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Discussion Starter #1
I spoke to a mechanic acquintence of mine that told me that it's better to have more torque than horsepower. It leads to engine longevity and power on demand. A higher torque to horsepower ratio is a completely different animal than a car with a higher horsepower to torque ratio . Cars with more torque has that power on demand whenever you need it. Cars like the celica and Honda S2000 on the other hand don't have anything at the lower RPM's (the normal day to day range). It has significantly more horsepower than torque and achieves that power only at the 8000 RPMs (ouch). It's probably more fun, but not something to enjoy everyday.. I guess the IS300 falls in between the two extremes...
Eric...
 

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Discussion Starter #2
The Acura CL-s is another example. It has 260horsepower but "where's the torque?" Which is the question I asked myself after test driving the thing... I guess it personal preference, but Torque rules in my book

Eric...
 

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In another torque/hp thread, someone said something that makes it easy to realize (and I'm paraphrasing here): Torque gets you moving, HP keeps you moving...

I'd rather have more low-end torque than high-end horsepower. That's why my Miata has a turbo.



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Tony
'01 Spectra Blue
'94 Turbo Miata
 

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It all depends on which part of the RPM bandwidth is more frequently used for the occasion. In daily traffic, higher torque at lower RPMs is preferable (flatter torque curve). But on a road course, one can work the shift to stay at higher RPMs and hence, higher HP is preferable (ascending torque curve)........ etc.
 

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Discussion Starter #5
Originally posted by LexusIS300:
It all depends on which part of the RPM bandwidth is more frequently used for the occasion. In daily traffic, higher torque at lower RPMs is preferable (flatter torque curve). But on a road course, one can work the shift to stay at higher RPMs and hence, higher HP is preferable (ascending torque curve)........ etc.
I agree with you there, but how often do we take our cars to the road course? I think torque at low RPM's is more usable in day to day driving. It's ironic that the commercial for the Toyota Celica (with the ketchup bottle) sums it up that the car demonstrates usable performance. Yeah... How often are you at 8000 RPM's?
Eric...
 

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Originally posted by EricK:
I agree with you there, but how often do we take our cars to the road course? I think torque at low RPM's is more usable in day to day driving. It's ironic that the commercial for the Toyota Celica (with the ketchup bottle) sums it up that the car demonstrates usable performance. Yeah... How often are you at 8000 RPM's?
Eric...
I keep a modded 3rd-gen RX-7 TT for the track. 400+ RWHP and 2,800 lb continuously at ~7,000 RPM about 2 dozen times a year........
And it is drivable in daily traffic too.

But as far as some of the marketing of cars such as the S2000, I suppose many people do NOT know what they are buying. They only find the concept of "racecar" appealing.

[This message has been edited by LexusIS300 (edited October 23, 2000).]
 

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Well said, LexusIS300. I totally agree.
 

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Well, what do you want?

1> Easy, strong acceleration from a standstill, and good acceleration regardless of which gear you are in (in other words a car that is easy to drive quickly)

Then you want lots of torque at low RPMs.

2> Maximum top speed, and maximum freeway passing power?

Then you want lots of top end horsepower.


If you are burdened by an automatic transmission, have a heavy car ( > 3000lbs), or plan to pull a trailer then you will want good low end torque.

If you are driving on the autobahn or another road with no speed limit then you will want maximum horsepower.

Personally I think a low torque, high HP (very high revving) engine only makes sense on a motorcycle or lightweight 2 seat sports car.

I want good low end torque because most of my driving is 0-40mph in traffic.

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Tony - just because you have a turbo doesn't automatically mean that you have an engine with good low end torque. You can shape the HP and torque curve of an engine with different turbo "sizing". A really big turbo on a small displacement engine can have lousy low end torque but good top end HP since it takes the turbo a while (and lots of RPMs) before it really gets spinning.

[The old 2.2 liter 4 cylinder Dodge Daytona Z (turbo) had a torque peak at 3200rpms.]

You can also have a big displacement turbo engine with a little tiny turbo that spools up quick - then you have great low end torque but max HP is limited (since there is an overall exhaust flow restriction).

[The Audi 2.7 liter 6 cylinder S4 (turbo) has a torque peak at 1850rpms.]

Lots of cars (like the Mustang SVO and Saab 900) started out with bigger turbos, then over the years they decided to switch to smaller turbos to move the torque peak lower and make the car more drivable.

I noticed this about a Miata "dyno day": http://www.realbig.com/miata/miata/1997-12/2030.html

Paul Turin Max.Torque: 177.0 Max.HP: 169.4
96 Miata, Bell Aerodyne Turbo, 2 1/4 exhaust
Chris King Max.Torque: 174.3 Max.HP: 196.6
93 Miata, Cartech turbo, FM ecu, Jackson Racing cat back

Notice that Paul has more torque, but less overall HP than Chris.
 

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hmm

the CLS is a high HP/lower torque car, and it does more than fine in low-speed driving conditions. and heavy? 3000lbs. plus, with an auto tranny.
 

