I think I've only seen 1 dyno chart that that wasn't true. (it was less that 5000).

Is it different for 4 cyl engines?

Just curious on the theory....

:patriot:

I think I've only seen 1 dyno chart that that wasn't true. (it was less that 5000).

Is it different for 4 cyl engines?

Just curious on the theory....

:patriot:
you know you could be right, i had to get out the dyno sheet on my 383, and yes hp and torque do cross right at 5300rpm but my hp doesnt peak til 6200rpm. thats odd tho

I think I've only seen 1 dyno chart that that wasn't true. (it was less that 5000).

Is it different for 4 cyl engines?

Just curious on the theory....

:patriot:

my guess is engine design it alot of weight to be throwing around that fast

you know you could be right, i had to get out the dyno sheet on my 383, and yes hp and torque do cross right at 5300rpm but my hp doesnt peak til 6200rpm. thats odd tho

Yep - weird huh.

What it really tells me is that you always need to shift before 5000 to keep in the torque band :burnout: during acceleration.

Yep - weird huh.

What it really tells me is that you always need to shift before 5000 to keep in the torque band :burnout: during acceleration.
actually ,you need to shift above that to get highest average power ,torque gets you started but horsepower gets you thru the trap or so ive been told by racers

actually ,you need to shift above that to get highest average power ,torque gets you started but horsepower gets you thru the trap or so ive been told by racers

Nope - when accelerating you want to be in the Torque band.

HP wins hearts and minds - Torque wins races.

Nope - when accelerating you want to be in the Torque band.

HP wins hearts and minds - Torque wins races.
disagree , my motor redlines at 6500 rpm , produces 501 hp @6200rpm ,are you really suggesting the best shift point for best times is 5200rpm? ever ?

disagree , my motor redlines at 6500 rpm , produces 501 hp @6200rpm ,are you really suggesting the best shift point for best times is 5200rpm? ever ?

What really accellerates the car? Torque or HP ?

Read this: http://www.elephantracing.com/techtopic/hpvstorque.htm

They suggest both are a factor, but only if you consider "Torque Multiplication"

Read the section of Torque Multiplication. Then consider his example that is a race car - 2nd is 1:1 whereas in a Vette, 4th is 1:1.

I'm sure it varies car to car as well. Mine loses power at 5500rpm and I find the 5200 to 5500 range doesn't do much - I stop accelerating.

What really accellerates the car? Torque or HP ?

Read this: http://www.elephantracing.com/techtopic/hpvstorque.htm

They suggest both are a factor, but only if you consider "Torque Multiplication"

Read the section of Torque Multiplication. Then consider his example that is a race car - 2nd is 1:1 whereas in a Vette, 4th is 1:1.

I'm sure it varies car to car as well. Mine loses power at 5500rpm and I find the 5200 to 5500 range doesn't do much - I stop accelerating.
you need to keep reading, at the conclusion of the author ,it says "car will accelerate FASTEST when gear selected puts engine ar PEAK HORSEPOWER not peak torque. it seems horsepower is good for selling cars AND WINNING RACES>" your article proves my point, you need to shift beyond torque peak to achieve best average power for best times. thanks for finding that article. like i said, any racer will tell you torque gets you started, horsepower wins the race. my motor pulls right to 6200rpm, i wont go any higher to see if it falls off

you need to keep reading, at the conclusion of the author ,it says "car will accelerate FASTEST when gear selected puts engine ar PEAK HORSEPOWER not peak torque. it seems horsepower is good for selling cars AND WINNING RACES>" your article proves my point, you need to shift beyond torque peak to achieve best average power for best times. thanks for finding that article. like i said, any racer will tell you torque gets you started, horsepower wins the race. my motor pulls right to 6200rpm, i wont go any higher to see if it falls off

I understand what he says, but he's refering to a 2 speed race car. He's also describing how HP makes Torque.

In my LS1 peak horsepower is about 5300 and it's a pretty sharp peak of about 100 rpm. My torque curve is flat for over 1000 rpm.

I posted another message about my engine getting rough at 5500 rpm - it literally dies off - like cylinders are missing. So maybe my conclusions are misguided by my bad experience :stupid: Still haven't resolved the problem - but haven't had the time.

Interesting too. The article did explain the 5250 rpm thing (actually 5252!)

I understand what he says, but he's refering to a 2 speed race car. He's also describing how HP makes Torque.

In my LS1 peak horsepower is about 5300 and it's a pretty sharp peak of about 100 rpm. My torque curve is flat for over 1000 rpm.

I posted another message about my engine getting rough at 5500 rpm - it literally dies off - like cylinders are missing. So maybe my conclusions are misguided by my bad experience :stupid: Still haven't resolved the problem - but haven't had the time.

