R Viper GTS vs Tuscan

[Mike Rotch]

Can those in the know please explain this to me the reason behind the following. As my tuscan has pretty much levelled anything within reason, i decided that it was time to build a suitable rival. So i picked a Viper GTS as a challenger, and put a mod on and took it up to 529 hp ( the tuscan is 487hp). After tuning and tuning, the Viper is consistently 3-4 secs off the pace at midfield. So i thought, well it must be the weight that is hampering the viper, after all it weighs 1307kgs to the tuscans 945kgs. But some digging revealed something interesting.

The tuscan manages 52.6kgs at 6000rpm of torque. The viper pushes out 74.5kgs/4000rpm. Thus the tuscan has 17.96kgs of weight per kg of torque and the viper 17.54 kgs of weight per kg of torque. The viper thus has a better power to weight ratio, despite being heavier.

Interestingly, the tuscan can do 0-200kph in 9.8secs and the viper can only manage a poor 11.1secs.

My questions is, why is the viper slower in virtually all regards, despite having more hp and 20kgs more torque?

 

[bla]

First of all I believe the normal power to weight ratio is measured dividing weight by the hp not the torque. So 1307/529 = 2.5 against 945/487 = 1.9 will show you the tuscan advantage. Still you can take those torque figures into considferation, but consider this as well: torque comes into play sooner lets in the lower rpms while pushing the car from a slower corner. Midfield apart from that slight climb near the end where torque also comes into play is more about speed thus hp. I´m no pro about this torque issue, just explaining you from my limited knowledge so you might want to hear a second opinion.

Second the gts is an horrible car with stock settings, he understeers like no other and when it loses some rear wheel traction he will spin easily. I had to play around with settings to find that lsdas well as other stuff would get the car to behave a lot better. Is he turning good? Cause if not you have your handicap there since I belive the car corners decently.

 

[Mike Rotch]

Originally posted by bla
First of all I believe the normal power to weight ratio is measured dividing weight by the hp not the torque. So 1307/529 = 2.5 against 945/487 = 1.9 will show you the tuscan advantage. Still you can take those torque figures into considferation, but consider this as well: torque comes into play sooner lets in the lower rpms while pushing the car from a slower corner. Midfield apart from that slight climb near the end where torque also comes into play is more about speed thus hp. I´m no pro about this torque issue, just explaining you from my limited knowledge so you might want to hear a second opinion.

Second the gts is an horrible car with stock settings, he understeers like no other and when it loses some rear wheel traction he will spin easily. I had to play around with settings to find that lsdas well as other stuff would get the car to behave a lot better. Is he turning good? Cause if not you have your handicap there since I belive the car corners decently.

Thanks bla, I appreciate the input

Firstly, the handling of the viper is A-OK. I slapped on the blue race mod, and to my surprise the turn in was crisp and predictable, without any unexpected oversteer on the exit (after all that to a large extent depends on where in the corner you step on the gas).

I see your point on looking at hp, and torque. I also think that torque plays a large part in accelaration out of corners, however, that is why i stuck the 0 - 200 kph figures in. The tuscan has far more top end accelaration, even tho the vipers torque curve is relatively flat compared to the tuscan. I'runno. maybe torque is not the distinguishing characteristic of a good car

 

[cmviper]

I Think the reason the viper is behind is its gearing. remember in GT1, the ratios were set to get the car to change into 6th at 394km/hthink.). The same is in GT2, the ratios are set such that the viper gets the maximum speed in the gears which is why sometimes it never even goes into 6th while the Tuscan has better in-gear accelaration.

 

[Mike Rotch]

Originally posted by cmviper
I Think the reason the viper is behind is its gearing. remember in GT1, the ratios were set to get the car to change into 6th at 394km/hthink.). The same is in GT2, the ratios are set such that the viper gets the maximum speed in the gears which is why sometimes it never even goes into 6th while the Tuscan has better in-gear accelaration.

Welcome to GTP

True in stock form, but that is all rectified via a customised gearbox

 

[Joey]

Aerodynamics?

 

[BadBatsuMaru]

I'd have to say it simply comes down to the fact that the Viper is so heavy. As far as this whole torque thing...

1 horsepower = pulling force required to lift 33,000 pounds 1 foot in 1 minute

1 foot pound torque = torsion required to hold a 1-pound weight at the end of a 1-foot bar (note that time is not a factor)

Torque and HP are completely tied together:

horsepower = torque * (RPM / 5252)
torque = horsepower / (RPM / 5252)

Torque tells you how hard you're getting pulled back into the seat. The torque curve perfectly matches the acceleration curve of a car. Torque factors out RPM, though, and RPM is obviously very important. Consider three imaginary cars:

Car 1: 300 ft-lbs torque @ 2626 RPM = 150 HP
Car 2: 300 ft-lbs torque @ 5252 RPM = 300 HP
Car 3: 300 ft-lbs torque @ 10504 RPM = 600 HP

Torque is basically telling you how much of a push one revolution of the engine makes. Therefore, Car 2 and Car 3 each double in power because the RPM doubles. It's impossible for a car to accelerate as fast once it's up around the redline, but that's still where the engine does most of the work. If torque were really that important, F1 cars would be diesel.

