Question for the engineers...
Thread Starter
Heel & Toe
Joined: Aug 2025
Posts: 16
Likes: 7
From: Western PA
Question for the engineers...
Assuming ideal road and weather conditions, at approximately what speed does the front splitter and the low profile rear spoiler, begin to have a noticeable effect on handling? Also, can (or should) they be added independently or in tandem?
Popular Reply
Dec 9, 2025, 08:25 AM
Pro
Joined: Sep 2018
Posts: 664
Likes: 302
From: Nova Scotia Canada
You might find this handy.
Melting Slicks
Joined: Sep 2020
Posts: 2,833
Likes: 2,151
From: Kelso, Wa
I'm no engineer and offer no elucidation but for clarification, noticeable (seat of the pants) or measurable (by instrumentation)?
I do know that generally, (not necessarily corvette wise) it's at about 40 mph that wind resistance becomes greater than mechanical drag on an automobile. That's very old info from before widespread wind tunnel optimization in the industry.
I do know that generally, (not necessarily corvette wise) it's at about 40 mph that wind resistance becomes greater than mechanical drag on an automobile. That's very old info from before widespread wind tunnel optimization in the industry.
Le Mans Master
Joined: Aug 2000
Posts: 5,529
Likes: 1,943
From: Austin Texas
Noticeable:: 60-80 MPH
Easily noticed:: 100 MPH
Hard to miss:: 120 MPH
As to together or independent::
{
a) you don't want the splitter without the spoiler over 100 MPH
b) you don't want the spoiler without the splitter in turns over 100 MPH
}
with current suspension settings {springs, shocks, ride height, wheel and tire sizes}
Easily noticed:: 100 MPH
Hard to miss:: 120 MPH
As to together or independent::
{
a) you don't want the splitter without the spoiler over 100 MPH
b) you don't want the spoiler without the splitter in turns over 100 MPH
}
with current suspension settings {springs, shocks, ride height, wheel and tire sizes}
Racer
Joined: Oct 2022
Posts: 270
Likes: 312
It's more an air dam than a splitter. It'll help both fuel economy and reduce lift by forcing air up and over (or through the grill openings) that would otherwise just go underneath the vehicle and cause lift. It's incredibly nuanced so generalities can't be really applied.
Same can be said about the spoiler. It's minor enough that really only at highway/track speeds the effect will reduce lift.
A real Wing and Splitter will be felt at almost all moving speeds and create real downforce.
Simple fact is, yes it will reduce lift at high speeds and over all help efficiency at high way speeds. Don't think about it to much unless you're tracking the vehicle. It's a cosmetic attachment more than anything.
Same can be said about the spoiler. It's minor enough that really only at highway/track speeds the effect will reduce lift.
A real Wing and Splitter will be felt at almost all moving speeds and create real downforce.
Simple fact is, yes it will reduce lift at high speeds and over all help efficiency at high way speeds. Don't think about it to much unless you're tracking the vehicle. It's a cosmetic attachment more than anything.
Melting Slicks
Joined: Jan 2006
Posts: 2,299
Likes: 1,860
From: Oregon
I would agree that somewhere over 60 mph you would begin to feel the benefits of downforce.
I say that after installing a wing and splitter on my C5. At low speeds I could not tell any difference.
From years of racing I learned: it's easy to put on a big rear wing and get downforce on the rear of the car.
The challenge is gaining an equal amount of downforce on the front.
If you only improve the rear, or upset the balance, you are going to end up with understeer, and that makes the car slower in the corners.
It is possible to have too much downforce for some tracks. You only need it in the corners.
Sonoma: all corners, the more downforce the better. Handling is everything here.
Portland PIR: long straights, need top speed, too much wing will slow you down.
I say that after installing a wing and splitter on my C5. At low speeds I could not tell any difference.
From years of racing I learned: it's easy to put on a big rear wing and get downforce on the rear of the car.
The challenge is gaining an equal amount of downforce on the front.
If you only improve the rear, or upset the balance, you are going to end up with understeer, and that makes the car slower in the corners.
It is possible to have too much downforce for some tracks. You only need it in the corners.
