S52 vs S54 M Coupe ( I have one of each)

Ok guys, about two weeks ago, I bought a 2001 S54 M Coupe.
Until I sell my S52 M Coupe, I have both cars to play with (and no $$$)

When I just had my S52 M Coupe and tried to defend how great I thought the S52 engine was and compared it to the S54 engine, I was blasted
by all the S54 dudes, defending their S54 engine. I really enjoyed the debates because it helped me decide if I really wanted to upgrade to a S54. Well, you guys must have done a good job because now I have a S54 M Coupe. Now I am trying to defend my OWN purchase of the S54 M Coupe.

I am going to upgrade the stock 3.15 diff to a 3.73 diff, as soon as I sell the S52 M Coupe.

I did some time testing with both the S52 and S54 M Coupes on my favorite stretch of (flat no-curve) expressway, this last weekend.

There is a test that "Metric Mechanic" suggests to test all cars/engines to eliminate the driver's skill level and to make all things even.

They call it the 60-80mph test in 3rd gear.
They claim that most engines are in there peak torque/horsepower RPM range at 60-80mph in 3rd gear (I now believe the S54 is higher).

Well, I tested both the S52 and S54 with this test.

The S52 times were 2.6, 2.7, 2.8 seconds, every time from 60-80 mph (4320-5760 RPMs) with the stock 3.23 diff.
The S54 times were all above 3.0 seconds, every time from 60-80 mph (4213-5617 RPMs) with the stock 3.15 diff. I could not get a time under 3 seconds. I was really shocked.

I know that the S54 torque curve is higher at an earlier RPM and stays flat longer and than the S52, which supposed to be better.
I also know that the S52 with the "Shark" software and CAI (like mine), does have more torque, for a real short RPM range (around 4000 RPM), but still I really thought that the S54 would produce lot better times than the S52.

I believe this test just happened to be testing the S52 in it's strongest RPM range.
I'm sure if the test was 50-90 mph, the S54 would have better times......I hope...
I hope with the 3.73 diff in the S54 makes a lot of difference.

I also received the latest software update from my BMW dealer Saturday on my S54 engine.
The BMW mechanic told me that ALL the S54 software updates were for the "Cold start" problem and not the throttle respond problem. Is that true?

Also, we talked about how BMW purposely "DE-tuned" the S54 engines for the M Roadster & Coupe from 333HP to 315HP, so they would not out perform the M3. It was not due to the more resticted exhaust system in the M Coupe (I had heard this before).

He said that the Dinan software upgrade for the S54 for M Coupe simply changes the engine back to 333HP. Is this true? I believe Jim Conforti now has "Shark" software for the S54. Is this true?

Oh, by the way, I have one of the best looking, best running and best maintained 1999 M Coupe FOR SALE. Someone better come and buy before I decide to keep it and sell the S54 (just kidding).



2001 M Coupe
Steel Gray with Imola Red/black
BBS RKII wheels

AFAIK the less HP is a combo of exhaust differences, intake diffeences and lower redline (7400 versus 8000).

Yes, Conforti has a Shark out for the 54, and I personally would believe that his claims are closer than Dinans claims.

Why not test your two at 50 - 90 and 60 - 90 and see if that helps the S54. But the S54 has a pretty flat torque curve, so its strength is in that the acceleration is pretty much the same throughout the rev range, unlike the S52, which does a a very definate peak.

And yes, to get a software upgrade at this point, you have to complain abuot cold start issues. I have to call and get our M3 in this week.

Airbox. The Coupe has a smaller airbox on it to fit under the Z hood.

We need to change this before we can change the software.

Mpire

Originally Posted by Pinecone

AFAIK the less HP is a combo of exhaust differences, intake diffeences and lower redline (7400 versus 8000).

Yes, Conforti has a Shark out for the 54, and I personally would believe that his claims are closer than Dinans claims.

Why not test your two at 50 - 90 and 60 - 90 and see if that helps the S54. But the S54 has a pretty flat torque curve, so its strength is in that the acceleration is pretty much the same throughout the rev range, unlike the S52, which does a a very definate peak.

And yes, to get a software upgrade at this point, you have to complain abuot cold start issues. I have to call and get our M3 in this week.

I drive a S54 M ROADSTER, I've tested the redline is 8000RPM as E46 M3's S54.
Well, if Dinan's software will turn back my M roadster back to 333HP, I will do it immediately

Originally Posted by songziou

I drive a S54 M ROADSTER, I've tested the redline is 8000RPM as E46 M3's S54.
Well, if Dinan's software will turn back my M roadster back to 333HP, I will do it immediately

Interesting, as the publsihed one is 7400 aqnd the Shark Injector takes it up.

