My comparison of 3 cars with 277PP in GT6.

[PikachuRacer11]

I had recently tested 3 stock city cars from my GT6 Garage that had 277pp on The Streets of Willow Springs circuit to see how legit the cars PP (Performance Points) ratings were given. The track has a balance of high speed and low speed sections, which were suitable for properly finding out each of the 3 cars' strengths and weaknesses.
Each car was running on Comfort Medium Tires, ran using absolutely no driving aids (ABS, Traction Control, etc.), and driven as hard as I could. Here are those cars by the order they finished:

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1st: Ford Ka
Year: 2001
Country: USA (Though actually made by Ford Europe)
Drivetrain: Front Engine / FWD
Power: 60hp
Torque: 77.3ft/lb
Weight: 965kg
Tuning done to car: Nothing

This is the most powerful of the 3, but also the heaviest. Handling was good with great steering response, but understeer was noticeable in the banked section and there was minor wheel lock-up while braking for the corner after the back straightaway. The extra power made it quickest on the launch and the high speed sections.

Time: 1:54.240
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2nd: Fiat Panda Super i.e.
Year: 1990
Country: Italy
Drivetrain: Front Engine / FWD
Power: 43hp
Torque: 54.2ft/lb
Weight: 730kg
Tuning done to car: Nothing

This car is the most balanced of the trio tested. Handling was good, but had some minor understeer in the low speed corners and steering was not as sharp as the Ford Ka. Acceleration is best in this car in 1st and 2nd gears. 3rd gear was okay, but became somewhat sluggish by 4th gear. Overall, it was much quicker than the Honda Today G.

Time: 1:55.411
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3rd: Honda Today G
Year: 1985
Country: Japan
Drivetrain: Front Engine / FWD
Power: 31hp
Torque: 33.4ft/lb
Weight: 550kg
Tuning done to car: Just a Oil Change

This car was originally only at 272pp, but after a oil change it had received a few extra ponies and was now at 277pp. Though underpowered compared to the others, it was the lightest of the trio. The combination of it's weight and very short gears on 1st to 3rd gear made it nearly as quick off the line as the Panda, but then started to struggle badly in the high speed sections due to the longer 4th and 5th gear. It took the corners very well due to a lightweight body and lack of power, but steering response was a bit numb at higher speeds. Though this car was easiest to drive, it wasn't enough to boost it's lap time.

Time:1:58.324
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The verdict to this test is the these 3 aren't so evenly matched as the PP implies them to be. Based on my findings, this would be more likely as the real PP numbers of these 3 cars by providing it's handling and overall driving performance into the equation:
Honda Today G '85: 276pp
Fiat Panda Super i.e '90: 288pp
Ford Ka '01: 293pp
Though PD did well in improving GT6's physics over GT5, I personally believe they should next rework the PP ranking system for the cars in this game. They should more accurately describe each car's overall performance by not only how good it is in terms of power and weight, but also how good overall it's acceleration is, how fast it can go, and how good it handles in the corners.

 

[Wide Boy]

It is totally impossible for anyone to make a rating system that is accurate due to the amount of factors involved.
Its supposed to be a quick guide to roughly similar cars & it does that well enough.
Go try the same 3 cars on a slower twisty track & see how they compare, say Autumn Ring.
My guess is they may be closer matched.
Conversely take them out on an oval & their will probably be an even bigger difference between them.

 

[Johnnypenso]

It is totally impossible for anyone to make a rating system that is accurate due to the amount of factors involved.
Its supposed to be a quick guide to roughly similar cars & it does that well enough.
Go try the same 3 cars on a slower twisty track & see how they compare, say Autumn Ring.
My guess is they may be closer matched.
Conversely take them out on an oval & their will probably be an even bigger difference between them.

Impossible to make a rating system that incorporates all cars I agree, but not impossible to make something that works within a narrower range of cars that belong on the track togther

 

[PikachuRacer11]

It is totally impossible for anyone to make a rating system that is accurate due to the amount of factors involved.

I understand that it isn't easy to perfect the PP system on a limited schedule, but at least the PI (Performance Index) from the Forza Series ranges the score between 100 and 999 and has additional results based on Launch, Acceleration, Braking, Top Speed, and Handling.
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Here is an example of the 2001 Acura Integra Type R which is found in both GT and Forza, and it's specs based on both rating systems (Note that I am not a diehard Forza Fan trying to mock GT6, I play both games evenly):

2001 Acura Integra Type-R (Gran Turismo 6)
Performance Points (PP): 403

2001 Acura Integra Type-R (Forza Motorsport 4)
Performance Index (PI): 388
Speed: 5.0
Handling: 4.7
Acceleration: 6.0
Launch: 6.3
Braking: 4.6
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I know this sounds more like it should be in the suggestion page, but all I can say is if they can't recalibrate the PP system to provide a bit more accurate results, maybe PD could simply throw in a more technical spec sheet similar to Forza's along side the current PP system, so it can give the player a more precise detail of what the car is about.
It could simply be on a scale of 1.0 (Not very good) to 10.0 (Incredible) for each major factor (Acceleration, Top Speed, Handling, and Braking), which can make it easier to purchase a car for the specific event they plan to use it for (Drag Racing, Drift, Circuit racing, etc.) even if they have a similar amount of performance points.

