Top Speed Parameters; interesting results! - Now with summary

[ConRollins]

I thought they proved that it just got better MPG?

Ok, if a car is getting better fuel mileage that means that more energy is being used to move the car and less on overcomming wind resistance which would mean a higher top speed. The problem with testing production cars is the top speed is governed and no amount cleaning or dirtying will affect the top speed. For example (hypothetical): A clean car can top at at 200mph. The same car in dirty configuration can top out at 210mph. But the car is governed for a top speed of 150mph. You'll never hit any of the cars potential speeds.

 

[ConRollins]

You should probably read up more about tire physics. I'm sorry, I'm too busy with work now to explain why you're wrong.

You should probably read up on the difference between top speed and acceleration. You are correct when looking at acceration but not top speed.
When was the last time you saw a Bonneville Salt Flat speed record car wearing hugh fat grippy Mickey Thompson slicks? Nope, thin, hard, easy rolling, no resistance tires are the way to go if you want top speeds.

 

[Morphisor]

Updated the main post with today's ballast testing....

It's rather lengthy, and as you can see more testing will be needed, but the results so far are shocking.

 

[Morphisor]

I have done further testing to find out how or why ballast works.
The details of such tests will no longer be directly in the main post, to prevent it from getting too long. Instead, I will post them here, and link to it from the main post.

I have also added a summary of my findings to the main post

------------------------------------------

Additional testing to confirm ballast effects 20-12

Test car 1: Toyota 86 GT '12

Car is the Toyota 86 GT '12 from my previous test with 'trick' setup applied (see main post). SS tires.
The speed achieved with this setup without adding ballast is 298.7km/h

This car has a basic weight distribution at 53/47, so biased towards the front instead. Let's see if that makes a difference maybe.

Front ballast (weight distribution):

25kg (54/46): 298.4
50kg (55/45): 298.2

Middle ballast:

25kg: 298.5
50kg: 298.3

Rear ballast:

25kg (52/48): 298.5
50kg (51/49): 298.4

This confuses things even further. With this car, front ballast is actually the worst of the three, and none of them has a positive effect. I also ran a check with RS tires, but the results were unchanged (well, a little faster).

I see two possibilities: either the Diablo having much higher power enables the front ballast 'feature', or it is related to the cars' original weight distribution.


Test car 2: Dodge Challenger SRT8 TC

Fully tuned, Transmission set to 420 km/h. RS tires.

Default suspension settings and minimal downforce resulted in a top speed of 359.2 km/h.

After changing the spring rates to minimum, setting the ride height to +60/-10, and maxing rear downforce, this top speed was increased to 366.4 km/h!

Time to test the effects of ballast on this particular car. At 825hp it has similar power as the Nomad Diablo, while its weight distribution of 56/44 is significantly different.

Front ballast:

25kg: 366.5
50kg: 366.7
100kg: 367.0
200kg: 367.2

Rear ballast:

25kg: 366.0
50kg: 365.5

The results clearly show the same effect that was shown with the Nomad Diablo. It would seem then that a certain amount of power is needed to trigger this 'feature'.


Test Car 3: Lancia Stratos Rally Car '77


I figured I should test one more car with medium power and a weight balance towards the rear to see what's what.

Fully tuned, Transmission set to 380 km/h, RS tires.

Default suspension settings and minimal downforce resulted in a top speed of 328.0 km/h.

After changing the spring rates to minimum, setting the ride height to +20/-50, and maxing rear downforce, this top speed was increased to 329.6 km/h.
Interestingly, downforce had a much smaller effect on the top speed of this car than it had on any of the previously tested cars.

Time for ballast testing. At 384hp this car's power is almost identical to the 86 GT tested earlier (which showed NO improvement from ballast), but a weight distribution of 40/60 is vastly different.

Front ballast:

25kg: 329.0
50kg: 328.5

Rear ballast:

25kg: 329.0
50kg: 328.4

Just like the 86 GT, ballast does not add to top speed at all with this car. This is a strong indication that high horsepower is needed for that to work.

