HP vs TQ and how it applies to trucks
#11
Torque is king but you still have to be able to get it to the track. Even my little 287 (4.7) has trouble hooking up. I haven't had it on the dyno with the turbo on it, but it's probably in the 450 to 500 ft-lb range anyway. (at the flywheel) Having mid-range torque is probably the most usable for a street vehicle that hits the track also.
#12
Adkoonerstrator
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Highest average torque in your expected rpm range. Of course that is the same as saying highest average horsepower since they are a function of each other related by rpm.
I agree with what BigKid said. When that stall converter stops multiplying torque in the mid rpm range you want as much power as possible at that point and above because you'll be relying on the engine and gear only then.
I always thought of it like this.
Stall it to get the best 60' you can and get the engine into the correct rpm range when it falls back on the upshifts.
Gear it to cross the traps at your max rpm or just a little above.
Build the biggest damn engine you can fit.
Obviously this is something that might not be exactly right the first time, might take some experimentation and parts changes to get it right but, with a good plan and goal in mind it can probably be close the first time.
I agree with what BigKid said. When that stall converter stops multiplying torque in the mid rpm range you want as much power as possible at that point and above because you'll be relying on the engine and gear only then.
I always thought of it like this.
Stall it to get the best 60' you can and get the engine into the correct rpm range when it falls back on the upshifts.
Gear it to cross the traps at your max rpm or just a little above.
Build the biggest damn engine you can fit.
Obviously this is something that might not be exactly right the first time, might take some experimentation and parts changes to get it right but, with a good plan and goal in mind it can probably be close the first time.
#14
Thanks for all the input guys!
What I would *really* like to do is:
382 (Eagle crank/rods, forged pistons)
AFR 205's
224/228-ish cam
Pacesetter LT's & Y
LS6 intake, ported TB
4L80-E w/ 3200 stall Yank
4.10s
Hope I can get enough money together to pull this off! ::crosses fingers::
What I would *really* like to do is:
382 (Eagle crank/rods, forged pistons)
AFR 205's
224/228-ish cam
Pacesetter LT's & Y
LS6 intake, ported TB
4L80-E w/ 3200 stall Yank
4.10s
Hope I can get enough money together to pull this off! ::crosses fingers::
#16
single digit dreamer
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Originally Posted by XLR8NSS
Highest average torque in your expected rpm range. Of course that is the same as saying highest average horsepower since they are a function of each other related by rpm.
for all out drag racing i dont think tq means ****. you can have 2 motors with the same peak tq and the same averge tq over the desired racing range but the motor that is spining higher will win. lets say both motors are averging 300tq each in a 3000rpm range. the motor spining 5000-8000 rpm will make way more hp than the motor spining 2000-5000rpm. if both vehicles are geared/stalled idealy for their set up's i say the motor that is spining higher(more hp) will kill the other motor. the higher rpm motor will have much steeper rear gears and be able to see higher tq multiplecation at the wheels.
i have an example, use a 500hp 1000tq deisel and race a 500hp/500tq gaser of the same weight. who will win? i say it will be a tie. you can use the hp/ET calculators and they are very acurate with gas motors or diesels even though the deisel will have double the tq of the gas motor.
rpms do matter when drag racing. the higher you can push the tq curve the faster you will be even if you dont increase the tq. this rule will only apply if you are stalled and geared for the higher rpms. leave a stock stall in there and a high rpm motor will be a dog.
#17
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That's why I said "in your expected rpm range" If that range is 6000-8000rpm then go for the most torque you can get in that range. It doesn't matter if you just look at torque or horsepower as long as you figure what rpm range you'll be in or want to be in. more torque=more power or vice versa doesn't matter how you look at it.
Sometimes I wish dynographs only had a hp line or torque line. It would make things less complicated looking at just one of them since they relate to each other anyway.
Sometimes I wish dynographs only had a hp line or torque line. It would make things less complicated looking at just one of them since they relate to each other anyway.
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