 

[BrodieBoi94]

Perhaps you should try an assortment of cars from a similar era, like all '90-'95.

 

[Johnnypenso]

2001 Acura Integra Type-R (Forza Motorsport 4)
Performance Index (PI): 388
Speed: 5.0
Handling: 4.7
Acceleration: 6.0
Launch: 6.3
Braking: 4.6

Accounting for handling or simply grip, is the weakness of the PP system. I'm not sure it accounts for grip at all to be honest. Through hybriding in GT5 I discovered you could alter the grip of any car and usually make it competitive and the PP system would automatically adjust your HP accordingly. Taking a stock 69' Vette for example, that came with 400+ HP at 500PP, and it was severely off the pace. You could simply add grip to it, the HP would be reduced to about 350 HP accordingly to keep it at 500PP, and all of a sudden it was a competitive car. This tells me the PP system undervalues grip and overvalues HP. It worked with every car too. Add grip, lose HP and the car would be more competitive, so long as you took it down to roughly the specs of the top cars.

 

[Wide Boy]

Accounting for handling or simply grip, is the weakness of the PP system. I'm not sure it accounts for grip at all to be honest. Through hybriding in GT5 I discovered you could alter the grip of any car and usually make it competitive and the PP system would automatically adjust your HP accordingly. Taking a stock 69' Vette for example, that came with 400+ HP at 500PP, and it was severely off the pace. You could simply add grip to it, the HP would be reduced to about 350 HP accordingly to keep it at 500PP, and all of a sudden it was a competitive car. This tells me the PP system undervalues grip and overvalues HP. It worked with every car too. Add grip, lose HP and the car would be more competitive, so long as you took it down to roughly the specs of the top cars.

In that case it does account for grip as its adjusting the HP to remain at the same PP
As you said its fair to conclude HP is overvalued in the PP system.
If you want a competitive car weight reduction normally seems to give a better return on your PPs than power.
I prefer not to travel the weight reduction road though as the cars start feeling similar.

Off topic but I would like an online light tune category, any of the following.
Can just fit & tune LSD as they are very generic.
Can also lightly tune engine, say stage 1 tune or any selection of parts that add up to less HP increase.
Also if power limiter is allowed can only decrease by a max of 5%
No other tuning allowed.

The idea is to force use of fairly similar cars & just allow some tuning to balance,
LSD is just a personal preference I find many mid to high power cars benefit hugely even from a slight tweak due to letting you put the power down quicker.

 

[PikachuRacer11]

Accounting for handling or simply grip, is the weakness of the PP system. I'm not sure it accounts for grip at all to be honest. Through hybriding in GT5 I discovered you could alter the grip of any car and usually make it competitive and the PP system would automatically adjust your HP accordingly. Taking a stock 69' Vette for example, that came with 400+ HP at 500PP, and it was severely off the pace. You could simply add grip to it, the HP would be reduced to about 350 HP accordingly to keep it at 500PP, and all of a sudden it was a competitive car. This tells me the PP system undervalues grip and overvalues HP. It worked with every car too. Add grip, lose HP and the car would be more competitive, so long as you took it down to roughly the specs of the top cars.

I understand your theory of the PP system favoring power over grip, and I do think that might be true as well.
I might just try that type of comparison, like comparing a 300pp car in stock form to an identical 300pp car that has been tuned for reduced weight, improved weight balance (via Ballast), and reduced power (making that car better on handling without changing PP).

However, I have seen that Suspension, Brakes, Tires, Gearbox, and Drivetrain (Clutch, Driveshaft, Limited-Slip) upgrades do not change a car's performance points in GT6. However, they do alter the car's performance.
So I will have to make sure not to apply them when doing that test, to provide as even of a comparison as possible.

 

[Johnnypenso]

In that case it does account for grip as its adjusting the HP to remain at the same PP
As you said its fair to conclude HP is overvalued in the PP system.
If you want a competitive car weight reduction normally seems to give a better return on your PPs than power.
I prefer not to travel the weight reduction road though as the cars start feeling similar.

Off topic but I would like an online light tune category, any of the following.
Can just fit & tune LSD as they are very generic.
Can also lightly tune engine, say stage 1 tune or any selection of parts that add up to less HP increase.
Also if power limiter is allowed can only decrease by a max of 5%
No other tuning allowed.

The idea is to force use of fairly similar cars & just allow some tuning to balance,
LSD is just a personal preference I find many mid to high power cars benefit hugely even from a slight tweak due to letting you put the power down quicker.

Right, sorry, what I meant to say was it overvalues HP and undervalues grip. Through hybriding I could roughly equalize grip values and it made the cars much closer on the track. I'd still like to see something along these lines where cars are grouped into categories and then tested by the community to determine how far off their expected performance they are, and then adjustments made accordingly but only within the category.