Sonoma: all corners, the more downforce the better. Handling is everything here.
Portland PIR: long straights, need top speed, too much wing will slow you down.
Race Director
Joined: Mar 2001
Posts: 19,954
Likes: 6,755
From: Bonneville Salt Flats
You don't need an engineer's input. Both are eye candy on the road, and good for discussions at coffee gathering. Hence, if you want only one or the other, go for it. You'll never know the difference at any speed you are ever going to drive on the street. 
Moderator
Joined: Feb 2006
Posts: 39,079
Likes: 17,935
From: DFW Area TX
The original C8 Z51 spoiler generated over 400 lbs of downforce at top speed (about 186 mph). Downforce is Downforce varies by the square of speed. So, if you cut the speed in half (93 mpg), downforce would be around 100 lbs. So, on highways in Texas at the speed limit (75-85 mph), it would be noticeable.
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Burning Brakes
Joined: Dec 2004
Posts: 967
Likes: 800
As a result, it wouldn't matter in which order they were changed.
Splitters/spoilers at non-racing speeds are simply part of the esthetics, so buy whichever ones you like best.
Racer
Joined: Jul 2025
Posts: 405
Likes: 236
From: Evansville(ish) Indiana
For my 100% street use they are purely cosmetic. If I want to play it is in the tight twisty stuff and not the high speed sweepers. It is a very unusual perspective based on the popularity of spoilers (I am an engineer, we have no taste, there is data to prove that) but to me they look hokey on a SR that is not tracked and I prefer keeping things clean in back.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,950
Likes: 12,363
From: NE South Carolina
I remember that article as it was just prior to me getting and early C7 Z51 in September 2013. The car came with a center air dam section in the hatch but the dealer was told not to install, but without a reason. In fact, the Bednarchick re "but (the air dam) also needed a removable center section for the Z51 performance option, to provide better stability at high rates of speed" did not clarify just why. That did not happen until Tadge Juechter is a presentation when the C7 Z06 came out said the increase downforce created by a large center air dam (which my C6 Z51 had) created increased downforce causing some "oversteer." We have a design criteria at GM of requiring slight "understeer" at speed! (Probably started after the Corviar and why Tadge said at the C8 intro he was "paranoid and deathly afraid" the C8 would have the oversteer of his Dad's early Porsche! He also said they did everything possible in the design to make the C8 as benign handling as possible.
SIDEBAR
Yep aero is very complex. It's NOT intuitive. Why F1 pays big bucks for Aerodynamicists, quoiting:
Ferrari recently attempted to re-hire Giuseppe Pesce, the key aerodynamics chief from McLaren, but the bid was unsuccessful. With over 20 years of experience in Formula 1, Pesce has progressed from a junior aerodynamicist at Ferrari to his current position as Director of Aerodynamics and Chief of Staff at McLaren F1. He left Ferrarifor family reasons. His wife is Britishand a doctor who would have considered moving to Italy if she could continue her profession.
Last edited by JerryU; Dec 9, 2025 at 09:38 AM.
Racer
Joined: Oct 2022
Posts: 270
Likes: 312
Here is what John Bednarchik, GMs Lead Aerodynamics Engineer said re the C7 in an article tilted, "Like a Knife:"He notes that the primary reason for refining aerodynamics on Chevrolet vehicles in general is to improve fuel efficiency, the Corvette presented added challenges. One of the big goals for the C7 was to enhance the lift performance, and we wanted the Cd [coefficient of drag] to be as low as possible.” Those are competing concerns, because as you reduce drag, lift increases. And conversely, as lift decreases and the car hunkers down, drag goes up. Balancing these two key elements more than doubled the amount of aerodynamic work, he notes. Doing so required not only developing an aero-optimized grille and air dam, but also a removable center section for the Z51 performance option, to provide better stability at high rates of speed. Bednarchik points out that 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 maximum velocity.
