fantastic info here. subscribed.

 

noob question: I Saw a few spliters in other threads. they where angled up, with the angle of the lip. wouldn't that cause lift? I always figures they should angle down.

 

i think it depends on the design of the bottom of the car. you want air to enter under the car and speed up to generate down force.

 

The Splitter angle of attack is vehicle design dependent, but for all intensive purposes, a splitter parallel to the ground is the optimal choice. Take for example a non aerobatic aircraft airfoil (wing): The top is rounded and the bottom is almost flat, creating a slow, high pressure zone below and a fast, low pressure zone above the wing. High pressure always moved to low pressure (just like the weather) thus creating lift. Now when you flip this same aircraft wing upside down what happens? You have high pressure above and low pressure below=downforce/drag, or in this case, the aircraft approaching the ground The goal is more so to generate a large area of high pressure above the splitter/and or bumper in relation low pressure under the car. Even the normal Evo IX front bumper generates some decent downforce with the ducts and intercooler air dams. I believe I read it's apx 30-40 kg depending on speed. Hope this helps.

 

that helps a lot, thank you. his splitter was shaped evenly on top and bottom, so it looked to me that it would cause the front to lift. so the splitter has no direct effect on downforce, but more of a passive role, as it splits the air so other aero pieces can work more effeciently?

 

Now how low should a splitter be is a question i think everyone would love to have answered. Its also goes to show that the "old" if you can stand on your splitter test is not a very important test IMO. There is not really all that much downforce put on the top of the splitter unless the AOA is wrong.

 

The way I have read and understand it, a splitter does at least these 2 things:

• creates downforce as a result of the high pressure area on the top of the splitter in front of the bumper/air dam
• allows less air to travel underneath the car (alternatively, can tune this) and creates a low pressure/high velocity air flow in this area

http://consultkeithyoung.com/content...er-preliminary

http://www.formula1-dictionary.net/splitter.html

Aiming a splitter down will help to increase the amount of air forced onto the top of the splitter but at the same time, create flow separation and turbulent air on the bottom of the splitter.

 

no, you have it backwards. voltex tested the stock 9 bumper/aero package to generate 30-40kg of LIFT not downforce which is why adding even a small proper splitter can make a huge difference.

 

At what speed?

 

ill dig up the video, gimme a few minutes....i thought i would have posted it in here.

 

at the 5 minute mark of this video they test a stock front bumper and no wing, i think it shows speed, but i just watched quickly. if not i have another video bookmarked somewhere that definitely shows speeds.

 

build DIY spliter. check. I'm sure this thread mentions canards. much easier than building a spliter.

 

definately not true. we had the APR splitter on one of out NASA cars without the turnbuckles on it and it ripped the lower portion of the bumper off on the first session and started dragging.

our pikes peak splitter had aluminum hangers holding it up directly behind the bumper along with 10-15 bolts through the bottom of the bumper. on the first test LAP on the front straight it DESTROYED the front end. ripped all the bolts out, and collapsed at the hanger. version 2 (which was used at PP), had 4 cables and was strong enough to stand on. we have no problems with it after that.

you cant have the splitter touching the ground ever or else you'll loose all your downforce. the closer to the ground without touching it means more ground effect though... its just hard to get close without touching unless you know exactly how much the car rolls and pitches under turning/braking.

 

The APR splitter is a joke with how its mounted so that is not a very good example.

I have 4 bolts holding mine up and it has never come off unless it was ripped off from going off course. This has been on my car and tested for over 7 years.

If you read those articles it talk's about the turnbuckles being used to keep the splitter parallel. If your splitter can bend down that it needs cables then it could equally bend up? I can see the turnbuckles maybe being needed but a cable?

 

Splitters make downforce not lift, don't need turnbuckles when cables work just as good when in tension.

I agree the apr mounting is weak (without the turnbuckles) but it proves the splitter (even a small one) makes enough downforce to rip the lip off the stock bumper.

Good news is we got out race car shock pot system all dialed in so we will be measuring all this stuff in the next week or so once we get the Ast shock back from being dynoed

Our test will be more real world then the voltex wind tunnel testing too