Interesting too. The article did explain the 5250 rpm thing (actually 5252!)
with my stock motor power fell off about 4500rpm but new motor is a whole different breed , it just keeps pulling. as for yours dying at 5500 ,could it be wear in the distributor ? bouncing at high rpm? what year is your car? or maybe worn cam or lifter floating ,not closing valve or not enough timing advance for the rpm or or any of a dozen other reasons good luck pinning it down

with my stock motor power fell off about 4500rpm but new motor is a whole different breed , it just keeps pulling. as for yours dying at 5500 ,could it be wear in the distributor ? bouncing at high rpm? what year is your car? or maybe worn cam or lifter floating ,not closing valve or not enough timing advance for the rpm or or any of a dozen other reasons good luck pinning it down

It's an 01 LS1 w/93k miles on it. (so no distrib) The bottom end is a good shape I'm told (no oil burning, etc) so I'm thinking about new heads/cam/intake.

I don't "hear" anything mechanical. Doesn't float cause some rattling sound? It really just sounds like a misfire. I've been thinking fuel pressure.

What's your old/new motor?

It's an 01 LS1 w/93k miles on it. (so no distrib) The bottom end is a good shape I'm told (no oil burning, etc) so I'm thinking about new heads/cam/intake.

I don't "hear" anything mechanical. Doesn't float cause some rattling sound? It really just sounds like a misfire. I've been thinking fuel pressure.

What's your old/new motor?
you know , it could be as simple as your plugs are too hot a heat range and blowing out or a plug wire, ,have you done a compression test to see if you have a weak cylinder? as for mine, i haxe 81 and 99. the 81 was stock smog engine no perfornance at all , now it is a Patriot Performance 383 stroker/ 500HP brute. it has unbeleivable power. the 99 is bone stock Ls1,way over matched by 81. hope you solve your mystery let me know when you figure it out

Basically, I believe torque is the measure of amount of work/force, and horsepower is the measure of how fast the work/force can be performed/applied.

you know , it could be as simple as your plugs are too hot a heat range and blowing out or a plug wire, ,have you done a compression test to see if you have a weak cylinder? as for mine, i haxe 81 and 99. the 81 was stock smog engine no perfornance at all , now it is a Patriot Performance 383 stroker/ 500HP brute. it has unbeleivable power. the 99 is bone stock Ls1,way over matched by 81. hope you solve your mystery let me know when you figure it out

I'll mess around. I had gone cooler on the plus (NGKs) and did replace the wires.......

I'll have to get a compression tester and a fuel pressure tester....

I'll mess around. I had gone cooler on the plus (NGKs) and did replace the wires.......

I'll have to get a compression tester and a fuel pressure tester....
that would be my next move, the diagnostic didnt give any clues, maybe a sensor not working , causing fuel to be too lean at high rpm?

Basically, I believe torque is the measure of amount of work/force, and horsepower is the measure of how fast the work/force can be performed/applied.
ill buy that, thats a pretty simplified explaination. torque is twisting something and HP is how fast , basically

I think I've only seen 1 dyno chart that that wasn't true. (it was less that 5000).

Is it different for 4 cyl engines?

Just curious on the theory....

:patriot:

Because the mathematical definition of Horsepower as it partains to torque is:
Horsepower = (Torque X RPM) / 5252

Therefore Horsepower must ALWAYS equal torque at 5252RPM, universally, regardless of what engine is being dynoed.

If it doesn't, you either have different scales for torque and hp, or you have a false chart ;)

For those wanting a more in-depth explanation, here is a reasonably good one:
http://www.revsearch.com/dynamometer/torque_vs_horsepower.html

Because the mathematical definition of Horsepower as it partains to torque is:
Horsepower = (Torque X RPM) / 5252

Therefore Horsepower must ALWAYS equal torque at 5252RPM, universally, regardless of what engine is being dynoed.

If it doesn't, you either have different scales for torque and hp, or you have a false chart ;)

For those wanting a more in-depth explanation, here is a reasonably good one:
http://www.revsearch.com/dynamometer/torque_vs_horsepower.html
yea, we covered that a few posts back, but thanks for the input always room for more . where are you located?

yea, we covered that a few posts back, but thanks for the input always room for more . where are you located?

My bad, I skimmed the thread and didn't see it spelled out :(

I'm located in NJ right now.

My bad, I skimmed the thread and didn't see it spelled out :(

I'm located in NJ right now.
south Louisiana, myself . always open to opinions . welcome

For myself I usually think in this way:
You have a scaffold plank pivot on a drum.
Put the drum close to one side i.e the short side and think of it as the rear axel and the long side of the plank the engine side.
1.Use power on long side to lift a known weight.
Shift the pivot [drum] more to centre
2.Use same power on long side to lift same known weight [same power but a little less torque]
3.Then put drum which is the pivvot point in the centre and use same power to lift the same known weight on the other side. Then power=torque
Looking at number 1, same power but much more torque? Number 2. same power less torque and 3. power equals torque.