 

[Astro_BS-AS]

You should probably read up on the difference between top speed and acceleration. You are correct when looking at acceration but not top speed.
When was the last time you saw a Bonneville Salt Flat speed record car wearing hugh fat grippy Mickey Thompson slicks? Nope, thin, hard, easy rolling, no resistance tires are the way to go if you want top speeds.

That depends.

The ultra thin wheels that you see in many rocket-propelled-record-braking cars are not made of rubber, but metal.

And even more, in that cases you don´t need to put power in the ground that cames from an engine, because the forward motion are being given by air movement, not traction.

What I don´t like in the GT5 Top Speed test track is that you can´t put any common sense into car tuning. Not having "air" in the game engine is quite a problem .

 

[Morphisor]

That depends.

The ultra thin wheels that you see in many rocket-propelled-record-braking cars are not made of rubber, but metal.

And even more, in that cases you don´t need to put power in the ground that cames from an engine, because the forward motion are being given by air movement, not traction.

What I don´t like in the GT5 Top Speed test track is that you can´t put any common sense into car tuning. Not having "air" in the game engine is quite a problem .

PD does seem to have a modifier on each car to represent it's drag coefficient. As you can see the 86 GT is 30km/h slower than the Stratos Rally Car, even though their power is nearly identical. The 200kg weight difference does not account for that big of a difference I can assure you

 

[frontrunner91]

PD does seem to have a modifier on each car to represent it's drag coefficient. As you can see the 86 GT is 30km/h slower than the Stratos Rally Car, even though their power is nearly identical. The 200kg weight difference does not account for that big of a difference I can assure you

You are assumming that similar hp means similar power. Not really how that works. Hp is calculated from torque and RPM. Torque is a real measurement. HP is a calculation. Hp= Torque X Rpm / 5252... IIRC.... 2 cars with very different torque curves can still produce similar HP numbers.

 

[Morphisor]

You are assumming that similar hp means similar power. Not really how that works. Hp is calculated from torque and RPM. Torque is a real measurement. HP is a calculation. Hp= Torque X Rpm / 5252... IIRC.... 2 cars with very different torque curves can still produce similar HP numbers.

Are you really trying to say Horsepower *doesn't* measure a car's power?
You said it yourself, horsepower is calculated from torque and RPM....but torque is NOT power.

It is power that accelerates a car beyond the launch, and that is what ultimately achieves top speed.

 

[frontrunner91]

Are you really trying to say Horsepower *doesn't* measure a car's power?
You said it yourself, horsepower is calculated from torque and RPM....but torque is NOT power.

It is power that accelerates a car beyond the launch, and that is what ultimately achieves top speed.

The real measurement is Torque which is then used to calculate Hp.

I never said torque was not power you put those words together. Don't try to twist what I stated into anything other than what it is.

I'm not gonna argue the point. I'll stick to stating fact.

 

[DickDastardly]

I noticed something a little strange yesterday while running on Route X. You'd think that, outside of the draft, a car would accelerate faster going down the hill than it would on the flat. This seems to be true for "normal" cars like the Cien Concept, but for the X2010, it actually seems to be held back on the downhill slope and then gets faster when the road flattens out.

Another thing I noticed was that when using the ride height and downforce tricks, sometimes the car loses its steering, needing several seconds of full lock just to change lanes. The weird thing is, as soon as the car hits the paved section containing the banking, the steering suddenly returns, even before the car has mounted the banking itself.

One final thing: it's quite funny when someone tries to PIT you when you're running max rear aero in an X2010. It's like a guided missile and is pretty much immune from spinning

 

[Morphisor]

The real measurement is Torque which is then used to calculate Hp.

I never said torque was not power you put those words together. Don't try to twist what I stated into anything other than what it is.

I'm not gonna argue the point. I'll stick to stating fact.

