Jump to content
Leeky

2017+ Facelift Spoiler - Downforce?

Recommended Posts

Hey All,

Does anyone know if the facelift 2017 spoiler has any genuine differences in downforce/drag compared to the pre-facelift spoiler?

I searched all over the net and forums but I cant find the answer to this.

Just to be clear, I’m talking about this Blue Pre-Facelift spoiler Vs this Black Facelift spoiler below.

I’d like to know if there was any genuine airflow improvements made by going to the facelift spoiler or whether they are both purely aesthetic.

And does adding the Perrin Risers to the Facelift spoiler actually increase downforce? Or again are these mainly a visual thing?

Cheers! :)

8DDB4A1B-2317-4385-9628-A3A5DDB2F977.jpeg

AB6B0AEB-BE85-4A76-8ED1-2826C6AA5341.jpeg

Share this post


Link to post
Share on other sites

As all OE parts often are overpriced, and spoilers often there are not so much to generate downforce as rather to prevent lift and to not cause lot of drag, i doubt there is much difference, especially warrantying "upgrade". Probably both do a job, but i prefer old one for one simple reason - it's easier to clean snof from car with old one :). AFAIK perrin or drambeenie 2017 risers, neither of those had any real CFD modeling or actual dowforce/drag testing done, so my bet is that it's just visual thing, to make wing-alike restyle spoiler look like aftermarket wing for cheap, by placing it higher.

Share this post


Link to post
Share on other sites

Cheers guys. So from that BRZ document there is suggestion of genuine aerodynamic qualities in the 2017+ spoiler but these seem to be compared with a car without a spoiler rather than an improvement over the earlier spoiler -

“The change to a "pedestal spoiler" design improves aerodynamic performance, stability and control over models without a spoiler, as a high-performance rear spoiler that provides more than just looks.”

”Faster airflow beneath the wing helps to generate downforce which in turn improves stability and control compared to models without a rear spoiler.“

So there doesn’t appear to be any figures that confirms the facelift spoiler is any better than the pre-facelift. Which is great as in that case I can see there being no benefit of upgrading.

However, in that case has anyone got the Maxton Spoiler extension on their pre-facelift spoiler? I’d be keen to see if anyone has noticed any downforce improvement on track with one of these.

A2FAB205-3333-4B65-AC6D-432558D304D5.jpeg

 

Share this post


Link to post
Share on other sites

Still seems bandaid, not serious aero. Imho worth going all-out with front splitter, real diffusor, gt wing (preferably if for actual use, eg. better laptimes, not just posing on streets with driving at legal speeds where extra downforce doesn't matter) .. or leave stock, not something in between. Without actual real use you won't use pros, but will get cons - you'll pay your own money to rise drag and to hurt fuel economy.

Share this post


Link to post
Share on other sites

If useful downforce would be generated, this should affect top speed. There are no separate top speed specs for cars with and without rear spoiler.

Share this post


Link to post
Share on other sites

Ok cool, thanks chaps. So ideally what i’m looking for is anyone with first hand experience/knowledge of these Maxton spoilers.

My car spends 99% of its life on track so fuel economy and looks aren’t important to me. Im really looking for any noticeable/measured improvements in downforce/aero without loading up the car with a load of expensive aftermarket parts that may not actually aid track use enough to warrant their price.

This Maxton spoiler attachment may well be stick on tat but it does have quite an aggressive angle and assuming its actually rigid it should cause some kind of airflow change (whether its a good or bad change is to be debated).

Share this post


Link to post
Share on other sites

The facelift spoiler (as on mine) is an aero design, to make the car slippery at speed, there isn't much rake if at all for downforce.  Frankly, the car doesn't go fast enough on public roads to generate any significant downforce with a wing of that size.

Share this post


Link to post
Share on other sites

Leeky: but what are your goals on track? Fun/learning, or setting competitive laptimes? For former imho no need for extensive aero, for later, worth also adding several things in addition (or imho even before) to aero parts, and those other things may impair daily usability of car. For example except lot of downforce generating aero parts even before that worth going for much stickier low thread wear slicks, much more track oriented brake setup, very stiff suspension setup with high spring rates, replacing most of bushings to less compliant poly or pillowball ones, do massive weight loss by interior stripping, deleting extra seats, A/C, stereo and alikes, adding rollcage, bucket seat and so on.

