Torque vs. HP

Interesting article. The cover was interesting too, a WRX STI "wiping up the track" with a 2003 Cobra. Do I believe it? Sure. Is Hot Rod a Chevy rag? Sure. But I'd like to read the article nonetheless... can anyone post it?

Thanks.

Brad S

"Brad" wrote in a message:

Hot Rod has always been biased towards Chevy, but they have published a lot of good articles on Fords too. As for posting the article, are you referring to the one I mentioned? (Torque vs HP) I can scan it and put it on my server tomorrow. The article goes into great detail, and gives some formulas as well. It is very informative, and confirms what I've been saying all along. If your building the car for drag racing, build the motor to make the torque up higher in the RPM range. They also say that torque down low is harder on the drive train.

"GEB" wrote in a message:

Ok. For those who want to read the article "Torque vs Horsepower" I scanned the full article and is available for download at

"Brad" wrote in a message:

If your referring to the SVT vs STI article, I scanned that as well. You can download the zip file at

Both articles are great. Thanks Gary. I appreciate it.

Brad S

"Brad" wrote in a message:

Glad I could help. Now if those who said I didn't know what I was talking about when I said that for drag racing purposes, that it is better to start making torque up higher in the RPM range, would read the article, they might realize that I do know what I talk about.

Hope everyone had a most enjoyable Thanksgiving day.

If you drive or race a relatively heavy car (3000+ lbs, most mustangs)then low/mid range torque will get it up to speed quicker than top end power. Not everybody drives a gutted out compact car.

"winze" wrote in a message:

So, when your teacher taught the rest of the class to read, did you skip class? What part of the article (if you actually read the whole thing) didn't you understand when they said massive amounts of low end torque is hard on the drive train? Did you understand the part where they said when you have massive amounts of low end torque it is hard to get the car to hook up at the track? Do you remember in the article where they said it's HP and RPMs that gets the car down the track faster, not torque? I originally started this conversation for those who were modding their cars to take to the track, and trying to get their cars faster, only to find out they had trouble getting their car to hook up. Did you read the part where they said the rear gears multiply torque, so it isn't necessary to build torque down low? What is one of the first thing everyone does to their car? Ummmm...lower rear gears! I seriously don't think you even read the article at all. If you did, you didn't understand a word they said. Most of that article was written with information given by engine builders, and I think I would believe them before I'd believe you. I scanned that article and made it available to those who drag race their cars, so they would understand why they have a problem getting their car to hook up and get better 60' and 1/4 mile times. I don't expect an arm chair racer to understand what is in that article, but I'm sure that those who actually race their car, and do all their own work on their car will understand it.

It's interesting Gary, cause the stock 5.0 has 300lbs. Even with the 2.73s I have in my car, I can light the tires at will. Everyone puts gears in their car, but I haven't yet, wondering if maybe there is a better way to spend the money... cause with 3.73s I can only imagine how much 'worse' it would get... That said, low end torque sure is a hell of a lot of fun! Anyone have any ideas on where better to spend the gear money?

Brad S

My thoughts on this...

Yes, a stock 2.73 geared 5.0 5-speed will blaze the tires up almost at will with stock tires and stock suspension on the street. Try it on the dragstrip with sticky tires and a slightly tuned rear suspension and you'll find a completely different story. Lower rear end gears drop ETs in almost every occasion (from a stock gear of 2.73-3.27), and especially if the car makes most of its power up high (which relates more to the 4.6 engines than the 5.0s). Too much gear on the street won't help much.. running 4.30's will wind you through first so fast that it's almost worthless on the street, but on the strip with some sticky tires and a properly tuned suspension, it'll help you blast out of the hole.

Guys in stock-engined early DOHC cars running 4.30's at the strip and turning out 12's will definately argue the benefits of gears, especially on these cars as they make most of their power up near 6500 RPM.

If you'd like to spend your gear money elsewhere, consider chassis stiffening. I'm assuming that since you said you had 2.73's (and that you could light up the tires easily) that you're running a later SEFI 5-speed Fox. Subframe connectors will help the car feel more solid and will help regardless of what kind of racing you'd like to get into, if any, and they're great on the street as well. A Tri-Ax shifter will help bang the gears a little easier. A suspension kit (depending on your driving style and use of the car) will help you either attack the twisties or hook up at the strip. Remove the air silencer if you haven't done so already for a couple free horsepower.

JS

"Brad" wrote in a message:

Brad: At least you understand what I was saying. The least I can say for Winze. Sure, being able to spin the tires at will is fun, in certain situations. But at the track, when your trying to get the car to hook up and getting good 60' times and improving your 1/8 & 1/4 mile times and speeds, you don't want to spin your tires. With a little research, cam, lifters, and valve springs will net you more HP, RPMs, and torque in the right place, and still be able to spin your tires at will with street tires, yet at the track with ET Streets, you can still get your car to hook up, and see improvements in your ET's across the board.

