I am making my winter project plans and will add Gt flares to the front fenders. I have a fiberglass lower front valance that works with the GT flares. How does this valance compare in regard to lift and down force compared to airdams? Their are so many choices but I like the look of the GT unit. Vince

Use the GT valance but install a "splitter" This will be a flat piece of black plastic attached to the lip of the valance.

I dont have pics.. but maybe someone will post one.

It is what we do on the 911's with the similar nose for the oil cooler.

The splitter should run back somewhat under the car (at least to the front of the control arm mounts)

This will give you some downforce that isnt achieved with the valance you like.

We use this same setup on late model factory Porsche race cars.


B

with Brad regarding adding a splitter.

Here is a front view showing the splitter protruding on the bottom of the air dam

Click to view attachment

Here is a rear shot showing how far back the splitter extends

Click to view attachment

is this the type of valence you are referring to?

It worked very well as it is. If I had kept the car longer I would have added a rear spoiler of some sort....Probably a 914 "duck tail" because it did cause some rear lightness at high speeds with no rear spoiler.

Dan, good question!

After I posted I wondered if maybe the 'GT Valence' mentioned is this one?

Click to view attachment

Yes the facory style is the one i am refering to. Is it possible to build the splitter for this valance?

I envisioned the one above this post.

That version REALLY responds well to a splitter.

Great pic Dan!!



B

What rules are you working to?

There's always my favorite..... shameless plug..... shown here with an SCCA-legal splitter. This splitter also has a flat bottom that extends to the back of the air dam.

Flip this valance over onto a long piece of paper and trace the top edge onto the paper. This will become the leading edge of the splitter. Just go straight across where the opening is for the oil cooler.

Take the paper and transfer to a piece of black poly/plastic. Make TWO of them, so you have a replacement when you drag off the first one..LOL


B

Kevin,

the ONLY drawback to that type of setup??

I have to remove/replace the whole thing if it is damaged.

I had the same problem with Roger Sheridans one piece front ends. He finally changed it a few years back and made the lower airdam/splitter seperate from the nose piece so we could easily carry spares and replace on the fly if need be.


B

Will 3/16" ABS work and I will guess it will Install independently from the valance?

3/16 will work fine. You want to attach it to the valance. Try to make it one piece.

Make one fully extended out to the leading edge of the bumper and one half the distance. The more extended the more downforce you will have on the front end. You'll need to experiment to determine what YOU need. I say start aggressive and trim back if need be.

Dont use a lot of screw to hold it on. Use something like 5 total so you can change them out easily. Two out on the ends just below the factory valance screws and one dead center.. then place the remaining 2 equal distance from the center.


B

I just hope that valance has some decent material on the bottom to screw too.


B

Where do you find the plastic to build this splitter? TAP?


KT

vince... i got a GT valence too...

its gonna be pretty hard to attach a flat piece to the bottom...

maybe bust out the fiberglass... and reshape the bottom.... so you have some meat to screw the splitter onto it

You nailed it Trek..TAP.

I would imagine the GT valance is thin at the lip like the stocker?

I'll look at a stocker tonight and see if I can figure something out quickly.

We are going to do this same thing in the Boxster spec series with the stocker Boxster noses.


B

Here's my version of a splitter for those of the Chalom persuasion. (Scott where are you?) I added a couple of winglets on the sides to be fancy. It extends under the car to the front of the torsion bars. This forces the air exiting the oil cooler to the sides and out the wheel wells instead of being dumped under the car. It's all aluminum, my favorite medium.

Thanks Brad....that was a few years back

I always worried about hitting a curb or going off into the weeds with that air dam since it was sooooo low. 19 row oil cooler was mounted to it behind the center screening.
As I remember the bottom edge of mine was pretty beefy...took some abuse on drive ways and such with no damage
I thought a splitter could mount to that one pretty easy....but then again that was 8 or so years ago and they may manufacture (lay up) the FG differently now than back then

You could be like me and go super cheap used Rich B spoiler for $89 and cut it to fit your cooler. LOL! I do let a lot of air under the car however!

Brad,

Not exactly true about having to remove the entire setup, the splitter is a seperate piece, bolted on from the bottom (bolt heads act like rub blocks through the pits). Certainly the air dam is not seperate.

Thanks Kevin!

Glad to hear it is more user friendly than it first appeared to me.


B

Grant,

you changed the picture?? That is an absolutely GREAT shot of your car. It tells alot about the car.


B

Whats it say? ....This is a cheap piece of #$%&! track car?

One of the first things I do is track down who is shooting pics at the event. Gather the pics and "read" them. If you dont have data acq.. I cant determine how much roll the car has in the different corners (only max roll with a shock marker of some sort) so pics are the next best bet.

I can see all 4 tires (looking for rollover) I can see what corner it is. I can see body roll. I can see your line. Typically I can see hands on the steering wheel.

I factor in everything I can get my hands on for setup.


B

I just looked at it with a tape and straight edge. It will need some more fiberglass reinforcing and bottom reshaped . I think i will make a plywood moc up first, then build it with plastic or ABS. Should look good and work well when it's done.

Anyone got pictures of one completed? Might be helpfull before i start.

Another version.

WOW! I would personally consider that "excessive" The very lower lip is what I consider the splittler, even though the air dam has one built into it. This pic is a good example of the actual lip.



B

A removable ABS splitter would make a fun winter project. Are they supposed to attach flush to the lower air dam, or is it supposed to be more effective with a small gap to let some air flow between lower dam and upper splitter? Looks like most of them have no gap. I like the comment that beefy bolt heads can help reduce scraping the splitter off. Gotta go with 13mm bolt heads, that wrench works almost everywhere else.

