Fix drafting

  • Thread starter Thread starter adramire
  • 73 comments
  • 7,704 views
zr1chris
If you watch Nascar races at Daytona and Talledega this is exactly what happens. Drafting = 20mph faster in those races
Click to expand...

yes, but that's because those cars run 200 less horsepower than the standard NASCAR stock cars and have slight aero changes that allow them to draft each other better. the ones we have in the game, the unrestricted models used at 32 of the 36 points-paying races in the NASCAR sprint cup series season, only have about a 5 MPH advantage in the draft, and even then, it's much more subtle than what you experience in GT5. the way you can draft on the straights at IMS is absolutely ridiculous.
 
I was on the nurb and had like a 1 second lead on a guy that was hitting walls going off into the grass the whole race but as soon as we hit the straight I was a little past half way down straight and he was coming off the last corner into straight, then the GT5 warp speed kicks in and by the end of the straight he is passing me.

It's so freaking frustrating when you race clean fast laps and then some fool bouncing off walls uses the ridiculous drafting to win.
 
i dont think i have a problem with this,as we just had a race limited to 610PP. we were all in the same car (GTR R35 specV 09') but our mods were of different. some having 707hp and some were only having 654hp like me. this is my experience for online race. hope i feed some points to you guys for some experiment to do.
 
Mr. Green
Not realistic but fun it is! :)
Click to expand...

Hi Yoda, I never knew you were a GT Planet member! The reverse syntax & "Mr. Green" user name kind of gave you away!


;)
 
1. The only time I've noticed it being extremely bad is in the FGT events, Monza and Fuji are ridiculous, it is impossible to lose the pack no matter how good you are.

2. Can anyone confirm if the aero-dynamics work both ways? For example, although drafting gives the second car the advantage on the straights, the second car is at a disadvantage through the corners because they do not get enough down-force in the "dirty air" to go through the corners at the maximum possible speed. This is seen a lot in F1. If it doesn't work both ways then the game needs serious fixing.

I can understand cars like the X1 and F1 cars having massive gains from drafting, because realistically they would do, as the down force is next to nothing when they are behind another car, and that is what limits their top speed.

But cars like the fiat 500 shouldn't be getting up to 15 mph boosts from 1 second behind...
 
have any of the complainers made any research about drafting? check out wiki...

i'm not saying it's perfect, but from what I read, when bump drafting (2 cars following with the trailing one bumping the leading one), Kyle Bush averaged 15 mph faster on a certain track (for the whole lap... while being IN FRONT)

Might buster tester trailing a cargo truck at 10 feet: 39% gain in fuel efficiency... that mean big time power freed for acceleration

so it might not be realist, but it certainly is much better than some of you think it is
 
WhitePhoenix, less than a dozen posts up, I cited an article on NASCAR.com which goes into very specific detail as to why it's this way, why it's a unique phenomena and SPECIFICALLY on tracks where the cars use restrictor plates to limit engine power. On tracks where engine restrictors are not used, the slipstream effect is no where near this strong. So it's essentially an artificially created phenomena.

In short, NO, it is NOT much better than we think it is.
 
jjaisli: waht do you do about this, cited from your link?:
"Even with restrictor plates limiting the airflow and cutting the horsepower nearly in half, cars at Talladega last weekend qualified by themselves at nearly 180 mph and raced in two-car packs at close to 195 mph"
those are average speed for a two-car team. +15 mph average, including for the front car. I think it still need more research

please note that it's not the restrictor plates that affect draft effect (as in less power = more draft) but that the restrictor are in place were the speeds would get too high, this meaning more draft. And about high speed, the straights at Sarthe, Fuji and Nur are much much longer
 
DraftCFD.png


DraftCFD2.png


DraftCFD3.png



I decided to do some CFD using LMP like cars at 150 mph




Lead Car
drag - 230 lb
lift - -145 lb



Trail Car
drag - 168 lb
lift - +32 lb

If we assume that the cars are outputting 600 hp after losses, the total force they are generating is 1500 lb.

The accelerating force on the lead car is 1270 lb
The accelerating force on the trail car is 1332 lb

A 5% difference in acceleration, and a massive loss in downforce.

Don't take this as definitive though, I didn't want to do a full detail CFD run, it would have taken much, much longer.
 
adramire
I was on the nurb and had like a 1 second lead on a guy that was hitting walls going off into the grass the whole race but as soon as we hit the straight I was a little past half way down straight and he was coming off the last corner into straight, then the GT5 warp speed kicks in and by the end of the straight he is passing me.

It's so freaking frustrating when you race clean fast laps and then some fool bouncing off walls uses the ridiculous drafting to win.
Click to expand...

You were clearly racing in a room with Boost on. This is not an effect of Drafting. You CANNOT get a draft from that far back. His car was likely faster in a straight line and was combined with boost.
 
I always avoid rooms with boost.

But anyway, one solution to fixing drafting is simply to stop drafting. If all clean racers just didn't draft on say the nurburgring long straight you'd get a proper comparison of your cars' top speeds and it would be more realistic that way.

Next time you're behind someone on the straight simply don't follow in his draft.
 
OK8
I always avoid rooms with boost.

But anyway, one solution to fixing drafting is simply to stop drafting. If all clean racers just didn't draft on say the nurburgring long straight you'd get a proper comparison of your cars' top speeds and it would be more realistic that way.

Next time you're behind someone on the straight simply don't follow in his draft.
Click to expand...
Thats what I typically do, I try to avoid abusing it to pass. But, that dosn't fix anything.
 