I'm not twisting anything, allow me to quote

You are assumming that similar hp means similar power. Not really how that works.

In my world, that's exactly how it works.

And it is the only thing that is relevant for a proper top speed run.
Yes torque is used to calculate it, but that is the only use torque has.

@DickDastardly: Yeah....the trick setup isn't exactly suited to turning a car in any way
Useful for straight speed runs only!

 

[CSLACR]

I almost forgot to use mixed spring rates as well. Will use the last 383km/h settings as starting point now, results:

Minimal front, standard rear (9.1/15.0): 379.6
Minimal front, maximal rear (9.1/19.0): 376.8
Standard front, minimal rear (13.0/10.5): 382.3
Maximal front, minimal rear (19.0/10.5): 381.9

Try
max/min
max/min
max/min
max/min
max/min
max/min
That certainly helps a few cars go fastest.

HP and TQ are exactly the same thing guys, just different forms.

 

[Morphisor]

Try
max/min
max/min
max/min
max/min
max/min
max/min
That certainly helps a few cars go fastest.

HP and TQ are exactly the same thing guys, just different forms.

Eh, if you look at the lines you're quoting, it's right there, at the bottom.

 

[kttheman001]

You have inspired me to try with my cien. Top speed set to 302.
This is my ride hight test:
20/20. 264.8
0/0. 264.8
-40/-40 264.8
-40/20 263.5
20/-40. 266.1
Notes: rest of the suspension is stock
This is in mph
My tranny is flipped for you draggers
I have 978 hp
Test on RS
no ballast
Aero at min with a wing on it
Lsd 5. 5. 20
No toe or camber on suspension

Will be doing a ballast and aero test with the fastest setup.

 

[kttheman001]

Weight test with same settings as before.
100kg in the middle: 264.7
100kg in the front: 264.6
100kg in the back:264.8
Note that im using the fastest ride hight 20/-40.
Ok.. Well thats confusing... Lets try no ballast aero test....
Minimum downforce was used for all previous tests
5/10: 266.1 (minimum aero)
15/55 aka maxxed: 259.9
Reset to default 12/35: 260.7
Hhhhmmm.... I couldent recreate the same experience, maybe diffrent cars have their little tricks ?

 

[Morphisor]

Weight test with same settings as before.
100kg in the middle: 264.7
100kg in the front: 264.6
100kg in the back:264.8
Note that im using the fastest ride hight 20/-40.
Ok.. Well thats confusing... Lets try no ballast aero test....
Minimum downforce was used for all previous tests
5/10: 266.1 (minimum aero)
15/55 aka maxxed: 259.9
Reset to default 12/35: 260.7
Hhhhmmm.... I couldent recreate the same experience, maybe diffrent cars have their little tricks ?

Interesting.

I *think* it could be down to 2 little differences between your setup and the one I have so far been successful with on all my test cars.

First, try minimising the spring rates.
Second, use rear downforce only.

If that combination yields result, try adding the ballast again!

 

[kttheman001]

Interesting.

I *think* it could be down to 2 little differences between your setup and the one I have so far been successful with on all my test cars.

First, try minimising the spring rates.
Second, use rear downforce only.

If that combination yields result, try adding the ballast again!

Ok, thanks will do.

 

[Aloha62_2]

I thought I would do some testing in the mclaren F1 only to find it tops out at 218mph then cant accelerate in 6th and starts slowing down instead.


There isnt enough forehead smacking in the world.

 

[frontrunner91]

In my world, that's exactly how it works.

In the real world and the game world that is not even close!

 

[CSLACR]

Eh, if you look at the lines you're quoting, it's right there, at the bottom.

That's just spring rate.

 

[Morphisor]

That's just spring rate.

Then what do you mean?

 

[Grayfox]

I thought they proved that it just got better MPG?

Not that I remember, They said a dimpled car(like a golf ball) gets better MPG.

Now to the auto manufacturers stop with these hybrids and just makes cars with dimples on them, for better MPG.

