dprantl

One of the best splitters I have ever seen.

Dan
'91 928GT S/C 475hp/460lb.ft

mark kibort

oh yeah, YOU NEED BRAKE DUCTS! even if you were to only cut them out of the bumper like stock, that might be enough. but you need to do that, if you plan on racing it. otherwise, forget about it! not enough air to the brakes. the stock later years did a great job with that set up. its a HUGE duct pointing directly at the deflectors at the rotor caliper area.

Abby Normal

That car never had brake ducts? On a front end with ducts, there would still be some opening.

VERY nice splitter!!

mark kibort

yeah, the older cars didnt have cut outs on the bumpers. easy to stensil and cut. i did this with the black 79 I had and converted to race car. just pick up some ducts, cut the holes and you are good to go!

justaguy

Jan
Seems like there is some interest, how mant pre-orders do you need to start production?

Jan K

As this one is for the 944 and we never made one for the 928 we has to use the experience that we has with the Ginetta g50 z, 944 and 997 RSR that we supply to the racing teams to give a good profile on it and then test drive them.
The idea is to make a two piece unit this way it`s easier for shipping and to replace just one side if needed.
The goal is to have them made for late May.

slate blue

Jan lot of work there, a couple points worth raising, the kick up at the side? What is the purpose? My guess is that it keeps the air attached to the body or closer to the body limiting drag through a smaller wake. I certainly could be wrong on that.

It can be a very sensitive aero area of the car, (the front corners where the front wheels and brake ducts are located) the Ferrari FXX has a crucial mod done to body on that area over the car it is based on the Ferrari Enzo. One of the reasons I think it gets very sensitive is the drag and lift caused by the front wheels. Need to keep the air away from the front of the wheels.

Now you don't have any brake ducts? Or none that are visible anyway. There is going to be a reduction in drag and lift with air being limited in that area but so will the cooling if there is no ducts. If you have proper ducts like what Mike Simard has on his race car you will also get lower drag and less lift. Some barge boards in front of the wheels would also help in lowering lift along with your splitter.

Greg

Jan K

Well, of course the car need to cool down the brakes (and bigger ones).
Maybe a good place is cutting out a the front bumper and spoiler!
An udder thing the splitter has is some small flaps to take away the air stream from the tires.
One the OEM 944 bumper we just use the buckets where the fog lamps use to be to make a scoop to the brakes. One our racing 951 as you can see in the photo we use a air ducts on the sides of the bumper

mark kibort

yep, brake ducts like your edit would be nice. looks like you have some little deflectors for the rotors under the splitter, but that is not near enough. one thing the 928 S4 air dam did, was have nice inlets for the brake rotors for air flow. with the older style, you need to cut those holes and use the stock or make up some new ducts since you are starting from scratch.

by the way, the little end plates is for the air that is hitting the side of the splitter , from rolling off the edge to give a little more downforce. however, that technique is usually more benificial if the splitter ends are turned up , incorporating a dive plane effect.


nice work!

dprantl

Oh wow, how about an entire front CF or FG bumper cover with ducts like that for a 928? You really have an eye for good looking front-end design.

Dan
'91 928GT S/C 475hp/460lb.ft

Jan K

The deflectors under is to pull away air from the wheels.
In the 944 i`ts different as I have a lot of air intakes. Water radiators on each side, intercooler in the centre and fresh air into the lamp area for a hungry V8 twin turbo or an angry 3.0L 16V turbo ( I haven't made up my mind jet).
We has been calculating that if we make some parts in CF the weight is about:
Hood 5.5lb
Doors 7lb
Front fenders 2.2lb
Rear hatch. 5lb
Front bumper 4.3lb
Rear bumper 4.5lb
Spoiler/splitter 5lb

mark kibort

well, that wont happen, because the air flows out of the wheels. best to direct air to the wheel and get it out of the wheels for added downforce. air under the car is at ambient or slightly higher depending on the splitter configuration. anyway, this is why the rotors crack on the outside not the inside. air is moving out .
best to use the deflector as the factory did, on the S4. direct air under the spliter to the rotors. or better yet, find a way to duct it to the inner side of the rotors.

slate blue

I think we may have a mix up of terminology, so just to be clear you want to direct as much air as possible away from the tire, not so much the rim/wheel. The deflectors on the S4 direct away from the tire not the brake area.

I would like to see a close up on a Nascar of how they do their fans around the brakes and all the reasons they do this. Ferrari use the "Donuts" to guide the air and I suspect limit the air through the brakes, remember they have carbon ceramic which don't mind the heat.

Also I saw an interesting article from Porsche on the development of the 997 cooling system, the reason it is relevant is where it is situated which is in the area we are discussing. In front of the wheel assembly. Air released in front of the wheel needs to be guided in a specific way to help lower lift and drag. Have a look at a 997 to get the location of the cooling outlet, it also has guide vanes to direct the air downwards. Those rubber deflectors are still used on current Porsche racecars although they are now plastic.


Greg

Drewster67

I would seriously be interested if the price is right. I need an air splitter for the track car ...

Jan K

Hi again

We are just starting to build a two piece Splitter/spoiler for the 928 but as we are in a hurry with a some track cars that's gone be at Porsche Spa Francorchamps day in may we have to wait after that to finish them.