Crazy draft has always been on the GT series

only way to get rid of it is by saying WE LOVE IT... and PD will take it away like drag racing, proper tuning, great tracks, testing courses, leaderboards, etc.
 
LordSandwich
Nope, never seen any actual data on here that supports their claims that drafting is unreal. Just a bunch of speculation and whining that amounts to nothing.
Click to expand...

When you ignore the video analysis of racing itself and computer simulation. There's no evidence besides that.
 
I would not say it is unrealistic. If u have ever watched NASCAR at daytona of a car is by itself the draft catches him fast. U have more speed in draft.
 
MooreOn123
I would not say it is unrealistic. If u have ever watched NASCAR at daytona of a car is by itself the draft catches him fast. U have more speed in draft.
Click to expand...

Yes but you don't gain 30mph from it, from 100 meters away like in the game.
 
johnnutz
This is especially frustrating on the ring. You build up a decent lead until you hit the final straight. Then that lead is gobbled up by the drafting.
Click to expand...

Certainly true. If two equal performance cars get into the final straight, the lead driver must be at least 4-5 seconds ahead to avoid being drafted. Since I´ve lost tons of races this way, I have developed some tactics for Nurb:

- If I can't take the first place by the 4th section, I keep second till last straight. In a competitive tight race, it's very difficult to get the required time gap over that distance.
- If someone overtaking me in the last straight, I let him pass as quickly as I can, so I can become the drafter later.
- If being overtaken no matter what I do, I keep the left side of the straight. When two cars arrive to the end of the straight together, the one on the right has more chances to end on the grass.
 
MooreOn123
I would not say it is unrealistic. If u have ever watched NASCAR at daytona of a car is by itself the draft catches him fast. U have more speed in draft.
Click to expand...

NASCAR isn't the only race series anyway. GT5 draft works everywhere, and there are no downsides like loss of downforce. In GT5, the draft down Laguna Seca's straight is enough change the outcome of a race. In 2009 at Laguna Seca, Jan Magnussen couldn't get around Joerg Bergmeister despite driving what seemed to be a faster car. In GT5 you can certainly build up enough speed to pass by the end of the straight.


EDIT

Redid the CFD with slightly higher accuracy and came up with a 4% increase in acceleration for the drafting car, so it seems to be even lower with a more accurate model.
 
If you want to confirm that drafting in GT5 is unrealistic you can do this experiment.

Car 1 : X2010
Car 2 : Bugatti Veyron
Car 3 : Mclaren F1


Say hello to the 300mph drafting train. You try that in real life.


Not to mention 240mph in a NASCAR stock car at daytona.
 
LordSandwich
Video analysis where? And how does your computer simulation prove that 20+mph drafts are impossible?
Click to expand...

This thread is new, but the debate is quite old. Search the old threads, there are a number of videos posted.

As for my CFD, it's suggesting that a car won't double it's acceleration even when trailing directly behind another car, unlike GT. No one says that 20 mph + draft is impossible, but real life isn't GT. In GT, you get in the draft and your car gains 100 hp.
 
zr1chris
Actually you would probably get pretty close to that speed if you didn't have the restrictor plate which GT5 doesn't.
Click to expand...

Oh definitely. Especially with the new surface, an unrestricted NASCAR could pretty easily reach 240MPH.
 
A bit more fiddling with CFD and calculations.

At 220 mph drag is

600 lb lead
529 lb trail

That comes to a 16% acceleration difference.

Top speed between the two cars (I estimated this, did not run the CFD)

265 mph lead
273 mph trail

Not even 10 mph difference at speeds over 250, and the cars are right behind each other.



eq9s41.png


2pzl8ic.png


It's clear that the wake behind the car isn't very big.

250qkvk.png


EDIT - my plot was off center in the above image, this one is the centered. The wake is a lot bigger in directly behind the car, though the velocity in the wake is rising quickly.

2j1omle.png


4j47sk.png
 
Last edited:
Exorcet
NASCAR isn't the only race series anyway. GT5 draft works everywhere, and there are no downsides like loss of downforce. In GT5, the draft down Laguna Seca's straight is enough change the outcome of a race. In 2009 at Laguna Seca, Jan Magnussen couldn't get around Joerg Bergmeister despite driving what seemed to be a faster car. In GT5 you can certainly build up enough speed to pass by the end of the straight.


EDIT

Redid the CFD with slightly higher accuracy and came up with a 4% increase in acceleration for the drafting car, so it seems to be even lower with a more accurate model.
Click to expand...

Take a car to La Sarthe and try to go through the Porsche Curves at the same speed as a clear lap. The loss of downforce is very evident there.
 
NFSCARBON1
Take a car to La Sarthe and try to go through the Porsche Curves at the same speed as a clear lap. The loss of downforce is very evident there.
Click to expand...

Yes, but I don't think it's loss of grip due to the affects of the car in front of you (I'm taking about in GT5). I think it's because when you're following another car through the Porsche curves at relatively high speed, the slipstream effect is so exaggerated and so over-blown, that your car will suddenly gain massive amounts of speed behind another car and the increased velocity will not allow you to maintain grip.

Last week, I ran a 2 hour event at La Sarthe in GT500 cars. And during practice, I noticed I understeered off the road several times, at exactly this spot, when following closely behind another car. But I also noticed it was because I was simply going much faster than I normally was. When you follow directly behind another car you gain massive amounts of speed, very quickly. When being mindful of the draft and maintaining my lines, I didn't have this problem.
 
Last edited:

Latest Posts

Back