harveyf

Bump for those that don't read Rennlist over the weekend.

ian

If people really wanted a 951 to go into the same set of tests, mine could be available. I would just want to fix my bat wing, and find an undertray before hand. I'd be currious to see real world differences between the 44 and 51.

1987Porsche944WithRealLongName

Very cool, glad someone was finally able to do this

Mangonesailor

Would the side skirts affect anything at all? Because I know where a set is.

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V2Rocket

is this the 944?


does anyone have aero data regarding the original 924 and the later 924s with the small wing? i believe the small spoiler was added to reduce the dirty air "vortices" coming off the flat back at the end of the sloped window but would like to see data..

this is all i have (no spoiler)

black944 turbo

As with Ian I would volunteer my car as well. All aero pieces are in place on mine as of now.

morghen

When you have a go, please measure the heights from the ends of the side skirts of the cars to determine how high the car sits from the ground in every test. please try to make a repeatable measure that everyone can use...perhaps use the edge of the metal as measured element instead of the plastic addons of the 951.
Not everyone uses the same wheels/tires/suspension and this data is beneficial for everybody only if we have the clear height and inclination of the car body from the ground.
Perhaps you can even get some of your spent money back from some of us...

ZR8ED

I was part of a group of Datsun Z car owners that chipped in $$ to rent one of the tunnels in SC and managed 17 runs with different configurations starting with stock. We had a small team of guys who were ready with 4 cars and different add on parts. As one run was being conducted, the rest of the team prepared for the next test, by adding parts/raising /lowering the car/ductaping seams and grill openings. It was a grueling day with lots of preplanning to ensure as little wasted time once there, as the booth was not cheap, and we had it for a full day. All the tests were pre laid out so everyone knew what to do. Everyone that chipped in $$$ got the results first, and much later on, the results were released to the public in a magazine article telling our story. It was EXTREMELY helpful in planning/building aero for my Z car.

Van

It's awesome that you took the time to do this - and share your results.

I'd think the 85 MPH data would be more important to you than the 120 MPH data. Here's a histogram of my speed from my fastest lap at the Summit Point race last weekend - which was pretty fast at a 1:26.5 - and I was only between 115 and 120 MPH for 3% of the lap.

I'd think you'd get the most impact if you could make a meaningful change in the 75-100 MPH range - that accounts for 50% of the lap. Increase your speed here and you've done something serious to improve your lap time.

V2Rocket

id put a big ol' air dam at the bottom of the spoiler, maybe some thick sheet rubber all the way to the ground, tape up the seams and some of the grille (in concert with good ducting) and remove the PS mirror (or both if legal)...put the same rubber as skirts on the sides and put some coroplast or fiberglass paneling over all the transmission/exhaust stuff...maybe some of those evo shark fins on/near the spoiler

maybe some rear wheel covers like a 90s caddy

btw the addition of the spoiler to the 924 turbo may have been slightly more significant than just 0.03 Cd - remember the 931 has the hood scoop and nose grilles as well, those could contribute to some losses. maybe the spoiler is good for 0.04 gotta say though...the wingless euro 924 is a nice looking car...

bordin34

I wonder how much an impact having the headlights up would have.

Reimu

I use my flipup headlights as airbrakes

944J

Nice car!

I see some possible problems with using this kind of wind tunnel to detect down force. The main thing is that the wind tunnel used has a limited volume of air. Also the wind is being pulled from behind in a limited volume space possibly creating a non normal air flow path and vortices. Also the windows are down so it can't be compared to a car with the windows rolled up.

I'm not an expert on this, these are just my first impressions since I've driven a stock 944 at 100+MPH and felt the car get sucked down.

I would think that a wind tunnel is good for detecting drag friction, but not for detecting down force.

I looked in Google quickly and others, like Ferrari, have had trouble using wind tunnels to detect down force.

J1NX3D

i remember a documentary on the Mclaren F1 that stated the decision to go with fixed headlights and not popups was the latter created downforce when up. IIRC.

bordin34

So the 944 has user-selective active front aero.