gnx7

iTrader: (10)

13BTNOS-

Do you know why torque/HP cross at 5250rpm all the time? Because HP is a mathematical equation based on torque. HP is Torque over time. They ALWAYS cross at 5250 rpm.

Torque wins races... bottom line. A POS 350 with 100hp NOS shot will kill a ported 12A with the same NOS shot. Because of torque.

Ian- A Dana 60 is probably the heaviest rear end you can put in a car. They work great for 4,000lb Mopars.... but a sub 3,000lb car would be fine with a much lighter $50 8.8" Mustang rear end with upgraded axles/LSD/gears. There are Mustangs running 7's on them... they work.

Do you want to pop a wheelie or be fast also? You should maybe looking into putting a ton of ballast in the rear... then you can wheelie the whole length of the track!

-GNX7

IanS

iTrader: (4)

He wants to go fast also. He is wanting a really fast street car that will pull the front end off when slicks are applied. So, basically what would you do to a 12A to make enough power to be able to pull the front end off? That is the real question here. The 8.8 rear end is fine with me and him. Also cheaper like you say.

razorback

what cars do the dana 60 come in?

edmcguirk

um... you can have any torque you want with the right gears. It's HP that makes torque. That's why they cross at 5250.

DamonB

No you cannot. Nobody had a 10 speed bike as a kid? Engines and transmissions in cars are no different.

Why couldn't I gear up my 10 speed to do 100 mph? Because my "engine" didn't have the power necessary to rotate the pedals because I lost all my torque multiplication.

Why couldn't I gear my bike down and pull bulldozers? Well, I could have. But I would have created huge torque multiplication at the cost of losing all my true power output at the rear wheel and would have been moving about as fast as grass grows. I would have been pedaling my brains out at maximum rpm and not going anywhere.

Cars are no different.

Hell, all we need to make a car do 500 mph is to put enough gears in the transmission! Bolgona. When you gear up you lose torque multilplication and once your engine no longer has the power to turn that load you go no faster. This is why your car accelerates so slowly in higher gears.

Drifters_Captn_01

Sorry if i'm writing for nothing, but somewhere in your posts you have said frequent lifting of the front end, any motor that has enough torque to lift the front tires means one of two things to me, 1st its got power which is always appealing, however with power comes twisting, more torque more twist, unless your partner has done or is considering frame additions, i would stick to a good driving car. If he in fact has or is going to add a frame to this beast it could cxertainly be a fun car.

I presently have a 86 and 87 my 86 has a 13-b and my 87 has been a project car since 2001, presently hosting a 2000 block 327 cu in Vortec fuel injected, with mod perf chip and whipple side mounted super charger, then cars runs 643 hp at the rear wheels.

edmcguirk

It sounds to me like you are mixing HP and torque in the same argument. You can get any torque you want with a big enough gear. You can't change your HP with gears. (double the torque, half the speed, same HP)

I could gear my bicycle to produce thousands of pounds of torque but my legs would "redline" at about 1 mile per day. I could gear my bike to move 100 MPH at my leg"s "redline" but I don't have the power to do it. Even if I go to the gym and do squats until I can press 800LBS with my legs (torque).

When I did that estimate of how much torque was necessary to lift the front wheels, I never said how fast you would be going at the time. If you want to lift the wheels at 10 MPH it will take the same amount of torque at the wheels as lifting the wheels at 50 MPH. The only problem is it will take 5 times more power.

The more accurate way to figure out how much is needed to lift the wheels would be to calculate how much acceleration is necessary to tilt the G forces so that the center of gravity points at the rear wheels. Much more difficult if you don't know how high the CG is.

ed

DamonB

That was my point. Because of this it's completely useless to gear a car that way and therefore useless to imply you can make the torque whatever you like. The mountain of torque doesn't mean anything when you're practially sitting still; the intent is to make the car go.

You're talking about making more torque through the use of gears but yet the torque and power from the motor will remain the same. The motor is the source of the power and thus the torque from the motor is what counts, not the torque that comes out of some magic gearbox. As we've proven you can do whatever you want with the gearing but that has no effect whatsoever on what your motor is really capable of doing.

fc3s-gxl

big port ona 12a or 13b doesnt have to be turbo,supercharged or nitrous it can do it all motor jus the porting and tuning

edmcguirk

I agree with everything you said and yet the opinion that I bring away from it is that torque means nothing because you can get any torque you want. Power is everything because power dictates what torque you can get at any speed.

nillahcaz

iTrader: (2)

[rant]
its posts like this that made me give up hope for this forum. This Club for events "at least local" is as unreliable as a stock 1st gen in the hands of a 16 year old ricer punk who treats it like a Honda.
If he wants to pop a wheelie tell him to make a rear engine funny car. If he wants to go fast and doesn't know what he is doing to the point of having such a dumb post he dose not need to be going that fast.
[/rant]

and oh ya...
power = The rate at which work is done, expressed as the amount of work per unit time and commonly measured in units such as the watt and horsepower.
work = Abbr. w Physics. The transfer of energy from one physical system to another, especially the transfer of energy to a body by the application of a force that moves the body in the direction of the force. It is calculated as the product of the force and the distance through which the body moves and is expressed in joules, ergs, and foot-pounds

so... " Power is everything because power dictates what torque you can get at any speed"
how dose that work, that is a X = Y+X style equation. power is HP and Torque and time "rpm" make HP so how can HP dictate torque. now shut up be for you hurt your self

and now im done

IanS

iTrader: (4)

Thank you for that insight

edmcguirk

You may know how to look up definitions but you clearly don't understand them.

