FF Aero Test Project

[gs shyner]

Background
The question has been nagging me for quite some time - to aero or not to aero?  Generally speaking, I'll take every aero bit available and bolt it on without thinking.  But why?  I flinch whenever I see the speed rating take a huge hit but I generally ignore that initial reaction on go right on bolting up that Forza wing.....

Suzuka Full

Cobalt SS without Aero (B700 at 2,199 lbs)
Best time - 131.798  see follow on message for a rerun
Benchmarks
S4.9 - A4.6 - B5.3 - H5.2  231hp 225 tq
0-60 - 4.732
0-100 - 10.834
Top Speed - 152.9
60-0 - 97.1
100-0 - 271.5
G's 60 - 1.13
G's 120 - 1.08

Track Notes
Under heavy braking, the car has a tendency to loosen up the rear tracking. Easier braking or just a little earlier lift then application of power brings it back into control.   There is lock up.
FF oversteer is present in the esses but easily managable.  Tire squeal is quite noticable.
Have to lift a bit for 130R.
Raced 5 laps with best lap coming on lap #4.
Done in Free Run so no tire wear but does look like I might drop the fronts down 1 PSI to more closely match the rear PSI of 32.5.


Cobalt SS with all Aero parts (B700 at 2,254 lbs)
Front Aero 50
Rear Aero 100
Best time - 132.416  see follow on message for an extroplated update.
Benchmarks
S4.3 - A4.6 - B5.9 - H5.7  240hp 233 tq
0-60 - 4.686
0-100 - 10.866
Top Speed - 149.1
60-0 - 97.5
100-0 - 264.2
G's 60 - 1.13
G's 120 - 1.11

Track Notes
Really predictable.  All lap times were pretty repeatable and driver limited.
Rear end is planted under braking. Lock up during braking is lessened considerably.
FF oversteer is lessened greatly and takes the esses sweet. Tire squeal is considerably less.
Just about can get away without lifting through 130R but a slight lift guarantees no penalty to corner cut or push off course after.
Raced 5 laps with best lap coming on lap #4.
tire pressures were slightly lower (.2-.4 PSI) then above setup for front and rear tires.



no aero best lap speed #'s -- S/F 130,  midT3 85, midT4 83, midT5 86, mid T6 85, mid T7 91, Bridge 82, midHairpin 39, Mid130R 130, SF 130
    aero best lap speed #'s -- S/F 127,  midT3 93, midT4 86, midT5 89, mid T6 84, mid T7 89, Bridge 84, midHairpin 41, Mid130R 128, SF 127
Looks like THIS much aero is detrimental to Suzuka full WRT to hotlapping, but if online or career, this might be better just for it's predictability.


******
Same car on Road Atlanta short.
best lap time in 10 laps Free Run.
PI 673 no aero  59.015
PI 673 aero      58.529
PI 700 no aero  58.359
PI 700 aero      58.267



any other testing needed?  questions?
George

[Detrick]

Great stuff GS.  I split the topic so we can keep the different drivetrain configurations seperated. 

My first reaction to the difference in lap times was  .  Especially since the acceleration and top speed characteristics of the car didn't change all that much according to the BM's. 

If time allows, you might want to try mixing and matching the aero pieces.  Specifically, I'm thinking you keep the Forza front aero and Forza bumper but ditch Forza RR wing.  Play with the build to keep the thing at PI 700.  This build might lend itself to even more oversteer than the original non-aero car under heavy braking.  You should be able to tune out the oversteer by adjusting the brake bias forward.  With that said, you may be able to drop those lap times even more.

Thanks for the work on this!

[Ske]

I noticed being marginally quicker with in the Focus ST with no rear wing. The same applies to the Mugen Integra and the 206 in D class. I'll always use the front wing and rear bumper if available, but the rear wing can come off some times.. especially in a car specific to fast tracks.

[Drift2XL]

I haven't used a rear wing on any of my FF cars.

It seems useless to plant the rear tires when they are only along for the ride.

Its usually the same as Ske, Front and rear bumper.

[Ske]

Well you want some grip on the rear to keep them from sliding around, it can actually cause understeer for some indirect reason. Most of my FFs handle better with the rear wing installed, though I always keep it at the lowest setting.

[Detrick]

Well you want some grip on the rear to keep them from sliding around, it can actually cause understeer for some indirect reason. Most of my FFs handle better with the rear wing installed, though I always keep it at the lowest setting.

I have pretty limited experience with FF cars in this game but the times I've run a few (FocusSport Focus, Cobalt SS) I've needed the RR Forza wing to keep the rear end planted.  Also, I seemed to get better lap times in my Focus ST with the rear wing - that car feels like it's on rails with full aero.  Thanks for the input Ske.  I've seen your tuning skills in action and respect your opinion highly.

[gs shyner]

Ever have one of those nights when everything is clicking?  Last nite's testing at Suzka was one.
I officially NO LONGER SUCK at Suzuka. 
note:
The full aero time I set above is no longer valid, so I reran original build (no aero) this night.  Re posted for ref.
I'd bet the full aero build would have a similiar time to the F/R bumper/R wing build (build A).

Aero testing continued with aero removal in stages.
PI kept at 700 for all tests with addition/removal of engine upgrades as addition/removal of aero warrants.


