Poor-sha

The one aspect of my C7 GS.R project that is very much up in the air is aero. I'm looking for a solution that has good aero balance, is ideally cost effective (splitters have a way of getting broken), and that I can actually install. I don't need to worry about parking lots, driveways, or aesthetics as my goal is simply ultimate track performance.

I've been canvasing the web and this forum to compile the options I know of and below are my notes. What I'm finding is a significant lack of detail on whether these pieces were ever tested or how they are expected to perform. There also is almost no info on what is involved in the install. Do I need the vendor to install? Is fabrication required? What other components are needed (e.g. undertray)? Finally, very few vendors seem to actually offer a balanced solution with matching front aero for the big wing. My experience with the C7 ZR1 was that it suffered from aero understeer even with the wing at the least aggressive angle. I'd like to avoid that with the GS.R project and give myself some flexibility.

So I'm starting this thread with the hope that I can get some vendor participation to fill in the gaps. I'd also like to hear from those of you that have these products and how they are performing on track.

Tikt

• Cost: $8000
• Includes frame mount and brackets but unclear what is involved in the install.
• No data on performance
• No matching front solution without their Z06 cooling system

APR

• GTC-500 wing seems to be a popular option.
• Mounts to decklid instead of frame which is something I'm unwilling to do.
• Claims to have been modeled using CFD but no data.
• Cost: $1950-$2700 for wing only.
• "Track pack" splitter is $1795 but looks to be the same as the GM stage 3 with canards.

LG Motorsports

• Cost: $2800 for GT2 wing
• Install: offer a mounting kit but no instructions online.
• No splitter option on their site
• No data provided but claims to have a racing pedigree

G-Speed

• Wing and mounts: $3900.
• Shows a CFD picture on the site but no data.
• No info on install.
• Splitter: $1000
• Requires factory stage 3 splitter as well (~$1200)
• No info on install or performance

Weapon-X
Ben has posted about making ZR1 aero available for the Z06/GS but I'm not clear where that sits. Here is what is on the web site that I could find but it all seems to be ZR1 specific.

• ZTXL splitter
  • Cost: $1500
  • Install: unclear how this would mount to a GS front bumper since it's a different shape. I'd love to get the ZR1 underwing functional.
  • Data: No data provided but claims to have used CFD. I feel the stock ZR1 aero lacked front aero grip.
• ZTXL wing
  • Cost: $3000 with brackets and spoiler replacement.
  • Data: claims to have used CFD on the enlarged version, I'm sure GM did aero testing on theirs but I wonder how much it was stylized over trying to be functional.
  • Install: I expect this would be one of the easier installs since it's just like factory. I'll have to pull the back off my 2019 GS to see if there are already holes to mount the brackets.

Faircloth Compsites
OK, not a forum vendor so if this is running afoul of the rules let me know and I'll remove it. In any case, I know they can't promote their products on the site so just including this for completeness in my notes.

• On vendor I saw with published wind tunnel testing (wing only)
• Cost: $2075 (wing only)
• No C7 wing mount shown
• No matching front splitter

lobsterroboto

Pretty much any off the shelf splitter isn't going to counter balance a 3D element.

I used LG's carbon fiber "splitter" (air dam) to cover the gap between my actual splitter and the bumper cover.

With just the LG "splitter" the car pushed really badly at COTA & again at NOLA, for NOLA I ended up using a field expedient bracket to remove some AOA (thanks Louis/GSpeed)

After that I had the splitter fabricated.

I will be adding diffuser tunnels to the splitter for some additional front downforce and then add some more AOA on the rear.

The LG wing/uprights the least amount of angle you can get is 6 degrees btw. You're unable to run 0 degrees without modifying.

The bullshit "stage whatever" aero for the GS/Z06 won't be enough to balance the car.

I've asked LG for data multiple times so I don't think they have any.

(picture below the angle makes the splitter look angled up, it's not, it's very much parallel to the ground)





Here you can see the splitter with the LG "splitter" on top.


