speed six motor Vs Bmw S54B32 (m3/Z4M)
Discussion
my local track was literally packed with tvrs this weekend, i was particuarly intrested in the speed six motored cars (sagaris, t350c ect ect) and i have to say what a gorgeous sound they make and even more they really do rocket those cars around, it just got me wondering how does the tvr motor stack up against the infamous s54b32 of the 46 m3s / Z4Ms ect ect?? torque and BHP wise whats the difference? and more importantly why doesny my ///M sound anywhere near as good, imo of course!??
The Speed 6 engined cars are a little more powerful than the M straight sixes, but they do have a larger capacity engine. Specific output is a little lower; 350bhp from the 3.6 TVR, and roughly 360bhp from most 4.0s, so less than the 100bhp/litre claimed from the M motor. The extra displacement of the TVR engine also gives you a bit more torque; 290lb.ft in the little 3.6, and 310 in the 4.0, compared with 260lb.ft in the BMW if I remember correctly.
Unlike the older Rover engined TVRs, and the AJP V8 in the Cerbera, most Speed 6 cars actually seem to produce the quoted power (or very close to it) on the dyno. I hear the M54 and S54 engines are also typically a little down on quoted power, so nothing much different there.
Mechanically the engines are quite similar: both twin cam 24v straight sixes, with individual throttle butterflies for each cylinder. In my view the big difference is the level of technology and refinement. The M/S54 engines feel very smooth, with very little mechanical noise and vibration, and has modern advances like variable valve timing. The Speed 6 by comparison is much more agricultural; no fancy valve control, not especially well balanced (it has a huge crankshaft damper), and lots of mechanical noise from the complicated timing chain setup. I'm not going to comment on reliability, as the Speed 6 top-end woes are pretty well documented, as are the VANOS and bearing shell failures on the BMW!
Basically the BMW engine shows what improvements you can expect in terms of refinement and longevity if you invest about 1000 times more than TVR did in the development of an engine, and if you're building evolutionary improvements to a proven design.
As for sound, have you ever heard the M straight 6 in a Weissman roadster? It sounds nothing like a standard BMW installation. Similarly for the BMW V8s in modern Morgans. The unique Tuscan and T350 sound is largely down to a distinct lack of silencing, very simple airbox/air filter layout, large diameter exhausts, and a simple arrangement of 3 cylinders for each exhaust pipe. I suspect if you stuck a pair of straight pipes on an M roadster it would sound almost as lairy, although without so much of the "nails in a cement mixture" clattering!
I'm surprised that no-one has put a BMW M straight six in a Tuscan yet. There was a Cerbera around with such a conversion a few years ago, but I hear that the engine is too tall for the Tuscan bonnet design - I'll wait to be proven wrong on that one though.
Cheers,
Pete
Unlike the older Rover engined TVRs, and the AJP V8 in the Cerbera, most Speed 6 cars actually seem to produce the quoted power (or very close to it) on the dyno. I hear the M54 and S54 engines are also typically a little down on quoted power, so nothing much different there.
Mechanically the engines are quite similar: both twin cam 24v straight sixes, with individual throttle butterflies for each cylinder. In my view the big difference is the level of technology and refinement. The M/S54 engines feel very smooth, with very little mechanical noise and vibration, and has modern advances like variable valve timing. The Speed 6 by comparison is much more agricultural; no fancy valve control, not especially well balanced (it has a huge crankshaft damper), and lots of mechanical noise from the complicated timing chain setup. I'm not going to comment on reliability, as the Speed 6 top-end woes are pretty well documented, as are the VANOS and bearing shell failures on the BMW!
Basically the BMW engine shows what improvements you can expect in terms of refinement and longevity if you invest about 1000 times more than TVR did in the development of an engine, and if you're building evolutionary improvements to a proven design.
As for sound, have you ever heard the M straight 6 in a Weissman roadster? It sounds nothing like a standard BMW installation. Similarly for the BMW V8s in modern Morgans. The unique Tuscan and T350 sound is largely down to a distinct lack of silencing, very simple airbox/air filter layout, large diameter exhausts, and a simple arrangement of 3 cylinders for each exhaust pipe. I suspect if you stuck a pair of straight pipes on an M roadster it would sound almost as lairy, although without so much of the "nails in a cement mixture" clattering!
I'm surprised that no-one has put a BMW M straight six in a Tuscan yet. There was a Cerbera around with such a conversion a few years ago, but I hear that the engine is too tall for the Tuscan bonnet design - I'll wait to be proven wrong on that one though.
Cheers,
Pete
Beedub said:
SO in your op which is the better motor!!?? and why??
Aaargh, the impossible question 
In a TVR, the Speed 6, in a BMW, the S54 
Undoubtedly the BMW engine is the better piece of engineering, but they are horses for courses. In my BMW I want a car which is bombproof, refined, and balances performance with real world usability (ok, I know I've got a boring diesel, but even so...). In my TVR I'm happy to compromise most of that for the sake of bonkers performance and an engine which is in keeping with the home-grown, cottage-industry character of the rest of the car.
Both great engines IMHO.
Pete
Great writing from Pete.
