Adding grip to the rear end is pretty easy, you just throw bigger wings at the car, and like Nils said seal off the rear bumper with a diffuser. Those parts are pretty robust and shouldn't get to much abuse at the track. The front end is another story.

Making grip up front means big splitters LOW to the ground. And that's something just looking to get ripped off at the track. I'd like to build a dedicated track splitter but I end up driving my car around town as well and a real splitter is a no go for town driving.

And you really don't want to put a massive wing out back unless you can balance it out with a larger front splitter. Otherwise the increased rear force will actually LIFT the front. I saw this when I was calibrating the sensors I have on my suspension.

 

yeah...I'm more interested in more front grip mostly. Last time I went to VIR, I had my second "off" ever (in 7 years) and exited the track at about 90 mph down a grass covered but very bumpy steep slope (South Bend). No harm to the car, but I think any splitter or low hanging bumper would have been toast.

 

From my limited experience at autocross speed it's hard to get any usable downforce in the front, especially with just generic splitters like the APR one. I had one and removing it between runs did not make that much of a difference in feel and time.

Reducing front lift is where you can see results at autox speed by limiting turbulence and the amount of air going under the car. For what it's worth, I made an effective lip (after giving up on the APR splitter) that goes under the bumper and changes the balance from slight understeer to a nice usable rotation.


I haven't tried anything in the rear because I like the balance now but I'm assuming that reducing rear lift should yield similar effects and make a loose car tighter/faster.

 

[QUOTE=EVOlutionary;6100092]

Especially if you can find one used, for the price the APR is not a bad piece. There is also a company that makes an aluminum front splitter for a decent price.

http://www.autovationparts.com/store...shilancer.html

[QUOTE]

These are really nicely made pieces if you like the Ali look. I'd wonder though how well it would survive a run in with a speed bump versus a CF splitter?

 

While the aluminum may bend, the carbon will shatter and splinter.

One good thing about the Autovation unit - it sits about 2" higher than any other splitter because it mounts between the bumper and lower lip section of the bumper.

If there's a speed bump THAT tall - you'd destroy your whold bumper anyway!

 

O no Rich! I had no idea you went off last time at VIR! Sorry to hear that man I'm glad you and the car are fine! I know what you mean though, I'm definitely looking for more aero aswell. The last time at VIR I had a few close experiences with my car lifting alot on the back straight. At about 140-150ish the car would get very light and coming into the braking zone it would be very unstable from the cars suspension being all unsettled. I'm in the same boat as you, I'd love the Voltex stuff but the $$ is high but in my mind it would be worth it for a dedicated track car like yours. I'll let you know what I come up with!

 

aero & 'budget' just dont go well together imo...

robispec & dhp are developing some fantastic areo for our cars... Its wonderful to see robi out there actually beating & testing the equipment.. david changing fixing it then robi back out testing again... if I had the cash id get one of those 3d splitters.

 

I guess it depends on how much of the price is determined by exotic materials vs. R&D time. For something like a wing or splitter, it seems like they could be just as functional in aluminum vs. CF/Kevlar and that the price might be a lot lower for just a little more weight but similar function...sort of like a Sport model HANS vs. the CF Pro model. Same function, more weight, fewer dollars...

 

except some of the wing designs are complex and not feasible to make out of aluminum. granted, fiberglass would be practical but then you lose the "street" value which I am sure is a big part of sales.

 

Just keying in to agree on the low speed aero. I took my wing off for a short bit for giggles, and 35-40mph turns the rear end felt a bit light. Even had it trail out a few times. Put the wing back on and it feels great.

I will admit though, letting the rear trail and then power sliding out felt great

 

I agree with the wing - aluminum should work just as well as carbon, just heavier. For example, the APR dual element wings. . .

Perhaps one reason why an aluminum sheet is not used for splitter material very often is due to the structural differences from 2 layers of carbon with a core material. You take a 6x3' sheet of aluminum vs the same size sheet of carbon with a foam, balsa, or honeycomb core and you can see the clear difference. The aluminum will be as floppy as a limp "you know what", while the cored carbon will be stiff and solid. . .

To get the same stiffness out of an aluminum sheet you'd need 1/4" thick or more sheet. That would be very heavy . . .

 

Sweet! Nice Find! that splitter will actually clear my silly steep driveway

 

Can you say holy crap?

http://www.flickr.com/photos/dhp_composites/

 

Wings from aluminum are tough because you need to create an airfoil shape, otherwise it's just a waste of space. That's why carbon is nice. But I see no reason that it can't be done in more common composites to cut costs.

When my car is back together and I have the underside sorted I plan on building my own rear wing, a large GT style wing. I think it should be a fun project.

Aluminum can work for the splitter, you just need the correct alloy so it's stiff - but that's $$$ too. And it ends up heavy. If you look around club racing leagues you'll notice a lot of cars use 100% organic splitters - plywood. Call it ghetto but you can build and test alot of splitters when they're made out of plywood in your garage and painted black with the Krylon touch. Here's an example of a car running a plywood splitter.

 

That's what DHP's first prototypes were - plywood. I think he still has the wood version on his car to this day . . .