Front spliter question

[P Clingman]

Hi ALL, I have an RSR style front splitter and without messing up my front geometry I cant get it closer to the track. Right now its 5.75" how much benefit
will I see getting it closer? And whats the best way to do it? its carbon fiber
I don't want to cut it and make a filler peace. I thought of making a aluminum lip
or a lip out of some carbon fiber honey comb I have. Thanks Palmer

[barney911rs]

Unless you are running very high spring rates, you need to leave room for the node of the car to drop under hard braking. That is more of an air dam and it usually made from some easily replaceable material, there was a recent thread on this subject. By splitter you mean the horizontal lip that sticks out forward, you will have to balance that with the amount of down force/reduced lift you have on the rear of the car. Make something you can slide in and out to change how much is sticking out.

[P Clingman]

John, I am running the largest tbars and sbars I could buy and yes I do mean the horizontal
lip the rear is a 3.8 rsr adjustable wing.I was thinking of making a peace to put below the lip
Palmer

[cstreit]

I made a fiberglass extension for my splitter. It was actually quite simple and designed to "break away" if I go into the gravel. It was made with 1/4" ply and a cardboard strip "mold" with fiberglass layed over. Looked very good once sanded and painted. Easy and cheap solution, takes about 5 hours to make 3-4 of them.

Documented it in my blog. This was the first version. In later version I just adhered the glass right over the ply/cardboard (instead of using those as a mold). It only weighed 2 pounds more and assembled much quicker.

Read about it here: http://www.moto-delta.com/wordpress/?p=86

[Mahler9th]

How much benefit? Not enough information here to say. Always best to look at local cars prepped by people that know what they are doing on things like this. That's by far the best way to get it right. I don't know where you are, but somewhere close there is likely a resource with PCA endorsement/customers. Much better than blind advice on the internet.

Chris's design is pretty cool-- impressive design and fab skills for sure.

I would not make a splitter out of carbon fiber-- waste of money in my opinion. Dive planes-- sure, why not (see pic of my wife below), but not a splitter. I consider splitters disposables, and frp makes less of a mess on the track than cf.

[175K911]

Originally Posted by cstreit

I made a fiberglass extension for my splitter. It was actually quite simple and designed to "break away" if I go into the gravel. It was made with 1/4" ply and a cardboard strip "mold" with fiberglass layed over. Looked very good once sanded and painted. Easy and cheap solution, takes about 5 hours to make 3-4 of them.

Documented it in my blog. This was the first version. In later version I just adhered the glass right over the ply/cardboard (instead of using those as a mold). It only weighed 2 pounds more and assembled much quicker.

Read about it here: http://www.moto-delta.com/wordpress/?p=86

Chris, when I'm back in town next week I'll touch base with you about how you fabbed the dive planes. Need to mount something similar on my car though perhaps a bit smaller.

[RaceProEngineer]

Originally Posted by P Clingman

Right now its 5.75" how much benefit
will I see getting it closer?

Sports racers and prototypes strive for ¼" to ½" "clearance" between the track surface and the bottom of the splitter, with the splitter occasionally touching under hardest braking. Here's why:

All else being equal, reducing the space between the splitter and the track to ½ reduces front end lift by a factor of 4! Now, if one can do this by lowering the chassis itself, the dividends are even greater.

LoPresti

[Mahler9th]

There is some interesting perspective on aero balance and dive planes in the most recent Racecar Engineering mag.

[cstreit]

Originally Posted by 175K911

Chris, when I'm back in town next week I'll touch base with you about how you fabbed the dive planes. Need to mount something similar on my car though perhaps a bit smaller.

NP, Give me a call. Construction was quite simple. Design was quite "plaguer-iffic"

Thanks for the comments on my "fab skills". Laying "disposable" glass (When it only needs to look good from 50 feet) is quite simple, seriously anyone can do it. These splitters cost me about $10 each to make i would guess. This is good because I seem to be going through one a weekend in the rainy season.

[Mahler9th]

I meant to convey that since splitters tend to get destroyed on go-off's, it might be best to make them out of less expensive material. Event strong S2 fiberglass is a lot cheaper than carbon fiber. For best strength to weight without spending a lot on layers, I often use Baltek mat from Tap Plastics as a core material. I also do a bit of vacuum bagging on parts. This helps optimize strength versus weight. I use a vac set up I purchased from a place called Aerospace Composite Products, in Livermore, about 25 minutes from my house. www.acpsales.com. I buy my carbon fiber from them as well.

The splitter height described b the original poster sounds really excessive... would be great to see a picture.

[barney911rs]

He also did not say if it's a street or track car, or some combination of both. A street car is going to need to keep more clearance then a track only car for everyday obstcles.

[P Clingman]

Thanks for all the replys the car is a race car the only reason I was going to use the CF honey
comb was that I have a lot of it and its 3/4 thick so its easy to build up some thickness.
I was hoping it would help out on the straits my car is the lowest hp in its class
Palmer

[Jack Olsen]

I can't think of any way a splitter would help you on the straights.

Mine comes apart into two pieces and goes into the trunk for the trips to and from the track. Flattening out the front with a sheet of horizontal ABS also means fewer chips in the front bumper.

On track:



On the drive up (at the memorial where James Dean died):



I agree with everyone else that you want something down low and easily replaceable. Although mine extends out 5 inches and so far has never been damaged.

[cstreit]

Jack you've turned driving your car to the track into an art form. Seeing you pulling aero bits out of the trunk for the event must be an interesting sight.

[barney911rs]

Jack,

you could make a side business either selling the plans or the whole kit for others for the wing and splitter.

[Jack Olsen]

But then the guys I run against might have as much downforce as I do.

[cstreit]

No one said you couldn't design in a little LESS downforce than the, uh, prototype.

[barney911rs]

I'm mostly interested in the splitter. Something that can can be installed and removed would make loading the trailer easier. Can't tell you over the years how many front ends I've seen cracked or ripped off on many different types of race cars. "Sure it clears, drive it up.... CRUNCH!!! "