Power is force through a distance over time.
Torque is just force. No movement involved.

Torque by itself is a useless number but torque available at a certain speed or torque at a specific RPM is useful. But when you have specified torque @ RPM, you have really specified a power level bacause RPM includes time and distance.

Acceleration is a measurement of force through a distance over time. That's power.
Top speed is a mesurement of wind resistance at MPH -> force through a distance over time. Hmm... power again.

The only example that doesn't have time and distance is trying to pull a stump out of your front lawn. Then all you need ia a big gear and your HP doesn't matter. You can get any torque you want but as soon as you move, you'll be talking about power and you'll need the power to make that gear last until 5MPH.

Both torque@RPM and power are legitimate ways to describe what's going on inside an engine but they are really flip sides of the same coin. When time and distance are involved, you can try to talk about torque but you are really talking about power.

ed

13btnos

iTrader: (1)

Hey all cars are different I don't deal with rx7 I build rx3, datsuns 1200, toyota starlets basically small cars. Torque matters when your dealing with weight my personal car is a datsun 1200 I'm trying to keep it under 1900lbs with me in it. I haven't weighed it and I still have all the factory glass in it but the front end is fiberglass. For the future I am looking to remove the factory glass and add fiberglass doors and trunk lid and by then I would like to see the weight of the car around 1700 with me in it. All my cage piping is chromoly I'm trying to keep it as light as possible and my projected HP output will be 580rwhp and yes this will be accomplished and be reliable. I don't race NHRA or IHRA or NOPI I race at my local tracks and race in heads up races with V8s. Ok now back to the 350 vs 12A deal it depends on the cars like I said before there are tons of variables to making a car go. If it's weight that's your issue you should look to make TORQUE to get your car down the track. And if you have looked at a dyno sheet after 5250rpms do you notice how fast torque drops off and HP takes over. Now tell me would you shift at your peak torque or your peak HP. Now tell me what gets you down the track. And for you V8 guys I love V8 I just don't have the money to build them the way I want. My dream car is a 1970 split bumper camaro with a twin turbo small block set up. When I finish my datsun and happy with it that will be my next goal. My friend has a 12A bridge port motor not a big bridge it isn't even past the seal or cut into the housing with nothing more than a Holley 600cfm carb and MSD ignition and 150shot of NOS has made 10.54 pass in his datsun 1200 guaranteed his ate up his share of V8s on juice. And if you have the time read this http://www.yawpower.com/tqvshp.html. Torque wins races... bottom line... YEAH right that's why NHRA Top Fuel & Funny Cars are always looking to hit the big HP numbers you don't hear them taking about torque because it's not an issue to them. For the HP they are making and the weight they have to pull TORQUE is not an issue. When you see trap speeds put up why do they say look at the horsepower they are making. Why don't they say look at the torque they are making. Like the saying goes different strokes for different folks. Hey I love Grand Nationals I love their engines anything with a turbo turns me on. Put a turbo on a Yugo and I'll think it's cool. Hey I'm not trying to burn on you GNX7 but you can't say that only ONE thing wins races it's a number of things. You can make all the torque/horsepower in the world but if you can't put it down your not going to win anything. Next time your at the track shift at your peak torque rpm since torque wins races and tell me then if torque gets you down the track faster. It might **** you off but hey the truth hurts sometimes. If you race I know that you shift at your peak HP rpm and what is getting you down the track horsepower yup that's right!!! Take a look at this it's my friends old setup which I have now and these times were done with the car weighing 2100 lbs http://www.raycar.freeservers.com/photo5.html

gnx7

iTrader: (10)

13BTNOS-

No offense taken.

Those cars are fast.. but 90% of the drag race cars out are over 2500lbs I'd imagine and torque does come into play. I don't need to get into any form of this is better than that match.... but like you said.... many factors come into play other than torque. We build what have available to us.

Hell a 6 cylinder turbo diesel truck motor puts out over 1000 ft/lbs tq... but only about 300hp. That probably wouldn't be the best drag motor either since it revs to about 3K. But since it does have tons of torque it certainly can move the mass thru its numerous gears.

The old school RX-3's/Datsuns are cool... but scary with such a short wheel base.

-GNX7

13btnos

iTrader: (1)

Yeah try a wheelbase of 90.6 in. in a Datsun 1200 with 500+rwhp talk about trying to keep the front end down nearly impossible. I've got my cars suspension way overpowered I'm still on the factory leaf hopefully next year I get it backhalved it's an on going project. Oh yeah on the Ford 8.8 rearend you talked about you should look at the 8.8s out of the 97- 2000 Explorer before they went independant it's 8.8 and are 31spline from the factory.

IanS

iTrader: (4)

Ok the '97 - '00 explorer 8.8 is better than, say a '92 Mustang GT 8.8? Just making sure of the better parts before money is spent on this project. To attempt to keep this discussion on topic as much as possible (the horsepower/torque thing was a good read btw) I have a simpler question:

Lets say you have a gutted '85 Mazda RX-7 base (12A). What would you do to the 12A and the rest of the driveline/suspension to make it do a wheelie on slicks? What parts would you use? From what vehicles are these parts from? Are they relatively easy to find in a junkyard?

fc3s-gxl

wrong,wat power is that 350 with nos putting out? okay when u figure wat its making ,think, it s a 12a ported with nitrous,ok so double it and add the 100 shot to the 12a becuz a 300hp piston wil get ownd buy a 300hp rotary