The splitters frame was custom fabricated. The splitter itself is birch plywood, I have a template to quickly make replacements.

The wing on a wide body will be easier to install (we had to really chop up the tail lights to make it work on my car) but other than that, it was straight forward.

ETA: the LG wing has garbo end plates, I had some larger thinner ones made

AJhartmanaero makes some high quality stuff. I would second reaching out to them. I didn't want to futz around with custom uprights and stuff though in retrospect I kind of wish i had.

Mordeth

I would also reach out to AJ Hartman. https://ajhartmanaero.com/ He doesn't have a bolt-on kit for a C7 that I am aware of, but it is worth a conversation with him. He is a super cool guy, a racer that lives at the track up here in the Northeast and he thinks of aero 24/7. He designs aero for Corvettes, Mustangs, Porsche, BMW etc. I used his chassis mounted, swan neck (top) Fulcrum 14" wing on my C6Z all last year with fantastic results at the Glen and NJMP. I'm switching to his dual element Apex 12 this year. All of his stuff has data, CFD analysis available and were designed by an F1 aerodynamicist. My car is on his site under the Fulcrum wing section and C6 canards section. There are some photos there too of my car and how I mounted it.

His uprights and chassis mounts are carbon fiber and for me fit perfectly. But I bet you could have a shop fabricate some and then bolt his wing onto it for C7. He can place the mounting points wherever you want on the wing element. So you can think of the uprights and wing as separate items here if you have someone that knows what they are doing. When I installed his uprights on my C6Z it was fairly straight forward with no issues. His wings work, period, and he has data to back it. Alot of guys up this way run his aero in NASA.

Here are a few pics:







I think your challenge is the front though. It is quite easy to unbalance the car once a wing producing many, many hundreds of pounds of downforce is bolted on. I had to take extreme measures with an extended front splitter, canards, splitter rods etc..I did quite a bit of testing at various wing angles and different front aero. I also took many, many high speed pics so that I could actually see what was happening. Here is me at speed coming down the front straight of the Glen.

topmover

I use or have used a few of these vendors in the past and have nothing bad to say about any of them. However, the guys at GSpeed seem to be extremely focused and engaged on building and supporting Corvette's. I've personally observed Louis and the crew at the track and they take it seriously. I'm certain they'd be helpful.

Fernando@LGMotorsports

We'll have a new C7 tunneled splitter to the market by summer. Full bolt unit with hardware and cradle included. Install only option available now if you just can't wait- PM me for details.

Prototype below...



Fernando

LG Motorsports

LG Motorsports

Poor-sha

Really great to see Lou and LG chiming in with some more info.

village idiot

I've seen the GSpeed wing in person and it's pretty nice. The best part is they barely cut into OEM body panels.

With that said, you've basically never going to get too much front splitter/front downforce with any of these off the shelf options, especially when you add a wing. They're all relative small splitters compared to actual race splitters. The GS just pushes, a lot, even on 315F/335R tires. I'd honestly consider a splitter and no wing. I run stage 3 front and 2 rear on 315/335 tires and it definitely pushes a good bit. I'll probably drop down to stage 1 in the rear next time out. You'll probably need to lower the car (LG spindles?) to really get optimum downforce from the splitter anyway.

You need something like the LG prototype above. The other "OEM-ish" ones- I doubt they'll even make 100lbs of downforce. You seem pretty handy- why not make your own out of wood? Easy to replace, durable and etc. Most guys run splitters they can remove to get on and off trailers.

Have you considered work to the underbody to make it smoother/flatter? That's "free" downforce. It will probably even reduce drag.




TBF: I have even tire wear at the track/on track tires, which means I probably need a bit more negative camber.

lobsterroboto

FWIW Op, GSpeed will easily customize the splitter for you to get a little more meat on it.


I second village idiots thoughts on doing actual splitter first, going with a wing first was very stupid of me. Car pushed so badly.

GSpeed, LG, Dashbuilt, GRE have all done C7 splitter frames which have been great.

