Anyone spraying 300 or more?
Originally Posted by Benji
Torque is not what makes cars fast. Horsepower is. Torque by itself doesn't matter. Torque @ RPM (Which is Horsepower, so let's just talk about it in terms of Horsepower!) is.
Originally Posted by 383LQ4SS
But it helps me to think about TQ at rpm to help my brain struggle to make sense of whats going on in a combo. Especially when comparing vastly different curves like a nitrous motor VS a turbo setup. Really...either way you look at it...you cant make any reall assumption unless you know either the TQ or hp figure at a specific rpm over the usable range. And with the use of either of those two number the third can be found. I just like to use TQ at rpm because I can think about cylinder pressure all at the same time.
Do that and you have made an effective combo that will spit out some good HP #
Originally Posted by Benji
Let's take this one step further.
Let's say I make 800HP @ 6,000 RPM and you make 800HP @ 9,000 RPM. Assuming the cars are geared properly and such, which one is faster?
Let's say I make 800HP @ 6,000 RPM and you make 800HP @ 9,000 RPM. Assuming the cars are geared properly and such, which one is faster?
The 9,000 RPM car would accelerate faster because it could take advantage of a bigger gear.
Originally Posted by Benji
Let's take this one step further.
Let's say I make 800HP @ 6,000 RPM and you make 800HP @ 9,000 RPM. Assuming the cars are geared properly and such, which one is faster?
Let's say I make 800HP @ 6,000 RPM and you make 800HP @ 9,000 RPM. Assuming the cars are geared properly and such, which one is faster?
Benji...you obviously have a point your trying to make
Just share what your thinking..lol. I would love to hear it. 
My answer to the above would be tha same as the previous example. I dont have enough info to make the call. I would need to see the full graph and not just the peaks if these are real motors.
Originally Posted by next
The 9,000 RPM car would accelerate faster because it could take advantage of a bigger gear.
Well...what if that 9000 rpm car was a 1.8 liter honda with a giant turbo that doesnt spool until 8500 rpm , made 800 hp at 9000 rpm and dies off at 9500 rpm? Or a peaky 347 with a badly made sheetmetal intake manifold doing the same thing.
And what if the 6000 rpm motor was a masterpiece and made 800 hp right at 6000 rpm but carried that HP (tq at rpm
) out and it still made 750 hp all the way out to 8000 rpm?There isno way to tell with these examples IMO just talking in terms of peak HP
Last edited by 383LQ4SS; Oct 7, 2005 at 06:02 PM.
I think you need to take into consideration TIME TO POWER, I say the 347 makes quicker ttp. As far as the 6000 vs 9000 rpm question, the 6000 will obviously make more torque, but the 9000 should mph higher!! In A short race I say TQ wins longer race MPH win's. assuming everything else is equal.
TECH Apprentice
Joined: Jan 2002
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From: Orlando
Originally Posted by Big Mike
I always looked at it this way, the larger the cylinder, the greater the chance to fill that cylinder up with pressure.
If you took an air tight room that was 5'x5' and filled it up with air and you took a room 15'x15' and filled it up with air, which would have the greater pressure of the 2?
Am I wrong?
If you took an air tight room that was 5'x5' and filled it up with air and you took a room 15'x15' and filled it up with air, which would have the greater pressure of the 2?
Am I wrong?
Originally Posted by mobius
they would both have the same pressure... the theory about larger ci more cylinder pressure is wrong imho, for the same amount of nitrous it is acting in a larger volume thus less psi... smaller engine same nitrous higher pressure...
Robert
TECH Junkie
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From: Fort Collins, CO
Originally Posted by next
The 9,000 RPM car would accelerate faster because it could take advantage of a bigger gear.
800HP @ 6,000 RPM = 700 FT. LBS.
800HP @ 9,000 RPM = 467 FT. LBS.
Let's say that for any give estimated MPH and tire size, the 6,000 RPM engine needs a 4.56 gear. Because the 9,000 RPM engine turns 50% more RPM, it needs 50% more gear, or, a 6.84 gear.
700 x 4.56 = 3,192 FT. LBS.
467 x 6.84 = 3,192 FT. LBS.
This is why, in my opinion, HP is HP is HP, no matter the RPM you make it at.
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Teching In
Joined: Jun 2005
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Originally Posted by Big Mike
Volume is volume. I still think the larger cylinder will create more pressure, unless someone can mathmetically show me how I'm wrong. Or I just have no ******* clue!
Pressure * Volume = number of molecules * ideal gas constant * temperature
assuming that everything on the right side of the equation is the same, as volume increases, pressure has to decrease, and as pressure increases, volume decreases. If Pressure stayed the same, and volume increased, then the right side of the equation would have an increase.
basically, larger cylinders will require less pressure to make the same power.
Adam
Originally Posted by fastcarfreak
Think of it in terms of the ideal gas law (even though this isn't what it is meant for) PV = nRT
Pressure * Volume = number of molecules * ideal gas constant * temperature
assuming that everything on the right side of the equation is the same, as volume increases, pressure has to decrease, and as pressure increases, volume decreases. If Pressure stayed the same, and volume increased, then the right side of the equation would have an increase.
basically, larger cylinders will require less pressure to make the same power.
Adam
Pressure * Volume = number of molecules * ideal gas constant * temperature
assuming that everything on the right side of the equation is the same, as volume increases, pressure has to decrease, and as pressure increases, volume decreases. If Pressure stayed the same, and volume increased, then the right side of the equation would have an increase.
basically, larger cylinders will require less pressure to make the same power.
Adam
Teching In
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Originally Posted by Benji
Prove it.
If the horsepower curve was perfectly linear for both motors, then your statement would be true. It really has to do with area under the curve.
If a 9000 rpm motor had exactly 1.5 times the area under the curve as the 6000 rpm motor and the gearing was perfectly matched as described earlier, then both motors would accelerate the 2 cars evenly.
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From: Fort Collins, CO
Originally Posted by fastcarfreak
If the horsepower curve was perfectly linear for both motors, then your statement would be true. It really has to do with area under the curve.
If a 9000 rpm motor had exactly 1.5 times the area under the curve as the 6000 rpm motor and the gearing was perfectly matched as described earlier, then both motors would accelerate the 2 cars evenly.
If a 9000 rpm motor had exactly 1.5 times the area under the curve as the 6000 rpm motor and the gearing was perfectly matched as described earlier, then both motors would accelerate the 2 cars evenly.
TECH Junkie
Joined: Aug 2002
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From: Fort Collins, CO
Originally Posted by fastcarfreak
If the horsepower curve was perfectly linear for both motors, then your statement would be true. It really has to do with area under the curve.
If a 9000 rpm motor had exactly 1.5 times the area under the curve as the 6000 rpm motor and the gearing was perfectly matched as described earlier, then both motors would accelerate the 2 cars evenly.
If a 9000 rpm motor had exactly 1.5 times the area under the curve as the 6000 rpm motor and the gearing was perfectly matched as described earlier, then both motors would accelerate the 2 cars evenly.