The thing that Winze fails to understand from the article is that Torque only gets the car moving, and HP is what gets you down the track, not torque. By building more HP, you will gain more RPMs, which can be done from a cam with higher lift and duration.

In closing, if your serious about drag racing your car, there is two programs I highly recommend . The first one is Desktop Dyno 2000. This program lets you see what changes you want to make to your motor will do to Torque, HP, and RPMs. Just remember, the figures it produces is at the engine, not the rear wheels, and allow for about a 10 % error. The second program is Desktop Drag Race, by the same company as Desktop Dyno. This program, you import the info from the dyno program, and enter stuff like car weight, tranny gear ratios, rear gear ratio, and stuff like that, and it will tell you what it should run in the 1/8 or 1/4 mile, again allowing around 10% for error. It also has a function that it can also recommend making certain changes to improve your setup. The advantage to using these two programs, is you can try different combinations and see their results without having to spend a penny on parts, vs the trial and error method, and lots of dyno time.

I am not affiliated with the company that sells these programs. I am only telling you about them because they are a useful tool.

Gary Drag Racers live by the code set down years ago: "If some is good, more is better, and too much is just right".

"JS" wrote in a message:.

I agree that the very first thing that should be done is stiffening the chassis with good welded in frame connectors. And I won't argue the rear gear issue either, provided you have enough RPMs to get through the 1/4 mile without using OD. Another thing he should consider is stronger rear axles if he intends to launch the car hard. Buzz Haze can tell you about stock axles and what happens to them launching the car hard with a manual tranny. Also don't forget the HD u-joints, and a drive shaft loop. Then there is Southside bars if it's a coil spring suspension, or Traction Master bars if it's a leaf spring suspension to eliminate wheel hop, and to improve weight transfer on the launch. Like you said, there is a lot he can do, but he needs to decide what he wants to do with the car first.

Gary Drag Racers live by the code set down years ago: "If some is good, more is better, and too much is just right".

improvements

Thanks for the tips and advice. Through the magic of working overtime the past few weeks, I literally have $500 in my pocket that I am going to drop into one of my vehicles.. the question is which one, and where? Subs and a shifter seem like the place to start (my 93 5.0 is completely stock except for synthetics and 15 degree timing)... but then again, I have a 6050lb 1980 Bronco with a 351 that is just crying for a 3 inch lift kit. :) (13mpg highway, 9 in the city!) :) Man, this is getting hard.... in the end, I know I'll work the 5.0. It's just such a fun car to drive and anything I can do to make it take off better is most welcome. But, last question, what about drag radials as a performance item? Do they make *any* difference on the hole shot? Thanks!

Brad S

magazine and bench racing 101! LOL

"winze" wrote in a message:

Talking about yourself again there Winze? You almost got it right. You left out lying Lawyer in your description of yourself. You should have stated: "magazine and bench racing lying lawyer, 101. I got a race car, time slips, and video to prove I drag race, how about you? Either post a link to time slips to prove you know what you claim you do, or shut up and go away!

Gary Drag Racers live by the code set down years ago: "If some is good, more is better, and too much is just right".

"Brad" wrote in a message:

They will help a little, but not as good as M/T ET Streets or Drags will.

Gary Drag Racers live by the code set down years ago: "If some is good, more is better, and too much is just right".

I agree with Gary that the M/T tires would probably help a bunch more... but just from a DOHC owner's point of reference.... (which may change things some as my car makes very little bottom-end torque and makes up for it on the high end)...

Launching my car as I would on the street if I needed to accelerate quickly only produced massive amounts of tirespin at the track on street tires, burnout or not (though not doing one helped). Trying to slip the clutch at

Enter Nitto drag radials. Big burnout to heat 'em up, try to launch at 2500 (not expecting much traction), and get rewarded with a huge bog. 3500, same thing. 4500 - finally working out a bit, but have to hammer the throttle as soon as I start releasing the clutch or it bogs again.

They definately made a huge difference on my car. YMMV...

JS

I don't subscribe to hot rod magazine and I don't race a desktop dyno either. Your old school wisdom has it's place but I wish you'd stop trying to push it on everybody, I'll take a torque motor any day over a peaky top end screamer. Have you ever compared Boss 302 or hi-po 289 et's to 87-88 5.0 mustang et's? the 87-88 will beat both, in factory trim.

"winze" wrote in a message:

I'm not pushing anything on anybody. And I don't race a Desktop Dyno. I see your not reading the full post again, or is it you just can't read? If you can't understand the fact that when someone says they can't get their car to hook up at the track, and I reply with a solution, that's your problem. I posted a link to a zip file that had the article from the Hot Rod Magazine so that anyone could download it and read it. It is very informative, and contains allot of formulas, and explains the difference between torque and horse power. I can't help it that your too stupid to read the damn article and learn something that pertains to drag racing. As for your comment about the 87-88 beating the Boss 302 and the 289 HiPo, well, if you build the

Gary Drag Racers live by the code set down years ago: "If some is good, more is better, and too much is just right".