merklebob

dont forget that torque is what make the car have lower 0-60 times. its a matter of how much torque/lb at what rpm. the motor with the better ratio earlier in the rpm band will record the better time.

horse power is just torque with prms for good measure. look at the honda with 155 ft-lb torque and 210ph at 9000 rpm. the 0-60 time is slow.

znod

Absolutely, torque is a critical ingredient. But, look at the 93-95 Mazda RX-7. 1.3 liters, low torque = very fast to 60, 1/4, etc.. Other things must be considered weight, gearing, RPM capability, transmission type, etc. Indeed, the M5 engine is low torque for a 500 HP engine.

swajames

Torque and HP will be related, but torque in itself isn't what drives 0-60 times. The 535 has monster amounts of torque but isn't quite as quick to 60 as some of the gas engined E60's that have much lower torque but greater RPM/HP.

Kadonny

Torque and HP will be related, but torque in itself isn't what drives 0-60 times. The 535 has monster amounts of torque but isn't quite as quick to 60 as some of the gas engined E60's that have much lower torque but greater RPM/HP.
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Right. I always thought of it this way. Torque gets you going and is useful in lower rpms, horsepower keeps you going especially in upper RPMs. Both are needed for a great 0-60 time. The Mazda cars must be in the upper RPM ranges at all times in every gear in order to turn in a good 0-60 time.

mehall2

Well you are in luck. I have both cars in the stable at this time, so I can go do all the back to back driving I want. Tonight, I met the wife for dinner and drove the 550i to meet her. After dinner, I took the 545i, she took the 550i. This is the first back to back I have done.

First Impressions. 550i feels like it has alot more HP than the 545i. Because the 550i is at 450 miles on the odo, I haven't even brought it above 4500rpm. Seat of the pants feels like the torque and responsiveness is much great than 35hp. and 30 FT LBS Torque. The wife even complemented on how much peppier the 550i felt, than her car. After driving the 545i, I am thinking something is wrong with it, as it seems down on power. I am sure it is all in my head and butt o meter. The torque seems to come on stronger and quicker in the 550i. I am also sure that is what an extra 400cc of displacement will do.

The other thing I noticed is the 545i is smoother on the downshifts and doesn't have any drag on the transmission when I let off the gas. The 550i, has a bit of a weird drag when I let off the gas and has an extra little kick in the 2nd to 1st downshift. This may have to do with the disc cleaning features and the pre load of the master cylinder for emergency stopping. Not bothersome, just different.

I do have a friend with a dyno, so I am going to get both cars dynoed and see what the real HP numbers are and what the differences really are.

I will keep all informed. I will eventually get both to a drag strip as well for some 1/4 mile times, but not until next spring.

Regards, Mike.

cannga

The other thing I noticed is the 545i is smoother on the downshifts and doesn't have any drag on the transmission when I let off the gas. The 550i, has a bit of a weird drag when I let off the gas and has an extra little kick in the 2nd to 1st downshift. This may have to do with the disc cleaning features and the pre load of the master cylinder for emergency stopping. Not bothersome, just different.


Regards, Mike.
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Hi Mike,

Someone was also complaining about this same "drag" on his 550i when the gas pedal was let off awhile back. (I can't find the post anymore). Was that you?

I ask because the issue's "irritating factor" might be high if 2 owners mentioned it already.

(Thinking of 550i for my wife.)

Thanks for the report.
Regards,
Can

znod

Right. I always thought of it this way. Torque gets you going and is useful in lower rpms, horsepower keeps you going especially in upper RPMs. Both are needed for a great 0-60 time. The Mazda cars must be in the upper RPM ranges at all times in every gear in order to turn in a good 0-60 time.
[/quote]
But, that's true for every car if it is going to run its best times. But, it's not true because engine torque is kept especially high using the procedure. It's because road torque is kept especially high.

darkside

It is a difficult comparison because my 545 test drive was last spring, and the 550i is still in the breakin period. I have been pretty careful with how much I push this car. What I can comment on, though, is that I am getting a great sensation of torque. As I mentioned, per lb this car has more torque than the e39 M5. And it has 100 lb/ft more than my M3 coupe and it weights only 400 lbs more. So I am getting that kick you back into your seat feeling way more than I did in the M3. And at highway speed it really gets up and moves. It is just so damn comfortable to drive around in compared to the M3, and with the SMG the M3 was a challenge to drive smoothly, particulary from a dead start with the lurching issues. What the 5 doesn't have that the 3 did was the absolute feeling of being on rails and complete control.
This is a different experience. I had the M3 for 3 years and wanted a change of venue (and color), and this car so far is not a dissappoitment.
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So Darkside, do you have the SMG on the new 550?
[/quote]
No, I have Steptronic. I had the SMGII in my e46 M3.

mehall2

Hi Mike,

Someone was also complaining about this same "drag" on his 550i when the gas pedal was let off awhile back. (I can't find the post anymore). Was that you?

I ask because the issue's "irritating factor" might be high if 2 owners mentioned it already.

(Thinking of 550i for my wife.)

Thanks for the report.
Regards,
Can

[/quote]

Can, it wasn't me on the original drag factor, and I do remember someone else mentioning it. I am going to have to drive the cars in true, back to back sessions to be sure about it. I just haven't had the time to do so.

I still wouldn't hesitate in buying the 550i, again. I did look at a 2006 911, but if I went with the Porsche, I would go with the Carrera S, model, and by the time I optioned it out, it was over 95K. A bit out of my budget. Congrats on your 911. I love Guards Red and the 911 is a great sports car!

Regards, Mike.

LuvE60

Hi Mike,

Someone was also complaining about this same "drag" on his 550i when the gas pedal was let off awhile back. (I can't find the post anymore). Was that you?

I ask because the issue's "irritating factor" might be high if 2 owners mentioned it already.

(Thinking of 550i for my wife.)

Thanks for the report.
Regards,
Can
[/quote]

I had the same drag in the early SW versions with my 545. It got a lot better with SW upgrades.