Flat Floors

[MajorBlixem]

I'm currently concentrating on the Toyota 86GT seasonal event. I bought the 86GT '12 and without looking at the available tune ups (great job on them btw) I made some initial tune ups like putting areo kits and.... a flat floor.

I started to look at the tune ups in the tune up directory. One that I particularly liked was a tune for 248HP at 1030kg for 450PP. I looked at my 86GT. It was 1030kg and 450PP with only 212HP. I had the flat floor on and I had to sacrifice 36HP for that! I was only able to 1:40's with it.

I started fresh, bought a new 86GT and did not add flat floor. I came to the same tune up - 450PP, 1030kg and 248HP. I'm currently running low 1:33's with room for improvement.

Can someone shed some light on the flat floor? Why is it even an option if you have to sacrifice that much power? In my case I'm 7 seconds per lap faster without it!

 

[Awong124]

You know you can remove the flat floor right? You didn't have to buy a new car just to not have it. Unless you wanted to keep both cars for the hell of it.

But yeah, the flat floor basically just adds rear downforce. I don't know why they made it have such a huge PP increase for not much, if any, gains in a lot of cases. You're basically taking a double penalty if you're trying to keep it under a certain PP. It already creates more drag so you lose straight line speed, but it also costs a lot of PP so you have to decrease power or increase weight to compensate and lose even more straight line speed. They're nice to have on a lot of MR cars though, stabilizes the rear a lot at the expense of some straight line speed if you're not limited by PP.

 

[FussyFez]

I like them for what they are, they increase stability, but given the top speed drop off, I think the PP gain is unbalanced.

I use them on my fun cars, that I drive for pleasure. I wouldn't use it if the event was PP regulated, as they are at an obvious disadvantage.

 

[MajorBlixem]

Yes Awong I could have just paid and have it removed but I thought I can use the second one because there are quite a lot of tune ups available. I like the 86GT and will set both up at various PP levels.

 

[STiG39]

If you find a tunnel you can drive on the ceiling upside down with a flat floor installed... just like the Saleen S7... i think... (sarcasm off)

 

[JLG_GT]

I actually find the flat floors useful on technical tracks. Handling and stability are key on these certain tracks. I have also wondered why such an increase of PPs, but there is a noticeable difference in the car with Flat Floors on/off.

In my tuning learning curve, I have noticed that a flawed tune (which happens to me more than I want) can be "masked" with the flat floors added. However, when you strike a nice setup with the flat floor you can make up some HP loss or weight gain.

Transmission setup (as always) is also key, even more so, if you decide to run with the flat floors.

I am sure there is a list of cars that have the option somewhere. I have a 550pp M3 coupe that can compete with others at that range, but has to be on a certain track for me to take it out.

I "think" (hope) that PD will adjust PP for maybe other aero parts (although I haven't notice a major difference for other aero options.) PP adjustment on tires and downforce would be nice also. Maybe the Flat floor will be more of an option when/if that happens.

 

[Gentoo64]

Flat floors on low PP cars is terrible, it makes them way too slow. Put them on ~600PP and it's more worthwhile. I did the same thing on the GT86 I used flat floors and golded it but knew it could have been much faster especially on that track.

 

[Adamaw11]

I would have thought a flat floor would reduce drag in real life, not increase it.

I wonder if its another thing they made the wrong way round, expecting it to increase speeds AND downforce they gave it a bigger PP penalty.

 

[JLG_GT]

Yeah I agree with the above (2) posts. You probably should avoid it all together if you are going to race with the car. I hadn't even tuned a car @ 600pp with them cause I figured it would get smoked...

 

[ACGreen86]

If you were to equate the downforce created by a flat floor into a number the way a wing works, what number would it be? I'm trying to tune my downforce and want to know how much downforce is actually made by the flat floor.

Example: A wing makes 20 downforce, and flat floors make ??? downforce.

 

[TexRex]

If you were to equate the downforce created by a flat floor into a number the way a wing works, what number would it be? I'm trying to tune my downforce and want to know how much downforce is actually made by the flat floor.

Example: A wing makes 20 downforce, and flat floors make ??? downforce.

I'm still thrown for a loop by the differences in available downforce, where a car with a simple lip spoiler lacking any sort of beneficial underside to reduce pressure has 40 default but a massive wing with so much surface area top and bottom maxes out at 20. Good question though, might actually warrant a dedicated thread if there is no such thread out there already.

