Why can a 1400 lb F1 car handle 1000 plus horsepower but a Viper can't?

Vigo wrote: In apps where the traction is actually critical, in the modern day, it is easily possible to have every bit of control over wheelspin that you could ever want. Building a 1000+ hp viper tuner car is not one of those situations. Just like the OP said, the car clearly wasnt built to go fast AROUND a racetrack. It was built to lay down dyno numbers, get photos smoking the tires at 150mph, and generally to win dick-waving contests. But if they wanted to control the wheelspin, they could.

Not sure how closely you follow F1, but all these and more were used on cars in the recent past, starting in the 1980's and playing a huge role in the early 90's. It was banned for a while because certain teams (Williams-Renault, in particular) were better at it than others, and it proved to be extremely effective.

It was reinstated in 2002 since it was no longer possible to police it's use ... basically every car had an engine ECM and associated electronics and it was impossible to truly peek into the box and know for sure what it was up to. The Williams cars had both traction control and active suspension integrated into the same computer management system.

As a consequence, teams never speed leaving the pit lanes anymore (which results in a penalty).

Somewhat different, but related to this discussion, is "launch control". That continues to be banned in F1. Basically, it was causing too many accidents at the start of the races. So, an F1 driver can now still spin the tires ;-)

One thing that keeps getting forgotten in the TQ vs. HP argument (though it has been mentioned in this thread).

Gearing.

In the above example, the formula car should have 4x the gearing reduction to keep things "equivalent".

Another example: a 200 hp, 2000lb car going 50 mph at peak power will accelerate EQUALLY QUICKLY to any other 200hp, 2000lb car going the same speed AT PEAK POWER regardless of tq curves. Ponder that.

Ultimately, all that matters is Tq to the wheels. Higher HP and optimized gearing=faster. You can make more tq at the engine, or spin it faster and multiply the tq.

njansenv wrote: One thing that keeps getting forgotten in the TQ vs. HP argument (though it has been mentioned in this thread). Gearing. In the above example, the formula car should have 4x the gearing reduction to keep things "equivalent". Another example: a 200 hp, 2000lb car going 50 mph at peak power will accelerate EQUALLY QUICKLY to any other 200hp, 2000lb car going the same speed AT PEAK POWER regardless of tq curves. Ponder that. Ultimately, all that matters is Tq to the wheels. Higher HP and optimized gearing=faster. You can make more tq at the engine, or spin it faster and multiply the tq.

Gearing is actually a torque multiplier. If your ratio is 2:1 then you get twice as much torque in that gear at the rear wheel as you would in "top gear" which would be 1:1. That's why dynos measure at top gear or alternately, carefully input the ratios at whatever gear you do test at. That's also why final drive ratio affects acceleration; higher ratios put more torque to the wheels.

But, if you account for the ratio, then the torque you measure at a given RPM is identical in every gear. If we measured engines based on MPH instead of RPM, you would get different torque values at a given speed, depending on which gear you were in.

Finally, you have to assume that a car has "appropriate" gearing to get moving and keep moving with the load (work) it's intended for. Certainly the final drive ratio of a car will limit top speed, for example, so you have limits to deal with; you need to compromise at some point.

Another factor is that ratio affects the strength of the gear ... if you want a small, light transmission, and still want top speed, you might have to use higher ratio gear sets, and a high numeric rear end combined with ... wait for it ... 20,000 RPM.

Conversely, if you have gobs of torque available at a low RPM, you may as well use it instead of leaving rubber on the road everywhere. So, beefier tranny and lower (numerically) rear end to get the same top speed at ... hmmm, letsee here ... 6,500 RPM, perhaps?

If a car has a limited poweband, you probably need more gears, but there is a practical limit to how much someone can be shifting in a race application. A Peterbilt has a narrow powerband ... roughly 1000 RPM. So the 15 or whatever gears in a tractor-trailer.

A locomotive has a wide powerband (and TONS of torque) because it uses an electric motor to drive the wheels, and electric motors have high torque in general and maximum torque at essentially 0 RPM. Lots of people think a locomotive has a diesel motor to drive the wheels, but it doesn't. The diesel engine drives an electric generator, which powers the electric motors that drive the wheels.

One thing that hasn't been mentioned yet is weight distribution front to rear... Most of the sports cars we're used to (including the Viper) have a front engine and rear wheel drive. The F1 car has a mid engine rear drive. IIRC, most mid-engine cars have a weight distribution somewhere in the range of 35-45% front and most front engined cars have a weight distribution in the range of 50-55% front.

Note that a Miata has a 50% or so F/R weight distribution with a front engine/transmission. A Corvette on the other hand, has a front engine with a rear transaxle. It makes for more mass right at the rear wheels.

My experience with a 350Z has shown that corner exit is affected significantly by weight bias. (Note that I've got 275s all around rather than staggered.) When I have a full tank of gas (gas tank in rear) I'm a bit less nimble, but can put down more power on exit. However, when I get down to a quarter of a tank (some 12 gallons * 6 lbs/gallon = 72lbs lighter), I'll be able to rotate better, but not put down the power as well.

scardeal wrote: One thing that hasn't been mentioned yet is weight distribution front to rear... Most of the sports cars we're used to (including the Viper) have a front engine and rear wheel drive. The F1 car has a mid engine rear drive. IIRC, most mid-engine cars have a weight distribution somewhere in the range of 35-45% front and most front engined cars have a weight distribution in the range of 50-55% front. Note that a Miata has a 50% or so F/R weight distribution with a front engine/transmission. A Corvette on the other hand, has a front engine with a rear transaxle. It makes for more mass right at the rear wheels. My experience with a 350Z has shown that corner exit is affected significantly by weight bias. (Note that I've got 275s all around rather than staggered.) When I have a full tank of gas (gas tank in rear) I'm a bit less nimble, but can put down more power on exit. However, when I get down to a quarter of a tank (some 12 gallons * 6 lbs/gallon = 72lbs lighter), I'll be able to rotate better, but not put down the power as well.

The Miata and the Corvette have similar F/R distribution; it's 52/48 in the Miata and 51/49 in the Corvette. I would be shocked to learn the Viper was much different, and I would bet GM's choice of a transaxle was all about keeping that ratio tight. It's easier to get near neutral handling when the car is near 50/50 but in the end most cars are biased to understeer or oversteer because it aids predictability.

When you have a car that is near 50/50 you can dial it in either way. Moving the weight distribution further from that ideal might limit your options to one or the other, with tuning to get as close to neutral as you can. So, many FWD vehicles are stuck with a tendency to oversteer and they work with that, while non-performance RWD drive vehicles are similarly stuck with understeer (say, a 1/2 ton truck, which has the added burden of a variable rear weight to deal with, so empty it's got to be heavy front).

A slight front F bias helps with braking and cornering. Mid-engine cars and rear engine cars have the biggest challenge there because the transition from oversteer to understeer can be very abrupt, ie less predictable.

Nice Car, by the way. Suspension is very complex and unique to the car and driver, but I'll bet you could dial that in a little closer to your preference; factory suspension has to assume rough roads, "average" drivers, etc so they are going to definitely compromise away from the very best handling and toward comfort and predictability.

If you can feel such a small change in weight then you probably can dial it in tighter and drive what you end up with faster ... most drivers wouldn't know their car that well, let alone feel 6 gallons at around 6 1/2 pounds a gallon.