Aerodynamic Drag / Speed Test (2.08)

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bigbear

bigbear

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Speed comparison between v.2.07 and v.2.08, in relation to downforce.

GT5 Update 2.08: "Amount of air resistance change when altering aerodynamic wing settings has been increased."

This test is intended to find how aerodynamic settings affect speed and how that effect changes with the update. I'm testing at the SSR-X Speed Test with Automatic Trans, TCS 5, and full-throttle launches. My results are precisely repeatable. For each car I select one trans setting that is effective with different aero packages and use that for each test. The following shows top speed achieved in miles per hour.

Ferrari F10 '10
Downforce/ v.2.07/ v.2.08/ Change
Min............ 223.6... 235.6....(+12.0)
Default....... 215.0... 215.0.... same
Max........... 210.5... 199.9....(-10.6)

Jaguar XJR-9 LM Race Car '88
Downforce/ v.2.07/ v.2.08/ Change
Min............ 241.7... 248.9....(+7.3)
Default....... 238.3... 238.3.... same
Max........... 237.9... 236.5....(-1.4)

Nissan Calsonic IMPUL GT-R '08
Downforce/ v.2.07/ v.2.08/ Change
Min............ 188.8... 192.6....(+3.8)
Default....... 187.0... 187.0.... same
Max........... 185.8... 183.4....(-2.4)

Chevrolet IMPALA (Stock Car) '11
Downforce/ v.2.07/ v.2.08/ Change
Min............ 225.3... 227.4....(+2.1)
Default....... 223.8... 223.8.... same
Max........... 219.3... 208.2....(-11.1)

Dodge Viper GTS-R Team Oreca Race Car #51 '00
Downforce/ v.2.07/ v.2.08/ Change
Min........... 200.9... 206.4....(+5.5)
Default...... 198.3... 198.3.... same
Max.......... 197.3... 195.7....(-1.6)

Amuse S2000 GT1 Turbo
Downforce/ v.2.07/ v.2.08/ Change
Min............ 203.5... 206.5....(+3.0)
Default....... 202.3... 202.3.... same
Max........... 201.5... 199.8....(-1.7)

Suzuki Cappuccino (EA21R) RM '95 [133hp]
Downforce/ v.2.07/ v.2.08/ Change
Min............ 138.4... 140.0....(+1.6)
Default....... 138.0... 138.0.... same
Max........... 137.8... 135.5....(-1.3)

Honda INTEGRA TYPE R (DC5) RM '04 [389hp]
Downforce/ v.2.07/ v.2.08/ Change
Min............ 188.4... 191.6....(+3.2)
Default....... 186.6... 186.6....same
Max........... 185.5... 182.9....(-2.6)

Gran Turismo Red Bull X2011 Prototype
Downforce/ v.2.07/ v.2.08/ Change
Min............ 316.0... 340.3....(+24.3)
Default....... 293.8... 293.8.... same
Max........... 276.1... 237.1....(-39.0)

McLaren F1 '94 (Control, no downforce)
Downforce/ v.2.07/ v.2.08/ Change
Default....... 221.1... 221.1.... same

Ferrari 458 Italia '09 (w/ GT Auto Aero Kit)
Downforce/ v.2.07/ v.2.08/ Change
None......... 204.4... 204.4.... same
Min............ 204.3... 203.8....(-0.5)
Default....... 204.2... 201.8....(-2.4)
Max........... 204.1... 200.9....(-3.2)

Acceleration and Front/Rear Downforce Tests:https://www.gtplanet.net/forum/showthread.php?p=7648420#post7648420
 
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This was the only time I have free to mess about with this before the update. If you don't like me setting this up before the update than I apologise. I wanted to work on the testing before the update so that everythings sorted out before the change. We won't be able to go back to 2.07 (without buying the Academy Edition) after the update is performed. And I'm not going back to v1.00 and then re-downloading all of the updates just to test things.

Many times I've seen people 'round here wishing they could compare things after an update, but by then it was too late.
 
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At least we can get some conversations out this.👍

I really hope that adding downforce adds way more drag than it currently does.

