my TIGRA AERO PROJECT

[cfg83]

fabrio -

Originally Posted by fabrio.

I had thought next to the possibility to realize the "boat tail" in the behind of rear wheel, but I cannot apply them because small gap between the rear wheel and the ends of car.
In Italy, is prohibited to lenghten the car, the police is little tolerant in order to car modifications; also it is present aesthetic factor and the realizazion difficulties.
I do not know...perhaps, I will do something useful.
...

Oh yes, you are right. I should have looked at your Tigra's read before commenting. But, this could be useful to others. For fun, I am watching for something like this at swap meets :



I would only need the hulls. Maybe I could use the sails for sail power, .

Other countries have similar laws for extending the length of the car. It makes sense because the bumper needs to be the farthest out for crashes.

CarloSW2

[fabrio.]

I want new friends with whom to discuss aerodynamics and compare my ideas, because, here in Italy, there is no one

[basjoos]

Fabrio, The "mini-boattails" behind my rear wheels are 30cm long and 12cm high. It looks like you might have room to install them behind your rear wheels. Even if you don't have the length to install a full-sized mini-boattail to block the entire width of your tire, you could make a shorter, reduced-width boattail to block part of the tire's width. That would be better than having nothing behind the tire to fill in the wake.





You might also consider installing double side skirts between the front and back wheels to help keep the air flow linear between the front and rear wheels.

I recently painted black my front wheel air deflecter, smooth hub caps, side skirts, and mini-boattail, so with the white front and rear wheel well skirts installed on my car and everything below that black so you can't see the wheels, from the distance my car looks like it is wheel-less and hovering.

[LostCause]

I love the creativity of your mods, especially the adjustable grill block.

I don't know how detailed you want to go with aerodynamics, but if I had a tigra, this is what I'd do...

Rear tire boat-tail: Since Italy has length laws, I would install "kammback" boat-tails. While it wouldn't be as useful as a true boat-tail, it will help.

Kammback Boat-tail


Full Wheel Fairings: Ideally, the wheels should eventually be enclosed in streamlined fairing. The FWS, in addition to wheel covers, kammback boat-tails, and front splitters will create the lowest drag condition. This technique can be seen on solar cars. Personally, I'd also connect the front and back wheels with a full length side-skirt.

Full Wheel Fairings


Underbody Panel: You already have an excellent underbody panel, but I would cover up the exhaust with aluminum or another heat-resistant/conductive material. Others on this site have done it without a problem. I'd also look into building a rear diffuser to help minimize the car's wake.

Rear Diffuser


Side Mirrors: I'm not familiar with the Italian vehicle code, but I'd lose the passenger side mirror if it is legal and you are comfortable doing so. It'll make a minor decrease in drag, but every bit helps. Functionality can be partially restored with an interior side-view mirror.

Fastback Fairing: As you stated in your other thread, a fastback fairing would certainly help lower drag by decreasing the roof angle. I think it would be important to fair it into the sides of the car with generous radii.

Cooling System: If you get really ambitious , you could create a radiator duct and vent the air over the hood. This would decrease cooling drag, which is a major contributor to overall drag, and lower the cL. This would not be easy to do, though.

Radiator Duct


Minor Details: If I wanted to do everything, I would tape every seam of the car and make sure the surface is waxed and smooth.

Just some thoughts to consider.

- LostCause

[fabrio.]

Originally Posted by basjoos

Fabrio, The "mini-boattails" behind my rear wheels are 30cm long and 12cm high. It looks like you might have room to install them behind your rear wheels. Even if you don't have the length to install a full-sized mini-boattail to block the entire width of your tire, you could make a shorter, reduced-width boattail to block part of the tire's width. That would be better than having nothing behind the tire to fill in the wake.


You might also consider installing double side skirts between the front and back wheels to help keep the air flow linear between the front and rear wheels.

I recently painted black my front wheel air deflecter, smooth hub caps, side skirts, and mini-boattail, so with the white front and rear wheel well skirts installed on my car and everything below that black so you can't see the wheels, from the distance my car looks like it is wheel-less and hovering.

I want to make changes you advice me, but my girlfriend kill me
What I can do, is build something barely visible.
Good, your idea to paint some elements ...I can to tray it, but if you do not see me more, you know the why

Seriously, now, I will go to mesure the rear end of my car for study this possibility.
I wanted to ask you how you developed the "mini-boattails" than your posted in your original post.
You speek of pattern, how this help you?

[fabrio.]

Originally Posted by LostCause

I love the creativity of your mods, especially the adjustable grill block.

I don't know how detailed you want to go with aerodynamics, but if I had a tigra, this is what I'd do...