 

[mrluckypants]

Hmm... High Front End + Low Rear End + Lots of Downforce = Higher Speed. GT2-3 Wheelie Glitch Anyone?

 

[BWX]

....................
..................
...................

4) GT5 DOES NOT PROCESS FLUIDS. (And the "air" its a fluid, after all). Its as simple as that. I remember reading and interview to Kaz in wich he specifically mentioned that FLUID PROCESSING wt of GT5 because of limitations in the PS3 (or any actual console out there). If I remember correctly (pretty limited internet here at work) it was after his time developing X-2010 in Red Bull HQ and testing its F1 simulator.

So, without fluid calculations, drag/wind/ground effect just do not exist as a factor that could be simulated in any way but with fixed parameters. And that why suspensions work in really strange ways doing those speed tests. I remember too the CLK-GTR flying in LeMans, and that won´t happen in GT5 because there is no "real" air in the track.

Just because there are no real time fluid calculations in GT5, it is no excuse for totally FUBAR downforce behavior. PD/Kaz could still easily fix the problem I will put below in a quote. I'm talking about the rear downforce PULLING the car FORWARD. You don't need realtime fluid dynamics to fix that bug, yet it's not fixed.

This bug:
https://www.gtplanet.net/forum/showthread.php?p=6531733#post6531733

Regarding the nose-up effect: It's actually about aerodynamics and not suspension. The bug in GT is how the downforce is applied, which is 90° to the cars bottom plate and not simply down to the track. So with nose up downforce pulls the car forward and not only down. You can prove this by testing a nose-up setup with different downforce levels. The higher the downforce, the faster the car can go. On the other hand cars without noticeable downforce don't see any advantage from nose-up at all.
..................

And the OP doesn't seem to get that it isn't a suspension problem, but a downforce problem.

 

[BWX]

As I proved another user wrong earlier, he also said he had problems with the downforce being "wrong", saying that an Audi R10 on Indy would not have a difference in speed whether or not you had max or minimum downforce, and I proved him wrong seeing as by the end of the front straight with no downforce I was able to reach 230 mph, and with max downforce I was only to reach 225, and to make sure, i tried twice to see if I didn't take a good line, and still got the same result, so, yeah, dowforce does affect top speed, end of story.

You didn't prove jack. Take note of DF bug.

https://www.gtplanet.net/forum/showthread.php?p=6521064#post6521064

Going around Indy oval with an Audi R10 TDI Le Mans '06 fully upgraded for example.

Downforce adjustment has very little affect on your top speed at the end of the straightaway. I was doing the Indy 500 endurance last week and wing adjustment made little difference. In real life, your top speed would be a lot higher if you took out HALF the downforce on each end of the car, regardless of how it affected corner speed. In GT5, higher downforce gives highest top speed at and of straightaway... it is wrong. I'm talking same tire wear, no draft, same fuel load.. it's wrong.

I guess we'll see what happens on a huge straightaway now.

I said I took out HALF of DF, then you take ALL adjustable DF out and post:

https://www.gtplanet.net/forum/showthread.php?p=6521780#post6521780

Alright, I just tested the same car on the same track, with the absolute minimum downforce for both the front and back I got to 230 mph by the end of the front straight. Then with Max downforce on both the front and back I only reached 225 mph by the front straight, and if you don't believe me, I will post footage later (but I have to go to my grandparents house to work on my real car right now). So I'm not sure about you, but those results seemed pretty diffinitive to me, I even tried it twice to see if maybe it was the line out of turn 4, but I got the same result. The car didn't want to go over 225.

Anyway, if you took out half of the DF adjustment.. You should go faster down the straight in that car but you don't... and I said compared to corner speed and only on ovals like Indy in a previous post.

regardless of any of that, I still think the DF is screwed up in GT5.. Not because of lack of real-time fluid dynamics calculations, but lack of static table calculations and basic bugs like the one I quoted in my post above which I've known about since GT5 day one. I think it was in GT5p too.

