I read the entire Aerocivic thread yesterday
I saw how he did his front fender skirts. I was unable to track down conveyor belt rollers, so I will build ones with a slight bulge outward. I hate to do this due to increasing frontal area. I am going to try and shape the bulge in the likeness of the Aerodynamic Template.
The stock height for a Escort ZX2 is 52.3 inches, from Wikipedia. For easier math, I am going to assume that I have a 2" drop along with 1" smaller tires(0.5" drop from stock), giving me a ride height of ~50". So I need to shoot for 200" or 16' 8". The car is already 175.2" long (14' 7"). According to Hucho, I need to add only 25" of boattail! The full length boattail puts me closer to 5X.
I think I am going to shoot for a 4-7* diffuser angle. This is enough angle to keep a majority of the flow attached to the bottom, yet allow me to go to Wal-Mart without fear
This will also reduce the length of my boattail to ~18'. Much better than 21'!
With only 20-mph wind speed needed, the full scale smoke testing seems to be my best and easiest bet. I will have to figure out a way to "inject" the smoke into the air stream. When we use it at church, it is sucked through the fan and it disperse rather quickly.
I have many answers to the BSFC problem
With drag reduction, I am going to be in the same boat as Darin was with the Civic. Here is the BSFC graph for my 2.0 ZETEC -
BSFC is around 270 at cruise now (50% load at ~2000 rpm). Decreasing drag will only make that number go towards 295 from decreasing the load. No no, it is going up!
I have a plan through deleting an intake valve through a custom intake cam to create a VTEC-e effect (1I, 2E creates high swirl, improves torque, possibly higher load through more throttle angle), retarding the intake cam to reduce pumping losses and have a more open throttle, and I will be utilizing lean burn to increase the load even farther. I really want to tune for variable leanness on the fly, so the engine will behave more like a diesel. I plan to add turbo with small boost (3 psi. max) to go even leaner. I know that this work will change the BSFC graph, but it should get me closer to ideal
I'm soon going to work on aero mods and should get some work done today! I will update the thread with pictures and commentary as work is completed!
Thank all of y'all for your support, direction and wisdom. It means a lot to this aerodynamic greenhorn