Aerodynamic Streamlining Template Overlay for ZX2?

[Frank Lee]

[Tygen1]

Ok, so I put a protractor to it and I got 24 degrees on the rear window. What you can't see is it's more bubble shaped. Water traces on the rear window would indicate that there is a good amount of air pushing the water off the window as it wraps around the sides, with very little to no air pushing the water down the middle third of the window, which I assume is because of the steep angle. I'm not going to be changing or adding to the rear window angle, so that might have to be dealt with some VG's. Anyhow, What about a little hitch mounted "carrier" the shape I have drawn, with an initial angle of 16 degrees coming off the trunk and bending down to 22degrees before being cut off. Just thinking about filling the wake with something... Is there any potential worth pursuing here? If there is, then it may be time for some tuft testing. If not, then I'll move on to other aerodynamic challenges....
Thanks for your help guys

[Tygen1]

Originally Posted by moorecomp

Thinking of my decklid extension spoiler?

I've had this idea for a while, but your decklid extention got the juices flowing....have you seen my question to Vit about tuning to run lean on TeamZX2? Check the "Performance Electronics" section. He can do it, you should requesition his services, he is the best for the Zetec.

[moorecomp]

It has been a challenge trying to get good mpg's with the cold weather here. I finally removed the restrictor I had in the disconnected vacuum line, and am running it wide open and the fitting on the air duct open too. Today I got 39 mpg on the way home from work (52 miles) and it was about 25 degrees outside and snowing. Not bad considering I recently lowered the air pressure in my tires to their winter pressure of 35 psi. Gotta get my snow tires on!

[aerohead]

Originally Posted by Tygen1

Am I even close in this overlay? I just scaled it so the bottom of the Template and the top of it met up with the ZX2, which happened to match up with the wheels as well.....

Right,you've got the height match correct,so as the others have already mentioned,move the car forward until the roof peak matches the max height demarcation on the template,which looks to be directly over the driver's headrest.

[Tygen1]

How about post #12 Aerohead? What merrit does this little addition behind the bumper trunk have?

[aerohead]

Originally Posted by Tygen1

How about post #12 Aerohead? What merrit does this little addition behind the bumper trunk have?

Clock is running out here,will have to look for number 12 later.
Your cheap fix,is to create a rear deck spoiler which extends rearward,and upward,no steeper than 30-degrees from horizontal,until it intersects the line of the template.
That will give you a locked vortex which the air above will skim over as if the car was more like the teardrop.
If the spoiler is steeper,you'll start inducing downforce which is induced- drag,and that will cost you at the gas pump

[Tygen1]

I'll clean up that picture for you, to make it easier to understand. Thanks for the input on the decklid/extention, I know Moorecomp is looking at something like that...

[aerohead]

Originally Posted by Tygen1

Am I even close in this overlay? I just scaled it so the bottom of the Template and the top of it met up with the ZX2, which happened to match up with the wheels as well.....

Tygen1,I don't know if you ever got a satisfactory response from me.
I still don't know what #12 image is,but lets work from your image here.
All the shaded area is separated flow turbulent wake,which is what is robbing you at the gas pump after highway travel.
Since totally re-configuring the back of the car is out of the question,the template overlay will help you cheat a little.
What you want to do,is project part of the car up until it just touches the top of the curve above it,essentially cutting through the entire gray shaded region.
The easiest way to do it,is to extend the upper rear edge of the trunklid backwards,and upwards simultaneously.Car and Driver Magazine used a piece of bent aluminum sheet on their Pinto project.
If the "spoiler" is angled up more than 30-degrees it will add drag.Extend as far back,at 30-degrees as you dare.If you can make it all the way to the upper curved line of the overlay,quit.Your done!
If you can't go all the way,go as far as you can.You're the boss of that.
Anything you do to approach the imaginary line of the overlay/template will cut drag.
Be mindful of pedestrians walking by the back of your car.
If you want to get a little more ambitious,you could try the bi-wing spoiler Ford patented and used on one of their Probe concepts and made it ino production with their Merkur XR4Ti. Their is a smoke flow image of it in the FLOW-IMAGES gallery somewhere.

[Tygen1]

If you look at Post number 12 you will see an attached picture where I added a sort of EV1 tail cone. I was wondering if there is any merit to that, but after spending the evening reading and looking at pictures of the EV1 I can see the boat tailing of the whole vehicle that made a tail cone like that possible. I'm gonna play around with my photo shop now and see if I can come up with something for you to gander at