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Originally posted by TEG:
Tony - just because you have a turbo doesn't automatically mean that you have an engine with good low end torque. You can shape the HP and torque curve of an engine with different turbo "sizing". A really big turbo on a small displacement engine can have lousy low end torque but good top end HP since it takes the turbo a while (and lots of RPMs) before it really gets spinning.
This is true. I should've stated it as "this is why my Miata has a relatively small (TD04) ball-bearing turbo".


And I was also referring more to the fact that the Miata has a fairly high-revving four cylinder renowned for it's lack of low-end power.

Regarding the S2000 comments - I've seen people that have taken them back to the dealer because they didn't realize the work it took to make it go fast. But man, there was one at Autocross on Saturday and that guy was fast. But he was beat by a phenomenal driver in a Miata.


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Tony
'01 Spectra Blue
'94 Turbo Miata

[This message has been edited by webmaster (edited October 23, 2000).]
 

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Paul Turin Max.Torque: 177.0 Max.HP: 169.4
96 Miata, Bell Aerodyne Turbo, 2 1/4 exhaust
Chris King Max.Torque: 174.3 Max.HP: 196.6
93 Miata, Cartech turbo, FM ecu, Jackson Racing cat back
The Aerodyne is a variable-vane turbo and is designed specifically to boost faster but runs at a much lower boost, 6-9 psi... Also the 93 is a 1.6L and the 96 is a 1.8L. The 93 is probably running 12-15 psi. But I of course understand your comparison.

Now the really nice car in that list is this one:

Shiv Pathak Max.Torque: 238.8 Max.HP: 258.0 94 Miata,BEGI System 3, TEC II, FM Exhaust, Free flow cat

Shiv now writes for SCC and his car "Frankenstein" made just shy of 300 RWHP before his friend rolled it over on a tuning drive.


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Tony
'01 Spectra Blue
'94 Turbo Miata

[From TEG: Yeah - and I think Shiv has a monster turbo Impreza 2.5RS now... ]

[This message has been edited by TEG (edited October 23, 2000).]
 

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Originally posted by EricK:
The Acura CL-s is another example. It has 260horsepower but "where's the torque?" Which is the question I asked myself after test driving the thing... I guess it personal preference, but Torque rules in my book

Eric...
232 lb-ft not enough for ya??? And don't even compare it to that darn E55

The CL-S is certainly not a torque-king, but 232 lb-ft from 3500-5500rpm isn't too shabby. You oughta drive an Accord V6.... Talk about no torque....
 

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Discussion Starter #13
Originally posted by Golden:
232 lb-ft not enough for ya??? And don't even compare it to that darn E55

The CL-S is certainly not a torque-king, but 232 lb-ft from 3500-5500rpm isn't too shabby. You oughta drive an Accord V6.... Talk about no torque....
Golden
I'm not comparing it to an E55. It just felt like the CL-s was getting most of its power at the upper range of the RPM's unlike the IS300 which was more linear in its power delivery. If you'd floor an IS300 and CL-s off the line, I think the IS300 would be able to keep up until the revs build on the CL-s. I like a strong off the line response. That's one thing I'm disappointed with my 225hp TT roadster. There is long turbo lag and you don't get anything until the RPM's build. The CL-s didn't have the off the line response the IS300 did actually. I test drove the Chrysler 300M just prior, and the CL-s felt like that off the line...
Eric...
 

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hehe...you knew it, mr clam was going to make an m3 comment. my car has MAD TORQUE at low rpms, stomping on the gas in 5th gear around 2k rpm still brings instantaneous power to the engine.....but the thing is, after hitting like 4.5k rpm, the power feels like it drops off(it does).....its a horrible feeling to have insane power from a launch(insane from my perspective anyways, this is the fastest car i'fve ever driven) and feel it drop off at higher rpm :p
 

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Originally posted by EricK:

Golden
I'm not comparing it to an E55. It just felt like the CL-s was getting most of its power at the upper range of the RPM's unlike the IS300 which was more linear in its power delivery. If you'd floor an IS300 and CL-s off the line, I think the IS300 would be able to keep up until the revs build on the CL-s. I like a strong off the line response. That's one thing I'm disappointed with my 225hp TT roadster. There is long turbo lag and you don't get anything until the RPM's build. The CL-s didn't have the off the line response the IS300 did actually. I test drove the Chrysler 300M just prior, and the CL-s felt like that off the line...
Eric...
I see what you mean. The torque curve is such that the CL-S does not feel as fast as it is... especially off the line. I have a friend with a Lincoln LS V8. That car feels like a monster off the line. Heck, even at speed, it feels faster than my CL-S. But when we ran 'em... we were (surprisingly)DEAD EVEN off the line and once I hit 4500rpm I was outta there pulling 3 cars on him by the end of 2nd gear.
 

