Thinking about getting an APR GT Wing

[E92inSG]

looking at 2 options from APR, the GT 250 and GTC 300.

They are different designs, one being a 2D "flatter" model and the GTC being a 3D model with the raised center. Which would be more effective for this track layout below (Top speed at the end of both straights around 220kmh)


Also I notice the GT and GTC have different ways of mounting to the trunk, they both mount to the outer edges of the trunk which I like but the GT seems to have mounting bases for the stands whereas the GTC stands mount directly to the trunk.

GT 250:


GTC 300:






Aesthetics wise I prefer the look of the GTC 300 3D wing but rather have the mounting bases that come with the GT 250. The reason for this is I will not be daily driving with the wing. So ease of removal would be a priority also.

I also consider the VARIS GT wing but I read somewhere that the side plates of the wing themselves should extend past the top to be really effective

VARIS GT Wing:




Would any of the APR vendors care to comment?

[TheKosherStogie]

All of the guys in Cali run the gt250. Including the time attack record holders and myself

[E92inSG]

Thanks for the reply. In your opinion, all things being equal, what would the typical drop in laptimes be on a 2m30s course with just the GT250 added?

Assuming no change in front aero (currently running a Gintani front lip with custom brake ducts)

[PrimeBMW]

I have the GTC 300 on my e46 M3 and a track buddy has the GT200. Both are good looking units and functional. The GTC300 does look pretty cool. The fit and finish is much better than other products I have seen. I would think either wing would drop a good amount of time off you lap.

[TheKosherStogie]

At WSIR I went from 1:32:8 to 1:30:9 only difference being the wing.

At buttonwillow 1:59:2 to 1:57:7 had front aero there thou.

The car understeers too much with just wing. I find you need front aero or it's a very boring drive cause the under steer

[NRBRNG]

I run the GT250 and agree the quality is great on both APR's. Run the full pedestal height as it's optimal.
For maximum benefit pair the wing with a good sized front splitter. I am not too sure of which Gintani you have, but I run the GT4 ducted.

In terms of reduced lap times- many factors play as you know,including type of track (med & fast sweeper tracks will offer the greatest aero/wing benefit- e.g. 3, 5, 6 and 13 in your above track). With my same suspension/tire set-up a I dropped 2 seconds or so from a similar track, less from ORP which has slower/tighter corners. Long high speed straights will be your enemy-having said that if they start with a fast sweeper before your entry onto the straight you will be much faster down the straight initially/longer (I only lost about 1-2 mph max straight speed on 134mph max). Again, depends on what the corner off the straight is like too.

[TheKosherStogie]

Also note I've only done 3 track days with aero. So times will come down more. Well hopefully

[MasterP]

If you're not daily driving with the wing doesn't that leave holes in the trunk?

[Billj747]

I'd go with 250. 300 is really draggy.

[Casey@RWE]

Originally Posted by Billj747

I'd go with 250. 300 is really draggy.

What Billy said. GT250 is much lower drag than the 300 and is a much better fit for the e9x platform.

We see an average drop in time of about 2 seconds with just the wing but as Kosher said, it really doesnt feel right without the splitter up front. Combined you can get ~4 seconds with the whole kit if your car is at the limits without aero.

[Wendall]

Originally Posted by Casey@RWE

What Billy said. GT250 is much lower drag than the 300 and is a much better fit for the e9x platform.

We see an average drop in time of about 2 seconds with just the wing but as Kosher said, it really doesnt feel right without the splitter up front. Combined you can get ~4 seconds with the whole kit if your car is at the limits without aero.

What about getting the GT250 61" version with 11" pedestals? Do you think that will pair well with the GTS V2 or GT4 lip?

[s85e90]

Call APR directly as they've done extensive research on these wings and I'm sure they would love to talk to you

[Casey@RWE]

Originally Posted by Wendall

What about getting the GT250 61" version with 11" pedestals? Do you think that will pair well with the GTS V2 or GT4 lip?

There's really no replacement for a proper splitter. There is however, plenty of data to show that just a wing will reduce lap times. Though as mentioned before, it will make the front feel a little lose and is always better paired with a splitter.

That said, both of the aforementioned lips will help in a small way, with a real gt4 being the second best option to a splitter. If you arent planning on getting a splitter, 250 61" out of the box with a gt4 is your best bet.