Torque tells you how hard a car pulls, and higher low-end torque means you don't have to really wind up the engine to get going.

S2000:
240 hp @ 8300 rpm
153 ftlbs torque @ 7500 rpm

Most people would say the S2000 isn't exactly the most fun car to drive to work every day, because it doesn't really pull till 7500 RPM. You really have to rev it up and dump the clutch to get going.

As far as GT3 is concerned, horsepower is still what matters. Torque is great, but it's mostly an indicator that the car has a nice wide powerband. A lot of low-end torque means you'd be better off using a manual transmission, since GT3 shifts pretty late with the automatic.

 

[Joey]

Ever driven an S2000? You'll be on the high end of 5000 most of the time for normal uses. It's got the metabolism of a hummingbird. Very educational post (you do know this is the GT2 forum, right?).

 

[Mike Rotch]

Originally posted by BadBatsuMaru
I'd have to say it simply comes down to the fact that the Viper is so heavy. As far as this whole torque thing...

1 horsepower = pulling force required to lift 33,000 pounds 1 foot in 1 minute

1 foot pound torque = torsion required to hold a 1-pound weight at the end of a 1-foot bar (note that time is not a factor)

Torque and HP are completely tied together:

horsepower = torque * (RPM / 5252)
torque = horsepower / (RPM / 5252)

Torque tells you how hard you're getting pulled back into the seat. The torque curve perfectly matches the acceleration curve of a car. Torque factors out RPM, though, and RPM is obviously very important. Consider three imaginary cars:

Car 1: 300 ft-lbs torque @ 2626 RPM = 150 HP
Car 2: 300 ft-lbs torque @ 5252 RPM = 300 HP
Car 3: 300 ft-lbs torque @ 10504 RPM = 600 HP

Torque is basically telling you how much of a push one revolution of the engine makes. Therefore, Car 2 and Car 3 each double in power because the RPM doubles. It's impossible for a car to accelerate as fast once it's up around the redline, but that's still where the engine does most of the work. If torque were really that important, F1 cars would be diesel.

Torque tells you how hard a car pulls, and higher low-end torque means you don't have to really wind up the engine to get going.

S2000:
240 hp @ 8300 rpm
153 ftlbs torque @ 7500 rpm

Most people would say the S2000 isn't exactly the most fun car to drive to work every day, because it doesn't really pull till 7500 RPM. You really have to rev it up and dump the clutch to get going.

As far as GT3 is concerned, horsepower is still what matters. Torque is great, but it's mostly an indicator that the car has a nice wide powerband. A lot of low-end torque means you'd be better off using a manual transmission, since GT3 shifts pretty late with the automatic.

Thanks very educational indeed

But does your theory check out? The viper has 74kgs of torque at 4000rpm, the tuscan 53 at 6000. That means that the viper has more power and more tractability in theory. Not so in the game so maybe the programmers got it wrong.

Very good post indeed tho

PS: Joey, aerodynamics both on full

 

[CerberaLM]

I would say a 20-25% power to weight advantage would be worth at least a few seconds around any track.

Competitors for the Tuscan are pretty hard to find. Maybe if you ran it in the GT All Stars races?

 

[Driftster]

The only reasoning I could think of is the gearing. I know that in real life a Stock Vipers gearing isn't all that agressive in the low end catagory, not to mention it is a V10, meaning there is alot more to move, that is the reason Top fuel dragsters don't usually use V10's and use v8's, V10's have too much moving and too much TO move, making their acceleration less of what it is capable of.

 

[Mike Rotch]

Originally posted by CerberaLM
I would say a 20-25% power to weight advantage would be worth at least a few seconds around any track.

Competitors for the Tuscan are pretty hard to find. Maybe if you ran it in the GT All Stars races?

AllStars races are too easy . Tryin the GT league 5 race is a whole lotta fun tho Trial mountain is hell on earth, mainly cos it is so bumpy and makes the tuscan feel as twitchy as a girl on a first date. Apricot is a certainty, as is LS. Rome is always a race of concentration as the GTOne usually runs away with it and thanks to the poor result at trial mnt a victory at midfield is a must. Then hopefully youve done enuff to beat the gt1.

Trial mountain bites tho. And i find as soon as i put more hp on the tusc, it understeers like a *****