My Toyota GT-One shouldn't be doing speeds of 230 mph with max downforce at around 750 HP.
 
It will be interesting to see what the change is. This could end up being an excellent update.

The cars do seem a touch to fast at times. Hopefully they improve the Aero effect without going too far.
 
Great idea! 💡 Will be nice to see the difference after 2.08, keep up the good work old chap.


👍
 
I may do some of these myself. But if you get the time, can you throw in a NASCAR car, or some GT300 cars?
 
As much as some people loathe it, and as little as I actually use it, shouldn't some variant of the Red Bull X1 be included in the test?

Being the fastest car in the game, you would see the maximum result of a downforce change before/after the update.
 
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SimonK
Um, maybe start the thread once you've actually got the update and done the test.
Click to expand...

Why be negative about this? Like... Really. This is a great idea and I am excited to see the results! If you are going to leave a negative comment on some one's work, make us all happy and save your post.

...:rolleyes:
 
MOTORTRENDmitch
Why be negative about this? Like... Really. This is a great idea and I am excited to see the results! If you are going to leave a negative comment on some one's work, make us all happy and save your post.

...:rolleyes:
Click to expand...

I think we would all be surprised if SimonK didn't have anything negative to say really. The guy spreads doom & gloom in virtually every thread he goes into.

Seriously, I reckon the guy would goto a funeral dressed as the Grim Reaper as he would think things are not depressing enough
 
xxDingerxx
I think we would all be surprised if SimonK didn't have anything negative to say really. The guy spreads doom & gloom in virtually every thread he goes into.

Seriously, I reckon the guy would goto a funeral dressed as the Grim Reaper as he would think things are not depressing enough
Click to expand...

:lol: True say...

In all honesty though, good Job Bear! :)
 
Niop
I may do some of these myself. But if you get the time, can you throw in a NASCAR car, or some GT300 cars?
Click to expand...

If I get time NIOP, I'll test a NASCAR car since this has been my primary car of use since day one. I have done extensive testing with these cars before and this interests me anyway. I'll post results here. Peace.
 
Looking forward to seeing the results after patch day.

I'd like to see something tested in the 500pp range. Usually I think the cars aren't fast enough to really generate much in the down-force department. However just for comparison to see if PD changes is to the extreme, like tire wear the first time around.
 
GTP_CargoRat
If I get time NIOP, I'll test a NASCAR car since this has been my primary car of use since day one. I have done extensive testing with these cars before and this interests me anyway. I'll post results here. Peace.
Click to expand...

👍
 
Great initiative, bigbear !!

I think anyone can contribute to the list. Pick cars that were in the extreme (fastest & slowest) and some mainstream cars (popular cars for online races)

I'll give it a go tomorrow.
 
For best and more reliable results, you should change the top gear in each test so that top speed is reached at peak power rpm.
 
MOTORTRENDmitch
Why be negative about this? Like... Really. This is a great idea and I am excited to see the results! If you are going to leave a negative comment on some one's work, make us all happy and save your post.

...:rolleyes:
Click to expand...

I never said it was a bad idea, I just thought it was odd to present findings in a thread before doing the second, important part of the test. Jeez.
 
xxDingerxx
I think we would all be surprised if SimonK didn't have anything negative to say really. The guy spreads doom & gloom in virtually every thread he goes into.

Seriously, I reckon the guy would goto a funeral dressed as the Grim Reaper as he would think things are not depressing enough
Click to expand...

That just made my day.

And great idea in reply to the OP. Can't wait to see the results.
 
Thanks to everyone for the support and input.

I updated the list with four more cars.

Chevrolet IMPALA (Stock Car) '11
Dodge Viper GTS-R Team Oreca Race Car #51 '00
Amuse S2000 GT1 Turbo
McLaren F1 '94

I won't post all of the cars I test unless I find something interesting. The results will probably be similar from car to car and I don't want to clutter up the place.

If anyone has their own findings to share they are surely welcome. It would be good to have some numbers to compare with mine.
 
