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Why Our Turbo Cobra's Don't Have Torque
- Thread starter KingCobra10Sec
- Start date
im not a turbo guy, but i am a math guy and i know that the formula for horsepower is as follows :
horse power = (torque x rpm) / 5252
so, given this equation its easy to see a couple of things. first of all when charting tq and h.p. on the same graph they are ALWAYS equal at 5252 rpm. the constant and the r.p.m. variable cancel each other out leaving horsepower = torque. now, having basic knowledge of the torque curve we know that we start losing torque at around 4000rpm but continue to make horsepower. whats happening to your turbos at 4000 rpm? they are makin more boost, and they will continue to make boost im assuming. so youre still losing torque at the same rate but making more boost. whats gonna happen? horseppower increase. im assuming the guys who make more torque than horsepower have boost controllers or something of that nature. also the higher you rev, the more h.p. youll make, look at the equation. like i said, im not a turbo guy, buthis seems pretty straight forward to me.
horse power = (torque x rpm) / 5252
so, given this equation its easy to see a couple of things. first of all when charting tq and h.p. on the same graph they are ALWAYS equal at 5252 rpm. the constant and the r.p.m. variable cancel each other out leaving horsepower = torque. now, having basic knowledge of the torque curve we know that we start losing torque at around 4000rpm but continue to make horsepower. whats happening to your turbos at 4000 rpm? they are makin more boost, and they will continue to make boost im assuming. so youre still losing torque at the same rate but making more boost. whats gonna happen? horseppower increase. im assuming the guys who make more torque than horsepower have boost controllers or something of that nature. also the higher you rev, the more h.p. youll make, look at the equation. like i said, im not a turbo guy, buthis seems pretty straight forward to me.
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Math wiz on SVTP FTW!
when my car is makin 888rwhp its making 950rwtq
888 hp = (950 x rpm)/5252
888 x 5252= 950 x rpm
(888 x 5252)/950= rpm
4909=rpm
these #'s will only occur at 4909 r.p.m.'s whats the car #'s at 6400 r.p.m.? probably a lot different
given that youre gonna lose about 13% of your torque from 4900 to 6400 its probably somewhere around 825 torque and 1005 hp. sound close? or am i way off?
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There are many factors to where you car makes your tq and hp but the biggest factor in a turbo car is of coarse the turbo. When you guys compare hp and tq you really need to see dyno graphs to see why different set ups make different numbers, or at least the rpm when peak tq and hp happen. Silver03Termi, your math is off because those numbers I'm pretty sure do not occur at the same rpm. Which is why rpm is important when comparing hp vs tq.
I will disagree with you on this based on my setup, I have a 4" downpipe am I am running dumps on the exhaust. I think a stock exhaust would provide the car with more torque because it has the back pressure on the exhaust gases.
Prime example when these honda civic boys add a huge exhaust system to there stock car they gain very little hp, but lose over 10rwtq.
while that can be true for an NA engine, turbo is a whole different ball game. you are aboslutely incorrect when you say causing back pressure helps torque with a turbo. do you understand how a turbo works? a turbo(or turbine) does a work output based off of expansion. you have high pressure in the exhaust before the turbo and low pressure on the other side on the turbo outlet. now, air flows from high to low pressure, so the larger the pressure difference between the two sides the more work can be done. by causing as low of pressure as possible on the outlet(see larger downpipe, straight through mufflers,...) you will in turn cause the turbo to do as much work(or torque) as possible. this work is transferred directly through the shaft to the compressor blade...
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Speak for yourself......Mine had a shit load of torque
With the stock turbo i beleive I was putting down 591rwhp/669rwtq on a mustang dyno with just a 4" downpipe @15 PSI
With the stock turbo i beleive I was putting down 591rwhp/669rwtq on a mustang dyno with just a 4" downpipe @15 PSI
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Ditto, 656rwtq at 13lbs with 616rwhp with a .96 hotside, although I do have some other factors.
Yes you guys are one of the rare ones. but post your cams, head, intake, and downpipe size and you will see why
haha, no kidding huh! just felt like rekindling with the basics lol...
Am I wrong in thinking that it has a lot to do with the flow potential of the turbo(s)? A lot of single kits make more torque than twins, but 1-76mm has less flow than 2-57mms (or 61mms, etc). Kinda like adding a 2.76 pulley to your Eaton which already had a 2.93/4#... you are closer to it's "limits", so the HP gains are smaller than the torque gains.
My point exactly, people who left heads/cam/intake stock made a TON of torque, what was your HP by the way?
adding a whipple and auto? more info please!
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