dan_uk

With a splitter on the car in 4th gear sweepers where I'm on the gas the cars understeering and when I lift to correct I get snapn oversteer.
Aero balance is great in slower corners no push? I think whats happenning the rear is sitting down on the gas and with the wing pushing it down more and the splitters pitching up. If the splitter is pitching up could it create lift? it seems like its not as effective since the cars pushing
I think when I let off the nose pitches down and the splitter catches air and the front grabs hard, a little too hard!

Whats the solution more spring? my car is about level on rake, should I raise the rear or pitch the splitter downwards?

I guess don't lift is the solution for now but these are corners I could go harder with just the rear wing and no splitter.. without the splitter the car needed less rear wing so I could set it to not create a push in high speed stuff - but then I was losing out in the slower stuff

06Estukay

What's the angle of attack on your splitter? I have about 1/4" rake, and have the front splitter set to 2* downwards. I know the splitter ideally should be flat, however I'm trying to counter act the the pitch angle of the car.

dan_uk

the car is raked flat so the splitter should be flat.. I guess I should put a level on it and find out for sure

DTP525

Text message sent

Slowcrash_101

What does your splitter look like? Is it a flat plate that sits under the car? Does it have endplates, do you have any turning or dive planes? Adding slot gaps reduces pitch sensitivity, adding strakes also reduces pitch sensitivity but is useless if you have a flat plate type splitter under the car. It sounds more like you have airflow separation problems under yaw, in this case adding end plates to the splitter would help, as would dive planes.

DTP525

^^ can't add dive planes or winglets without taking additional points for NASA TT

dan_uk

yea its flat no endplates or dive planes allowed..
I don't know whats going on but it felt like the car had tons of front end at medium speed but I was losing that at high speed (95/100mph) when on the gas
Like I said I had a little lift to get the nose in but it bit super hard and put me more sideways pointed at a wall than you ever want to be at 105mph

BlueBarchetta

You have more experience than me, but it looks like your splitter is set to maximum forward distance. More forward than I think mine is.

If the rear is real planted like you say, maybe that is causing slight nose up, like you speculate. This cannot be overcome by the splitter. However, the slight mid corner lift then loweres the nose, and the splitter bites hard. Exercabated by the general tendency to have lift throttle oversteer anyway.

Maybe, the solution is to make the splitter slightly less effective by shortening the forward reach. This could make the car more drive able at the transition from full power to slightly less power. In other words, live with a little understeer, but make it controllable, and hope to eliminate the snap.

Or, maybe find a way to get the nose down with springs, rake, or angle of attack on the splitter.

Just ideas, maybe I'm wrong.

Slowcrash_101

Hmmm looking at your picture I can tell you that your splitter is interacting negatively with your front wheel well. At 90 mph the front plastic bumper cover is actually starting to deflect, and allowing air to seal in the air pressure in the wheel well, the increased pressure in this area is negating the effect of the splitter. All you need to do is eliminate the gap from the splitter to the bumper cover, and or move the splitter further from the front tires. Granted it's easier said than done, but that should give you better front end downforce at speed.

dan_uk

thanks I had been wondering if there was something going on there - I am working on drilling holes to bolt the bumper down to the splitter

I ended my trackday sunday after I lost a the right side liner under the wheel at 120mph+ so I think air was definitely getting in between the splitter and the bumper