I know some other sims had identical bug and I remember the day it got fixed over 4 years ago. I can't remember if it was Live for Speed or rFactor. I'm getting old I guess.

 

[Machate-man]

Just because there are no real time fluid calculations in GT5, it is no excuse for totally FUBAR downforce behavior. PD/Kaz could still easily fix the problem I will put below in a quote. I'm talking about the rear downforce PULLING the car FORWARD. You don't need realtime fluid dynamics to fix that bug, yet it's not fixed.

I thought that the downforce issue:

1) Provided rear traction at speed
2) Reduced front wheel drag/resistance by decreasing load on front (From rear downforce)

Please correct me, unless I am right

 

[BWX]

I thought that the downforce issue:

1) Provided rear traction at speed
2) Reduced front wheel drag/resistance by decreasing load on front (From rear downforce)

Please correct me, unless I am right

Nope the bug I'm talking about is the rear downforce acting as a ''pulling'' force straight down to the ground.

Now when you lift the nose of car and lower rear of car, what happens to straight line pointing down? It moves slightly toward front of car.

That ''downforce'' in GT5 help pull car FORWARD in GT5 and gives added top speed. It is completey wrong.

Look at the post I quoted from Z1-AV69 above. Read it. See what I'm saying now?
Do I need to draw a picture? I am an artist, I could draw a pic if needed.

 

[Morphisor]

Just because there are no real time fluid calculations in GT5, it is no excuse for totally FUBAR downforce behavior. PD/Kaz could still easily fix the problem I will put below in a quote. I'm talking about the rear downforce PULLING the car FORWARD. You don't need realtime fluid dynamics to fix that bug, yet it's not fixed.

This bug:
https://www.gtplanet.net/forum/showthread.php?p=6531733#post6531733


And the OP doesn't seem to get that it isn't a suspension problem, but a downforce problem.

Will you please take another look at my testing, thanks.

It clearly shows that lifting the nose up without using any downforce already added to top speed.

By itself downforce does NOT help, it only amplifies the problem already there.

 

[BWX]

Will you please take another look at my testing, thanks.

It clearly shows that lifting the nose up without using any downforce already added to top speed.

By itself downforce does NOT help, it only amplifies the problem already there.

I did look closely. It amplifies bug when you turn up rear downforce. Problem IS downforce. It is only ''already there''because downforce is ''already there'' when set to a lower setting.

Look, you wrote:

''Astonishing results, which led me to try again to raise the rear downforce only, to see if raising the front end of the car is what's needed for that trick to work. So, max rear downforce , minimal front, and +10/-15 ride height, minimal spring rates.

Result: 383.0 km/h!''

Then right after you say suspension is wrong and downforce is correct.. Huh?


Then you prove me right with the Toyota 86 GT '12, fully modded.

+45/-20: 297.9
Let's see if adding the downforce back in now will add to this madness though...Why yes it does! Speed was increased to 298.7 km/h!!!

EDIT- LOL it's only ''madness'' if you don't understand why the rear downforce is making car go faster.

Smaller amount of rear downforce compared to first car, smaller gain, but still a gain with more downforce.
Now you say suspension is making car faster. I'm saying whacked out high front, low rear suspension is revealing downforce bug I described above.

You just proved it twice.

This rear downforce bug pulling car forward is a known bug. That's why high front, low rear is faster with rear downforce higher. There may be exceptions.


EDIT TWO.
Look at this post below by Z1-AV69. Are you calling him wrong too? Why aren't you acknowledging his post?
https://www.gtplanet.net/forum/showthread.php?p=6531733#post6531733

 

[Morphisor]

How do you manage to completely ignore the parts that come BEFORE the adding of downforce, where I show that extreme ride height ALONE increases speed already?

I'm not saying there is nothing wrong with downforce - it shouldn't be adding to the speed.
What I am saying is, it's not the intrinsic cause of the problem.