Gen 3 Type 65 Coupe-R Aero Testing Report

[Sgt.Gator]

Interesting post over in the Type 65 Forum for those who don't regularly read there:

Gen 3 Type 65 Coupe-R Aero Testing Report

http://thefactoryfiveforum.com/showt...Testing-Report

[Canadian818]

Thanks for sharing, wouldn't have seen it otherwise. Interesting that the fender vents added some downforce without the wheels turning. IMO the biggest downfall to most wind tunnel testing is the wheels not spinning, as this effects everything.

[phil1734]

That and the road not moving, making all your underbody data worthless. And the tunnel they use maxes out at 85mph (45mph for using the smoke wand.)

Glad that they are finally acknowledging these shortcomings though. It seemed to me that with the 818 tests they were immediately on the defensive that their tunnel tests were perfect and the data flawless. I still get a chuckle every time someone someone references it and asserts that the rocker extensions do nothing but add drag. Apparently these guys must know something they don't:
Ford-GT-racing-Chevrolet-Corvette-C7R-at-Daytona.jpg

If FFR really wanted to drop some coin they could buy time at Windshear, but last I checked there's a waiting list, it runs about $3/second, and you need to make your own wheel retention system.

[EODTech87]

Always a good time when watching Formula 1 and they talk about the multi million dollar piece of carbon fiber that they spent months developing. Then a few laps later they break a piece of it off and actually go faster because their wind tunnel results aren't always the most accurate and they ignore a whole lot of variables.

[Canadian818]

Always a good time when watching Formula 1 and they talk about the multi million dollar piece of carbon fiber that they spent months developing. Then a few laps later they break a piece of it off and actually go faster because their wind tunnel results aren't always the most accurate and they ignore a whole lot of variables.

I remember Vettel loosing an end plate back in his red bull days and lap times were unaffected, the commentator kept going on about it. This is why they still do on track aero testing with those funny looking tube arm setups. Not sure if they still use the flo-vis paint stuff, but that's neat, I wonder if there's a good DIY version.

I believe the 818 rocket pieces added some lift but lowered drag on their tests. Definitely not a definitive test, but imo they're very different than the skirts pictured above as they don't protrude down at all.

[RetroRacing]

We are extending the rocker lip down to prevent "spilling" out of the side of the car when we need it to go down the length of the car through the diffuser.

[Mark Dougherty]

when extending the sides down
be careful
we are using the race height setup and john has hit the frame on the pavement
so make sure there is room for flex

[phil1734]

I remember Vettel loosing an end plate back in his red bull days and lap times were unaffected, the commentator kept going on about it. This is why they still do on track aero testing with those funny looking tube arm setups. Not sure if they still use the flo-vis paint stuff, but that's neat, I wonder if there's a good DIY version.

I believe the 818 rocket pieces added some lift but lowered drag on their tests. Definitely not a definitive test, but imo they're very different than the skirts pictured above as they don't protrude down at all.

The funny tubes are kiel probes. Similar, but just different enough from a pitot tube to earn it's own special name.
CIQb8jYWUAEiSf_.jpg

Flow-viz is still used, almost exclusively on open wheel cars and only as a last ditch effort to understand why something isn't working the way it should. The problem is that it doesn't provide any quantifiable data, and if you can see it, so can the team next to you. It is very handy though for finding high and low pressure areas of a car should you ever need/want to add a scoop or duct to your AAIC, Oil Cooler or anything else. I prefer to use a combination of road dirt, brake dust and a quiet street that has just been rained on - though more technical and pricey solutions do certainly exist.

[Sgt.Gator]

There are DIY versions of Flow-Viz available. But like Phil said , they only tell you what the flow next to the car skin is doing. I prefer to use the wool tufts method. I've found some very interesting things with them.
Here on my STI the wool that should be flowing into the radiator is flowing sideways left, sideways right, and sometimes backwards!
..

So then I taped up the OEM hood scoop TMIC intake and the flow thru the radiator was perfect:



Then I put the wool on my rear window. As expected the flow bent around the rear pillars and angled across. What surprised me was the flow meets in the middle and flows backwards up the window!!!!



I haven't re-run the test now that I have vortex generators above the window. Soon.