Carter Customs C2 rear race diffuser

[vetracer]

I just installed the Carter Customs rear race diffuser on my S197 2011 GT track day car. First I had to move the vapor canister to the upper side of the wheel well. It sits in the well nicely but takes some plumbing to connect everything up. The diffuser is a well made unit even though its a little heavier than I would have liked. The one issue I had was that it did not come with installation instructions. It took a little time to figure out but I able to install it without too much effort. The problem I had with the design is that the forward edge of the diffuser ends at the mid point of of the wheel well. The wheel well has a large convex center section when looking from the bottom so there is a large gap between the diffuser and the wheel well floor. At speed this gap would create turbulence just as the air enters the diffuser where you want clean air flow. I addressed the problem by making a plate that enclosed the wheel well area so the air flow goes over a flat surface before entering the diffuser. See photos below. I had to limit width to clear exhaust. I'm hoping in conjunction with the Steeda wing the rear will feel more planted on high speed corner entry. I'm running at Homestead in February so I'll report back on how it works.

 

[Vettel-ish]

$425 is not bad, any proof it works?

How about if you have a rear spoiler?

 

[vetracer]

$425 is not bad, any proof it works?

How about if you have a rear spoiler?

I have no hard proof it works. I won't know until I go to track in a few weeks. Even then results will be seat of pants as opposed to solid technical measurements. Totally absurd observation but when I drove car on street and returned to my garage rear bumper and trunk area which normally picks up lots of dust when driven was surprisingly dust free. Kona Blue shows every bit of dust. When I wiped off trunk area before putting car cover back on there was very little dust on micro towel. Diffuser must be doing something. I have a Steeda rear wing which I hope will work in conjunction with the diffuser to add grip on high speed corner entry. As for a spoiler, I'm not sure the diffuser will help because of the large negative pressure and turbulance created at the rear of the car if the diffuser is of any meaningful height.

 

[Bill Pemberton]

Heh, Larry , if nothing else I bet it is an effective intimidation tool, ha! Remember when your fellow Mustang drivers ask you about it, or even better yet Camaro drivers, the proper " Smack Talk " is that you dropped 2 seconds with the increased downforce and the car is much more stable. Okay, a little poetic license, but it may make them move over when they see you in their mirrors, ha.

 

[vetracer]

Heh, Larry , if nothing else I bet it is an effective intimidation tool, ha! Remember when your fellow Mustang drivers ask you about it, or even better yet Camaro drivers, the proper " Smack Talk " is that you dropped 2 seconds with the increased downforce and the car is much more stable. Okay, a little poetic license, but it may make them move over when they see you in their mirrors, ha.

Bill. If anything diffuser is a good shield to hide my flux capacitor mounted under trunk floor. My secret weapon for passing \*_*/

 

[Bill Pemberton]

........or it can throw clagg back at your competitors who are following too close!

 

[stevbd]

As for a spoiler, I'm not sure the diffuser will help because of the large negative pressure and turbulance created at the rear of the car if the diffuser is of any meaningful height.

I'm sorry, I don't follow what you mean here?

Nice work, I think your diffuser looks promising!

 

[Bill Pemberton]

What he is saying is the massive airborne turbulence caused by the oscillating vanes of molecules in the lower atmosphere coupled with the downforce whipping of dirt, sand and clagg from the track formulates a tornadic wave of air movement causing unknown forces of pulsating vents of aeration, sucking the vortexes in a manner not always conducive with the freshening of ventilation to the underside of the vehicle unless on a downward spiraling off camber turn - I think?!

 

[EF1]

I have looked at the Carter's Custom products a couple of times but haven't decided to bite yet. Has anyone tried their front splitters?

 

[vetracer]

I'm sorry, I don't follow what you mean here?

Nice work, I think your diffuser looks promising!

Whoops. What I meant to say was if the SPOILER was of any significant height.

 

[steeda5]

I have one of there front splitters on my SN 95 race car. Mounted to a 03 cobra front bumper. Fit was amazing. I had great results with mine.

 

[Ewheels]

The price point has me very interested but the lack of CFD data and the ABS plastic construction has me concerned. Will it warp at higher speeds??

Very curious how your track event goes. If you notice a difference, I may buy as well.

 

[vetracer]

The price point has me very interested but the lack of CFD data and the ABS plastic construction has me concerned. Will it warp at higher speeds??

Very curious how your track event goes. If you notice a difference, I may buy as well.

The diffuser is made of a composite, aluminum surfaces separated by abs plastic. It's pretty solidly constructed. I doubt if it will move at speed. CFD data would be nice but no small manufacturer can afford it. If they dis CFD price would be much higher. Sometimes you just have to go with your gut and take a chance.

 

[Ewheels]

The diffuser is made of a composite, aluminum surfaces separated by abs plastic. It's pretty solidly constructed. I doubt if it will move at speed. CFD data would be nice but no small manufacturer can afford it. If they dis CFD price would be much higher. Sometimes you just have to go with your gut and take a chance.

Fair point.

You mentioned it was heavy - did you weigh it by chance?

 

[RES_22]

An option is Verus Engineering piece...

Eric has a solid crew over there at Verus.

 

[vetracer]

Fair point.

You mentioned it was heavy - did you weigh it by chance?

No I didn't weigh it. Here is link to material

https://www.piedmontplastics.com/resources/literatures/piedmont-sign-gradeR-alupolyR

.240" thick weighs 1.38 lbs/sq ft. If I had to guess I'd say whole assy weighed 12 lbs.

 

[vetracer]

An option is Verus Engineering piece...

Eric has a solid crew over there at Verus.

I looked at their site. They only have a diffuser for an S550 and it looks more for decoration than for function.

 

[mavisky]

I looked at their site. They only have a diffuser for an S550 and it looks more for decoration than for function.

I have one. Solid unit. Closes off the back bumper very well, but is more for drag reduction than actual downforce. Due to the diff cooler and rear bumper, it's impossible to get much of an upsweep without extending beyond the bumper or cutting into the lower valance. I still scrape it every once in a while, but luckily the aluminum it's constructed from is pretty sturdy.