I’m just happy to see someone keeping the camera out of the airstream. My inner aero nerd self can’t put a camera there. Even at my snails pace in 206 I like to think the aero is doing its thing and a giant camera is a huge disruption to that.
I noticed at BATB people doing all manner of trickery such as $250 M7 nassau panels and metal rear bumpers over plastic ones, all supposedly to reduce drag yet they missed the glaring elephant in the room, namely a full length floor tray. Nothing in the rules say you can’t run a full floor at events I’ve run and we even did it in 125 gearbox when I ran on road (car) circuits.
I’ve never had the facility to do a full aero study but a floor is almost certainly a larger reducer in turbulence than an M7 nassau panel and metal bumper combined.
Is there any way to quantify this without a wind tunnel and computers?
Best real world testing is just a coast down test. Throw on different fairing. Get up to a set speed, let off the throttle in the same hopefully flat spot on a straight, and coast down to a set speed. Then you need to check traces on your data sets. Not sure how accurate/precise a Mychron or Alfonso is for gps speeds. Wheel speed sensor would be preferred.
Interesting, thanks.
Some info here on coast down and CFD tests for CIK karts… not M7 specifically though. (Looks like I posted it further up… but we’ve got some recent uptick in the topic)
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James, Interesting reads. Looks like the coast downs and accelerations runs are just for validating CFD. No swapping of bodywork. I’m not a facebook guy, was there any results from the 206 NCMP guys?
I know a couple of people who have run full length trays at bigger events recently so there are people doing it. I’ve also seen executions of it where the trays are mounted too soundly to the full chassis causing it not to want to flex properly so you have to be careful with the execution of said aero device.
Coming to a supernats near you?
Has anyone tried a semi-rigid material? It doesn’t need to structurally support anything right? Wouldn’t a material that bends slightly work, assuming it’s rigid enough to not sag or flex too much.
I’ve seen people toying around with them locally. One was even trying to build a diffuser, but I believe the airflow to the floor is just not adequate and the available real estate to build a proper diffuser will not work. That being said a full length floor supposedly made a difference. I believe it’s legal in WKA and USPKS, but SKUSA has wording prohibiting full length floors. Trying to get the floor sealed to the chassis frame rails to avoid air leaking and not increasing rigidity is key.
I’ll post pictures of my experiment. ABS plastic and zip ties will be my attachment method to ensure I don’t alter the chassis rigidity.
I was wondering if you could use rubber or plastic “P” clips to suspend the floor without being a very rigid attachment, especially around the seat and rear of the chasis where there are no attachment points. Wouldn’t take much to catch a ziptie and rip it off.
Honestly, I have a huge skepticism on front Nassau aero for karts.
If there was a significant difference, you’d see changes in the other body parts in the kart to take advantage of that airflow. Once the airflow goes over the front nose and bumper, there are so many gaps in the bodywork and seals that it’s just a giant mess. (Plus there is that annoying driver and other things that wind flows over.
Also, I honestly, think that if it really mattered you either see a huge convergence of aero philosophies on aero kits, or SOMEONE would have spent a huge amount of money to do some proper aero testing of a kart in a wind-tunnel for funizes.
Karts are largely mechanically gripped machines. I’d find way more time properly getting a good balance and powerful engine, rather than a nose piece that is typically poorly aligned.
Easy test would just be to either run without one on a test day, or just cover it all up in tape, or something silly to disrupt the airflow and see if you notice a big change in your data down the straights.
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You’re right. But multiple attachment points. And 070 abs is plenty rigid but still flexible
I will agree several kits are very poorly aligned. I spent a good amount of time ensuring alignment was solid and the panels sealed together as good as possible. The main reason I agree with the Nassau at least having some play is the dynamica and the m7 both focus on getting air around the driver.
The dynamica was supposedly developed in a wind tunnel. And from my limited learnings in CFD I still see where some improvements could be made. For me the aero stuff is just because I have such an interest in cfd development.
But being ‘developed in a wind tunnel’ and ‘actually working’ are two different things.
I could develop a sandwich in a windtunnel, if I wanted.
Like I said, want an easy answer? Take off the Nassau and run without it. If it did anything significant, you’d notice immediately
And we’re back. 
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slow claps 
(20 char)
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So is a kart still a kart if there’s any sort of downforce?