ok i have searched and found some info but not exactly what i am looking for my question is if you have 2 cars that make 1000 hp both are turbocharged and they weigh the same and all things are identical except one is a 4 cylinder and the other is a big block v8 the 4 cylinder makes 400 tq and the big block makes 1200 tq and that is the only difference in the cars how would the car with more torque faster say in the eighth mile if niether car has any tire spin at all. thanks guys for any info

 

There is not enough information here to decide. The 400lb-ft car could be faster. The 400lb-ft car could still have more average power.

The car that has more average power will be faster. If both engines run the same speed then the one that makes more peak torque will have more average power. If one engine runs faster than the other one it becomes harder to glance at the numbers.

Even if you plot the torque speed curves on the same graph if they run different speeds then it is hard to tell. You would have to normalize them to the same speed.

If these engines were N/A we would know for sure that the larger engine made more average power but since they are turbo it is only likey that the larger engine wins.

 

i guess my question is if your speed comes from horsepower then is there an advantage to haveing lots more torque and why the reason i am asking is my car has a 460 ford mostly stock with a turbo and it makes alot of torque but is that going to make my car faster than a car with much less torque but the same horsepower

 

I think weight would play a huge factor heavy cars need torque to get off the line. An extreme example would be a crotch rocket; It would take alot of torque and HP for a 3000lb car to keep up with a stock CBR1000.

 

Speed does not come from power. Power comes from speed and torque.

Typically a "mostly stock" turboed engine will be faster than a "high performance" turboed engine of the same power. This is because typically a mostly stock engine has a better torque curve than a high performance engine. If your asking if a big displacement turboed engine will always be faster than a small displacement turboed engine the answer would be no. The turbo changes things.

 

It's perhaps a good idea to consider what horsepower actually is. As mentioned in the last post, horsepower is the combination of torque x rpm divided by a constant (5252 if memory serves). Whereas torque is literally the turning FORCE of the drivetrain.

The torque (or force) is what changes the speed of a car from say a standstill to 100mph. Force has to be applied to make this change otherwise the car would remain at rest. Thus it is torque (or the magnitude of torque) that pins you in your seat when accelerating.

Horsepower on the other hand is simply a number derived from the torque multipled by the rpm (or cycles) of the engine know as the amount of work being done in a given amount of time aka the power.

In answer to your question, 1200ft/lb will accelerate a given car faster than 400ft/lb would as more force is acting upon it. If both cars have 1000bhp that's just a peak power figure suggesting that both would 'eventually' reach a similar maximum speed (but not necessarily with 1/8 or 1/4 mile). Think of it like this - torque for acceleration, peak bhp for top speed.

 

This is misleading.

Since one engine makes 1200lb-ft and one makes 400lb-ft yet the engines have the same power it sugests that one engine runs about three times as fast as the other. It is rediculous to think of a 1000Hp engine that only makes 400lb-ft but if one existed it would be because it ran rediculously fast. You must assume that if these two engines are in a car then they both have optimized gearing. The faster engine would have a ratio three times the other engine and therefore produce the same torque at the wheels. Since force at the ground is what produces acceleration both engines accelerate the car at the same rate.

DO NOT think of it this way. Average power makes cars fast not torque. Diesel engines make lots of torque but will not accelerate you car as fast as an engine that makes lots of power.

 

The HP # is what is important. Torque is the potential to do work but is nothing until combined w/RPM to get HP. Acceleration and speed relate to time - HP, and the formula for torque doesn't.

I'd say geared correctly and at the same weight,the cars would run about the same.

A formula 1 engine only makes about 200ft.lbs of torque but at 19,000 rpms that adds up to over 700 HP.

 

thanks guys for the info

 

As it has been stated, horsepower is derived from torque. Anything above 5252 rpms you will have a higher hp rating than torque rating. So if you start in low rpms, two cars with identical everything, the higher torque car will accelerate faster, but that is until 5252 rpms. Then you might have the big engine die off and the small one run to 12k rpm, so there are a lot of factors.

Think about this, ever see the 700-1000hp supras run 11's-12's at the track? Sure they have a huge peak hp, but they only have it for a split second and then they are out of gear and back out of the power range. Once they shift they have almost no power, then eventually they blast through the top of the gear, rinse, repeat.

I agree it takes more of an average power curve, not strictly peak values

 

A simple way to think if it is that hp is tq past 5252. And before anyone says it, yes I realize hp is made pre 5252 as we'll.

 

just try get the max torque number HIGHER in rpm..
then u will naturally have more hp..

 

I remember reading somewhere more peak tq before 5250 is like free horsepower after 5250 ? or something to that effect

 

Actually that's very incorrect. By your theory it wouldn't be possible for a big single supra to run a good number. The reason some supras run horrible times has to do with suspension, tires, many other factors. I assure you a single turbo supra has around atleast 3000 rpms of a buttload of power. (5-8000+). Shifting at around 8000still leaves you at around 6000 atleast.
I assure you the record setting 6 speed supra has what you are considering a short powerband but went high 7's at almost 200

You may wanna do a little research before posting "information", that's what's wrong with tech on the internet in the first place

 

think he was just using a supra as an "example" dont get your panties in a bunch

 

How is correcting wrong information getting my panties in a bunch? I would also correct him if he gave wrong info on a mustang/camaro/fiat as well. So don't get sand in your vagina

 

1994 supra-allmost stock

 

+1

 

Very interesting read.

 

I guess I should've been more specific. I've seen plenty of supras done right, that have a nice powerband. I've seen more that seems like they have a light switch for power, I watched an 1100hp supra lose to about 10 cars one night, all less than 500hp, all because it needed a driver mod along with a usable powerband. It was basically stock everything with built internals, and a massive turbo that spooled at around 7k, plus water/meth etc. He would launch, spin, next gear, bog, spin, next gear, bog, spin revlimiter bouncing, pretty flames... Some people just dont need fast cars.

I raced a 733hp supra though, he was running 10's, but started having issues, and when I ran him he only ran in the 11's. A 700hp car should be a lot higher than that.

You can't assure me of anything about every supra on the road. How do you know every single turbo supra has 3k of usable power? How about this one?


So I'm not just hating on supras, It just seems that they are more prone to over sized turbos with narrow powerbands. I would rather have a 600hp car with a huge flat powerband than a 750hp car that had all of 1000rpm that made that power