944 roof wing?
04-27-2011, 01:02 AM
#1
Rennlist Member
Thread Starter
944 roof wing?
Fot the last several years, I've supersized to GTS-1 at NASA Nationals. I was toying with the idea of bolting on some very simple aero to help stay more competitive there, but have to be able to easily revert to my native 944 Spec trim between sessions.
The splitter is fairly easy, and cheap, but mounting a "quick release" rear wing is more tricky. It occurred to me that the OEM threaded mounts for the roof rack in the rear hatch area would make an easy bolt on/off mounting place for a spoiler - right where the rear roof rack is here:
The result would be something similar to a MK II Toyota Supra, but a bit larger.
It is right over the rear axle, but would this be functional, or just separate the airflow from the rear of the car, and create drag>downforce?
Or maybe I should just put a Gurney lip on the rear spoiler.
The splitter is fairly easy, and cheap, but mounting a "quick release" rear wing is more tricky. It occurred to me that the OEM threaded mounts for the roof rack in the rear hatch area would make an easy bolt on/off mounting place for a spoiler - right where the rear roof rack is here:
The result would be something similar to a MK II Toyota Supra, but a bit larger.
It is right over the rear axle, but would this be functional, or just separate the airflow from the rear of the car, and create drag>downforce?
Or maybe I should just put a Gurney lip on the rear spoiler.
04-27-2011, 10:38 AM
#4
Race Director
eric,
You can bolt a rear wing to the rear of the car just under the spoiler. Then fab some brackets to have it clear the stock rubber spoiler and allow for quick release.
The biggest issue yo will have however is that you will have a hard time with chassis balance. What works in non-wing car may not work with the wing. Unless you can do a quick sway bar adjustment it may not be worth it.
In the end even at Mid-ohio my guess is your time will be quite limited at nationals to change over so swap tires, ballast and possibly tweak the sway bars. I think you will get really tired of changing over ther car between groups. I saw Jim Foxx do this back in 2009. He spent alot of time swapping tires and taking his ballast in and out. Not sure it would have been worth his time to also try to swap wings/splitters.
You can bolt a rear wing to the rear of the car just under the spoiler. Then fab some brackets to have it clear the stock rubber spoiler and allow for quick release.
The biggest issue yo will have however is that you will have a hard time with chassis balance. What works in non-wing car may not work with the wing. Unless you can do a quick sway bar adjustment it may not be worth it.
In the end even at Mid-ohio my guess is your time will be quite limited at nationals to change over so swap tires, ballast and possibly tweak the sway bars. I think you will get really tired of changing over ther car between groups. I saw Jim Foxx do this back in 2009. He spent alot of time swapping tires and taking his ballast in and out. Not sure it would have been worth his time to also try to swap wings/splitters.
04-27-2011, 11:46 AM
#5
Three Wheelin'
A roof mounted wing could be an interesting thing to try. I suspect though that it actually is not the ideal place for a wing, or we'd see more of it (edit: on road racers ...). On the flip side, I have seen a couple 914s over the years with wings mounted on the stock rollover structure at the rear of the roof area, so perhaps in some cases it does work.
The couple things that come to mind that might make the roof a less than ideal place to put a wing:
1. Most cars tend to get lighter in the back at high speed due to aero lift as air passes over the rear half of the car. A rear mounted wing often makes sense because it tends to counteract this by providing rear downforce at high speed. A mid mounted wing (like on the roof) would put downforce right in the middle of the car's wheelbase. While this might seem ideal since it would keep the car's front/rear balance about the same, at higher speeds you might wind up with oversteer much the same way as a car without any rear spoiler or wing oversteers at higher speeds.
2. Wings cause a lot of disruption to air flow. At the back of the car this can actually help to clean up "dirty" air that all cars have in the wake of air they leave behind. I would think that a wing over the roof might disrupt the air flowing over the back of a 944. You'd probably still get your downforce, but it might come with a penalty of high drag.
If you wind up experimenting with this, please report back on how it goes!
Scott
The couple things that come to mind that might make the roof a less than ideal place to put a wing:
1. Most cars tend to get lighter in the back at high speed due to aero lift as air passes over the rear half of the car. A rear mounted wing often makes sense because it tends to counteract this by providing rear downforce at high speed. A mid mounted wing (like on the roof) would put downforce right in the middle of the car's wheelbase. While this might seem ideal since it would keep the car's front/rear balance about the same, at higher speeds you might wind up with oversteer much the same way as a car without any rear spoiler or wing oversteers at higher speeds.
2. Wings cause a lot of disruption to air flow. At the back of the car this can actually help to clean up "dirty" air that all cars have in the wake of air they leave behind. I would think that a wing over the roof might disrupt the air flowing over the back of a 944. You'd probably still get your downforce, but it might come with a penalty of high drag.
If you wind up experimenting with this, please report back on how it goes!
Scott
Last edited by stownsen914; 04-27-2011 at 12:18 PM.
04-27-2011, 12:10 PM
#6
Drifting
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This might work for shorter, lower-speed tracks.
My amateur aero mind thinks that you would probably want to preserve some airflow over the rear window hatch, and that would suggest a wing that sits a few inches above the roof. If it sprouts from the roof, you'd get dirty air tumbling all the way down the rear window.
My amateur aero mind thinks that you would probably want to preserve some airflow over the rear window hatch, and that would suggest a wing that sits a few inches above the roof. If it sprouts from the roof, you'd get dirty air tumbling all the way down the rear window.
04-28-2011, 09:01 AM
#7
Rennlist Member
Thread Starter
Yes, the swap could be an issue. I've been able to manage tire & ballast swaps OK, with some help from friends trackside, but this adds another level. It may not be practical as a no budget home project.
Maybe a simple NASCAR style duck tail would be easier? I would also use this in enduros this year, as I've moved the car up to E2 this year for a new challenge, having won the E3 series last year. I also would like to see 944's win both E2 & E3
.
Maybe a simple NASCAR style duck tail would be easier? I would also use this in enduros this year, as I've moved the car up to E2 this year for a new challenge, having won the E3 series last year. I also would like to see 944's win both E2 & E3
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04-28-2011, 01:06 PM
#8
Rennlist Member
keep in mind, the air flow over the roof line has upward direction which would be hard to direct for downforce, unless it was really up high. also, the pressure zone is the lowest which reduces its effectiveness. it would have to be pretty large to be effective. better to put a small wing on the back and a spitter up front. figure out some way to make it removable to solve the convenience goal.
04-28-2011, 01:08 PM
#9
Rennlist Member