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SHIRAKAWA Akira
For best and more reliable results, you should change the top gear in each test so that top speed is reached at peak power rpm.
Click to expand...

I've been using one setting for each car and changing downforce only. My goal is to find how the aero package is affecting the cars performance. If I change any other settings they become added variables which may skew results.

If I tune the trans for every set-up and do better with some than others, it will affect the outcome.
 
bigbear
I've been using one setting for each car and changing downforce only. My goal is to find how the aero package is affecting the cars performance. If I change any other settings they become added variables which may skew results.

If I tune the trans for every set-up and do better with some than others, it will affect the outcome.
Click to expand...
If you tune the transmission so that top speed is reached at peak power rpm you're actually reducing the variables involved. If performance will be noticeably affected by this change, your cars might hit the rev limiter too soon (when decreasing downforce) or run at rpm far below peak power (when increasing it), which will affect top speed too.

By keeping max speed rpm fixed you will have an actual indication of how new aerodynamics affect top speed. Without tweaking anything else, it's really only possible to tell if the change has been small or large.
 
gordongt
That means the speed test database I've worked hard on is now all for nothing :(
Click to expand...

Whatever work you've done is fine as long as you keep the testing the same after the update.

SHIRAKAWA Akira
If you tune the transmission so that top speed is reached at peak power rpm you're actually reducing the variables involved. If performance will be noticeably affected by this change, your cars might hit the rev limiter too soon (when decreasing downforce) or run at rpm far below peak power (when increasing it), which will affect top speed too.

By keeping max speed rpm fixed you will have an actual indication of how new aerodynamics affect top speed. Without tweaking anything else, it's really only possible to tell if the change has been small or large.
Click to expand...

Changing gear ratios affects the cars performance. For the purpose of this test I want the aero settings to be the only thing changing, and affecting the cars performance. I think the test can be done accurately the way you're suggesting, but would require carefull tuning and I'm not comfortable with introducing this into the test.

If you add downforce slowing the car, and then tighten the ratios speeding it back up a bit, you are skewing the result. My purpose is not to find how fast a car can go with a certain aero package. It's to find how changing the aero changes performance.

I understand that if the car hits the limiter after the update it won't give an accurate result so I've set the ratios to allow decent performance regardless of aero set-up.
 
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bigbear
Whatever work you've done is fine as long as you keep the testing the same after the update.

Regardless I will try testing the cars with different settings.
Click to expand...

That's good then. I don't want to do it all again
 
Another question: may you please do a large test with one car that checks if front downforce adds more drag than the rear or vice versa?
 
Great setup thread for the new update. Well done.

Question, I run NASCAR here. Would the possible aero changes that we are about to see, have any effect on drafting / slipstreaming, thus potentially making it even more realistic?

I mean, is there the potential that these aero tweaks mean you wouldn't be able to catch someone's slipstream from about 10+ car lengths away?

Or would the two factors (in GT5) just not be effected by one another.

Hope that question makes sense, and appreciate we may not know till we get to test it.
 
Added Suzuki Cappuccino (EA21R) RM '95

I've also recorded acceleration numbers for the cars. Though I probably won't add them to the OP. I will post some of them after the update.

TexasTyme214
Another question: may you please do a large test with one car that checks if front downforce adds more drag than the rear or vice versa?
Click to expand...

Thats an interesting idea. I'll look into it.

Knelly
Question, I run NASCAR here. Would the possible aero changes that we are about to see, have any effect on drafting / slipstreaming, thus potentially making it even more realistic?

I mean, is there the potential that these aero tweaks mean you wouldn't be able to catch someone's slipstream from about 10+ car lengths away?

Or would the two factors (in GT5) just not be effected by one another.another.

Hope that question makes sense, and appreciate we may not know till we get to test it.
Click to expand...

Good question. Any change to the cars performance will affect how drafting plays out ,but whether there will be any direct change to the drafting effect itself I don't know. Unfortunately there isn't an easy way to test drafting in a controlled manner. I hope you post you're findings after you try it out.
 
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