FR-S Spoiler, functionality?
 

So I've seen plenty of chatter about the spoiler that is on the pre-facelift BRZ/86/GT-86 as equipped pretty much everywhere but the U.S., where the FR-S got its own style of spoiler that doesn't have the little strakes (for lack of a better term) on the ends like the BRZ does. I'm curious to know, after trying to dig for it on my own unsuccessfully, if anyone has any knowledge or documented proof of whether or not the FR-S spoiler has the same functionality as the BRZ one, or if it ended up being something done for aesthetics and is just in the way of otherwise good airflow?

Not looking for any eyeballed opinions, really just trying to see if there is anything out there giving any proof of a drag improvement in the same way the BRZ spoiler is stated to do. I really can't find anything other than info on the BRZ one.

The only "proof" I have seen for the BRZ spoiler came from the JDM versions which also have the under body panels, and the net effect for both combined was going from 0.29 to 0.27...

I have never seen any proof of the BRZ spoiler having positive effects in isolation (e.g. without other supporting modifications). Our US FRS cars do not have the same underbody panels (part of the cost reduction by Scion).

In any event the total effect of the pre facelift spoilers (BRZ and FRS) even with underbody panels is almost meaningless for practical purposes.

The tS wing, with proper adjustment, might be interesting on a track... but is a bit too much for my tastes as a daily driver.

Good luck - I doubt you will find much hard evidence on the FRS spoiler.

Thanks, next. I have a feeling I won't likely find info, either, and you're talking about the same situation I found when it comes to the BRZ improvements. People around here seem to find obscure stuff now and then, so I'm hoping someone may turn up with info, good/bad/otherwise. I do plan to get the underbody panels for my car, so that's what got me wondering more about whether or not the spoiler on my car is functional like the BRZ one. To me a potential .02 drop in drag coefficient is pretty significant, even if the most benefit I'll get from it is a tiny bump in fuel economy in my daily driving.

daily driving for 150+K miles .. that 0.02 drag drop gains will add up.

The best thing about the BRZ spoiler is that you can put a gurney flap on it which will generate some DF (or at least reduce aero lift). Not as much DF as a wing, but you don't get wing drag either.

The OEM rear wing is just mostly for aesthetics, the functionality of a spoiler is for down force but not effective until after a certain speed. For improved fuel economy the OEM wing and under body panels is the way to go.

Aero starts to function, as soon as air passes over the surfaces. The effect increases, roughly as a square function, so double the speed, and you get 4X the downforce. To say it does not become effective until a certain speed, is incorrect.

Spoilers don't add downforce.

And OP no one can will be able to answer your question. The OEM BRZ spoiler reduces drag and this is known because it was wind tunnel tested. There has been no testing on the FRS spoiler.

Please explain?

The OEM spoilers are flat and don't have the aggressive angle described by that picture. Adding a gurney flap would fit the picture more aptly.

Guys, there's already a thread with plenty of theory discussion in it, let's not bring that here.

To wit, @plucas, I found a thread dealing with aerodynamics that had a lot of input from you and your partner from very early on in this car's existence. By any chance would you have any info or data for the FR-S spoiler?

As for gurney flaps and such suggested above, I'm not looking to do something to add downforce and increase drag like that. I'd rather decrease drag and if I'm able to decrease some lift while I'm at it, even better.

I would just get the Velox rear diffuser then. Reduces drag and lift, I ordered mine on Sunday.


Fun fact: the OEM valence (not the $400 plastic OEM diffuser thing) reduces CD by .01, just like the BRZ spoiler and underbody panels. So in a way all 86s comes with aero =)

Which would you be referring to? And where would your reference for said fun fact be?

The Velox may happen, but may not because of something else I have planned that may make fitting that an issue. And then there's still the matter of whether or not the plastic hanging off the end of my trunk lid is doing something useful or just hangin out.

Without aero-tunnel data from toyota we'll probably won't get our hands on or at very least well made CFD simulation it will be speculation at best. If it's there, just leave it, if not, maybe it doesn't matter that much. It's just guesswork anyway. If there are no underpanels, i'd install them though even without real experimental data/measurement to back it. Streamlining underside of car works for all the other cars out there, so with very high probability on ours too.