IMHO BMW are the only mass production competition for TVR replacement, but does need the pipes as described to give it that noise factor. Unfortunately I could buy 3 Tivs for the price and they all still look better.
You can't beat the road presence of a TVR, and the feel good factor it brings. There won't be many BMW drivers waving when you pass them.
IMHO BMW are the only mass production competition for TVR replacement, but does need the pipes as described to give it that noise factor. Unfortunately I could buy 3 Tivs for the price and they all still look better.
You can't beat the road presence of a TVR, and the feel good factor it brings. There won't be many BMW drivers waving when you pass them.
tail slide said:
.. and if you want to go the whole hog with a 4.3 rebuild, you can enjoy 997T owners not waving as you pass them either!
Now just run in at 3.5k miles, mine records consistent 2 secs 80-100 in 3rd on the Racelogic box, as against the Turbo's roadtest best of 2.4...
Is it really that quick with your new 4.3 engine!? 997t's accelerate like nothing I have ever experienced before.Now just run in at 3.5k miles, mine records consistent 2 secs 80-100 in 3rd on the Racelogic box, as against the Turbo's roadtest best of 2.4...
Does it still have that lazy, "whooops I am doing 120 mph by mistake and I didn't feel a thing" type of acceleration (like my stock 350) or the "f*ck me! My neck is going to fall off and my co-passenger is terrified!" type of acceleration like the 997 I passengered in recently!?
Recommended or does the driveability suffer?
AdvocatusD said:
Is it really that quick with your new 4.3 engine!? 997t's accelerate like nothing I have ever experienced before.
Does it still have that lazy, "whooops I am doing 120 mph by mistake and I didn't feel a thing" type of acceleration (like my stock 350) or the "f*ck me! My neck is going to fall off and my co-passenger is terrified!" type of acceleration like the 997 I passengered in recently!?
Recommended or does the driveability suffer?
Does it still have that lazy, "whooops I am doing 120 mph by mistake and I didn't feel a thing" type of acceleration (like my stock 350) or the "f*ck me! My neck is going to fall off and my co-passenger is terrified!" type of acceleration like the 997 I passengered in recently!?
Recommended or does the driveability suffer?
'Tis the truth. Welcome to sample if you're in Shropshire area sometime. In particular very strong mid-range so same acceleration from 4750-6750, driveability same at lower speeds. Minor issue on T350s is that after initial testing, mine did need mods to get more airflow through the rad above 60mph, but can be subtle.
tail slide said:
AdvocatusD said:
Is it really that quick with your new 4.3 engine!? 997t's accelerate like nothing I have ever experienced before.
Does it still have that lazy, "whooops I am doing 120 mph by mistake and I didn't feel a thing" type of acceleration (like my stock 350) or the "f*ck me! My neck is going to fall off and my co-passenger is terrified!" type of acceleration like the 997 I passengered in recently!?
Recommended or does the driveability suffer?
Does it still have that lazy, "whooops I am doing 120 mph by mistake and I didn't feel a thing" type of acceleration (like my stock 350) or the "f*ck me! My neck is going to fall off and my co-passenger is terrified!" type of acceleration like the 997 I passengered in recently!?
Recommended or does the driveability suffer?
'Tis the truth. Welcome to sample if you're in Shropshire area sometime. In particular very strong mid-range so same acceleration from 4750-6750, driveability same at lower speeds. Minor issue on T350s is that after initial testing, mine did need mods to get more airflow through the rad above 60mph, but can be subtle.
sidewayz said:
tail slide said:
AdvocatusD said:
Is it really that quick with your new 4.3 engine!? 997t's accelerate like nothing I have ever experienced before.
Does it still have that lazy, "whooops I am doing 120 mph by mistake and I didn't feel a thing" type of acceleration (like my stock 350) or the "f*ck me! My neck is going to fall off and my co-passenger is terrified!" type of acceleration like the 997 I passengered in recently!?
Recommended or does the driveability suffer?
Does it still have that lazy, "whooops I am doing 120 mph by mistake and I didn't feel a thing" type of acceleration (like my stock 350) or the "f*ck me! My neck is going to fall off and my co-passenger is terrified!" type of acceleration like the 997 I passengered in recently!?
Recommended or does the driveability suffer?
'Tis the truth. Welcome to sample if you're in Shropshire area sometime. In particular very strong mid-range so same acceleration from 4750-6750, driveability same at lower speeds. Minor issue on T350s is that after initial testing, mine did need mods to get more airflow through the rad above 60mph, but can be subtle.
So we can wave at the 997T's as we go by!
G
Yee Ha and all that. Nice little motor pete said:
I'm surprised that no-one has put a BMW M straight six in a Tuscan yet.
Pete
I'm surprised at you Pete...Pete
Your profile suggests you are a TVR owner but yet you make these absurd heretic profanities.
God rest PW, I feel him turning in his grave.
A GERMAN engine in a TVR what are you thinking of man????
Now go & flagette yourself & bathe your welds in 95 ron until you feel cleansed
Offer your prayers to the lord Trevor & hope you are blessed with his forgiveness, for you do not really appreciate your sins my child.
I shall pray for your soul tonight for I feel you need absolution.
One day you too shall see the true light & walk the enlighted path that is TVR
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