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Inside rear of door, label under the latch pin shows MM/YY. You can ask Chevy Cust Svc for the exact build date at the "Order Tracking" sticky.
Looking at this more closely, it may be that the center "air deflector" is the same for all 2014-17 Stingray, GS, and Z06 (Z51 doesn't have one). I would guess it's the same for 2018-19, too. The gap in GS and Z06 may be created by shorter left and right sections. See application chart at this reference.
If yours doesn't have one it could be the dealer just didn't install it, as I think that's done at prep time to reduce damage claims in transit. Same for side skirts and splitter, IIRC. I've seen reports here where dealers failed to install all of them on GS/Z06s.
Every GS I've seen has one, which may not be readily apparent since it is narrower and provides large gaps between it and the side air dams. I assume these gaps facilitate added cooling for brakes.
Originally Posted by JGarland
I know what I'm talking about.
The only model that has the center is the base Stingray.
Turns out the only model that for sure does not have a center air dam is the Z51! Been that way since I got mine in October 2013!
Below is a GM chart that shows the base Grand Sport and the Base Z06 have them-or at least since 2017 have them!
From GM of what models have what! I did not include the Base C7 and Z51 for clarity. But all Base cars have a center air dam and all Z51 do not!
Turns out the only model that for sure does not have a center air dam is the Z51! Been that way since I got mine in October
2013!Below is a GM chart that shows the base Grand Sport and the Base Z06 have them-or at least since 2017 have them!
From GM of what models have what! I did not include the Bse C7 and Z51 for clarity. But all Base cars have a center air dam and all Z51 do not!
Well, beside the fact that they do perform a distinct aerodynamic service at high speeds, they serve as an early warning alarm that something vital may be damaged.
As said they are a wear item, and are basically sacrificial. You won't get too many long time/high mileage C6 or C7 drivers that actually recommend removing them.
I keep my side air dams partly for the decreased Drag AND as you note they perform a "curb feeler" function.
I scraped my C6 Z51 "skid pads" (GM calls it a radiator support-it performs both functions.) That aluminum tubing scraping on pavement makes the air dam scaping sound like "Music!" It's horrible.
Intetesting. My GS is stage 1 and therefore has the center piece. I'm thinking of adding stage 2 all around and am now curious if I should remove it when I install it since it doesn't come on stage 2 cars from the factory.
Yep, and I continue to learn something every day, several things today. I can take the rest of the day off now [sounds of pop-top opening].
Do you have a GS with the standard splitter/skirt package? If not I guess that's the reason you don't have a center deflector.
Originally Posted by JerryU
I keep my side air dams partly for the decreased Drag....
I'm wondering if adding the wider side deflectors from a Stingray would decrease drag enough to justify the effort. If driven on the street the added brake cooling presumably afforded by the gaps in the GS deflectors may not be needed. Probably not justifiable but might be if I ever break one and have to replace it.
Originally Posted by JerryU
I scraped my C6 Z51 "skid pads" (GM calls it a radiator support-it performs both functions.) That aluminum tubing scraping on pavement makes the air dam scaping sound like "Music!" It's horrible.
I did that several times on my C6, too, but haven't done it once on two C7s. I think that's partly because I had to relearn basic driving skills with these cars, mostly avoiding curbs.
Intetesting. My GS is stage 1 and therefore has the center piece. I'm thinking of adding stage 2 all around and am now curious if I should remove it when I install it since it doesn't come on stage 2 cars from the factory.
Stage 1 aero on the Z06 has the center air dam also. I know the recommendation on the Z06 is to remove the center piece when changing from Stage 1 to 2 and 3.
It probably doesn't make that much difference if you are not tracking it, but if it was me, I would take it off. Probably a little more balance in regard to under-steer and over-steer at high speeds.
Last edited by joemessman; 06-20-2018 at 12:42 PM.
Thanks for the useful advice. Now I know I should jackhammer my drive way, bring in a backhoe and regrade the angle, and re-cement the drive way. Thanks again.
First, you need to get the terms corrent or it creates confusion in your question!
A Spoiler is in the rear and sticks up in the air!
An Air Dam hangs down in the front and reduces drag (a Chevy Volt and many cars have them! At high speeds, >100 mph, it also provides downforce.)
A Splitter sticks out in the front-not down, and provides downforce in the front not drag reduction.
Don't mean to sound negative many confuse these and when asking questions get funny answers.
That said, the reason for responding is I scraped my C6 center air dam every time I left my driveway! It never broke! I did drive very slowly and at a slight angle to minimize scaping. All I did in 6 years was sand off the bottom edge a few times per year. They are designed to scape and bend! It appears to me with more folks talking about it breaking on C7s that GM may be using a different plastic? Not sure if that has been changed.
