Originally Posted by alexgchris
I bought a Sapphire SRT-6 Coupe a week ago. I also think the wing is too boy racerish. I do drive my cars fast so I emailed CTD for data comparing the downforce of their rear diffuser (its like a tray under the car) to the regular wing and the SRT wing; I hope they respond.
I want to add that in deciding whether 40 pounds of downforce is significant, you need to know if that's the cumulative effect. ie is that net compared to say a lift factor of 100 pound without the wing which would mean the wing has a 140 pound effect OR does the wing reduce 100 pounds of lift to 60.
I'll post any answer I get from CTD. Vmaxx also sells diffusers.
Yikes, an aerodynamicist... Good, we need one of those on this forum... Here's what I know from online research and two years of track experience (my crossfire is only a track car, gutted, caged, etc).
The shape of the body produces a counter clockwise vortice at the rear-end (this is known to me from a wind tunnel test video I found online a few years ago) and a few half-azzed (non-professional) tests we did in November of 2006, when we were trying to figure out the optimum angle of a aftermarket racing wing that I currently have on the car.
That being said, I am assuming that the engineers realized the vortice was causing lift which makes the rear-end less stable as speeds increase. And they needed a QUICK FIX to offset that lift with some form of rear downforce to counteract it. If you look at the photos of the prototype of the crossfire, there is no wing... It must have been during the design / production / testing process that this rear-end lift was discovered and the wing was added.
Again, that being said. I have first hand experience that the OEM wing is effective to a point and does offer enough downforce for the purposes that car was designed for, public highway driving... However, since my crossfire is a track car only, I had to try and create more downforce on the rear, (1st) to offset the removal of the intrusive (negative) effects of the traction control, (2nd) to add more downforce to offset the 400 lbs that has been removed from the car, (3rd) to keep my AZZ firmly planted on the ground in high speed turns.
As far as CTD knowing the specs. of the aerodynamics (wing) to respond to your e-mail, the engineers in charge of the Crossfire here in the USA (Diamler / Chrysler) told me in January of 2006, that they
never had a very comprehensive list of the engineering specs from the German factory (MB / Karmann) because everything was handled by the MB factory and was not shared with the "CHRYSLER" staff.
I hope this helps you... I have the aftermarket diffusers and have replaced the OEM wing with a (BUTT UGLY RACER WING) that is fully adjustable, and depending on the track I am running, is capable of producing 200 lbs of downforce at 100 mph.
But then again, my car is on a trailer back and forth from the track...