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Just got back from the dyno:

Mods:

LPE
Stealth FFV
B&B headers/no cats
X pipe w/ 3" B&B exhaust
Stealth V tune

372RWHP/354 RWTQ.

What do you think?
In the summer time I did the same dyno run and had only 325RWTQ, HP was the same.
Looks like Rick found a little more Torque in his program.
 

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2009 Z06 / 2013 F150 EcoBeast / 2008 Twin-Turbo Bimmer
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It's interesting to see your results as we are running identical calibrations except for your no-cat changes. Mine was 360.7/348.6 earlier this week. It would be interestng to put them both on the same dyno and see how closely they match up.

As you know, the extra torque is one reason why its hard to keep the tires hooked up in 1st and 2nd. Broke mine loose in 3rd gear today just pressing the accelerator down hopping on the freeway this morning (low 30's and dry). The wife was not impressed. Oh well. :D
 

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2005 Stealth Gray CTS-V, 2009 Black CTS-V
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Apologies for possible thread jack, but his comment above about HP being the same just makes me go back to what I have been struggling with for years to understand...

Can someone please explain to me the usefulness of horsepower? It's such a meaningless number to me...

Torque is what it is all about to me. Torque is nothing more then twisting force. Grab a doorknob, twist and there you have it. This is exactly what a motor does; it twists (spins) a crankshaft, transmission, axle, differential, etc.

As a motor's "power" is expressed in "pound feet," I believe you could visualize this in the following manner: If you have a motor that generates 500 pound feet of torque, that would be the equalivent of taking a foot-long wrench and applying 500 pounds to one end. Seems easy to understand so far to me...

As such, a car accelerating should be nothing more then the product of engine torque pitted against the mass of the car, nothing more. As a matter of fact, what more can it be?? It *SHOULD* be the simple.

These days, however, there is this hard-to-understand concept of horsepower...

I beleive horsepower is calculated as a numeric product of measured torque multiplied by engine RPM, divided by 5,252 (this is why Marc needs to double check his dyno results...:p ). I think the 5,252 is used to cancel out minutes and seconds and, somehow, convert straight-line force into rotational force units, but I'm still working on that conceptually...

But what's the point? Why go through all the mechanics of calculating this phantom horsepower number if all that is really necessary is to measure engine (output) torque vs. the mass of the car?

Someone, please help the lab-monkey (that's me) understand what I'm missing when it comes to horsepower...
 

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My simple way of looking at it...

Torque gets things spinning...

Horsepower is an extrapolated measurement of how well they keep spinning.
 

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2005 Stealth Gray CTS-V, 2009 Black CTS-V
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Closer_2001 said:
My simple way of looking at it...

Torque gets things spinning...

Horsepower is an extrapolated measurement of how well they keep spinning.
Yeah, okay, but what does that really mean? :)

If one wanted to analyze which car would be, in theory, faster, what does HP have to do with anything?
 

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Luna. said:
Yeah, okay, but what does that really mean? :)

If one wanted to analyze which car would be, in theory, faster, what does HP have to do with anything?
What it really means to me is that torque gets you off the line and moving. Horsepower is what keeps you moving and what keeps you going fast. So torque is more important from and in lower rpm bands, whereas HP is more important at faster speeds and higher rpm bands.

Now how they directly correlate is over my head, but I do know that you can have a high hp car with low torque, but I dont think you can have a high torque car with low hp.........I think.

Back on topic. Those gains look good to me :D
 

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willsctsv, nice numbers! I looked up my old #s just for a comparison.

Mods:

More CAI/stock tube
Corsa
Stainlessworks long tubes
High flow metal cats
DTE tune

375.0 rwhp 375.2 rwtq

Dyno-jet dyno.
 

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High torque and low HP = Diesel.

For example the Cummins turbo diesel in the Dodge truck puts out 610 pounds-feet of torque and 325 horsepower.
 

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willsctsv said:
OK, here are the graphs from both runs. One from the Summer and one from today with a revised Stealth V tune.
You still had about 400 rpm to go on the last run. Looks to me like he shut it down at 6000 rpm where the first run (on the right) went to 6400 rpm.. He could have gotten a little higher hp number if he'd of stayed in the throttle just a little longer. That would correspond with your higher torque number the second go round. You can see your first run bounced off the rev limiter and the second never hit it.
 

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Will,
Where did you go for the dyno? I'm looking to baseline before I hit the tuning software. Thanks.
-ace
 

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Kadonny said:
What it really means to me is that torque gets you off the line and moving. Horsepower is what keeps you moving and what keeps you going fast. So torque is more important from and in lower rpm bands, whereas HP is more important at faster speeds and higher rpm bands.

Now how they directly correlate is over my head, but I do know that you can have a high hp car with low torque, but I dont think you can have a high torque car with low hp.........I think.

Back on topic. Those gains look good to me :D

Good point on the relationship but of course there are tons of motors with high torque and low HP

You drive more on torque but race on HP - especially high speed races.
The new M5 has less torque than the CTS-V!
 

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MCaesar said:
Good point on the relationship but of course there are tons of motors with high torque and low HP
You drive more on torque but race on HP - especially high speed races.
The new M5 has less torque than the CTS-V!
True, the M5 has less torque. However, I believe that another consideration would be where that torque is on the powerband. In other words, the M5 would benefit from gear multiplication over the V, yes?

I've always rationalized that is the "benefit" of the horsepower calculation, but I still like to look at it in terms of torque (& where it is on the powerband) and go from there.

It still just baffles me. :)

EDIT: 2004ctsv--yeah, I've read that before, but I honestly don't know how to apply that in "real-world" terms. Oh, and the Steelers rule. :xsmile:
 

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Being a non-mechanical engineer, I consider torque the ability to increase rpm but horsepower is the maintenance of rpm.

One of our smarter mechE's should chime in here
 
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