skinnywhite

any engineers out there who understand fluid dynamics and would be willing to provide advice or recommend a functional diffuser i can order?

i'd considered removing the back-up lights/panel on the lower rear of my C6Z Carbon edition

if i did so, i'd want to replace with a functional diffuser, but other than reading on wikipedia about bernoulli's principle, i'm not sure I have the sophisticated understanding/knowledge to make sure the product i select would work effectively:

" . . . [they work] by providing a degree of "wake infill" or more accurately, pressure recovery . . . "

https://en.wikipedia.org/wiki/Diffuser_%28automotive%29


most of the products i see searching here on the forum seem to be focused primarily on improving appearance -- rather than focused on function. and while some have a nice fit/finish -- i wonder if they are 1) not long enough to really get bernoulli's principle to work, and 2) not making use of the exhaust gases.

compare this supervettes product to the length of a ferrari 430 diffuser -- the ferrari diffuser appears to be over twice the length and has strakes that are farther apart:

http://www.supervettes.com/c6-z06-cu...-diffuser.html

(vs)

http://www.ebay.com/itm/Carbon-Fiber...-/300639466990

if any engineers can advise me i'd be grateful for the help. i will be adding the LG GT2 front splitter and rear wing -- but would also like to [as wiki says]

" . . . enhance the transition between the high-velocity airflow underneath the car and the much slower freestream airflow of the ambient atmosphere . . . "

that's if i can find a product i can order. my budget is about 2k, and i'd prefer to stick with an exhaust that allows me to run at laguna (aka quiet).

many thanks in advance if you have time to help!

VGLNTE1

I've been designing my Aero for quite some time. So I know a little. The point is, there is no real diffuser to buy. They are all bumper add ons. For a diffuser to work like it should, you need a flat bottom car and roughly a 7° raise to vent. The Apr version looks promising, but still will catch air on the leading edge. Google c5r and c6r rear diffuser. Good pictures there. Most us road racers build our own.

The difference between those Ferrari's and a corvette is the bottom. The vette is about as aerodynamic as a brick.

skinnywhite

thank you VGLANTE1. would you feel comfortable sharing an photos of what you have built and how you did it?

i did get 3 PMs from engineers that were extremely detailed. helpful. scientific. but over my head a bit too.

one told me that i should have mentioned the application -- I compete in TT with N.A.S.A so I'm a road course guy. and as i said this car will have the LG motorsports splitter/wing combination

but from what i'm reading and what i've been told by people smarter than me is that what is happening under the car is just as important if not more so than what is happening on the top of the car in terms of fluid dynamics

VGLNTE1

I think under is more important as well. The 458 Ferrari makes 800 lbs of down force with just it's diffuser and flat bottom. That's zero drag. Pretty cool. My 911 turbo is also flat on bottom with naca ducts feeding the motor and trans. Better engineering than American muscle stuff. Anyway, I've yet to get into my bottom and diffuser. Still thinking. Once you block off the bottom, you need trans and diff coolers. That's what's stopping me for now. Below is the splitter I did. It's a full undertray all the way to the cross member. Granted it's a c5, but same car pretty much. It's now a front breather with a sealed off rad cover. My oil cooler is in front of my rad. I have a 416 cube Ls3 and still use the stock rad. Water temps never go above 205 even on a hot 90° track day. Pretty cool. I run a 72" kognition wing mounted to the frame. I get massive grip now, but I notice my top end suffered a ton. Used to be a 200mph car. Now it's all I can do to reach 170. Granted most tracks I go to 150 is as fast as I go, and that's road America. I know once I get into the bottom I can dial that top stuff back and have equal, or more down force and less drag. Wish fluid dynamics in college covered race Cars. Haha.

skinnywhite

VGLANT1 !!!!

that is a real race car. with a real splitter. nice. i used to be a porsche guy. had a cayman street car. a cayman track car. and a 997s

i miss that engineering and refinement. but i do enjoy the Z06 carbon more on the track.

the LS7 has been trouble-free for me. and the torque just adds flexibility and lowers lap times.

and the rotors/pads are expensive on the carbon brakes. but they are the best stoppers i've ever felt. and i've spent some time in GT3 and cup cars.

i look forward to seeing how much the LG splitter/wing combo slows the car. it is stock power. but i'm looking forward to the grip and finding out what impact it has on my laptimes. going with coilovers.

wish there was a diffuser on the market i could buy and bolt up -- but as you point out -- there's already too much heat in that center tunnel.

VGLNTE1

Thank you...it does well for an old c5 ;-) I also run the g2 LG coil overs with 700# springs front and rear. They are the best mod I've done. Amazing. Kinda thinking they should have been 800/800 though. Could stiffen up a wee more. I use Kumho v710 slicks. Love them. They have a fraction less bite than the Hoosiers, but last alot longer...for me anyway. As far as brakes I still use the stock caliper and dba rotors with some crazy pfc compound pads. I've also gutted it and ran the exhaust through the trunk in prep for the diffuser. The guys at rpm got a kick out of it.