Anyone has this diffuser? Other than cosmetic looks does it do anything functional?
 

In theory
 

frankly it will be for looks far more than function unless she really gets pushed on a track/race day. Being a poor recently retired school teacher
I bought a set of individual diffusers fins and had them installed. Looks great and came to a grand total of about 325 bucks installed.....

My Difflow:
No drilling, uses OEM attachment points.

https://cimg8.ibsrv.net/gimg/www.cor...9cfe742049.jpg
https://cimg9.ibsrv.net/gimg/www.cor...c043c11579.jpg

virtually zero functional improvement. Looks only.

Simple answer... no... and no. It does nothing but add needless weight while pleasing the eye of some. Your call. :yesnod:

See top post "OP" for link, prices, under body construction.
Whooppsss. I see you are the OP. your link has the info.

:iagree: Sums it up.

Diffusers don't do anything unless they're super low to the ground. You'd have to lower your car by a lot.

Wow
I'm quite impressed by the number of forum members who have access to wind tunnels
and have tested this diffuser to definitively state that it provides no functional improvement.. :lurk:

Mechanical engineer
Formerly worked in motorsports (as an engineer)
Also designed components for turbine engines (which is a lot of fluid flow, obviously)
Used wind tunnels plenty (school and work)
Have cars with (real aero)

It's not a magic crap shoot. It's a pretty well understood principle of fluid dynamics.

To say it "doesn't work" is a little bit of a misnomer imo.

It has an under tray from the rear axle to the rear of the car. This will help with the low pressure air moving under the car.

With that said, I do have a revised "track version" of their diffuser that im more or less beta testing, the fences are longer and taller My car is fairly low and coupled with the taller fences I imagine it may be a little bit functional.

https://cimg2.ibsrv.net/gimg/www.cor...e38eeadcd.jpeg
https://cimg3.ibsrv.net/gimg/www.cor...4a64b92ad.jpeg

If it uses OE attachment points and only takes 20 min to install for the first time, it's a safe bet that it's not doing much. Any diffuser that provides meaningful downforce would rip the rear bumper off the car if it was only attached how the factory "lower bumper fascia" is attached.

Just like most "diffusers" on the market today, few are more functional than helping to win a trophy at your local cars and coffee shows.

A diffuser isn't localized downforce, This diffuser isn't going to be ripped off of the subframe mounts this thing uses. It does exactly what it sounds like... Diffuses the air leaving the underside of the car. . So low pressure under the car increases and high pressure above the car does (not above the diffuser as it's not a wing)


The size of the venturi tunnels very much matters and some differs are a lot more effective than others and theirs not a whole lot but still v0v

There are tons of compsosite race splitters (RHR for example) would be much more effective and you're required to custom mount that diffuser on your car, with that one I would use the same attachment points that I am.


Oh and as far as the Op, you wouldn't notice anything. the amount of downforce it would create could mroe than likely be calculated by the pound not by hundreds of pounds and unless you're consistently at the limit of your car and can tell when your car is porpoising and your aerodynamic grip fluctuates mid corner you're not gonna be able to tell.

hell, the silver car up there with the louvers on the windows looks like it would reduce the effectiveness of the spoiler and would have a net loss of downforce.

The only possible benefit would be at very high speeds on tracks with long straights. It does nothing for you in street use unless you're just interested in looking "bad ass" and/or going to jail.

It's about as useful as the front splitter or anything else that is added onto the car. Which is no difference at all. If you like the looks buy it and put it on the car. Looks great to me!

lol wut?

Im assuming you mean "What"?

Long way to say it does nothing for performance. Other than add weight which is a downfall. If you like it. Buy one and install it.

I think it will add about ten pounds of downforce!

I've worked with a few race cars that actually have down force producing devices on them. One of the main reasons for using a diffuser is to help activate the rear wing. But in order for it to work ramp angles and distance to the road surface all need to be at optimum to work. This one isn't even close. I've never seen a diffuser that was worth anything have flat horizontal surfaces, they're all curved like the bottom side of a wing (on a car). And they won't do squat below at least 60 Mph. And they won't do squat without airflow either.

If you're going to test it you need some specialized equipment such as pressure taps, and at minimum ride height sensors at all four corners. Load cells would be better. All hooked up to a decent data acquisition unit.

The "stage1" splitter is for looks but the Stage 3 GM splitter does work, it's not incredibly functional but along with the stage 3 spoiler there is actual data supporting the additional downforce.

Wings and splitters and diffusers have quantifiable results. Some more than others. To say that adding aero components doesn't give you a benefit is weird. There are tons of things you can stick on a car to make them better.

Aerodynamic grip isn't a thing you can just not believe in. It's a real thing.

At COTA T16/17/18 I'm carrying 7.3mph more through there with a wing than without.

Same for T19 and virtually any high speed corner. Some corners I couldn't take flat before I can now.

now will it add any performance for the op? not if he doesn't go to the track I suppose.