Rocket Bunny Kit
 

Is the rocket bunny kit functional? It looks like the type of body kit that they would put on a competition car, but there are some things about it that seem like they may be a point of drag.

Those parts of the fenders that are sunk in expose the tire. Isn't that a point of drag?

If you look at the back of the fender, there is also a sunk in part. Does that have any benefits? Is it for looks? Is it not aerodynamic?

What about the rivets? Does that produce minimal drag or is the drag non-existent? Is it just for looks?

What about the wing? Im sure it produces some drag. I'm not so eager to add drag to the car since the body kit will also add weight. This car has a very low drag coefficient. I wouldn't want it to sky rocket to .37 or something like that. Is that much downforce really necessary if you only have 187 whp or so?

Are there any other functional kits? If it looks really nice and it will add a little bit of drag than obviously I would install the kit because it is a street car.

Isn't the sunk in gas cap a point of drag?

Is the diffuser or front lip a point of drag?

I watched a video about the aerodynamics of the FR-S and they said that the size and shape of the rear fenders and the tail lights play a role in the aerodynamics of the car. Will the over-fenders disrupt the tail lights' roles in aerodynamics?

IMHO It's just a showcar kit... Would be hard to track a car with huge spacers on...

but do you actually know whether or not its actually functional or if any kit are functional

You bring up good points. Compare the Rocket Bunny kit to the one used on the Super GT car (BRZ GT300):

http://www.tune86.com/sites/default/...uper_GT_02.JPG

http://www.tune86.com/sites/default/...uper_GT_07.JPG

Although this one doesn't have the original motor (it's an EJ20, pushing a lot more than 187 whp :D). I would imagine that those "sunken in" parts on the RB kit don't do a lot aerodynamically, but I'm not an engineer. They seem to have corrected it on this shell though. You don't see rivets either. The kit appears to have bypassed the taillights entirely.

There is a difference between a spoiler (whose purpose is to reduce drag and lift) and an aerodynamic wing (whose purpose is to generate downforce, and possibly reduce oversteer).

I agree with the others though. If you were looking for maximizing downforce and minimizing drag, you would be custom-making front and rear spoilers that are adjustable to weather conditions, not purchasing a mass produced kit. If you look at a lot of the cars with RB kits on them, look at their suspension setups. Probably not designed for track use in mind. Not saying that there aren't any, but it looks to be designed for appearance purposes than racing.

Any engineers on this board care to offer an opinion? :thumbup:

I think the flares are there just to make the wider/spaced out wheel not look out of place. Plenty of time attack cars have a similar wide body kit only covering the top portion. I take it all with a grain or salt but, look at F1 cars that have the majority of the tires exposed.

They're functional in the drift world, as you can stick wider tires under the fenders. The extra space in the front wheel arch also allows you to run a tighter turning radius. I'd imagine the rivets and gas cap produce no noticeable drag.

http://www.fluxauto.com/wp-content/u...frs-retaks.jpg

Like the only way to have wheels that poke out further is spacers....

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Things that make cars drift are not the same things that make cars go fast.

ya but the tires being exposed is a point of a lot of aerodynamic problems, that is why the Tyrrell P34 was developed with the smaller tires in the front to help out with that

i looked at it the same way, theres no way that lip helps any at all. it seems to scoop more air under the car then performing any splitting action

I think you're more than a little bit too worried about aerodynamics on a vehicle that you said will just be a street car anyways.

The added drag of some rivets would matter if you were a 200mph Formula 1 car -- not so much for you 50mph commute to work. The impact of CdA on acceleration operates on an exponential curve, and even with very large (+50%) differences in CdA the effect on acceleration is only appreciable as your speed approaches 100mph. For any and all driving outside of the track, you will notice virtually no difference to your acceleration barring ludicrously massive changes to your drag -- and you're not going to get that from some rivets. In fact, the added frontal area created by the widebody kit itself is probably a much larger determiner of your CdA than any minor change to the drag coefficient change itself created by the rivets or other small changes.

^^^

Exactly. Worrying about something like this is really trivial on a street car with lacking power such as the FR-S/BRZ. Even F1 cars that have highly sophisticated and sensitive aero bits that costs thousands and thousands, when damaged will relatively keep the same pace without it (I'm mainly talking about the front wing extra bits). It's been seen in countless races.

I seriously doubt the RB kit really serves much functional purpose than to widen the fenders and look nice (according to personal taste of course). RB isn't really a track race team (with the exception such as the 380SX but that's still a bit different) and with that in mind the style/philosophy isn't geared toward that anyway.

Originally Posted by Kiske
I think the flares are there just to make the wider/spaced out wheel not look out of place. Plenty of time attack cars have a similar wide body kit only covering the top portion. I take it all with a grain or salt but, look at F1 cars that have the majority of the tires exposed.


....


yeah but i read somewhere that the f1 cars are some of the least aero dynamic because they have to produce so much down force.

are there any known functional body kits?

i was considering designing my own body kit because i like the look of the frs stock, i like the five axis kit, the rb kit, the duraflex kits, and a bunch of the others that are available and i cant choose between them and some of them add drag and stuff. i figured i'd design a custom body kit and test it. like i said its a street car. if the cda goes up to .29 and it looks exactly the way i want it, i would make the sacrifice.

lol thanks OP for blurring my face on the pic... little weird but alright.

hmmm im running a rocket bunny with no spacers, problem?