Venting the front fenders for race car
09-21-2017, 11:46 AM
#31
Registered User
Hi all here's picture. please note temp and wool tuffs. also note the car is on the 1000hp dyno rollers so we are actually driving so we could get the temps out of the vents from the engine/radiator. Rear wing placement, using the rear window as grounds effect that's the reason for rear wing position.
09-21-2017, 12:38 PM
#32
Rennlist Member
Kman, does testing show that rear wing height and fore/aft positioning in picture is correct...?
Just curious, usually rules dictate "no higher than roof" so there is an advantage expected to get wing into clean air but the Mantis car is low enough to pick up air adhered to the roof and down the deck as per factory rear rubber wing.
TIA,
T
Just curious, usually rules dictate "no higher than roof" so there is an advantage expected to get wing into clean air but the Mantis car is low enough to pick up air adhered to the roof and down the deck as per factory rear rubber wing.
TIA,
T
I tried various bandaids to try and remove the side to side oscillation but couldn't stop it.
09-21-2017, 12:52 PM
#34
Race Car
I found that if you get the wing too high it is extremely hard to stabilize. I had mine originally at roof level and you could feel the side to side movement over 120 or so. I lowered mine by about 3 inches and eliminated the side to side movement.
I tried various bandaids to try and remove the side to side oscillation but couldn't stop it.
I tried various bandaids to try and remove the side to side oscillation but couldn't stop it.
LOL, inside joke only an F1 fan would get.
I'm WAAAAAY out there sometimes....
T
09-21-2017, 12:55 PM
#35
Race Car
Yes, it is.
Pretty much just what I'd expect too.
What's amazing is, we all talk about theory and what we each think is best blah blah blah.
And then you are forced to race with windows in the down position or removed.
The air entering the windows and filling the rear deck is a parachute as far as streamlining goes.
By the way, I've said this before here and it applies here too, with all the instruments and best college educated techs in fluid dynamics at their disposal, the pinnacle of motorsports, Formula 1, should all come to the same exact conclusion re aero.
Yet they don't.
T
09-21-2017, 09:39 PM
#37
Race Car
Mantis definitely has some proven R & D over the years, modded oil pans, other oiling improvements, of just the ones I know of....and on that note, I'd buy the paper just for the heck of it. Tough to search and find something on the SAE Automotive site though.
A couple of changes in the car from since the wind tunnel pics.
K-man, I figure you recognize the car behind my son in the green/black/white #187 2.5 NA SP2 in this pic...?
Should be 2016, and I'm guessing this is Ernie J. at the wheel in the Mantis car....?
He was at the front of Sp3 and way fast that weekend.
Ernie has the Sebring track record for SP2 also, my son Eon is at 99.1% of his record, one of the few tracks we visit that Eon doesn't own track record.
T
09-21-2017, 11:51 PM
#38
Rennlist Member
That's cheap for Wind Tunnel testing!! As I've said before, I'd love to be able to utilise your services. Just need to invent that Teleportation Chamber first!
Re the rear wing height and location. It makes a Ton (no pun intended) of difference where it's located. With all due respect to the white S2 in the pics, I would have to guess that this is rules dictated as this is far from the ideal position. Our glass hatch actually creates problems due to the fastback profile compared to normal sedan or even hatchback shapes. Essentially unless the wing is raised quite a lot, it is too close to the hatch and just doesn't work nearly as effectively as it should. We have been advised to move our wing higher and further rearward by the Aero company. The issue of stability can be surmounted.
Re the rear wing height and location. It makes a Ton (no pun intended) of difference where it's located. With all due respect to the white S2 in the pics, I would have to guess that this is rules dictated as this is far from the ideal position. Our glass hatch actually creates problems due to the fastback profile compared to normal sedan or even hatchback shapes. Essentially unless the wing is raised quite a lot, it is too close to the hatch and just doesn't work nearly as effectively as it should. We have been advised to move our wing higher and further rearward by the Aero company. The issue of stability can be surmounted.
09-22-2017, 08:09 AM
#39
Race Car
That's cheap for Wind Tunnel testing!! As I've said before, I'd love to be able to utilise your services. Just need to invent that Teleportation Chamber first!
Re the rear wing height and location. It makes a Ton (no pun intended) of difference where it's located. With all due respect to the white S2 in the pics, I would have to guess that this is rules dictated as this is far from the ideal position. Our glass hatch actually creates problems due to the fastback profile compared to normal sedan or even hatchback shapes. Essentially unless the wing is raised quite a lot, it is too close to the hatch and just doesn't work nearly as effectively as it should. We have been advised to move our wing higher and further rearward by the Aero company. The issue of stability can be surmounted.
Re the rear wing height and location. It makes a Ton (no pun intended) of difference where it's located. With all due respect to the white S2 in the pics, I would have to guess that this is rules dictated as this is far from the ideal position. Our glass hatch actually creates problems due to the fastback profile compared to normal sedan or even hatchback shapes. Essentially unless the wing is raised quite a lot, it is too close to the hatch and just doesn't work nearly as effectively as it should. We have been advised to move our wing higher and further rearward by the Aero company. The issue of stability can be surmounted.
That's why earlier I paraphrased "no higher than roof line" because I know the class they race and I know those rules because that's where I am bumping to.
He makes mention above of using "ground effect" and that would explain the proximity to the deck, the deck is substituting as the ground, and I am assuming their theory would be for the bottom of the wing depth-wise to be concave but the chord of the wing would have to be WAY wide.
Maybe it's a translation thing and he meant something else...?
T
09-22-2017, 09:15 AM
#40
Rennlist Member
Can't tell conclusively but to me that wing sits lower than the top of the roofline. Our wing sits bang on roofline and looks clearly higher than this one. There's a hole in our local T/A rules which I hoped to utilise. Apparently others are although I won't broadcast on the net...just in case. ;-)
09-22-2017, 10:48 AM
#41
Registered User
Hi all , after spending about 100 hrs in the tunnel, lots of time was spent setup the tunnel with scales, 3 versions before we came up with the setup which is in the floor now. We can even yaw the car, run the engine drive the rear wheels, check brake cooling ducts, radiator air flow, heat issues, I came up with our setup, its all about drag vs downforce. At Daytona i don't even use the rear wing , we use a small flat spoiler of the back of the deck. No one was able pull a draft off the car , it was a bit loose in the in field. Until you test in a wind tunnel , what you think should work sometimes does'nt. Will be in the tunnel soon, end of October.
09-23-2017, 03:16 AM
#42
Rennlist Member
Hi all , after spending about 100 hrs in the tunnel, lots of time was spent setup the tunnel with scales, 3 versions before we came up with the setup which is in the floor now. We can even yaw the car, run the engine drive the rear wheels, check brake cooling ducts, radiator air flow, heat issues, I came up with our setup, its all about drag vs downforce. At Daytona i don't even use the rear wing , we use a small flat spoiler of the back of the deck. No one was able pull a draft off the car , it was a bit loose in the in field. Until you test in a wind tunnel , what you think should work sometimes does'nt. Will be in the tunnel soon, end of October.
I'd say you have a good knowledge of this car by now. I'll try and drop by if I'm ever up your way.