 

[BKGlover]

I'll keep my thoughts short, I don't like the PP system at all and I think it needs to go away altogether. Classify by power, size, and what upgrades are allowed or disallowed. I have yet to see a real life racing series that used a PP system. I don't like it here, I don't like it in Forza, I think it's a flawed concept to which there is no right answer.

 

[Johnnypenso]

I understand your theory of the PP system favoring power over grip, and I do think that might be true as well.

It's not really a theory, for me it's a fact. Take any car that performs well at any PP level. The grippiest cars are always the fastest and you can confirm this with cornering speeds. Hybriding simply confirmed this for me because every slow car that I added grip to (which automatically reduced HP under the PP system) got faster and none of them got slower. There was a sweet spot of course and you could add too much grip and then be slower but the best cars in the game like the Elise, NSX, LFA etc. are always right around the sweet spot.

 

[PikachuRacer11]

I have done a test of Johnnypenso's find on how handling is underrated in the PP system. Instead of hybriding (of which was how he found out about this), I went and adjusted the power and weight of the car to provide identical Performance Points.
No driving aids were used in this test. The run was started from a complete stop at the starting line of the track (like in a typical online race). Both cars were ran on their stock tires, suspension, gearbox, drivetrain and brakes to keep the test as legitimate as possible.

First, I ran a bone stock 2000 Chevrolet Camaro SS on Silverstone's GP (Grand Prix) Circuit.
Power: 325hp
Weight: 1560kg
Weight Distribution: 54 front / 46 rear
Performance Points: 460pp
Lap Time: 2:37.993
On the high speed sections, it handled fine with good acceleration. However on the chicanes and the low to mid speed corners, the car experienced both understeer while braking and oversteer on acceleration. This resulted me to feather the brakes earlier upon entry and use the throttle more delicately while steering in the corners, which slowed down my lap time.

Next, I did a similar run with the same 2000 Camaro SS, but this time it was carefully tuned to keep it's stock Performance Points while improving the balance and handling on the car. I did a full weight modification and added ballast accordingly to provide a balanced weight distribution, while the power limiter was reduced by around 5%.
Power: 307hp (23hp less)
Weight: 1448kg (112kg lighter)
Weight Distribution: 50 front / 50 rear
Performance Points: 460pp
Lap Time: 2:35.802 (2.191sec faster)
The car was faster than the stock model in the lower gears, but only slightly slower than the stock model on the straights. Handling was incredibly improved over stock, which as a result provided it with faster cornering speeds and little effort keeping it in control. Though there was minor understeer in the final low speed chicane of the course, this was easily corrected and had minimal effect on the car's faster lap time.

So, Johnnypenso was correct with the fact of the car's handling being underrated in the PP system. Doesn't matter if a car was tuned using hybriding or tuned legitimately in-game, it has been proven in the GT games that a 460pp car with less power and more grip has faster lap times on a race track than an identical 460pp car with more power and less grip.

 

[Johnnypenso]

I have done a test of Johnnypenso's find on how handling is underrated in the PP system. Instead of hybriding (of which was how he found out about this), I went and adjusted the power and weight of the car to provide identical Performance Points.
No driving aids were used in this test. The run was started from a complete stop at the starting line of the track (like in a typical online race). Both cars were ran on their stock tires, suspension, gearbox, drivetrain and brakes to keep the test as legitimate as possible.

First, I ran a bone stock 2000 Chevrolet Camaro SS on Silverstone's GP (Grand Prix) Circuit.
Power: 325hp
Weight: 1560kg
Weight Distribution: 54 front / 46 rear
Performance Points: 460pp
Lap Time: 2:37.993
On the high speed sections, it handled fine with good acceleration. However on the chicanes and the low to mid speed corners, the car experienced both understeer while braking and oversteer on acceleration. This resulted me to feather the brakes earlier upon entry and use the throttle more delicately while steering in the corners, which slowed down my lap time.

Next, I did a similar run with the same 2000 Camaro SS, but this time it was carefully tuned to keep it's stock Performance Points while improving the balance and handling on the car. I did a full weight modification and added ballast accordingly to provide a balanced weight distribution, while the power limiter was reduced by around 5%.
Power: 307hp (23hp less)
Weight: 1448kg (112kg lighter)
Weight Distribution: 50 front / 50 rear
Performance Points: 460pp
Lap Time: 2:35.802 (2.191sec faster)
The car was faster than the stock model in the lower gears, but only slightly slower than the stock model on the straights. Handling was incredibly improved over stock, which as a result provided it with faster cornering speeds and little effort keeping it in control. Though there was minor understeer in the final low speed chicane of the course, this was easily corrected and had minimal effect on the car's faster lap time.

So, Johnnypenso was correct with the fact of the car's handling being underrated in the PP system. Doesn't matter if a car was tuned using hybriding or tuned legitimately in-game, it has been proven in the GT games that a 460pp car with less power and more grip has faster lap times on a race track than an identical 460pp car with more power and less grip.

Well done:tup: I wouldn't have thought of doing this test myself but it's one that others can easily repeat and should work for most cars, although I'm not sure some of the really light or really heavy cars will benefit as much and maybe not at all. The PP system tends to fall apart when you start to go below 900 kgs or so.