I see you'll be at VIR tomorrow. I won't be there for the charity laps, but if you want to stick around to check out my Wasp splitter, I should be there as the gates open at 5:30PM Friday to check in for this weekend's event. You can take the bumper cover off and see how it mounts and the angle can be changed. PM to exchange numbers if interested.

 

Sounds great! I've been "getting away" with going to VIR for charity laps. As boring as it sounds I saw 120 on the back straight

Thanks for all the advice guys. These damper sensors seem like an expensive item! Cheaper to rent a wind tunnel?

I look (eye ball) at these installs of front splitters and it seems to me some of them might actually create lift + drag rather than usable downforce

 

Having a front splitter angle that is slightly raised from 0, horizontal, does not necessarily create lift. There should be enough static pressure build up from hitting the vertical wall, the bumper face and lower edge of the splitter, to overcome any pressure lift from directing air downwards under the underside of the splitter. In a full undertray design, it can actually be advantageous to lift the leading edge of the splitter to increase velocity under the car using the venturi principle.

For us grassroots guys the best way to figure out what works best is slap something together and go testing. What ever makes the car feel the best and fastest is the right way to go

 

the butt dyno has never been accurate for me I need hard data

 

I look forward to seeing you at VIR. CMP is about to feel flat and wide open :-)

If you just want to go fast and don't care how you got there, this forum has many case studies full of best practices and specialty vendors like Urge Designs that have done the research for you. I am confident most contributors in this forum will give you solid advice on setting up a fast track car.

However, based on your question and responses, you seem to be more analytical in your approach and want to know how and why your mod helps. Using best practices alone can hide this from you. They are great starting points, but the how and why is based on individual drivers, the aggregate of your mods, and the track you are driving. Thankfully, you only need one beautifully simple tool to measure the effectiveness of your splitter's AOA, or any other mod for that matter, and that's a lap timer.

The lap timer works best because. There are pros and cons to every mod (i.e., downforce vs drag), and they will each appear at different places on the track. Down force will give you faster exit speeds and drag will cost you on top end. Ultimately, you need to know if one pay for the other. Measuring top speed through an off-camber sweeping curve tells you that you increased downforce in a traction-limited section, but will it pay out when you give up 4mph to drag on the power-limited straight? It really depends on how much you add and the track. Some tracks are traction limited, some are power limited, and the fun ones have both. The only gauge that can measure the sum of the mod's pros and cons is a timer testing both variations on each track. And it's more accurate than the "butt dyno."

However, this method carries a strong caveat: be sure you are pushing your current configuration to its max limit. Otherwise, your skill is the largest variable and not the mod. Once you make the mod, you will de facto become the variable until you are able to push the new limit. In the above example, just because we have a lower speed at first due to slower straight-line speed doesn't mean we won't recover that speed as we become comfortable with and pushed our new limits in the corners.

I know it's exciting to add go-fast mods. I added Öhlins DFVs before I was able to feel my OEM coilovers working. To this day, I cannot tell you what that mod did. I know my car handles extremely well, but I cannot tell the difference between OEM and Öhlins because when I made that change, my skill was the largest variable by far - I have no real baseline for my experiment, and I really miss knowing for myself what difference the mod made.

Now that I understand and appreciate this method, I exercise a lot of discipline, and it's not easy. For example, I bought a wing and Gurney flap this winter. The wing is mounted, and I've taken the Gurney flap to two events waiting to mount it. I am now comfortable with my new downforce and got several really good laps, but my lap timer crashed, so I don't have data and didn't add the flap. I need to know what the difference is, and that requires a baseline.

If you prefer the analytical approach, my advice would be to invest in seat time not wind tunnels or fancy gauges, and only add mods as you max your current setup. Seat time in an unwieldy car at lower speed will make you a better driver, give you real data to measure the effectiveness of mods, and, for most, it's a lot more fun than reading graphs.

If you just want to go fast, or you are at max limit of your current setup now, many best practices indicate a 3-3.5" wasp splitter and APR-GTC-200 wing are solid mods that work well and offer far more pros than cons on any track. That's what I have (after 2.5 seasons without aero). Set wing to 0° AOA, and adjust as needed per track according to the lap timer results. Best practice on splitter is 1/16" lower in front measured on a flat surface regardless of track.

 

"Otherwise, your skill is the largest variable and not the mod. "

You just nailed it. I wish I was as consistent as most of the guys on here, but the truth is that Im still pretty novice and my lap times vary by as much as two seconds.

Speaking of Ohlins, I've tracked (as you know) my S at CMP at least one a year for the past 4, and go to the Dragon once or twice a year for the past 5. Adding Ohlins and getting them dialed in was an EXTREME upgrade, and worth every penny. Don't feel bad about them, they rock! I put it to a friend this way: they took a set of warn out Conti DWs and turned them into brand new star specs...there was that much added confidence.

My reason for this thread is because I want more stability through the kink (and since VIR is in the future, the climbing S's and diving into the roller coaster at VIR as well), and I know rear downforce would definitely help, but I also want to ensure the front end is planted as well.

Will, this is great advice and you're absolutely right...the biggest mod is me.

 

if you are lacking front end thru the kink if its understeering I'm pretty sure you need to adjust the balance of the car springs/bar
the kink is more about rear stability over the bumps an S2k should be just about able to go flat thru there on street tires with a decent wing

all a splitter is going to do thru the kunk is scrape the kerbs its not going to work with the right 2 wheels up in the air

 

HA! Seriously, hook the rest of us up!