4-cylinder, 8-cylinder
09-13-2009, 07:42 PM
#1
4-cylinder, 8-cylinder Never understood this.
LS1s, Mustang motors, hemis all make very good torque along with the horsepower.
You'll find your adj 402/408 making 500/485. Torque always seems to be +/-50 with the horsepower.
Now there is exceptions, 346 will make 500/430. An F1 V8 will make 800/500.
And some exitocs make awesome power, but not so great torque.
Now we have the amazing hondas! with their turbochargers. Making 300/180, 197/121.
Mostly are the K & B series motors with a turbo.
Now thats **** torque.
Someone came up with an awesome decription of torque on this fourm board:
http://www.superhonda.com/forum/f93/...lained-124793/
Now that does not explain those VW, EVOs, and STIs.
I can mostly speek from a VW (winter car) with a 1.8t. That little motor makes 140hp & 192tq.
As horsepower builds up so does torque. I have seen guys make 450fwhp and 425fwtq.
EVOs, and STIs are doing similar things.
So the question is why do some motors make ALOT less torque? Is it the geometry of the motor?
Honda 2.0 turbocharged = 400fwhp / 200fwtq
VW 1.8t = 400fwhp / 350+fwtq
LSx = whatever you can dream.
LS1s, Mustang motors, hemis all make very good torque along with the horsepower.
You'll find your adj 402/408 making 500/485. Torque always seems to be +/-50 with the horsepower.
Now there is exceptions, 346 will make 500/430. An F1 V8 will make 800/500.
And some exitocs make awesome power, but not so great torque.
Now we have the amazing hondas! with their turbochargers. Making 300/180, 197/121.
Mostly are the K & B series motors with a turbo.
Now thats **** torque.
Someone came up with an awesome decription of torque on this fourm board:
http://www.superhonda.com/forum/f93/...lained-124793/
Now that does not explain those VW, EVOs, and STIs.
I can mostly speek from a VW (winter car) with a 1.8t. That little motor makes 140hp & 192tq.
As horsepower builds up so does torque. I have seen guys make 450fwhp and 425fwtq.
EVOs, and STIs are doing similar things.
So the question is why do some motors make ALOT less torque? Is it the geometry of the motor?
Honda 2.0 turbocharged = 400fwhp / 200fwtq
VW 1.8t = 400fwhp / 350+fwtq
LSx = whatever you can dream.
09-13-2009, 08:03 PM
#2
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Torque=HPx5252/RPM. That's the formula for torque and HP. That's one of the useless things you learn working for the army corps of engineers. That is useless unless someone is wondering
Not sure if it always works for cars b/c i haven't tried it. I would say the differences in torque are coming through different drivetrains. Sorry if it said that in the link....didn't bother looking.
Not sure if it always works for cars b/c i haven't tried it. I would say the differences in torque are coming through different drivetrains. Sorry if it said that in the link....didn't bother looking.
09-13-2009, 08:08 PM
#3
Torque=HPx5252/RPM. That's the formula for torque and HP. That's one of the useless things you learn working for the army corps of engineers. That is useless unless someone is wondering Not sure if it always works for cars b/c i haven't tried it. I would say the differences in torque are coming through different drivetrains. Sorry if it said that in the link....didn't bother looking.
Not sure if it always works for cars b/c i haven't tried it. I would say the differences in torque are coming through different drivetrains. Sorry if it said that in the link....didn't bother looking.
09-13-2009, 08:45 PM
#5
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its simply because those motors don't make a lot of torque, but they spin at a higher rpm.
for example 300 ft-lb @ 5252 rpm is 300 hp. now if you have a motor that spins up to say, 7000 rpm and that same 300 ft-lb you have 399.85 hp.
now as to why you have hondas making so much hp with so little torque... say your honda is making 250 ft lb (generous, but some of them are with FI) @ 9000 rpm, you are making 428 hp.
For something similar to supras... 500 ft-lb @ 9000 rpm = 857 hp
for example 300 ft-lb @ 5252 rpm is 300 hp. now if you have a motor that spins up to say, 7000 rpm and that same 300 ft-lb you have 399.85 hp.
now as to why you have hondas making so much hp with so little torque... say your honda is making 250 ft lb (generous, but some of them are with FI) @ 9000 rpm, you are making 428 hp.
For something similar to supras... 500 ft-lb @ 9000 rpm = 857 hp
09-13-2009, 08:52 PM
#6
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well to be perfectly honest this is one of those questions where i dont think anyone on here can anwser. i mean everything/every motor has different variables. you wanna talk about crazy my buddies sti uncorrected put down 331hp/331tq. at 22psi and hitting fuel cutout. so you wanna hear crazy stuff. lol explain that. and taht was on the most reliable dyno i believe. they take your wheels off and dyno it by bolting the machine to your hubs instead of putting her on a treadmill.
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09-13-2009, 08:54 PM
#8
It has everything to do with the fact that:
HP = (Torque X RPM) / 5252
It is all based on the characteristics of the engine and how much you rev it.
Cam, intake, and exhaust design determine whether the engine makes its torque low in the rpm curve or high.
An engine that makes very little torque in the low rpm range but gradually keeps on increasing it in the high rpm will typically see high peak HP output and a low torque output. (generally seen with honda mills)
An engine that makes a lot of torque in the low rpm range and drops off in the high rpm range will generally see a much larger torque peak than HP.
