mikew968

Does anyone have any 968 aero experience? A 944s2 with a big splitter and high rear wing just ran a 1.37.5 on the pro couse at Mid Ohio. (My best time was a low 1.40 and Jim C was in the 39's) This beat the old record of 1.38.5 +/- set by Jim C (on a perfect 65 degree couldy day) from 2007. The 2nd place car was a M3 with similar aero and the 3rd place car was a 968 with a TS front and rear splitter/spoiler. I can share min corner speeds if that helps to figure if aero can be a benefit.


Mike

Lemming

Let me guess, Scott G.?

That's a great time, but I don't think it is that surprising. When I was at Nationals running the Pro course in TTB, John Slinkard did a 1:36.5 in an S2000 in TTB trim with lots of aero.

I can tell you that a 2-4" front splitter coupled with a good wing makes all the difference in the corners and under braking. You do lose a bit of top-end speed but I believe that you can get that time back at most tracks.

IIRC, Scott posted that he is running a lot of tire, like 285 front and 300+ in the rear, so he is likely faster in the corners and better under braking even in the slower corners where the aero has less effect.

rdhayward

That's a pretty big time difference. You sure it's just the aero package, and not something else lurking underneath?

Lemming

Yes, if it is Scott, then there this is a very good driver lurking in the cockpit

mikew968

Tim

how is the aero for you?

Lemming

My car is much better this year than last year. However, it is difficult for me to accurately determine only the aero effects, since I changed a number of things this winter (bigger brakes and rotors, bigger wheels and tires; in addition to aero).

With that in mind, changing the rear wing on my car has measurable effects on cornering, braking, and straight-line speed. I'm picking up a new front splitter next month with the goal of installing it in a way that allows me to vary the frontal edge. Right now my front splitter is 4", which is great for slower tracks (Barber) but likely hinders me at faster tracks (Road Atlanta, VIR). My rear wing has enough movement that I should be able to adjust it to match any changes to the front end.

I thought that I heard that Jim C. added a front splitter and rear wing to his car this year. Jim, is that true and if so, how is it working?

Jim Child

Actually it was last year when I added the Turbo S style splitter and adjustable rear wing. They make a difference, but they pale in comparison to the size of the wings Mike is talking about.

The car in question has a splitter at least 3 times the size of mine. Its rear wing is roughly 4 times the size of mine, has endplates, and is mounted several inches above the car's roofline. I would say that my car has very basic and modest aero, while the car in question has BIG aero.

If I had the money and wasn't determined to keep my car legal for PCA E class I would definitely be pursuing BIG aero mods for my car to keep up.

Lemming

Jim and Mike,

How much has the aero slowed the S2 in the straights?

Jim Child

I can't stay close enough to him to find out!

Lemming

Then I think it's time for you (and Mike) to consider the aero. With a little thought, I'm sure you could come up with a wing and splitter that are easily removed and replaced with the stuff you need to keep you PCA legal. Start thinking outside the box, there is no need to buy the $2,000 wing from JoePorscheSpecialtyShop. Mine was $70 shipped on Ebay and yes it does work (looks are questionable). My front splitter is made from plywood, coated with fiberglass resin. I will be getting 3 NASCAR composite front splitters for dirt cheap and with a little work they should fit the 944/968 front end very well (and they are light weight). This is the front splitter that I hope to make adjustable in length for different tracks. If it works, I won't need three and will sell one for cheap.

So, get out that and do it, I know you want to be at the front of the pack.

SpeedBump

Looks like it works and that is all that really matters. Actually on a track car I think it looks fine, if you were driving around town like that I would probably laugh my *** off.

Lemming

And it would be well deserved

rdhayward

Lemming, I'm sure you know what you're doing more than most of us when it comes to your car's aerodynamic setup. But how can you really optimize the add-ons without some wind tunnel time? Also, have any of you racer types considered experimenting with a diffuser, such as cutting out the lower bumper cover and installing screen?

http://en.wikipedia.org/wiki/Diffuser_(automotive)

Lemming

Wind tunnel would be great, just not many around and not cheap to rent. Data acquisition is what I have been using. Just use a test and tune to compare lap times, corner speeds, straight line speed, etc., as you modify the wing angle of attack. Hopefully I will be able to change front splitter length as well, but that won't be till next season.

I've considered a diffuser, but try to find one for a 944/968. I've been told that the one for an early RX7 works with some modification but the ones that I have seen are pricey. You also have to modify the car quite a bit, such as cutting out the spare wheel well.