[Wendall]

Originally Posted by Casey@RWE

There's really no replacement for a proper splitter. There is however, plenty of data to show that just a wing will reduce lap times. Though as mentioned before, it will make the front feel a little lose and is always better paired with a splitter.

That said, both of the aforementioned lips will help in a small way, with a real gt4 being the second best option to a splitter. If you arent planning on getting a splitter, 250 61" out of the box with a gt4 is your best bet.

Thanks for your input. I am currently running the GTS lip and the GTS wing and i feel the car still has more downforce upfront and is a little light in the rear. Especially after ripping out the rear seats and trunk weight. So i was thinking about going bigger wing on the rear. However, my car feels pretty balanced right now. Maybe ill stick to my current configuration and increase the angle of attack at the track.

[s85e90]

Originally Posted by Wendall

Thanks for your input. I am currently running the GTS lip and the GTS wing and i feel the car still has more downforce upfront and is a little light in the rear. Especially after ripping out the rear seats and trunk weight. So i was thinking about going bigger wing on the rear. However, my car feels pretty balanced right now. Maybe ill stick to my current configuration and increase the angle of attack at the track.

Have you adjusted the attack angle of the GTS wing first?


Edit: see you mention that at bottom. That should be your first move rather than changing parts

[E92inSG]

this is the Gintani splitter i'm currently running.


square setup with 285/30/18 all round. Have more of an issue with oversteer than understeer at the momemnt which is why i'm either considering getting a GT Wing or swapping to 265/35/18 up front staggered.

I guess concensus is GT250 will definitely get me faster lap times.

No one cares to comment on the VARIS GT WING?

[TheKosherStogie]

A few people run the Varis. Seen good lap times with it as well.

If u add a proper wing u won't be oversteering but will defy understeer without front aero or some sort of adjustment at least at middle to high speeds.

Still trying to get my car sorted as it understeers at higher speed sweepers 70+ and I have the splitter.

[tom @ eas]

Big fan of our APR wing, our M3 was used in the development process since we're not far from their facility.

Here's a couple of shots from ECGP:





NRBRNG's correct, you will need a front splitter to balance out.

Got your PM, following up now.

[Billj747]

Originally Posted by TheKosherStogie

A few people run the Varis. Seen good lap times with it as well.

If u add a proper wing u won't be oversteering but will defy understeer without front aero or some sort of adjustment at least at middle to high speeds.

Still trying to get my car sorted as it understeers at higher speed sweepers 70+ and I have the splitter.

Have you tried taking some wing angle out of it to balance out the aero?

[TheKosherStogie]

Originally Posted by Billj747

Have you tried taking some wing angle out of it to balance out the aero?

Have it set completely flat. Kept lowering it the first day out. If I go with any less AOA it will look like it gives lift.
the first time I ran it at WSIR I didn't have the splitter so it was insane understeer. Then went to button willow with the addition of the splitter and the understeer was reduced, would only happen on riverside and the sweeper.
So ill have to see what happens again at WSIR but I have a feeling I already Know as I drove a buddys car similarly set up and had more understeer than I like.

Maybe need more front camber? Running -3.0 camber 0 toe and 2.2 camber 1/8 toe in rear.

Tried messing with the KWs by increasing rear dampening and the car felt snappy. Would understeer then snap a bit. Maybe Ill just soften the front a bit and see what happens

[skxf430]

Kosher,

How about softening the front sway to dial out some understeer??

[s85e90]

Originally Posted by TheKosherStogie

Have it set completely flat. Kept lowering it the first day out. If I go with any less AOA it will look like it gives lift.
the first time I ran it at WSIR I didn't have the splitter so it was insane understeer. Then went to button willow with the addition of the splitter and the understeer was reduced, would only happen on riverside and the sweeper.
So ill have to see what happens again at WSIR but I have a feeling I already Know as I drove a buddys car similarly set up and had more understeer than I like.

Maybe need more front camber? Running -3.0 camber 0 toe and 2.2 camber 1/8 toe in rear.

Tried messing with the KWs by increasing rear dampening and the car felt snappy. Would understeer then snap a bit. Maybe Ill just soften the front a bit and see what happens

try running a veryslightly negative toe. When entering a corner hot with this setup, as soon as the throttle is lifted, the car easily snap oversteers right into the turn. Really amazing what a little change makes.