Before messing with your driveway, just don't use a center air dam! At most up to 100 mph you'll get slightly less mpg on the highway-probably a few 10ths at 75 mph!
The lift issue that IMO and Tadge statement caused them to remove the center air dam on the Z51 and some Grand Sports and Z06s is a factor at 125 to 150 mph! If you're not Tracking a none issue!
Stage 1 aero on the Z06 has the center air dam also. I know the recommendation on the Z06 is to remove the center piece when changing from Stage 1 to 2 and 3.
It probably doesn't make that much difference if you are not tracking it, but if it was me, I would take it off. Probably a little more balance in regard to under-steer and over-steer at high speeds.
This is what I assumed. I' m getting stage 2 this weekeend and didn't realize the center air dam wasn't included above stage 1. I know the difference is most likely not noticeable around the street but I like knowing that its done the way it would come from the factory, the engineers did it for a reason! I will most likely remove the center air dam upon installation of stage 2.
Intetesting. My GS is stage 1 and therefore has the center piece. I'm thinking of adding stage 2 all around and am now curious if I should remove it when I install it since it doesn't come on stage 2 cars from the factory.
My take is that cars that come without the center deflector are skewed more toward track use. As Jerry and Joe already suggested, if you don't track the car it might be better to leave it installed, as it would likely provide a better CD. My thoughts were that the air dam provides some down-force at the front, but the quotes below nix that idea.
Harlan Charles (Corvette Museum) has been quoted saying that the lack of a Z51 center deflector provides more down force on the nose. It seems that if the air is allowed under the nose and then vented up and over the hood and out the side vents it allows them to put the bigger spoiler on the rear to balance it. I guess the net result is better high-speed handling. I would assume adding the full deflector package on the base Stingray decreases CD at normal street speeds and thus improves mileage. Harlan also has said that the C7 "breathes through the nose and not under the nose like the C4, C5 and partially like the C6."
All that doesn't quite make sense to me but I would never attempt to second-guess that wisdom based on the data I have on hand, which is none. Anyway, I'm confused [sound of another pop-top opening].
Since I got my 2014 Z51 in October 2013 and we were told at the last minute from actual tests GM said the Z51 would not have a center air dam BUT were not told WHY! My C6 Z51 had one so I have followed his issue very closely.
There have been a number of GM folks quoted that have said various things about the lack of a center air dam. If you follow the statemants below it becomes clear- high speed understeer versus oversteer was the main issue:
This was one of the first I read: "The GM Chief Aerodynamicist, John Bednarchik, in an article about the C7 aerodynamics published October 2, 2013 in Super Chevy magazine (about the time I got my September 2013 built Z51,) entitled “2014 Corvette C7 Stingray-Like A Knife,” stated, “While shapes for improving fuel efficiency typically begin to have an effect at highway speeds, lift and drag components become critical from 150 mph to max velocity."
I’ll come back to that word “critical,” which he used!
In another rear brake cooling was mentioned. "Some quote a GM marketing exec, saying the reason was to allow more air to reach the rear brakes. However, I searched forum comments and found this statement from that same marketing exec. A forum member posted on May 23, 2013 when he asked him at Sebring, quoting, “He further explained that this was due to the different way the Z51 package diverts the air,” The poster indicated he was puzzled with the answer! Like Bednarchik he left the details unanswered!"
“At the Bash in April 2014, Tadge said the aerodynamics is changed by the Z51's rear spoiler so the center air dam is deleted to balance the lift characteristics.”
This supports what Bednarchik was quoted as saying in the October 2, 2013 published article!
In a 2016 forum post, Tadge stated; “We have strict criteria for pitch moment. The ratio needs to be held within a fairly narrow range so that the vehicle handling remains consistent. Too much down force on the rear and the car will understeer at higher speeds. Too much on the front and the car will oversteer. We tune all our cars to maintain neutral handling biased slightly towards understeer.”
"That statement was reinforced by Tadge Juechter’s comments in 2015 about the Z06. He stated in a video, the center air dam was not used because it increased downforce excessively and resulted in Oversteer at high speeds when they require Understeer!"
The real reason comes out -it’s safety related! They no doubt did not want to give Ralph Nader info for another book! Having a modified Corvair I understand Oversteer!
IMO all statements may have "some truth" and some were "marketing speak" to not have to say the main reason was a high speed safety type issue!
Bottom Line: GM does a lot of wind tunnel testing. Tadge also said today's computational aerodynamics software gives results very close to a wind tunnel! Since computer aero simulation is cheap, they probably ran all options though their computer program and what they suggest is probably optimum-depending what you do. If you never go past ~100 mph GM's "Pitch Balamce" is probably not a big issue unless you add some aftermarket rear wing etc!