I remember that article as it was just prior to me getting and early C7 Z51 in September 2013. The car came with a center air dam section in the hatch but the dealer was told not to install, but without a reason. In fact, the Bednarchick re "but (the air dam) also needed a removable center section for the Z51 performance option, to provide better stability at high rates of speed" did not clarify just why. That did not happen until Tadge Juechter is a presentation when the C7 Z06 came out said the increase downforce created by a large center air dam (which my C6 Z51 had) created increased downforce causing some "oversteer." We have a design criteria at GM of requiring slight "understeer" at speed! (Probably started after the Corviar and why Tadge said at the C8 intro he was "paranoid and deathly afraid" the C8 would have the oversteer of his Dad's early Porsche! He also said they did everything possible in the design to make the C8 as benign handling as possible.
SIDEBAR
Yep aero is very complex. It's NOT intuitive. Why F1 pays big bucks for Aerodynamicists, quoiting:
Ferrari recently attempted to re-hire Giuseppe Pesce, the key aerodynamics chief from McLaren, but the bid was unsuccessful. With over 20 years of experience in Formula 1, Pesce has progressed from a junior aerodynamicist at Ferrari to his current position as Director of Aerodynamics and Chief of Staff at McLaren F1. He left Ferrarifor family reasons. His wife is Britishand a doctor who would have considered moving to Italy if she could continue her profession.
I remember that article as it was just prior to me getting and early C7 Z51 in September 2013. The car came with a center air dam section in the hatch but the dealer was told not to install, but without a reason. In fact, the Bednarchick re "but (the air dam) also needed a removable center section for the Z51 performance option, to provide better stability at high rates of speed" did not clarify just why. That did not happen until Tadge Juechter is a presentation when the C7 Z06 came out said the increase downforce created by a large center air dam (which my C6 Z51 had) created increased downforce causing some "oversteer." We have a design criteria at GM of requiring slight "understeer" at speed! (Probably started after the Corviar and why Tadge said at the C8 intro he was "paranoid and deathly afraid" the C8 would have the oversteer of his Dad's early Porsche! He also said they did everything possible in the design to make the C8 as benign handling as possible.
SIDEBAR
Yep aero is very complex. It's NOT intuitive. Why F1 pays big bucks for Aerodynamicists, quoiting:
Ferrari recently attempted to re-hire Giuseppe Pesce, the key aerodynamics chief from McLaren, but the bid was unsuccessful. With over 20 years of experience in Formula 1, Pesce has progressed from a junior aerodynamicist at Ferrari to his current position as Director of Aerodynamics and Chief of Staff at McLaren F1. He left Ferrarifor family reasons. His wife is Britishand a doctor who would have considered moving to Italy if she could continue her profession.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,950
Likes: 12,363
From: NE South Carolina
Bednarchik points out that 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 maximum velocity.
He also said the air dam in the Chevy volt was a large and deep as the Corvette to add mpg at highway speeds.
I thought his comment supplied good for the OP's question: "approximately what speed does the front splitter and the low profile rear spoiler, begin to have a noticeable effect on handling?" The answer is at high speeds well past 125 mph!
SIDEBAR (posting for the Silent Majority who won't/don't post. On this thread ~650 so far versus the <15 vocal minority who do!)
Hmm, I'm not marketing anything! Just pointed out why it took ~2 years to define why the Center Air Dam that was on the 2014 C7 was NOT on the Z51! It is subtle stuff no easy answer! Accept perhaps for folks who think they know the answer!
There was finally after 3 years a bulletin that defined where a large center air dam is and isn't used. BUT only Tadge's comment re to eliminate Oversteer at high speeds,
This is data by Paragon, a good source for reliable data including this on aero effect with speed.
Last edited by JerryU; Dec 10, 2025 at 12:00 PM.
Racer
Joined: Jul 2025
Posts: 405
Likes: 236
From: Evansville(ish) Indiana
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,950
Likes: 12,363
From: NE South Carolina
This was the best data we have from GM in an "Ask Tadge Post for the C7" and what has been documented re the C8. Note just adding the Wing in the C8 (like the C7) increased the drag coeffect ~20%. It was similar difference for what Tadge published for the C7. The Z51 front splitter probably has a much lower drag effect than the wing. Note some quote a lower value for the C8 Z51 CD closer to the C7 difference bit still ~15% higher than the Base no wing or splitter.
Last edited by JerryU; Dec 10, 2025 at 12:30 PM.