My only real complain is that my splitter is comparatively high off the ground even with the car on coilovers and what not. It will still just barely scrape while turning or heavy braking on an incline. They are disposable tho, get the frame built, build two. go here - https://professionalawesome.com/prod...iffusers-pair/ and buy those.
Install in one of your splitters and compare.

(AJHartmanaero also has some tunnels but pro awesome are pretty cheap just to experiment with)

mfain

WELL DESIGNED splitter tunnels make a lot of downforce, especially if the walls of the tunnels are properly positioned to shed the vortexes that are generated away from "dead end" airflow paths (the tires, for example). Rear diffusers add good downforce without significant increases in drag. Be leery of the "all-show, no-go" diffusers that diverge at too great an angle (roughly 12-15 degrees) as they will stall the air and lose downforce. I track an ACR and the wing and the very long, deep diffuser do a great job of planting the rear. The front splitter is fairly deep and when it is almost on the track with full suspension compression, it comes close to balancing the rear aero. It will sometimes push a little with the nose up when accelerating off an apex. Though not winged cars, here are a couple of interesting C7 shots with different levels of rear spoiler that show the difference in airflow at close to 180 mph. You have to look closely to see the air off the spoilers. Note the vertical angle of the air off both the spoiler and diffuser - more vertical component results in more downforce (and more drag).

Pappy

Dane@LGmotorsports

White Road Race build at Daytona a little over a year ago. Little harder to see the rooster tail on the video, it was crazy in person.

village idiot

Rooster tails are awesome to watch in person. I've wanted to modify my (mostly street) GS to have a rooster tail purely for hooligan highway purposes. I was an engineer in a former life and helped design a car with one. It was awesome just to drive behind it in the rain.

GSpeed

Hi Sean, Everyone can extend their proverbial genitalia online. We dont advertise much because the C7 platform is still in its infancy. We built very expensive, light weight carbon splitters for the C6, and guys tore them off left and right and complained about replacement cost. Our design criteria for the C7 was functional, yet cost effective. The splitters are plastic and quite heady, but to replace just the splitter itself is less than 250$. It does take a 18lb weight penalty over carbon. The other issue is that with all of the cooling for the Z06, there is no room for underbody tunnels. If you do, there is room left on the table for cooling.

Needless to say, with the C7 getting beat on track by C5s and C6s, the cost per mile to run them due to the large amount of HP and abnormally high weight (3500+), plus the cost of entry (car plus cooling, and/or brake mods) they are not popular, nor fast at the track.

Our rear wing is quite functional, minimally evasive, light weight, and can be removed in less than 5 minutes leaving nothing more than 4 holes on the lower valence.

https://gspeed.com/product/c7-corvette-wing/

Give us a call, or send us a message if we can help. We would enjoy being part of your build. We also now offer another wing style which reduces the price approximately 500$. Also bearin mind, you dont have to remove the bumper, nor cut it to install our system. This saves valuable install labor that is often overlooked.

fmcokc

Sean, I can help you obtain a full aero analysis from Simon McBeath. It was paid for something we recently discussed. Let me know if you are interested and I can make the connection.

fmcokc

Also, I would go with the GSpeed rear wing mounts. They are really strong, lightweight and easily removable.

The GSpeed front splitter does not require the Stage 3 splitter. The newer design uses the stage 1 splitter.




Here is roostertails for ya...
https://www.icloud.com/photos/#0fBOB...327CJwGivGuMDw

lobsterroboto

Oh wow I'm interested in that. I hadn't heard of simon mcBeath.

fmcokc

He wrote the book...literally

Poor-sha

I have that book! I'll send you a PM.

RapidC84B

Historically on these cars you can't make enough downforce up front to need a huge wing with a lot of angle. On our ST2 car with ACP's Splitter we only ran like 3 degrees AOA. Wing was an old Hardbar airfoil; worked well.

I like the idea of making a disposable splitter... they get destroyed eventually. I PMed you regarding wings as I'm currently in the market as well.