944 Wind Tunnel Testing
10-02-2012, 09:18 PM
#32
There's no reason that a properly run and calibrated Wind Tunnel cant successfully record down force.
There are very few road cars that produce down force. When car companies talk about down force on road cars they are normally talking about that produced by wings and not sum total generated by the whole car.
There are very few road cars that produce down force. When car companies talk about down force on road cars they are normally talking about that produced by wings and not sum total generated by the whole car.
10-02-2012, 09:22 PM
#33
Team Owner
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did you all know the 944's front end has an issue with getting loose at high speeds over 125~140 mph ?
have any of you ever seen a Porsche 968 in a wind tunnel ?
yes... this could be your lucky day....
it appears someone was nice enough to bring a camera to the Porsche Museum.
yep, it's 968 week on the 944 channel.
.
have any of you ever seen a Porsche 968 in a wind tunnel ?
yes... this could be your lucky day....
it appears someone was nice enough to bring a camera to the Porsche Museum.
yep, it's 968 week on the 944 channel.
.
10-02-2012, 10:21 PM
#34
Racer
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Do you know more about this?
Thanks for the video!
Jeff
10-02-2012, 10:39 PM
#35
Drifting
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i did 137 in my 8v....very long straight, won't say where either. it never felt loose in the front, very planted in fact.
i'll spend 500/hr for my stealth, no one has ever wind tunnel tested one to see if the rear spoiler does anything
i'll spend 500/hr for my stealth, no one has ever wind tunnel tested one to see if the rear spoiler does anything
10-03-2012, 04:55 AM
#36
Three Wheelin'
bwhahaha 
really? how do you know this? early 944s or later ones as well? well..its good that the 968s dont suck as bad as the 944s...what are you, 5?
I drove my 924 (951 front end, 937 rear end) at 162mph and the car was planted to the road all the time....that would be a simple judgement from myself if it werent for the 2012 Carrera S in front of me that i was chasing. The 924/931/937/951 that i have stayed right on the tracks of the brand new 911 even at 162mph.
As a side note my car is lowered about an inch both front and rear compared to the factory european market 944.
I drove my 924 (951 front end, 937 rear end) at 162mph and the car was planted to the road all the time....that would be a simple judgement from myself if it werent for the 2012 Carrera S in front of me that i was chasing. The 924/931/937/951 that i have stayed right on the tracks of the brand new 911 even at 162mph.
As a side note my car is lowered about an inch both front and rear compared to the factory european market 944.
10-03-2012, 09:06 AM
#37
Three Wheelin'
Nice, very cool write up and excellent information to know! Was living a bit closer in Salisbury but just moved over to Burlington, NC so I'm not too far away with my 951 either.
10-03-2012, 01:46 PM
#40
Rennlist Member
Thread Starter
I have really enjoyed reading through the discussion this topic has generated.
For what it's worth, I had the 944 up to 4400 rpm in 5th gear (whatever that works out to be, I don't have a speedometer) on the back straight at Road Atlanta last weekend and the car was very stable. I still have the tape on the front of the car from the wind tunnel testing but of course did not have any rake, as I was back to it's normal stance.
For what it's worth, I had the 944 up to 4400 rpm in 5th gear (whatever that works out to be, I don't have a speedometer) on the back straight at Road Atlanta last weekend and the car was very stable. I still have the tape on the front of the car from the wind tunnel testing but of course did not have any rake, as I was back to it's normal stance.
10-03-2012, 05:25 PM
#41
Rennlist Member
Thread Starter
I have really enjoyed reading through the discussion this topic has generated.
For what it's worth, I had the 944 up to 4400 rpm in 5th gear (whatever that works out to be, I don't have a speedometer) on the back straight at Road Atlanta last weekend and the car was very stable. I still have the tape on the front of the car from the wind tunnel testing but of course did not have any rake, as I was back to it's normal stance.
For what it's worth, I had the 944 up to 4400 rpm in 5th gear (whatever that works out to be, I don't have a speedometer) on the back straight at Road Atlanta last weekend and the car was very stable. I still have the tape on the front of the car from the wind tunnel testing but of course did not have any rake, as I was back to it's normal stance.
10-04-2012, 12:12 AM
#42
Rennlist Member
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.
10-04-2012, 05:11 PM
#43
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As for some key information that we gleamed from the results transfers to almost any car. The rest is very specific to the car.
1. Most cars only require approx 4x12 inches of radiator opening to maintain cooling and maximize the efficency of the radiator without greatly affecting aero. Street cars are unfortunately subjected to stop and go traffic, and varying climates, so 4x12 may not be appropriate for all cars in all conditions.
2 Air dams and wings etc had limited effects on their own, and in somecases hurt the aero (by aero, I'm generalizing the term to include drag, and front/rear downforce/lift) It was proven that these enhancements need to be used as a matched "system" in order to maximize the benefits. In other words, not all air dams worked well with all spoilers/wings.
3 Tires had a larger impact on drag than thought. Wide tires, or tires that stuck out past the fenders (exposed to oncoming air) Keeping them covered as much as possible (not talking about wheel well covers like old limos) many times the wheels stick out slightly when viewing the car from the front (normally down low on the fender where it curves in slightly)
4 Windows down causes significant drag (not an option for some racecars)
5 vortex generators (mounted near the rear of the hatch where the air normally begins to delaminate do work.
6 In the case of the Datsun's sugar scoop headlight buckets, installing covers is a huge improvement, so I expect switching to non flip ups for the 944 to have a similar effect.
7 Belly pans. even stock ones are important and effective. Home made rear diffusers much less so (only because of the r&d required to design them correctly.)
8 Filling in seams/holes/ducts that are not needed showed lots of potential, though again the front of a Datsun has terrible aero, that has huge potential gains when modifying it with air dams, belly pans, radiator ducting etc.
9 Getting air OUT of the engine bay either out the sides or under the car helps air pass through the rad, and reduces the amount of air that can "pile up" in front of the rad.
There was a ton more learned, and I used most of the info when designing/modding my 280z.
Disclaimer. I am not an aeronautical engineer. I am just a nutso car enthusiast that had way too much fun playing with cars for 25yrs and counting. I am just generalizing what I learned from the wind tunnel, and my personal racing experience.
10-04-2012, 05:28 PM
#44
Rennlist Member
Thanks for that. Nice write up. Indeed an interesting field and one most of us pay scant attention to. Wonder if the small opening required for the radiator to work efficiently is also shared for front mount intercoolers?