I've always been skeptical and have never put side skirts on any of my cars as I figured they'd only work "at speed".
Figured best place to see affects of a 1% gain (side skirts) is Nissan Speedway.
I enabled and followed the suggested line so that I would be as consistent as possible for those 5 laps and have a believable best.

FULL aero                                      Remove side skirts only (PI did not change)
Nissan Speedway 5 laps.                  Nissan Speedway
car weight = 2254 lbs.                     car weight = 2245 lbs.
best time - 60.218                          best time - 60.317
highest speed = 145mph                  highest speed = 144

not sure WHERE the skirts "come in" but they do work "at speed"

now on to the REAL STUFF
removed suggested line.

SUZUKA full
Cobalt SS without Aero (B700 at 2,199 lbs)
Best time - 131.497
Benchmarks
S4.9 - A4.6 - B5.3 - H5.2  231hp 225 tq
0-60 - 4.732
0-100 - 10.834
Top Speed - 152.9
60-0 - 97.1
100-0 - 271.5
G's 60 - 1.13
G's 120 - 1.08

    A=2245 lbs                B=2227 lbs                C=2221 lbs                D=2238 lbs                E=2216 lbs               F=2223 lbs                G=2205 lbs
hp 240  tq 233            hp 232  tq 225           hp 228  tq 223           hp 234  tq 227           hp 239  tq 233          hp 244  tq238            hp 236  tq 230
F/R bumper, Rwing       F/R bumper               R bumper                  R bumper, R wing         R wing                     F bumper, R wing        F bumper
F/R dforce 50/100       F/R dforce 45/NA        F/R dforce NA/NA       F/R dforce NA/90         F/R dforce NA/90       F/R dforce 50/100       F/R dforce 45/NA
best time - 131.665     best time - 132.145    best time - 131.757    best time - 131.730     best time - 131.576    best time - 130.988    best time - 132.622
S4.3, A4.6, B5.9, H5.7 S4.6, A4.6, B5.7, H5.5 S4.9, A4.5, B5.5, H5.3 S4.5, A4.6, B5.7, H5.5 S4.5, A4.7, B5.6, H5.4 S4.3, A4.7, B5.8, H5.5 S4.6, A4.7, B5.6, H5.3
0-60 - 4.686              0-60 - 4.748              0-60 - 4.763              0-60 - 4.732              0-60 - 4.686             0-60 - 4.640              0-60 - 4.686
0-100 - 10.850           0-100 - 10.947           0-100 - 10.979           0-100 - 10.979          0-100 - 10.786          0-100 - 10.705           0-100 - 10.754
top spd - 148.8          top spd - 155.1          top spd - 158.9           top spd - 152.0          top spd - 151.6         top spd - 148.2          top spd - 154.6
60-0 - 97.1                60-0 - 96.8               60-0 - 97.6                60-0 - 97.0               60-0 - 97.1               60-0 - 95.9               60-0 - 98.1
120-0 - 264.0            120-0 - 269.3             120-0 - 272.5             120-0 - 267.6           120-0 - 265.6            120-0 - 264.3            120-0 -270.9
G's 60 - 1.13              G's 60 - 1.13              G's 60 - 1.13              G's 60 - 1.13             G's 60 - 1.13             G's 60 - 1.13             G's 60 - 1.13
G's 120 - 1.11            G's 120 - 1.10             G's 120 - 1.09            G's 120 - 1.09           G's 120 - 1.08            G's 120 - 1.10           G's 120 - 1.10

Build notes:
A = best lap 4/5 -- nothing out of the ordinary, drives like the Full aero build.
B = best lap 4/5 -- OVERSTEER. Took me an initial 3-4 laps to adjust to driving it.  Restart and drove it like a Porsche RR.
Not to bad after that but if you pointed 'er in the wrong direction she went wrong!  She is capable of < 132 sec. lap
C= best lap 8/8 -- Pushes on throttle, slightly loose off throttle.  Drives like the differential is all screwed up but managable.
D= best lap 2/5 -- Slight tendency to push on throttle and in high speed corners but no bad tendencies.
E= best lap 5/5 -- Less tendency to push than above and "FELT" better/lighter.
F= best lap 4/5 -- OMG! No bad tendencis, real balanced and car drove great.
G= best lap 6/6 -- Oversteer.  Drove it like B and made sure I was pointing where I wanted and ready on the throttle to get out of trouble.


Overall impressions.
Car seemed to behave and run as I'd think with the various aero configurations and accompanying HP adjustments.
If able to drive and tune without aero, car will set good times as driver becomes familiar.
BALANCED Downforce and used sparingly can make that same car better and more importantly consistent.

I'm inclinded to no longer use the rear bumper and use a wing and front bumper build.
In this case the rear bumper only build adds unadjustable unbalanced downforce at 2 lbs less weight and 16 lower HP than the Front bumper/ R Wing build.

Comments?
George (short lived #1 on the friends list B-class Suzuka full) 

[JG4tr]

Congrats on the Suzuka non-suckage. Sometimes it just takes a lot of laps to find the rhythm of a track. I still find it hard to get the spoon curve right even after hundereds of laps.

Nice job with the Aero testing!