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Originally posted by mrclam:
.....but the thing is, after hitting like 4.5k rpm, the power feels like it drops off(it does).....its a horrible feeling to have insane power from a launch(insane from my perspective anyways, this is the fastest car i'fve ever driven) and feel it drop off at higher rpm :p
That must be wierd. When I did get my first VVT experience on the highway and going up the rpm range and it there was a sudden surge of power it felt like there was another gear. It was a great feeling. Tourqe is great though, and probably used a lot more often than HP
 

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I think what is actually happening is that at 4.5K is where the VANOS kicks in and keeps the torque curve flat. But when I looked at my dyno sheet and everyone else that was stock there is a slight dip around 4.5K rpm. In my car, I don't really feel that drop off as much as in M3s but then again my car has a different exhaust system and breaths better at higher rpm.

Personally, I like a balance of torque and hp. I'm not sure if I like the new E46 M3 with it's 260pounds of torque but 330hp. I guess I'll have to drive it see if I like it


Rick Kim

Originally posted by mrclam:
hehe...you knew it, mr clam was going to make an m3 comment. my car has MAD TORQUE at low rpms, stomping on the gas in 5th gear around 2k rpm still brings instantaneous power to the engine.....but the thing is, after hitting like 4.5k rpm, the power feels like it drops off(it does).....its a horrible feeling to have insane power from a launch(insane from my perspective anyways, this is the fastest car i'fve ever driven) and feel it drop off at higher rpm :p
 

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the new m3's engine is definitely more strained and will DEFINITELY be harder to pull any more hp out of. i dont' know how long a turbo in that car would last, and i think 380 might even be a dream of a figure for that car without extensive mods. of course in that car, you don't really need mods, its nice stock from the factory
 

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It's been implied in several comments here, but nobody has said it outright, so here it goes. A high peak horsepower number is relatively meaningless. A high peak torque figure is just about as meaningless. What you want is a nice fat torque CURVE. You want the torque to start high at a low RPM and stay high through the entire RPM range. I remember someone on bimmer.org was ridiculing the seemingly low "peak torque" stat for the new M3. But someone else astutely pointed out that there are F1 or Indy test cars with peak torque numbers just as low that can do 0-60 in under 3 seconds!!! What they have going for them is torque that starts near it's peak at a low RPM and just stays there till 16,000 RPM!!! The new M3 is like that...you get something like 80% of peak torque at 2000 RPM and you still have a bunch of it as you redline near 8000!!

By the way, what REALLY makes a car go fast is the DRIVER. The first "mod" you should do for your car is a high performance driving school for yourself.
 

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Originally posted by Young:
It's been implied in several comments here, but nobody has said it outright, so here it goes. A high peak horsepower number is relatively meaningless. A high peak torque figure is just about as meaningless. What you want is a nice fat torque CURVE. You want the torque to start high at a low RPM and stay high through the entire RPM range. I remember someone on bimmer.org was ridiculing the seemingly low "peak torque" stat for the new M3. But someone else astutely pointed out that there are F1 or Indy test cars with peak torque numbers just as low that can do 0-60 in under 3 seconds!!! What they have going for them is torque that starts near it's peak at a low RPM and just stays there till 16,000 RPM!!! The new M3 is like that...you get something like 80% of peak torque at 2000 RPM and you still have a bunch of it as you redline near 8000!!

By the way, what REALLY makes a car go fast is the DRIVER. The first "mod" you should do for your car is a high performance driving school for yourself.

The comment about driving school is very accurate. But the comment about the torque curve is NOT necessarily true. If you want to go into detail, the acceleration time is calculated with the differential form,

t= dv/ a

where t is the acceleration time, v is the velocity, a is the acceleration. Converting velocity and acceleration back to RPM and torque with the gear ratios and the wheel diameter would give,

t is proportional to (RPM range)* Average(1/ Torque)

According to the above relation the acceleration time is,

1. dependent on the RPM range of interest;
2. dependent on the average of (1/ Torque).

#1 indicates that the acceleration time is minimized as long as the overall torque is high within the RPM range of interest. Nevertheless, this RPM range can vary for different occasions. For example, low-RPM torque (flatter or slightly decending torque curve) is preferred in daily traffic and high-RPM torque (ascending torque curve) is preferred in a road course.

#2 indicates that it is the COMBINATION of peak torque and the shape of the torque curve which matters to the acceleration time, i.e. once again, there is NO single type of preferable shape for the torque curve. The peak torque or the shape of the torque curve are both undescriptive alone by itself.

To make a simple illustration, one car (such as a E46 M3) has a flat torque curve of 270 lb-ft from 2,500-7,900 RPM and a second car has a peaky torque curve which starts with 270 lb-ft at 2,500 RPM and peaks with 400 lb-ft at 7,900. For the same gear ratios, is it obvious that the second car is faster? You may say that, "Hey, the peak torques are different!". Of course, this is the point ----- the combination of peak torque and the shape of the torque curve, i.e. the average of (1/ Torque) over the RPM range of interest.

As far as the F-1 cars are concerned, their peak RPM between 13,500-18,000 is a huge advantage. They can stay in a lower gear (more torque) for much higher speeds than a street car. For example at ~70 MPH, the F-1 cars are still in 1st gear, while a street car is already in 3rd gear. The major difference here is peak RPM and gearing instead.
 
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