Front RACE splitter back lip removed or not?

[Frank818]

Hi racing guys,

For those with the front race splitter (the bigger one with 2 small upwards section in the back), I noticed the 90-deg lip at the back. I do not see any benefit of that lip and it would probably block some air and reduce airflow and add drag in worst case, did you cut that lip or kept it? If you kept it, does it really do any good?

56943

[Bob_n_Cincy]

Hi racing guys,

For those with the front race splitter (the bigger one with 2 small upwards section in the back), I noticed the 90-deg lip at the back. I do not see any benefit of that lip and it would probably block some air and reduce airflow and add drag in worst case, did you cut that lip or kept it? If you kept it, does it really do any good?

56943

Frank
There should be no air flow on top the splitter, so aero penalty. The lip does add a lot of needed strength to the back edge of the splitter.
Bob

[Canadian818]

Shouldn't there be air flow above the splitter feeding the rad? And the way Frank has it left, all that air would go under the car rather than through the rad? There's an aluminum panel that goes where the splitter is for cars that didn't come with the splitter. And unless I'm mistaken, I remember seeing many builders using both the splitter and said aluminum panel together. Another option would be to just make a small panel going from that lip to the rad.

[Frank818]

Bob I understand what you're saying, but that's not how it's designed with the new nose. There is a lot of air between the splitter and rad floor pan. 3-3.5", give or take 1" or so cuz you can adjust height on the fender supports. The splitter is fixed that amount of inches under the rad pan and in the nose insert there is an opening to let air flow between the 2 panels.

Check out this pic. In red the opening. Underneath, the splitter. Above, the rad pan. You can even see the fish fins opened up through the mesh.

56955

Adam, the lip is too far backwards to direct it to the rad. On the street splitter it's different cuz the panel is smaller and doesn't even have a lip if I remember (unless they changed the design). I will soon take pix of my own setup to see the splitter, rad panel and under steering rack panel. But I remember someone on another thread who sketched up a drawing with colors about these panels there was an opening at the end of the splitter. The air that doesn't suck up to the rad through the fins (if opened) will all go straight to the under steering rack panel and diverted to under battery tray and rest the car follows.

[Bob_n_Cincy]

Bob I understand what you're saying, but that's not how it's designed with the new nose. There is a lot of air between the splitter and rad floor pan. 3-3.5", give or take 1" or so cuz you can adjust height on the fender supports. The splitter is fixed that amount of inches under the rad pan and in the nose insert there is an opening to let air flow between the 2 panels.

Check out this pic. In red the opening. Underneath, the splitter. Above, the rad pan. You can even see the fish fins opened up through the mesh.

56955

Adam, the lip is too far backwards to direct it to the rad. On the street splitter it's different cuz the panel is smaller and doesn't even have a lip if I remember (unless they changed the design). I will soon take pix of my own setup to see the splitter, rad panel and under steering rack panel. But I remember someone on another thread who sketched up a drawing with colors about these panels there was an opening at the end of the splitter. The air that doesn't suck up to the rad through the fins (if opened) will all go straight to the under steering rack panel and diverted to under battery tray and rest the car follows.

Frank,
You want to have high pressure (stopped air) on top the splitter and fast moving low pressure air on the bottom side. This is what creates the down force. You want any openings in the front of the car to do useful stuff, like cooling radiator or brakes. All other opening should be blocked off.

Here is a quote from Jim:

"In the end our best numbers came with the extra radiator ducts taped off, the new splitter with the air gap taped off, 5 degrees of wing angle, the rear diffuser in place, no side skirts, and a level ride height of 3-3/8 inch. The max downforce produced was 120 lbs front and 164 lbs rear at 100mph, this increases to 271lbs front and 369 lbs rear downforce at 150mph."

http://bmw-m-power.tripod.com/splitter.htm

Bob

[Frank818]

Ok, ok, so it's not cuz FFR poked a hole in the lower new nose section that we have to use it. Then I assume this means when using a splitter we have to block off that bottom hole if we want to take full advantage of the splitter's power. Will do. Tnx Bob, as always.