I have a track day on Nov 12th at Sears and would like to have mine made by then.

I'll modify the Sweeper Dam so the splitter can hang from the rubber skirting. It'll firm up the air dam for the track and will still have give when I hit stuff


KT

Trek,

I just looked at Grants Laguna pics.. I was going to suggest to you that you need to remove the sweeper dam for track events and go to something else. The sweeper works well for AutoX, but it might be slowing you down on the big tracks.


B

Heres a shot you may have missed from TH at speed. The Sweeper folds away.


KT

Trekkor,

The FIA is gonna penalize you for using a movable aerodynamic device!

This year there was a big controversey in F1 concerning flexible wings. As a result, only Ferrari is permitted to use them.

We have already asked Trekkor to remove his fluid bag that he keeps in the front trunk


B

Huh?


Click to view attachment


I already removed *that*.




KT

F1 cars had a fluid bag of sorts mounted in the front nose for some reason I cant recall. They banned it.

B

That fluid bag was called Advanced Damping System.

Renault and Ferrari and others maybe used this device.

Banned for this reason according tho the FIA (all devices influencing aerodynamic performance of the car must be rigidly secured to the entirely sprung part of the car and must remain immobile in relation to the sprung part of the car)

The system worked by suspending a mass in the fluid of the damper. The effect of this is used in many other applications, from cranes to geophysics and gave the cars an advantage over rough terrain like curbs where the tire wall could not damp enough of the vibration.

With this technology gone, the Renault and Ferrari (and others) may find it a little more difficult to 'ride the curbs' as they have in the past, and I would assume the FIA are hoping it will lower corner speeds as a result.

Yeah.. what he said..LOL

I have now viewed a total of 3 F1 races in my life


I would rather read about setups in RaceCar Engineering.


B

F1.com has a neat section about the changes each team makes between each race... all the tech is amazing.

We added 3 little holes in the side of the wing and gained 10% more downforce, and lost 4% of drag...

BJH

First mock-up of my splitter.

Yes, I've been to Home Depot and yes, that's plywood.

Once I get the angle right, I will take it all apart and laminate fiberglass over it, sand it out and paint to match.

What do you think?

What is a good target angle for the splitter? Should it just be parallel to the ground?

It only weighs a few pounds more now.


KT

I think your onto something there trekkor!

Oh Maybe a nice round over with your router, and you are good to go. You could get the dark fiberglass mat, that makes it look like carbon fiber and glass it with the resin and a UV stabilizer. Or use the Plywood as a pattren and cut it out something else. No angle of attack needed, if I remeber correctly. I am thinking that if you scrap plywood and fiber glass, it is pretty easily repaired.

It might just keep your sweeper in place, at speed, thou I might condiser some bracing, casue if that thing bends down and catches, you are in for a ride. Ever seen a 914 play leap frog with its spoiler?

Oh, you where already having an issue with too much front downforce compared to the rear???? You might need to up the rear wing a bit, to compinsate for the front.

So Trek,
now you have to worry about dry rot and termites along with the rust

Now are you going to attach it to the air dam? And what about support so it does not deform at speed?

I plan on using adjustable braces out front. Turnbuckles attached to "u-bolts" at 45 degree angles...As many as four of them.

Behind each Dzus fastener is an "L" bracket bolted through the splitter and through the rubber skirting of the Sweeper.

I will also add bracing behind the rubber so it does not deform.

I'll need to do some "vineyard testing", of course.


KT

Why are you looking for more front down force

I'm not sure how this is going to feel.

I'm looking for more stability, less air under the car and more air into the cooler.

I may add a four inch tall adjustable plexi rear spoiler extention.

What do you think I will experience with this new set-up?


KT

If you use just the splitter, you will feel more lightness in the rear at speed.
Balancing it with more rear spoiler will probably help, but you will also be generating more drag

If it were me I would go to a more conventional front spoiler (HPH) or Le type with your small duck tail....I think the car would be more balanced that way.
IMHO.
I ran my RSR spoiler for 4+ years with no rear spoiler and had no problems other than high speed lightness in the rear end, above 100mph...
Nascar turn at BW and main straight.
Main straight at Laguna
and both straights at TH.
It was drivable but probably would have benefitted with a small rear spoiler to balance at high speeds.

I have another LE front spoiler.

I think I will set it up for the brake and oil cooling inlets and compare feel and lap times before modifying the rear spoiler.

Does that sound like a good idea?

Will you come to Sears on the 12th? The Spec Boxter Plus™ will be there, too.



KT

I think that would be a good comparison

Have both with you to interchange in see which feels better overall.

I'll have to check my social calander

what group are you running with?

This is another Trackmasters event along with SVR/PCA.


KT

Thanks for point the thread out to me Trekkor.

I'm sorta doing the same thing. Slowly trying to get everything togeher though. The metal guys are really taking there sweet time getting the aliminum sheet over to me though. Slowly gonna become a winter project.

Figured aluminum would be a good choice because if it got bent I could just hammer it back into place. If it was real back I could just whip out the tig and fix it. I'm going to fasten it at the back to the car but I wasn't thinking to use turnbuckles on the front. That might be a good idea because all that holding the airdam to the bumper is some tiny rivets. I could see the downforce ripping the nose right off wouldn't that be fun!!!

Still haven't decided what to do in back. Tall wing for optimal downforce or rear lip because it looks pretty.


Anyways where do you guys get those turnbuckles at???