APR GTC200 Setting

[CSG Mike]

Less drag, with less downforce. Are you out of options to increase front downforce and/or ways to make the rear looser?

I use a much, much larger wing than your GTC200, with a higher mount, without balance issues.

[Sleepless]

Originally Posted by Icecreamtruk

My balanced got quite a bit better after I installed canards. So if you havent done that, its a cheap and effective way of getting more front downforce, but it will cost you extra drag, so to keep that in mind.

This is not how I understand canards to work. My understanding is that drag reduction is their main purpose by causing the air flow to be smoother around the front wheels. I'm pretty sure you'd needs some seriously massive canards to actually generate any downforce.

[Sleepless]

Originally Posted by CSG Mike

Less drag, with less downforce. Are you out of options to increase front downforce and/or ways to make the rear looser?

I use a much, much larger wing than your GTC200, with a higher mount, without balance issues.

Mike, what is your current aero setup (parts only; not asking for secret tuning sauce )

Thx

[CSG Mike]

Originally Posted by Sleepless

This is not how I understand canards to work. My understanding is that drag reduction is their main purpose by causing the air flow to be smoother around the front wheels. I'm pretty sure you'd needs some seriously massive canards to actually generate any downforce.

It depends on the specific placement and design of the canard. Some can make front downforce, a different placement/design can reduce drag, and yet others can shape airflow around the car to increase rear wing efficiency. There are other effects/uses as well, but these are the most common.

[CSG Mike]

Originally Posted by Sleepless

Mike, what is your current aero setup (parts only; not asking for secret tuning sauce )

Thx

APR front lip, Trackspec hood louvers, and Voltex wing (Type 1S, 2, and 12 in rotation at the moment).

Remember there is both static and dynamic balance involved, in getting the cornering behavior you want out of a car. When one limits you, you can use the other to (somewhat) compensate/balance.

[lutfy]

Originally Posted by CSG Mike

Less drag, with less downforce. Are you out of options to increase front downforce and/or ways to make the rear looser?

I use a much, much larger wing than your GTC200, with a higher mount, without balance issues.

Mike logical step is to run down (negative AOA). Currently at -1 at full low (rod setting) and APR sent me a new shorter rod so will try -3 and ultimately -4. There is still DF at negative AOA given the 3d curve.

Lutfy

[CSG Mike]

Originally Posted by lutfy

Mike logical step is to run down (negative AOA). Currently at -1 at full low (rod setting) and APR sent me a new shorter rod so will try -3 and ultimately -4. There is still DF at negative AOA given the 3d curve.

Lutfy

There is still downforce at negative AOA, because your AOA measurement is relative to the ground, and not the plane of the airflow over/around the car, hitting your wing.

[AndyBRZ]

Originally Posted by lutfy

Mike logical step is to run down (negative AOA). Currently at -1 at full low (rod setting) and APR sent me a new shorter rod so will try -3 and ultimately -4. There is still DF at negative AOA given the 3d curve.

Lutfy

Thank you very much for posting this helpful thread.
Like you, I was missing a few MPH at the end of most tracks when comparing to before Aero BRZ in my case. Awesome on the shorty and twisty ones. After reading your thread, I have no doubt what was causing the drag. I was running 6 degrees positive AOA at the center
Really out of ignorance more than anything and basing myself in the curves I saw in the internet.
I am going to shorten the eyelets myself and go to -2 degrees AOA at the center of the wing to start with. That should suffice.
For the record, the two eyelets when threaded into the rod are too long to bottom out inside the rod and you will not get them any closer with the potential to break them. I plan to shorten all eyelet threads at least 1/4" on each end so it should give me what I need for down to -4 AOA at the center and to avoid contact between them.
Please keep us posted with your results on the different AOA at the center of it and your impression on downforce and drag.
I do have the canards and the APR front splitter along with the APR rear spats and the FT86 aggressive rear diffuser with differential covers.
Like you, I have contemplated to swap this wing for the GT250 which I know produces less drag cause I have driven on it on my buddy's BRZ but it is much more $$ and I am on a tight budget.
On the other hand, I had talked to the guys from GoodAero and I wish I had the budget to really invest with them. They are awesome and very thorough but unfortunately, cannot afford it.

[lutfy]

Originally Posted by AndyBRZ

Thank you very much for posting this helpful thread.
Like you, I was missing a few MPH at the end of most tracks when comparing to before Aero BRZ in my case. Awesome on the shorty and twisty ones. After reading your thread, I have no doubt what was causing the drag. I was running 6 degrees positive AOA at the center
Really out of ignorance more than anything and basing myself in the curves I saw in the internet.
I am going to shorten the eyelets myself and go to -2 degrees AOA at the center of the wing to start with. That should suffice.
For the record, the two eyelets when threaded into the rod are too long to bottom out inside the rod and you will not get them any closer with the potential to break them. I plan to shorten all eyelet threads at least 1/4" on each end so it should give me what I need for down to -4 AOA at the center and to avoid contact between them.
Please keep us posted with your results on the different AOA at the center of it and your impression on downforce and drag.
I do have the canards and the APR front splitter along with the APR rear spats and the FT86 aggressive rear diffuser with differential covers.
Like you, I have contemplated to swap this wing for the GT250 which I know produces less drag cause I have driven on it on my buddy's BRZ but it is much more $$ and I am on a tight budget.
On the other hand, I had talked to the guys from GoodAero and I wish I had the budget to really invest with them. They are awesome and very thorough but unfortunately, cannot afford it.

