I was looking at some dyno sheets and had a question. Why is it that the higher u go in hp the torque number does'nt stay even. Like for instance. Wotm 2j makes 1399hp but 999 tq. If we were able to make numbers like this would our torgue numbers be higher. What makes torque?
Torque
- Thread starter turbodriz
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Because hp = (tq * rpm) / 5252
A 7m might do 999 ft-lbs of torque @ 6200rpm. a 2JZ might do 999 ft-lbs of torque @ 7200 rpm.
Do the math
The point is, the JZ series when making 1000+hp, does it at very high rpm. This shows up as a very large hp value, with a correspondingly low torque value.
The high hp 7Ms are making the power at lower RPM, so they show higher corresponding torque values.
As far as I am concerned, a motor making 1000hp @ 6000rpm is more 'powerful' than another motor making 1000hp @ 8000rpm.
A 7m might do 999 ft-lbs of torque @ 6200rpm. a 2JZ might do 999 ft-lbs of torque @ 7200 rpm.
Do the math
The point is, the JZ series when making 1000+hp, does it at very high rpm. This shows up as a very large hp value, with a correspondingly low torque value.
The high hp 7Ms are making the power at lower RPM, so they show higher corresponding torque values.
As far as I am concerned, a motor making 1000hp @ 6000rpm is more 'powerful' than another motor making 1000hp @ 8000rpm.
rod length can affect torque, but it doesn't make it. Torque is a derivative of force and the distance that force moves. That's why motors with a longer stroke make more torque. What longer rods do, is keep the piston at the top of the rotation for longer, which helps generate more force when the combustion takes place. This will help increase torque a bit and improve your torque curve, but stroke is really where torque is generated. Of course, compression, combustion, cam timing, bore size, etc. also play a part in power. The higher the compression, the more power you'll generate...same with bringing in more air and fuel via bigger injectors/carb, forced induction, big-runner heads, intake, etc.
So what would be somethings to address when u want the torque to stay up with the hp when going for a high hp build?
Driz: If you pull a lot of weight out of the reciprocating assembly the way Dyno's work will show this as an increase in Tq as it gets on the ramp earlier.
I went from 960 Nm to 1154 Nm when I installed my lightened crank.
I went from 960 Nm to 1154 Nm when I installed my lightened crank.
turbodriz;958759 said:
Already answered. Displacement. Other things can tune it, as noted.
Actually, engines don't make torque. They convert fuel into torque.
turbodriz;959199 said:
Depends on if you're building an N/A motor or forced induction. Some things already mentioned are displacement and lightening the rotating assembly. Any way you can increase the force and/or decrease the energy needed to move the rotating assembly is going to give you more power. Spark timing, cam timing, cam profile, octane rating of the fuel, etc. can all affect your power output. Also, you should look at the exhaust side of things as well. You want to keep the exhaust velocity up, and picking the right size exhuast can play a part in that. Head porting is another area where you can make a difference. Having the right balance between size and shape of the port can have an effect on your hp/tq curves. Just remember that high-CFM ratings of a head porting isn't the end-all-be-all, the velocity needs to be there too.
^ Good info!
Combination makes Tq.
Everytime I take my car to a new dyno the operators tap the screen reboot the Dyno PC shake thier heads in disbelief.
I dyno'd on 2 consecutive days at different dyno's with different types of dyno's to verify that they were reading correctly.
Combination makes Tq.
Everytime I take my car to a new dyno the operators tap the screen reboot the Dyno PC shake thier heads in disbelief.
I dyno'd on 2 consecutive days at different dyno's with different types of dyno's to verify that they were reading correctly.
AJ: Very close
Both these shops tune "Mullet Mobiles" so had trouble believing my little 3.0L could make that sort of Tq.
Both these shops tune "Mullet Mobiles" so had trouble believing my little 3.0L could make that sort of Tq.
hehe.
Extra stroke increases torque, because of mechanical advantage. (as the crank clears 90 degrees ATDC, the longer the stroke, the more leverage the pressure has on the crank)
Extra stroke increases torque, because of mechanical advantage. (as the crank clears 90 degrees ATDC, the longer the stroke, the more leverage the pressure has on the crank
)
KicknAsphlt;959298 said:
Yep. Great post. A 3 inch exhaust on stock 7MGE will only hurt velocity.
IJ.;959322 said:AJ: Very close
Both these shops tune "Mullet Mobiles" so had trouble believing my little 3.0L could make that sort of Tq.
lol, mullet mobiles...and you guys don't even have the plethora of "real" mullet rustangs/firebirds/camaros. I suppose the mid-90s falcon with open exhaust does count though...