Rear tire boat-tail: Since Italy has length laws, I would install "kammback" boat-tails. While it wouldn't be as useful as a true boat-tail, it will help.

Kammback Boat-tail



Full Wheel Fairings: Ideally, the wheels should eventually be enclosed in streamlined fairing. The FWS, in addition to wheel covers, kammback boat-tails, and front splitters will create the lowest drag condition. This technique can be seen on solar cars. Personally, I'd also connect the front and back wheels with a full length side-skirt.

Full Wheel Fairings

Underbody Panel: You already have an excellent underbody panel, but I would cover up the exhaust with aluminum or another heat-resistant/conductive material. Others on this site have done it without a problem. I'd also look into building a rear diffuser to help minimize the car's wake.

Rear Diffuser


Side Mirrors: I'm not familiar with the Italian vehicle code, but I'd lose the passenger side mirror if it is legal and you are comfortable doing so. It'll make a minor decrease in drag, but every bit helps. Functionality can be partially restored with an interior side-view mirror.

Fastback Fairing: As you stated in your other thread, a fastback fairing would certainly help lower drag by decreasing the roof angle. I think it would be important to fair it into the sides of the car with generous radii.

Cooling System: If you get really ambitious , you could create a radiator duct and vent the air over the hood. This would decrease cooling drag, which is a major contributor to overall drag, and lower the cL. This would not be easy to do, though.

Radiator Duct


Minor Details: If I wanted to do everything, I would tape every seam of the car and make sure the surface is waxed and smooth.

Just some thoughts to consider.

- LostCause

LostCause, I agree with everything that you write...

GRIL BLOCK

thankyou...you are too good, but my sledge has problems with scrolling beacose with the dirt the mechanism dirt him hardens.
It is necessary to replace with other mecanism (like a throttle valve)
like this from crxmpg.com, (in preparation for an electronic control hole)



But I non know how to make it.

REAR TIRE BOAT TAIL

Yes, it is the best solution, I think we seriously after all these recommendations.

FULL WHEEL FAIRINGS

I am evaluate to ralize it with plexiglass, but I do not know if I can be capable

COOLING DUCT

this is on of most my main thought.
So, If I realize a good exhaust duct for engine ad radiator hot air , I can to eliminate the front grill block, but for this one, I must to dreate an electric controled opening in the under cover.


this one, is one of my project.
First of any motor controll of opening, I whont to create a raised duct to minimize the interference of hot ait with the front air flow (blue line)
This elementary duct it is employed on BMW 320D

UNDERBODY PANELS

No, my realization isnt' good: his covers only fraction car.
Area of transversal strut arm of rear sospension, and nomes points are not covered.
The exhaust line, is anhoter sensitive area because hot temperature.
Aluminium is good material, but the hot can to forward to internal car..ca in damage?
Have you an experience?...racommendiation?
the rear diffuser do not cover the muffler , I must create fibreglass, and add vertical fins for an more stable flow.
Time, I

SIDE MIRRIOR:

I cant' to remove it, not legal!!!!
But if the removing it is legal, I cannot to remove because I use they

FASTBACK FAIRING.

I think that the rear profile of Tigra is close to optimal angle in according with some nomenclature.
I suppose than I must to solve the problem of bubble beetwen the rear windows and the deklid.

Originally Posted by LostCause

Minor Details: If I wanted to do everything, I would tape every seam of the car and make sure the surface is waxed and smooth.

Just some thoughts to consider.

- LostCause

minor details....

I have filled any frontal gap headlamp bumper, ecc.. (I do not know the name of various elements of car )

I need time and spur, but for the last one, I am in the right route thanks at all you

[Cd]

Fabrio, do you intend to install smooth wheels ? The ones you have now might create some drag.

[basjoos]

Originally Posted by fabrio.

I wanted to ask you how you developed the "mini-boattails" than your posted in your original post.
You speek of pattern, how this help you?

The Loremo and the Daihatsu UFE-III have long boattails behind their rear wheels, so I just made a shorter version of theirs using the same taper I used for my car's boattail. I made the taper different on the 2 sides of the mini-boattail so it would help to direct air under my car's boattail. I made the mini-boattails out of sheet aluminum, cut and pop-riveted to form a triangular box that I pop-riveted to the bottom of my car.

[Otto]

Why not make the boat tails out of spray foam like Great Stuff canned insulation? It can be shaped, sanded, sculpted, painted, etc.. ~$4 to ~$5 per can, this should be enough for one car. If you hit a curb while parking, no big deal.

[fabrio.]

Originally Posted by .Cd

Fabrio, do you intend to install smooth wheels ? The ones you have now might create some drag.

I looks some example of this one like the moondish or self made, but this work, seem more easy to say than make!
I am seriously thinking of us, only for rear wheels