Is it bad to use the power limiter?

[esoxhntr]

back when we had speed test in gt5 this was very easy to test (and test I did). it may be a good question to ask the drag racing people too as they tune for optimum accelleration -- though i don't know if they race equal PPs or not.

the car with excessive power limiter but same PP was slower to accelerate (and top speed) than the same car with little or no power limiting at the same pp -- all else, including gearing, weight, and max rpms the same.

we need the speed test back.

 

[donpost]

Updated my post with the missing word!

What do you mean by "rev vs power peak's rpm"? I might be able to help...

 

[BlueShift]

Updated my post with the missing word!

What do you mean by "rev vs power peak's rpm"? I might be able to help...

I explained him first PP in GT, then power limiter (he confirmed they worked irl like how @MrGrado explained).

The question I had is :
- Same PP, two cars.
- One is power limited, the other not.
- The pl one got a flat hp "peak", the other not, but higher HP.
- The pl one reach max HP at x rpm and stay, the other grow until x+y rpm then fall, then both cars hit the rev.

Is reaching a HP flat peak sooner is better than reaching a HP peak later, if you consider windforce / rolling res ?
Then I asked if redline is calculated/set with power peak in mind or not.

He said "ok, that exist" with the "launching effect" I explained but said he couldn't pronounce if that was a good thing or not toward performances of the car.
He told the problem is irl all of this is calculated by ingeneers and he doesn't have that knowledge, irl you never have 0 wind so you don't look about this. But said also irl most if not all passenger car comes out with a power limiter so there must be something. He said also that passengers cars and race cars are really different kind of beasts so he couldn't say much about racecars.

He only know how to review gearboxes/materials, how "making" them is not usefull in his work (irl he don't set a gearbox at will, people give him variables and he does this and that, sometimes test the car but is not an ingeneer).

Let's be pragmatic then, I'll ask him next time if most racecars use a power limiter or not. All of the ingeneers that make racecars know what is good and what is not
The only problem is they don't have PP :/

 

[donpost]

I'll throw down the three things I know and maybe it will help or maybe you'll know this already.

1. The best time to change gear is when at the rpm where the new lower rpm in the next gear up is the at same level of HP as the current gear at the current RPM.
2. To get the maximum top speed you must tune your gearbox so that you hit your top speed at the same time as you hit your max HP rpm.
3. To find the best set of gears to maximise acceleration taking into account drag etc. you need to make a computer program that simulates the acceleration, and an algorithm to figure out the best gear ratios. This isn't possible with GT because the power graphs are so inaccurate and there is no telemetry for us to work them out ourselves.

Is that any help?

 

[esoxhntr]

I'll throw down the three things I know and maybe it will help or maybe you'll know this already.

1. The best time to change gear is when at the rpm where the new lower rpm in the next gear up is the at same level of HP as the current gear at the current RPM.
2. To get the maximum top speed you must tune your gearbox so that you hit your top speed at the same time as you hit your max HP rpm.
3. To find the best set of gears to maximise acceleration taking into account drag etc. you need to make a computer program that simulates the acceleration, and an algorithm to figure out the best gear ratios. This isn't possible with GT because the power graphs are so inaccurate and there is no telemetry for us to work them out ourselves.

Is that any help?

you're bang on with 2 and 3. although you can make decent educated guesses with #3.

but with 1, the best time to shift is when the power to the wheels (which is torque * gearing) in the next gear's rpms is equal to the power to the wheels at the rpm of the gear you are in. you cannot just use HP because HP alone, does not take gearing into account.

unless i am misunderstanding you somehow.

 

[donpost]

Yeah sorry by HP I mean power (to the wheels, I ignored powertrain losses). I worded that one terribly!

Just to clarify, I'm saying changing when the power in the new gear is the same as power in the old gear is the SAME as changing when torque x gearing in new gear = torque x gearing in old gear. It looks like that is impossible when you look at the graphs for power and torque, but the torque graphs scales between gears because of gear ratios, whereas the HP graph doesn't change between gears.

 

[MindsMirror]

Let's be pragmatic then, I'll ask him next time if most racecars use a power limiter or not. All of the ingeneers that make racecars know what is good and what is not
The only problem is they don't have PP :/

I would think that race car engines are limited only by the specifications of the class they are in. Probably something like displacement, number of cylinders, fuel type, turbos allowed or not, etc. Apart from those physical limitations, the engineers would be free to squeeze as much power as they want from it, there would be no reason to limit power. I guess there are some classes of cars that have a specific power requirement. Doesn't GT500 mean 500hp limit? Their specifications would probably require them to use a power limiter.

 

[BlueShift]

I'll throw down the three things I know and maybe it will help or maybe you'll know this already.

1. The best time to change gear is when at the rpm where the new lower rpm in the next gear up is the at same level of HP as the current gear at the current RPM.
2. To get the maximum top speed you must tune your gearbox so that you hit your top speed at the same time as you hit your max HP rpm.
3. To find the best set of gears to maximise acceleration taking into account drag etc. you need to make a computer program that simulates the acceleration, and an algorithm to figure out the best gear ratios. This isn't possible with GT because the power graphs are so inaccurate and there is no telemetry for us to work them out ourselves.

Is that any help?

3. could be worked around rigth now, I've got an idea to how be puting rolling resistance in sqat, but that's for a v3 or v4. Sqat v2 does #2 allready. The problem for #1 is putting the power curve in the software :/