S54B32 - the best engine this side of supercar lunacy!
- Thread starter Beats
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BMWZ4MC said:It would be far less fun in the E89 - it would spin up the inside rear wheel and not make much further progress. It doesn't have an LSD as it's designed to be a boulevard cruiser / tourer and not a serious sports car (by which I mean for track use etc so please let's not have another debate about the definition of a sports car as I'm not trying to detract from the E89 just highlight its different design brief).
THISSSSSS
On these roads all grimy and horrid, I can't peg it in 2nd without wheel spin... Not sure I'd want MORE torque 
The Z4M isn't an everyday driver, let's face it. For everyday driving the 3.0si is a much easier car to live with. But for driving like a hooligan, the S54 provides ample power, noise and smiles
The Z4M isn't an everyday driver, let's face it. For everyday driving the 3.0si is a much easier car to live with. But for driving like a hooligan, the S54 provides ample power, noise and smiles
BMWZ4MC said:
^ +1
From datalogging my Z4MC, acceleration in all gears from around 2000rpm is virtually linear throughout the rev range with a bit of a decline at around 7500rpm and above, this shows that there's sufficient torque to sustain a constant rate of acceleration from low revs which is what really matters. Datalogging also shows that the ECU regulates fuelling in 1st gear as a torque limiter to ensure that acceleration is constant in this gear too. However, as we all know, if you really want to accelerate fast, you would take the revs to nearer 8k rpm in a lower gear and then change up which would then bring you to above 5k rpm in the next gear, so any complaint that the S54 engine is lacking low down torque is both untrue and pointless.
You only have to look at the in gear acceleration times to see the lack of torque comment is nonsense. Even now, as a 10 year old car and a 15 year old engine the Z4M has in-gear times that would, at best embarrass and at worst, keep honest, the current crop of turbo'd mega-hatches.
Not sure Flimper. I've only ever driven one and that was on a track. Would depend on its weight (it was a lardy old thing the E92), the torque curve and gearing I suppose. Off the top of my head hasn't it got about 295lb/ft? Not sure what revs that is delivered at or how flat the curve is though.
I posted the Z4MC in gear times a couple of years ago and they would still be considered quick now.
I posted the Z4MC in gear times a couple of years ago and they would still be considered quick now.
I had a look at both engine's power curves side by side. The difference between a naturally aspirated (NA) engine (no forced air induction) vs a forced air induction engine with twin turbos. Turbos engines make huge amounts of torque with little effort. (all my 3 Z4m's where put on a dyno so just averaged the data from all 3) the turbos on my e89 are smaller and runs at 8.8 psi and you feel no lag as they spool up quick.
IMHO, for street driving up to 120 mph+, torque is far more important than horsepower. Torque is that axle twisting, seat of the pants feeling you get when you take off from a stop light. Horsepower really comes into play around 5,000 rpm and above.
You will note the z4m engine builds torque slowly off the line and then peaks around 4,900 rpm at 262 Ibft. This engine would depend on higher rpm's and horsepower even for everyday driving - just like it's older brother with it's very peaky s52. You'll have to keep you foot in the go peddle most of the time to get maximum enjoyment. Note reaches max horsepower just before 7900 rpm!
The Z4 35is twin turbo engine on the other hand, has a nice flat torque profile (1500 - 5000 rpm). It reaches max torque just above idle and stays there until almost 5,000. This engine is a street engine that will take you to 120 mph+ in a hurry and then reaches maximum horsepower at 6,000 to 6,500 rpm. The 35is will produce 331.9 lb/ft from 1500 rpm then the 500Nm overboost (368 lb/ft) on hard acceleration.
So in comparison, the Z4M may have slight better track suspension (harder springs, etc.), but would not a really be a great overall daily driver + high performance car like the Z4 35is. As I said I think both cars are great and go about their business in different ways, would I own another Z4M E85 .. yes I would, has the E89 faults that niggle me .. yes sure it has.
As said just a comparison debate as I have owned both models and not knocking any of the forum owners, as the Z4M is a great car .. but I feel people dismiss the 35is without really owning one, a quick test drive is no good.
when I was making the point about low torque I was referring to the below
for a Z4M
at 2000 rpm - it is just above 190 lb/ft
at 4900 rpm - it is just above 262 lb/ft this is peak
at 7900 rpm - it drops to roughly 206 lb/ft
when I spoke to DMS yesterday for a ECU flash upgrade for the 35is e89 (with unlimited re flashes back to stock) I would get 402 BHP with 453 lb/ft without one mechanical mod. Also the 35IS gets the extra cooling and duct oil coolers like the 1M.
Also the whole LSD debate is easily fixed with a Quaife ATB LSD for about just over a £1k if one was needed. Also when I start my E89 35is up it sounds exactly the same as a Z4M, and with the 10db sports exhaust (with vacuum flaps) as standard sounds just as nice as the Z4M S54
Any way all the above is just my input from owning both cars .. just a opinion, I am not saying one is better then the other .. both get to 4.8s 0 - 60 in different ways.
enough from me .. enjoy the rest of the weekend
Best regards
IMHO, for street driving up to 120 mph+, torque is far more important than horsepower. Torque is that axle twisting, seat of the pants feeling you get when you take off from a stop light. Horsepower really comes into play around 5,000 rpm and above.
You will note the z4m engine builds torque slowly off the line and then peaks around 4,900 rpm at 262 Ibft. This engine would depend on higher rpm's and horsepower even for everyday driving - just like it's older brother with it's very peaky s52. You'll have to keep you foot in the go peddle most of the time to get maximum enjoyment. Note reaches max horsepower just before 7900 rpm!
The Z4 35is twin turbo engine on the other hand, has a nice flat torque profile (1500 - 5000 rpm). It reaches max torque just above idle and stays there until almost 5,000. This engine is a street engine that will take you to 120 mph+ in a hurry and then reaches maximum horsepower at 6,000 to 6,500 rpm. The 35is will produce 331.9 lb/ft from 1500 rpm then the 500Nm overboost (368 lb/ft) on hard acceleration.
So in comparison, the Z4M may have slight better track suspension (harder springs, etc.), but would not a really be a great overall daily driver + high performance car like the Z4 35is. As I said I think both cars are great and go about their business in different ways, would I own another Z4M E85 .. yes I would, has the E89 faults that niggle me .. yes sure it has.
As said just a comparison debate as I have owned both models and not knocking any of the forum owners, as the Z4M is a great car .. but I feel people dismiss the 35is without really owning one, a quick test drive is no good.
when I was making the point about low torque I was referring to the below
for a Z4M
at 2000 rpm - it is just above 190 lb/ft
at 4900 rpm - it is just above 262 lb/ft this is peak
at 7900 rpm - it drops to roughly 206 lb/ft
when I spoke to DMS yesterday for a ECU flash upgrade for the 35is e89 (with unlimited re flashes back to stock) I would get 402 BHP with 453 lb/ft without one mechanical mod. Also the 35IS gets the extra cooling and duct oil coolers like the 1M.
Also the whole LSD debate is easily fixed with a Quaife ATB LSD for about just over a £1k if one was needed. Also when I start my E89 35is up it sounds exactly the same as a Z4M, and with the 10db sports exhaust (with vacuum flaps) as standard sounds just as nice as the Z4M S54
Any way all the above is just my input from owning both cars .. just a opinion, I am not saying one is better then the other .. both get to 4.8s 0 - 60 in different ways.
enough from me .. enjoy the rest of the weekend
Best regards