 

[Otaliema]

If you were to equate the downforce created by a flat floor into a number the way a wing works, what number would it be? I'm trying to tune my downforce and want to know how much downforce is actually made by the flat floor.

Example: A wing makes 20 downforce, and flat floors make ??? downforce.

Based on the time I have used Flat floors. the floor generates approximately 150 points of down force, but unlike wings that have to have x speed to work the floor works at any speed. BUT there is a ~13% speed penitently. Aero kit testing pre 1.09. I hosted a Viper Strike FITT event that was geared to allow the use of the Flat floor with out taking the PP into considerations to find out just what it can do. The cars that didn't use the Flat floor where 2+ seconds slower at the same horse power and weight on the Trial Mountain track.

Edit if anyone has a suggestion for a street car and a race car that can have simular stats i'm all ears to confirm the guesstamite of 150 points. All counterpart cars have too much of a weight/power difference to really confirm this it's just based on the handling and time difference.

 

[ACGreen86]

Well, I'll take educated guesses at this point too. Thanks Otaliema, I'll start off with that information in mind and see where I get.

 

[funz]

I have only ever run a flat floor in a room where it's a BHP limited racing and not PP. The BHP sacrificed in lieu of a flat floor is not viable when racing PP limited events in my opinion.

I have done testing with the BRZ at 450-550PP with floor and no floor and floor has always been that little bit slower over the course of the whole lap (even at places like Monaco). However, the flat floor does give a bit of extra stability, corner speed, and seems to be easier on the tyres etc but trades off so much straight line speed. 30-40 HP is a lot to lose at ~500pp.

My next step is doing some further testing with same BHP and test floor/no floor, but I rarely come across rooms where BHP is the room regulation so I haven't bothered testing it as yet. Otaliema's information sounds pretty solid though with loss of top speed.

 

[Johnnypenso]

I tried a flat floor on the Jag Seasonal back in January I think it was and it was competitive. I don't remember my final result but I was quite happy with it. I think it's beneficial in higher PP street cars on the less grippy tires, especially the cars that aren't grippy to begin with like the big, heavy Jag.

 

[Otaliema]

Yeah slapping the floor on a high powered under tire car and you will have good and noticeable gains for the car with out too much loss on the lap time, but the over all gains are currently out weighed by the sheer loss of power, in the hands of a good driver a no floor car vrs a floored car the no floor will always come out on top, when speaking in terms of a PP limited race, in a hp capped race the floored car will always win.

 

[ScottPuss20]

I had the same conundrum

 

[LeGeNd-1]

It really only helps on very high powered RWD cars on less grippy tires. On all other cases you'll be much faster without it because of the drag/top speed/PP handicap. Not to mention it makes the car's handling so stable and lifeless. Shame really, as some cars look really good with it.

 

[Tutorialtest]

Yeah, PP unfair! PD damnit!

 

[GolimLongshanks]

Perhaps we could have a "vanity" rear diffuser option.

 

[GT_Luuva]

Good question and some great answers for what to use it in.

 

[Otaliema]

I did think about one other use for the flat floor, install it on a power capped car and you can run it against cars 30-80pp higher and have a decent chance of winning, unless they changed something with power capped cars they always punch above the pp they are at. I haven't run a Capped car in a while so I do t know if this is true still.

 

[ALB123]

Based on the time I have used Flat floors. the floor generates approximately 150 points of down force, but unlike wings that have to have x speed to work the floor works at any speed. BUT there is a ~13% speed penitently...I hosted a Viper Strike FITT event that was geared to allow the use of the Flat floor with out taking the PP into considerations to find out just what it can do. The cars that didn't use the Flat floor where 2+ seconds slower at the same horse power and weight on the Trial Mountain track.

When you say "150 points of downforce", you're talking about in Car Settings, under Body where the Downforce settings are...you're saying that adding the Flat Floor is the equivalent of 150 points? Does that apply to the car as a whole or just to the rear? It's surprising that the velocity lost by adding a flat floor would be 13%. That is a significant loss of velocity...

I have only ever run a flat floor in a room where it's a BHP limited racing and not PP. The BHP sacrificed in lieu of a flat floor is not viable when racing PP limited events in my opinion.

My next step is doing some further testing with same BHP and test floor/no floor, but I rarely come across rooms where BHP is the room regulation so I haven't bothered testing it as yet. Otaliema's information sounds pretty solid though with loss of top speed.

