Thinking about taking the plunge and getting the APR GTC-300 wing. It comes with an optional 61" or 67" wingspan both sitting at a height of 13". I was initially thinking about getting the 67" span, but now rethinking for the 61". I want to keep the car balanced and not overwhelm the rear with the giant wing. Currently only have the mugen splitter in the front. Should I go for the 61"?

-Arax

 

I think it really depends on the rest of your setup. Are you running non-staggered tire setup? What suspension are you running?

 

Tein SRCs, 225/255 on Azenis for now.

 

You can set up a 67-inch wing to have exactly the same downforce as a 60-inch wing.

The 67-inch wing will have less induced drag than the 60-inch wing, so that's good.

But it will be heavier (obviously). And it has more surface area so it has more viscous drag.

Typically wings are most efficient when the viscous drag is about the same as the induced drag. If the viscous drag is much smaller, your wingspan is too short. If the viscous drag is much bigger, your wingspan is too long.

All this is in the way of saying that you are asking the wrong question. It's not that a 67-inch wing will necessarily make too much downforce for the car. The real question is whether the wing is too long to efficiently make the amount of downforce that you want.

 

I would say the GTC-200 is sufficient for you. The GTC-300 will produce too much understeer. I run staggered 225/255 NT01 on OEM MY2003 suspension (which has stiffer rear rates and stiffer rear bar), and I am seeing high-speed understeer with the GTC-200 wing, even at my current +3-degrees angle (the center of the wing is pointed up). I'd say the GTC-300 is overkill for a staggered setup on SRCs. If you decide to go with a non-staggered setup, then I would say go with the smaller of the GTC-300 wings, or with a J's/Voltex Type 1.

Basically, your setup doesn't require too much downforce at high speed, so go with a smaller wing.