TAChad

I had my car dyno'd today and had a few questions about the difference beteween HP and torque and how they relate to track times. The last time i dyno'd was with the 4l60e, stroker and 150 shot with the mods below. HP on motor with the TC locked when ed wright tuned it wsa 410 RWHP and 444.8 RWTQ, then i dyno'd it locally and got 399.3 RWHP and 399.7 RWTQ, (motor) and 475 HP and 480 TQ on 125 shot(wsant a very good pull). my best time was an 11.1 at 128 MPH with that setup. I went to dyno today, had the same mods as I had before for the most part, but i have a moser 12 bolt, with 4.11's and 28" ET streets and a TH350 with 4000 non lockup stall. on motor I made 336.3 HP and 457 TQ and 448 HP and 550 TQ on juice. I figured Id lose quite a bit of HP through the drivetrain (loose convertor and heaver rear end, big slicks) but i didnt think id lose that much. BUT, the torque increased greatly. So i guess my question is, wich will make better times, horsepower or torque? thanks

Chad

aintno6

I dunno how much I can help. But no matter what people are going to say... But the way your car will react at the track will make the biggest difference. How well were you hooking up before this combo?

Generally the more HP you make, the better it helps with the MPH, which would make ur E.T.'s improve. But if you 60's improve drasticly with ur new combo, then that may help even more. I guess what Im saying is, you wont know till u make those runs at the track. But you probably know that allready.

TAChad

thanks for the reply. I hooked up pretty well, but my best 60 ft was a 1.62....I am almost positive i have lowered that down with this setup. I know you cant necessarily go by the way it feels, but with the trans brake and bigger stall, it launches like hell and pulls hard. I'm just getting anxious. ive missed 10's by a couple tenths for the last year or so and all the tracks are closed now.

Chad

stereomandan

Forget horsepower. Really. Forget it. It is only a function of TQ. TQ is what accererates your car. Your car accelerates exactly the way your TQ curve is shaped. When looking at your HP/TQ curves. The only line you should be concerned with is the TQ curve.

Horsepower = TQ / (Engine RPM/5250)

That is why all HP/TQ curves cross at 5250 rpms. The HP and TQ numbers are equal at 5250 rpm.

So you can see, Horsepower is a function of TQ.

The higher the TQ, the greater your acceleration.

One way that people get their HP to look good is to spin the motor very high. You can see from the equation above that the higher you spin the engine, the higher the HP generally. That is, unless your TQ falls on it's face in the upper RPMs.

Dan

NewbieWar

basicly the same thing stereomandan said... forget horsepower...

look at 2 things where ur peak is for the torque, and what the peak is... for torque the best thing u can do is try to make it as little of a curve as u can and make it more of a flat line (not falling on its face)...

so ur torque looks like ------------^-----------------
and ur horsepoer will just keep goin up.

TAChad

thanks for the excellent answer to my question. my torque line on the dyno chart isnt anywhere near straight, but its a steady drop off at almost exactly a 45 degree angle. It starts at 550 Tq at about 4000 RPMS and ends at 350 Tq at 6500 RPMs. It seems like the torque line drops off at more of an angle on nitrous than on motor, is there a reason for that?

Chad

stereomandan

I'm guessing that your's heads/exhaust can't flow high enough to support that much HP/TQ in the higher RPM's with the nitrous running, or maybe it's in the design of your cam.

Wish I had your problem.

Dan