That is a fantastic idea! Instead of using the PP system for event regulations, I could set HP and weight restrictions and allow flat floor if wanted. Perhaps if a racer did not want to use a flat floor I would have to figure out how to adjust his specifications to make the cars more equally matched. I don't know why I never thought of this before. Up until now, the Flat Floor has always been a terrible waste, in my eyes, because of the enormous increase in PP value. Your PP amount skyrockets but my top-end speed goes down?!?! What kind of poopypants nonsense is this?!

 

[Draggon]

I found out that flat floors don't work well on all cars, and certainly don't work well on the Nurburgring of all places. My approximately 480pp scirocco was 10 seconds slower at 500pp with flat floors.

 

[Exorcet]

Based on the time I have used Flat floors. the floor generates approximately 150 points of down force, but unlike wings that have to have x speed to work the floor works at any speed. BUT there is a ~13% speed penitently. Aero kit testing pre 1.09.

Drag is proportional to speed^2 (all aero forces are, so the flat floor performance should vary exactly like wings do), you can't just test one car and take a top speed ratio and apply it everywhere. It would be better to calculate the drag difference and the drag ratio and see which one is used by testing a few different cars.

Edit if anyone has a suggestion for a street car and a race car that can have simular stats i'm all ears to confirm the guesstamite of 150 points. All counterpart cars have too much of a weight/power difference to really confirm this it's just based on the handling and time difference.

Measure lateral g. GT6 still uses hard coded tire grip I think. Compare grip with the floor on to off, you can then take a car with innate downforce and see how much grip it has. They should both be street cars as race cars have higher grip multipliers.

Up until now, the Flat Floor has always been a terrible waste, in my eyes, because of the enormous increase in PP value. Your PP amount skyrockets but my top-end speed goes down?!?! What kind of poopypants nonsense is this?!

That's how race cars work. Downforce provides enormous performance gains for a huge cost to top speed. The problem in GT is that flat floors should increase top speed and increase downforce, but they don't. Conceptually, from a game balance standpoint, they seem to work. You would have to weigh the pros and cons based on car/track.

 

[Otaliema]

Drag is proportional to speed^2 (all aero forces are, so the flat floor performance should vary exactly like wings do), you can't just test one car and take a top speed ratio and apply it everywhere. It would be better to calculate the drag difference and the drag ratio and see which one is used by testing a few different cars.

That is in process I'm working a Elise right now I will also test the c7 at lower power as well

 

[Halcyon925]

Does anyone know if flat floors make 4WD cars corner better? I know more downforce in the rear increases understeer but adds stability, but wouldn't that technically handicap FFs or 4WDs?

 

[Otaliema]

Does anyone know if flat floors make 4WD cars corner better? I know more downforce in the rear increases understeer but adds stability, but wouldn't that technically handicap FFs or 4WDs?

I have not tried FF or 4WD with a flat floor but the way it seems to work is a even suction to the track so in theory it will help them by sucking the nose down

 

[Halcyon925]

I have not tried FF or 4WD with a flat floor but the way it seems to work is a even suction to the track so in theory it will help them by sucking the nose down

Well, maybe not suck the nose down, but only the rear from my understanding. It is plausable that flat floors help the front in suction, but I doubt it since they are placed in the rear; and they give us only more stability in the rear.

 

[Exorcet]

Does anyone know if flat floors make 4WD cars corner better? I know more downforce in the rear increases understeer but adds stability, but wouldn't that technically handicap FFs or 4WDs?

In real life the floors help. In GT it's harder to say.

Rear downforce helps all cars, including FF. All four tires are used for cornering and FF's are prone to lift off oversteer because of the lack of weight on the back. Rear downforce will prevent the back end from sliding out during a sudden release of the throttle at high speed and allows you to run more front downforce.

A full flat underbody panel also doesn't produce downforce solely at the rear. It's produced all along the floor. There are low pressure peaks though, usually the splitter and the diffuser entrance. (blue in the image below)

The relative strengths of the peaks can move the center of pressure forward or backward and change grip balance.

This could all mean nothing in GT though. We already know floors incorrectly produce drag, so they may be modeled poorly in other ways. The fact that they add drag is not only bad for top speed, but potentially also for handling. It depends on where the drag force is compared to the center of mass.

Race cars have wings mounted low even though the air is cleaner up high because the drag on a wing produces a moment that lifts the front wheels. If the GT6 flat floor adds drag above the center of mass of the car, you will end up losing some front grip (but probably not enough to negate the benefits of downforce). This can be made up for with some suspension tuning to put less weight on the front tires.

Which ever way the GT floor works, all cars should see a benefit, at least when tuned properly.