First, you need to get the terms corrent or it creates confusion in your question! Don't mean to sound negative many confuse these and when asking questions get funny answers.
Yes, thanks. I corrected myself in post #6.
Meanwhile, I too scraped my air dams on my C5 and C6 Z06's with no visible damage over years of backing out of my driveway. But the C6Z also had a hard plastic piece that I suppose acted as a splitter but was more integrated to the lines of the front bumper than are the winglets of the C7's splitter. That got pretty rough from more infrequent scraping out of shopping centers, really steep driveways, and the driveway out of Corvette Mike's shop in Anaheim, CA (shout-out). And I lightly sanded that every 6 months or so. You can see my two previous Z's here. They both had air dams (not sure if they had center air dams anymore...I don't think so, but I forget) but the C6 had that plastic piece (splitter?) under the front bumper and the C5 did not.
Anyway, instead of dealing with the center air dam of the C7, I'm thinking of leaving it off and getting a stage 2 aero in the front. Question is whether I need to make any additional changes to compensate for the aero effect (I have standard GS short rockers and a standard GS spoiler).
Unrelated to your post above-see "iclick" post #19 on this Thread and the arrow he added pointing to a center air dam!
That small pice of plastic in the above pic is NOT big enough to call or function as a splitter! If you want to see a splitter, google a current NASCAR pic (in Google or Bing Image) and see a very long splitter -they all have them-big ones!
Under 100 mph the C7 splitter has little aero effect so if you are adding for looks go for it! That is what most did on our 2014's etc. You indicated in other posts that you don't Track. GM's issue as to why they were removed from some cars is a ~150 mph issue NOT highway speeds.
Now if you want to experience slower speed Oversteer get yourself an old Corvair! I had a modified one with headers, 14 inch wide wheels/tires etc. All or the aero stuff could not change that balance at 100 mph!
You can take off your center air dam and the only effect you'll have is a few 10ths reduction in mpg at 75 mph! It you are adding a splitter to add front downforce to compensate- forget it! At 100 mph you won't feel it! If you are adding for looks as most who add splitters are doing that's fine! Just be careful of hitting things like 18 wheeler tire treads etc! Now if you're not wanting to divulge that you have a location where you exceed 150 mph that's something else!
I'm wondering if adding the wider side deflectors from a Stingray would decrease drag enough to justify the effort. If driven on the street the added brake cooling presumably afforded by the gaps in the GS deflectors may not be needed. Probably not justifiable but might be if I ever break one and have to replace it.
I did that several times on my C6, too, but haven't done it once on two C7s. I think that's partly because I had to relearn basic driving skills with these cars, mostly avoiding curbs.
The difference in size of a Z51/GS side air dam and the Base car is so small I don't think it makes a difference. If I recall, when you bought them from GM it came with a template that said "cut here" and that was for air flow to the front brakes on a Z51.
The C6 air dam was slightly lower. In my driveway is was very difficult not to scape slightly when exiting with my C6. It's hard to get mine to scape with my C7- I have to exit pretty fast!
For anyone with broken tabs on the center air dam, it might be easily fixable. The far-left tab on my GS center air dam broke about a year ago and rather than replace the part I fabricated a small piece of sheet aluminum and bolted it where the original screw was fitted. It lays over the broken plastic tab on the air dam, which has held for almost a year now. I actually think this is sturdier than the stock setup, but the other tabs could eventually break in turn. If they do I'll jury rig them the same way until they fail to hold. I can shoot a quick photo of it if anyone needs a better description. It was an easy fix with stuff I had lying around.
Originally Posted by JerryU
The C6 air dam was slightly lower. In my driveway is was very difficult not to scape slightly when exiting with my C6. It's hard to get mine to scape with my C7- I have to exit pretty fast!
Same experience here. My C6 scraped the air dam much easier than either of my C7s.
For anyone with broken tabs on the center air dam, it might be easily fixable. The far-left tab on my GS center air dam broke about a year ago and rather than replace the part I fabricated a small piece of sheet aluminum and bolted it where the original screw was fitted. It lays over the broken plastic tab on the air dam, which has held for almost a year now. I actually think this is sturdier than the stock setup, but the other tabs could eventually break in turn. If they do I'll jury rig them the same way until they fail to hold. I can shoot a quick photo of it if anyone needs a better description. It was an easy fix with stuff I had lying around.
Yup. I did the same thing when the left-most tab of my center air dam broke, but I used a piece of thick, flat, hard rubber epoxy'd across the broken tab and the main dam. That eventually broke again and dragged the next tab down, too. I think I'll employ your aluminum idea and maybe do that to all the tabs as long as the center dam is now off the car.
06-20-2018, 11:21 AM
I keep my side air dams partly for the decreased Drag AND as you note they perform a "curb feeler" function.