6 degrees is too much. You can eliminate the screws sandwiched between the eye bolt and the rod for more clearance. Mine would collapse all way without touching. I got shorter rods from APR and restarting from 0 AOA and going down from there.

I realized no need to get rid of the wing just find a way to adjust.

Will update with new settings soon.

Lutfy

[Icecreamtruk]

Originally Posted by lutfy

6 degrees is too much. You can eliminate the screws sandwiched between the eye bolt and the rod for more clearance. Mine would collapse all way without touching. I got shorter rods from APR and restarting from 0 AOA and going down from there.

I realized no need to get rid of the wing just find a way to adjust.

Will update with new settings soon.

Lutfy

To get back to this, I ran the wing at around 1 degree last weekend at Circuit Mont-Tremblant (high speed track, old Canadian F1 layout). The car is looser in high speed sections but not by as much as I had initially though. I gained some 3mph or so down the straight, so not huge, but car balance was way better. Comparing times to a different day with higher wing settings, newer tires, colder temps, I should have been a second slower or so, but was instead able to get within 0.1s of my best time there, so it did help I think.

I also had an offtrack excursion at 110mph, so now Im rebuilding my splitter (the rest can be left to imagination). Im going for a bigger and more robust splitter this time, trying to add front downforce instead of removing more from the rear.

[lutfy]

Originally Posted by Icecreamtruk

To get back to this, I ran the wing at around 1 degree last weekend at Circuit Mont-Tremblant (high speed track, old Canadian F1 layout). The car is looser in high speed sections but not by as much as I had initially though. I gained some 3mph or so down the straight, so not huge, but car balance was way better. Comparing times to a different day with higher wing settings, newer tires, colder temps, I should have been a second slower or so, but was instead able to get within 0.1s of my best time there, so it did help I think.

I also had an offtrack excursion at 110mph, so now Im rebuilding my splitter (the rest can be left to imagination). Im going for a bigger and more robust splitter this time, trying to add front downforce instead of removing more from the rear.

Thanks for sharing and sorry about the mishap

When you got it down to 1 degree, was your current rod height set to full low? Mine was maxxed out (low end) before I got shorter rods. Do you know your previous setting (angle) prior?

Even at fully maxxed out (low), I was facing touch of high speed understeer but rear end stability was very confidence inspiring. I could put the power down (was limited by LSD until I got that fixed) much earlier. BUT it was costing me some speed....

Lutfy

[Icecreamtruk]

Originally Posted by lutfy

Thanks for sharing and sorry about the mishap

When you got it down to 1 degree, was your current rod height set to full low? Mine was maxxed out (low end) before I got shorter rods. Do you know your previous setting (angle) prior?

Even at fully maxxed out (low), I was facing touch of high speed understeer but rear end stability was very confidence inspiring. I could put the power down (was limited by LSD until I got that fixed) much earlier. BUT it was costing me some speed....

Lutfy

It was around 5 degrees earlier (calculated from hand taken measurements), the rods can go down a bit more, probably 1 more degree or 2, but not much more. At very high speeds (well, for this kind of power at least), the car still had a touch of understeer as well but it was rotating well for most of the track. I dont think it cost me much time to be honest, I was actually gaining time vs everyone else on those sections, but was loosing time in the slowest sections of the track, during turn-in mostly, which points towards something else so I think at this angle the balance was about right for me (I do have the canards and you dont, so you probably do want less angle than me).

[lutfy]

Originally Posted by Icecreamtruk

It was around 5 degrees earlier (calculated from hand taken measurements), the rods can go down a bit more, probably 1 more degree or 2, but not much more. At very high speeds (well, for this kind of power at least), the car still had a touch of understeer as well but it was rotating well for most of the track. I dont think it cost me much time to be honest, I was actually gaining time vs everyone else on those sections, but was loosing time in the slowest sections of the track, during turn-in mostly, which points towards something else so I think at this angle the balance was about right for me (I do have the canards and you dont, so you probably do want less angle than me).

If its at the slowest part of the track, then you want to tinker with your suspension.

FWIW, I am running -3.2 front, -2.6~ rear with zero toe. I had 550/550lbs square but had to get 650lbs rear to get rid of the nasty push. Now the car is balanced (mostly and very well indeed with a touch of understeer), I was trying to gradually reduce aero (back) to gain some time and experiment.

I'll have to admit, the LSD made a fair bit of difference in my car. I had to go from almost full stiff (compression) at the back to middle setting. In the past I was using shock as a bandaid to balance but thats not the issue now.

Lutfy

[CSG Mike]

Originally Posted by Icecreamtruk

To get back to this, I ran the wing at around 1 degree last weekend at Circuit Mont-Tremblant (high speed track, old Canadian F1 layout). The car is looser in high speed sections but not by as much as I had initially though. I gained some 3mph or so down the straight, so not huge, but car balance was way better. Comparing times to a different day with higher wing settings, newer tires, colder temps, I should have been a second slower or so, but was instead able to get within 0.1s of my best time there, so it did help I think.

I also had an offtrack excursion at 110mph, so now Im rebuilding my splitter (the rest can be left to imagination). Im going for a bigger and more robust splitter this time, trying to add front downforce instead of removing more from the rear.

Remember that a splitter that is too strong will just pass in the force to other things. I prefer splitters designed to be "just enough", so that if something needs to break away or fail, to prevent other damage, the splitter goes, rather than something else.