters and city traffic.

Even with 2 passengers in the e34, I would beat the e31 M70 (brother drove the 850i with the Comforti chips, S3 mode) at the stoplight and highway. M70 is well maintained. As a head to head difference, I think while torque is force, the horsepower here is how the torque is being realized in speed. Perhaps also less rotating mass contributes to the engine spinning up faster too. No doubt, the S38 with mild mods is faster than an M60 in an e31 (my e34 S38 was faster than several e34 M60s). I sold the 3.6, but wonder if the e31 M70 would have done better with an EML chip.

The e34 S38 was for fun and a good sleeper, but the e31 is still the long-term keeper. I had to "explain" the e34 for people to get it, not so with the e31.

[Echo31]

I'd stay away from the S38 motor.
I have a 1991 M5 with S38B36 (owned since new) sitting along side my 1997 850 M73B54 (owned since 2004) in the garage.
The S38B36 (high RPM HP motor) has the engine sounds to die for, however the M73B54 (torque monster) is King for cruising.
With that, more V12 have been put into E34 chassis than L6's have been put into the E31 and for good reasons!!
The S38, L6 engine (extremely limited production 12,200 cars 1998-1996) will cost you more than any other motor you could put into an E31 and it only has 315 Hp and 265 lb-ft of torque.
The S62B50 V8 from the E39, M5 with 394 HP & 369 lb-ft of torque would show much more power and be a less expensive motor swap.
Personal experience: I have chased all kinds of cars on the mountain roads of California and while the M5 may scream like a banshee at 7k RPMs as you row through the gears the 850 with the 5.4L V12 and 5-speed auto is faster despite the extra weight.

I completely agree. It's an interesting departure, and good to know someone out there did something truly silly with their 8.

[Stantz]

I’m not certain that it’s exactly 2X more fun than the normal V-12 version, but it does look like an amazing example of skill, technical knowledge, persistence, and perhaps a bit of insanity. I like it!

[dragon850]

Does anyone have a lead on an s38 for sale? I would love to convert E32 735i manual...

[shogun]

On German regional Ebay: Bmw e34 M5 S38B36 Motor 5.000 € , offer no./ Anzeigennr.: 1319765094 https://www.ebay-kleinanzeigen.de/s-...65094-223-4480
S38 are rare and expensive