Share this post


Link to post
Share on other sites
45 minutes ago, Church said:

Leeky: but what are your goals on track? Fun/learning, or setting competitive laptimes? For former imho no need for extensive aero, for later, worth also adding several things in addition (or imho even before) to aero parts, and those other things may impair daily usability of car. For example except lot of downforce generating aero parts even before that worth going for much stickier low thread wear slicks, much more track oriented brake setup, very stiff suspension setup with high spring rates, replacing most of bushings to less compliant poly or pillowball ones, do massive weight loss by interior stripping, deleting extra seats, A/C, stereo and alikes, adding rollcage, bucket seat and so on.

Thanks for the advice but I’m an experienced circuit driver/tuner and my car is already set up to my specs. Just simply dialling out my few remaining gripes with the car and now looking for some rear downforce. What I really struggled with recently at Nurburgring and Spa was high speed cornering. The rear felt too light/numb when pushing power on through the longer/faster bends. I don't want to make any further tyre/suspension/weight distribution changes as i’m very happy with its grip/balance as it is. I currently want to improve rear feedback/feeling/confidence. What I do lack is any form of aftermarket aero; totally factory from the outside and I think with every else on the car dialled up its going to be hard to go any further with it now whilst still keep the outside looking stock.

Share this post


Link to post
Share on other sites

Something like diffuser i'd prefer even before agressive wing, as something hurting drag less. And if upping rear downforce, for balance sake i'd wish to add front splitter for front downforce too. And btw, some extra rear toe-in won't help a bit for more stable rear?

Share this post


Link to post
Share on other sites
Guest EB2429

I think you would struggle to find people with actual data apart from manufacturers due to the cost of wind tunnel testing. 

Versus in the USA seem to do some CFD simulation.  https://www.verus-engineering.com/

The diffusers from Versus look like a good solution without adding a big wing.  But the tuft test on the rear diffuser didn't seem convincing enough and its a lot of money for a car not really close enough to the ground to make full use of diffuser.

Speculation alert: The old design rear spoiler looks like it only 'spoils' the air flow as it leaves the boot to slow the flow of air, and thus reduce speed of air over the rear attempting to reduce lift a small amount. It doesn't have any noticeable angle of attack, and the leading forward edge on the boot lid looks a bit thick to really help the flow of air. The new design spoiler/wing approaches the idea differently and aims to reduce lift by the design concept mentioned (speed airflow on the under side). Neither will create down force, booth will likely reduce lift by different means and I think the newer design is likely to just be a more efficient way of doing it i.e may minimize wake.

 

(church beat me to it)

 

 

Share this post


Link to post
Share on other sites

Thanks chaps. A diffuser does sound like a good idea and there is also some stats on the Verus website about the lift reduction. I’ll certainly look into it!

Share this post


Link to post
Share on other sites
Guest EB2429

Another option

If you wanted to do something to the rear spoiler without too much adjustment you could fit a simple Gurney flap, very little drag penalty, but will reduce lift even further. Way cheaper than some of the under body verus parts and you can't go wrong with a Gurney flap, just depends on how much reduction in lift you think you may need.

STI do a Gurney flap for the older style wing.

https://www.sti.jp/en/parts/subarubrz_zc/aero/ST96010AS000/

 

 

Interesting vid @ 7:00 onwards

https://www.youtube.com/watch?v=TK8-VuwPqq4

Share this post


Link to post
Share on other sites

Very nice  I didn't realize STI did a Gurney flap. And they talk about genuine testing/results too!

"After comprehensive wind tunnel testing by STI, this product has been developed to increase downforce by rectifying air flowing over the wing surface, without increasing air resistance (CD)."

I only knew about the Perrin one which looked like it would remove its own screws after a while lol

Verus did some great analysis into the perrin gurney flap on the BRZ -

https://www.verus-engineering.com/single-post/2016/10/17/Subaru-BRZ-Perrin-Gurney-Flap-Analysis

Cheers for the tip! I'll certainly look into one of these.

A gurney flap is probably going to be ideal for me. As I have the Cosworth Exhaust that hangs low it fouls pretty much all the diffusers on the market.

Share this post


Link to post
Share on other sites

Hi all,

I have also been wondering the effectiveness of the 2017+ rear wing. I’m struggling to find a CAD model to run my own simulations with, so if anyone knows where I may be able to find this, any help would be much appreciated.

At first glance, the 2D profile in the above BRZ document looks like a wing profile so I’d hazard a guess at there being a small production of lift, rather than downforce.

(28/12/2019 19:13) EDIT: I have a 2D CFD code on my PC and in fundamentally shows it does produce downforce :) I'll have a play and see if I can extract any useful data from it...

Edited by Luke86
Updated

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×