Diesels are a great example. They make astronomical amounts of torque but very little HP in comparison. This is simply due to the fact that they typically cannot rev beyond 3000 rpm.
Torque curve is designed with the end usage in mind. Truck engines are usually designed with lots of low end torque but suffer high end hp dropoff as a result. The reasoning is that truck owners want to be able to tow and haul. Designing an engine with lots of peak HP and very little off idle torque would suck when pulling an 8000lb trailer and getting on the interstate or leaving a stoplight.
HP = (Torque X RPM) / 5252
It is all based on the characteristics of the engine and how much you rev it.
Cam, intake, and exhaust design determine whether the engine makes its torque low in the rpm curve or high.
An engine that makes very little torque in the low rpm range but gradually keeps on increasing it in the high rpm will typically see high peak HP output and a low torque output. (generally seen with honda mills)
An engine that makes a lot of torque in the low rpm range and drops off in the high rpm range will generally see a much larger torque peak than HP.
Diesels are a great example. They make astronomical amounts of torque but very little HP in comparison. This is simply due to the fact that they typically cannot rev beyond 3000 rpm.
Torque curve is designed with the end usage in mind. Truck engines are usually designed with lots of low end torque but suffer high end hp dropoff as a result. The reasoning is that truck owners want to be able to tow and haul. Designing an engine with lots of peak HP and very little off idle torque would suck when pulling an 8000lb trailer and getting on the interstate or leaving a stoplight.
09-13-2009, 09:46 PM
#11
On The Tree
its simply because those motors don't make a lot of torque, but they spin at a higher rpm.
for example 300 ft-lb @ 5252 rpm is 300 hp. now if you have a motor that spins up to say, 7000 rpm and that same 300 ft-lb you have 399.85 hp.
now as to why you have hondas making so much hp with so little torque... say your honda is making 250 ft lb (generous, but some of them are with FI) @ 9000 rpm, you are making 428 hp.
For something similar to supras... 500 ft-lb @ 9000 rpm = 857 hp
for example 300 ft-lb @ 5252 rpm is 300 hp. now if you have a motor that spins up to say, 7000 rpm and that same 300 ft-lb you have 399.85 hp.
now as to why you have hondas making so much hp with so little torque... say your honda is making 250 ft lb (generous, but some of them are with FI) @ 9000 rpm, you are making 428 hp.
For something similar to supras... 500 ft-lb @ 9000 rpm = 857 hp
09-13-2009, 09:51 PM
#12
On The Tree
In the honda thread he stated that the shorter gearing of the s2000 helps for the lack of tq down low, while the mustang makes the tq down low but has taller gearing. What happens when you put shorter gears in the stang with good tq?
09-13-2009, 09:59 PM
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it all depends on the torque curve on the dyno graph
example: Look at this bike dyno, its got double the hp as torque, but look how high it has to spin the motor to make those numbers.
http://image.sportrider.com/f/182641...a_high_rpm.jpg
another example: Dirt bike, its torque drops off enough to where the hp drops as rpm goes up.
Last edited by StoleIt; 09-15-2009 at 10:58 PM.
09-13-2009, 10:04 PM
#14
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HP = (torque X rpms) / 5252
car 1: (300ft-lbs X 9000rpms) / 5252 = 514hp
car 2: (300ft-lbs X 6000rpms) / 5252 = 342hp
car 1 makes more horsepower, so most of the time, it'd win the race.
i just picked 9000rpm and 6000rpm as the "redline" for each car. im pretty sure this is right but someone correct me if im wrong. and this is assuming that each car continues to make power at that rpm range.
09-14-2009, 11:45 PM
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well lets say that each car has 300ft-lbs of torque...
HP = (torque X rpms) / 5252
car 1: (300ft-lbs X 9000rpms) / 5252 = 514hp
car 2: (300ft-lbs X 6000rpms) / 5252 = 342hp
car 1 makes more horsepower, so most of the time, it'd win the race.
i just picked 9000rpm and 6000rpm as the "redline" for each car. im pretty sure this is right but someone correct me if im wrong. and this is assuming that each car continues to make power at that rpm range.
HP = (torque X rpms) / 5252
car 1: (300ft-lbs X 9000rpms) / 5252 = 514hp
car 2: (300ft-lbs X 6000rpms) / 5252 = 342hp
car 1 makes more horsepower, so most of the time, it'd win the race.
i just picked 9000rpm and 6000rpm as the "redline" for each car. im pretty sure this is right but someone correct me if im wrong. and this is assuming that each car continues to make power at that rpm range.
No, you dont use the REDLINE. you use the point(RPM) where you make the most power.
I really dont feel like rambling... I need to get to bed.
But its things like these that are my PET PEEVES.
People are do ******* stereotypical and think they know everything when really they are ignorant!!!!
So just to break this down, as i was taught IN A REAL LIFE COLLEGE LEVEL PHYSICS CLASS...
IT has nothing to do with the fact that a 4cyl doesnt make torque,
So please stop saying that.
Its because Horsepower is a function of torque.
And they are just numbers.
but...
Most 4cyl or smaller engines are designed to make max power at a high RPM to make up for their lower displacement.
Torque x (RPM of Max Power/5250)
For example, if you make max power at say 10,500 RPM
And you make say 300 TRQ
Then the math would be...
300 x (10500/5250) = 300 x 2 = 600HP
Hope this helps,,, and that my maths all right,, im drunk
I have calc 2 at 8am tomorrow,,, its gonna suck
So much for not rambling... but again. ive been drinking.