But teh S54 rev limiter is known to be soft. M3s have been taken well over 8000 with tripping the limiter. Each car seems to behave slightly differently.

And no way does the Dinan software give you back the 18 HP.

This board is getting to be like the comics,But it has some real funny but fun articles to read!This info is like saying the if you add Jon`s spare tire you will go faster.

Originally Posted by ARC///M

if you add Jon`s spare tire you will go faster.

That's just nuts.

Now - on the other hand - if you upgrade to curved M badges, well then that's a horse of a different color.

Well I can not remember what Ron said with the tire it is faster in a side by side or that wright if the tire light comes on he wins any way~!So yes the tire makes you faster if yours is flat.P/S THE S-52 May be faster in the long Run as engines are still stopping permentaly in are S-54 cars.aLSO jon give me a price on the tire please!And how much for the 99 coup please.I want one to race.

Originally Posted by Pinecone

Interesting, as the publsihed one is 7400 aqnd the Shark Injector takes it up.

But teh S54 rev limiter is known to be soft. M3s have been taken well over 8000 with tripping the limiter. Each car seems to behave slightly differently.

And no way does the Dinan software give you back the 18 HP.

Rev limit on the M-Z3's is 7600. But like the speedometer the tach is also not accurate.

The S52 times were 2.6, 2.7, 2.8 seconds, every time from 60-80 mph (4320-5760 RPMs) with the stock 3.23 diff.

Sounds like you have been correct all along....lol, IMO 60-80 mph does me very little or no good at all. But a cool bit of info you have provided.

My favorite barometer is the tried and true 0-100 MPH, easily done & would tell you which car is packing the hot-sauce ! perhaps you can do this & test the S54 with both axle ratios...???

I will bet the 0-100 test will turn the tables a bit.

Hopefully you end up keeping the right car too !!

Are there any relations between the de-tuned 18HP and MZ3's 5MT instead of M3's 6MT ????????

Originally Posted by songziou

Are there any relations between the de-tuned 18HP and MZ3's 5MT instead of M3's 6MT ????????

No. As Terry said, it has to do with engine breathing, or lack thereof.

Originally Posted by Ron Stygar

Rev limit on the M-Z3's is 7600. But like the speedometer the tach is also not accurate.

Ron ... The tach may not be accurate, but I sure hope the rev limiter is! Would you know?

Originally Posted by D///Mill

Ron ... The tach may not be accurate, but I sure hope the rev limiter is! Would you know?

I would think so. I'll check it this Spring.

Originally Posted by JonM

That's just nuts.

Now - on the other hand - if you upgrade to curved M badges, well then that's a horse of a different color.

And I thought the oil baggie was good for 20 hp not to mention the taco I had for dinner last night...

Originally Posted by Ron Stygar

Rev limit on the M-Z3's is 7600. But like the speedometer the tach is also not accurate.

How for off is the tach? I use it as my speedometer.

Originally Posted by D///Mill

Ron ... The tach may not be accurate, but I sure hope the rev limiter is! Would you know?

At least int he M3s it is not. It is quite soft. People have gone WELL past the rev limit and it has later shown up in a DME dump (failed engines early in the time frame).

BMW used the DME dumps to "prove" missed shifts, until SMG cars started showing up with failed engines and DME dumps showing 8200 - 8500 max RPM.

Originally Posted by ///M Rakete

How for off is the tach? I use it as my speedometer.

me too...

i have tested the "tach as speedo" against gps and it was w/in 2mph.

I have a 2001 S54 that I was thinking about selling, and I was wondering if you knew a good price to set it at? Or if you knew a good place to sell it. It is a rare car and a lot of people don't know what it is.

Thanks,
Ken

Try Rondel that real safe,Or Ebay.

Originally Posted by kenkalan

I have a 2001 S54 that I was thinking about selling, and I was wondering if you knew a good price to set it at? Or if you knew a good place to sell it. It is a rare car and a lot of people don't know what it is.

Thanks,
Ken

And this 3 year old thread has something to do with you selling a car because....

Originally Posted by blairrm

And this 3 year old thread has something to do with you selling a car because....

I had a very early 2001 M3 (neat car no roof hole & M cloth inserts) and now have very early 2006 Z4MC. Are both S-54?

I think he sold the S54 for around $34K.

I wouldn't expect to get that much w/o a motor warranty in the dead of winter.

Wonder how he likes the Z4 Coupe compared to the Z3s. Respond if you are out there Dennis.