S54B2HP

[wyshyvanuk]

Hi. Has anyone looked at modifying our ///M S54 engines to some of the specs on the S54B2HP engine, as found in the M3 CSL? Camshafts, alone, would be about $1700. I'm guessing that with some of the other necessary parts, you'd be in the $3K neighborhood, and still not match the 355 HP figure shown. But hope springs eternal.

From a couple of web sources:

"Streamlined, lightweight S54 engine, mounted only on the M3 CSL E46 and officially designated – S54B32HP. Its peculiarity lies in the air intake of carbon fiber, modified camshafts, lightweight exhaust manifold (intake and exhaust manifolds slightly improved engine performance), the DME control system and more efficient air intake system, which is supplied mainly from the round hole on the front bumper. In addition to this, the vehicle is equipped with lightweight exhaust system made of thin steel."

"An upgraded version of the S54 engine was used in the E46 M3 CSL. This engine is designated S54B32HP and the changes include a revised intake made from carbon fiber, revised camshafts, a MAP sensor (instead of the MAF sensor used in the regular S54), a lightweight exhaust manifold with a straighter air path (which later become standard on the regular S54) and a straightened intake manifold."

[Azeka1]

Common path is: Schrick Cams, CSL Intake (BimmerWorld, Evolve, etc), headers and tune. Compared to an FI application, it will always be relatively more expensive to extract power out of an NA motor.

M-Cast build also included a stroker kit and made 377HP at the wheels: https://www.zpost.com/forums/showthr...1399423&page=6

mattfwalters is a very nice build to look into as well:
https://www.zpost.com/forums/showthread.php?t=1417073

[M-Cast]

Originally Posted by Azeka1

Common path is: Schrick Cams, CSL Intake (BimmerWorld, Evolve, etc), headers and tune. Compared to an FI application, it will always be relatively more expensive to extract power out of an NA motor.

M-Cast build also included a stroker kit and made 377HP at the wheels: https://www.zpost.com/forums/showthr...423&page=6

mattfwalters is a very nice build to look into as well:
https://www.zpost.com/forums/showthread.php?t=1417073

There are a few in and outs on the stroker motor and it's not the cheapest route, but it's awesome on the track. Mine is a fuller built race motor and I spent close to 30k on the engine. It's not the way to go if you are on a budget, but if you are going to track the car you will pick up about 125hp to the wheels from stock. Crank Hp on my car is around 430hp

[wyshyvanuk]

Thank you, gentlemen. Exactly the information I was seeking.

[mattfwalters]

Originally Posted by Azeka1

Common path is: Schrick Cams, CSL Intake (BimmerWorld, Evolve, etc), headers and tune. Compared to an FI application, it will always be relatively more expensive to extract power out of an NA motor.

M-Cast build also included a stroker kit and made 377HP at the wheels: https://www.zpost.com/forums/showthr...1399423&page=6

mattfwalters is a very nice build to look into as well:
https://www.zpost.com/forums/showthread.php?t=1417073

Thanks for the kind words. Mine hasn't run yet, let alone hit the dyno, so your guess is as good as mine about horsepower.

As I understand it, though, a significant amount of the CSL's horsepower gain comes from running alpha-n (RPM vs. throttle position) after opening up the breathing with the cams. i.e. it sacrifices efficiency (power, fuel consumption) at mid-throttle and safety (lack of MAP / MAF) everywhere in order to make maximum full-throttle power.

So it all depends on your goals. Note that the Schrick cams are around $1,700 but you have to replace your followers at the same time - all 24 of them - and they're at least $50 a pop. So cams are a $3k hit, and you do need the improved breathing (airbox + exhaust headers) to take advantage of those big nasty cams, and then there's tuning. And if you put a CSL airbox on, you're running alpha-n and part-throttle sucks and don't drive your California-tuned car in Colorado...

So I'm taking a slightly different route and running speed-density (RPM vs. MAP sensor) with a CSL-style airbox and 288/280 degree cams. I've also taken a bunch of weight out of the rotating assembly (pistons, rods, valves). I'm looking at the "rev higher" approach, and we'll see how that goes. Kind of trying to build a pretty rev-happy peaky engine that can be managed safely by careful electronics.

I suspect that M-Cast made the right choice, in the end. More displacement means more power everywhere and at lower RPM, which is way easier on the engine than either forced induction or dizzying rev limits. I've got around $20k in my engine and it's going to be a lot more delicate than his.