Tunnel Support Plate
Safety Car
Joined: Sep 2007
Posts: 4,359
Likes: 6
From: Los Alamitos California
St. Jude Donor '09
Drifting
Joined: Jan 2000
Posts: 1,407
Likes: 170
From: Austin, TX, U.S.A.
I put a 3/8" ceramic coated plate on my car. I can't tell much if any difference in handling. The car stays cooler inside...for a while...but on long trips the heat eventually builds up and makes its way into the car. That being said, I've never found the cabin heat to be all that bad. Its not like a Viper.
-D
-D
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
Other than a slight reduction of cabin temperatures (when not moving), the biggest advantage of a thicker plate is to lower the center of gravity. A drawback is having to haul around the extra weight.
From an engineering standpoint it will not stiffen the chassis measureably. The mounting holes are .41 diameter and the screw is .23 and only tightened to 89 inch pounds torque. The .125 thickness is attached to six seperate .05 thick steel sheet metal angles. When you recognize the close proximity of the exhaust pipes and the fact that aluminum has an expansion rate of 3 times that of steel, you'll understand why those attachment holes, screw sizes, and torque specs exist. Thermal expansion and required assembly tolerances are the influencing factors for the heat shield that is commonly called the tunnel plate. Chassis stiffness plays no role in the design.
If one wanted to improve the design, a scoop directing cooling air around the exhaust pipes would be one direction to investigate.
From an engineering standpoint it will not stiffen the chassis measureably. The mounting holes are .41 diameter and the screw is .23 and only tightened to 89 inch pounds torque. The .125 thickness is attached to six seperate .05 thick steel sheet metal angles. When you recognize the close proximity of the exhaust pipes and the fact that aluminum has an expansion rate of 3 times that of steel, you'll understand why those attachment holes, screw sizes, and torque specs exist. Thermal expansion and required assembly tolerances are the influencing factors for the heat shield that is commonly called the tunnel plate. Chassis stiffness plays no role in the design.
If one wanted to improve the design, a scoop directing cooling air around the exhaust pipes would be one direction to investigate.
Safety Car
Joined: Nov 2007
Posts: 4,537
Likes: 1,403
From: Bethesda MD
The car stays cooler inside...for a while..
Race Director
Joined: Sep 2007
Posts: 16,557
Likes: 2,106
From: Peoria/Phoenix AZ
C6 of Year Finalist (performance mods) 2019
The thickness would have no effect on the roof, but the torque on the bolts might. If the originals had loosened (and they do) and/or the torque was excessive when the new unit was installed, then the body flex could be affected.
Safety Car
Joined: Nov 2007
Posts: 4,537
Likes: 1,403
From: Bethesda MD
I had to R&R the factory plate for my header install so they did not have the factory installed torque prior to deciding on trying the Elite plate. I don't recall the bolts being loose either when the Elite plate went in, but unless it just about fell off, I doubt any thought would have been given to it.
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Retired & lovin' it!
Joined: Mar 2005
Posts: 4,473
Likes: 547
From: Jackson NJ
Installed the Elite ceramic coated plate on my '05 Vert couple of years ago.....hard to judge if there was an actual improvement in chassis stiffness, but it feels tighter. Also, as others have noted, reduced transfer of exhaust heat into the cabin.
Race Director
Joined: Dec 2005
Posts: 11,277
Likes: 943
From: Carlsbad Ca
I have the Elite .250" plate. It's been there for 4+ years. The stock plate is .140". I noticed a slight torsional stiffness change, but now I'm used to it. I had to grind some exhaust coller material off as it rubbed while WFO.
The heat issue: It does help, but eventually, the exhaust saturates the thicker plate too. Once this is done, it'll take the plate longer to cool off as it has more mass.
Weight difference is negligable.
I talked with my trusted GM engineer, and he said the C6 is certified for crashworthiness with the standard plate installed. Any change to this may change the energies transferred during an impact. For this reason, he suggested not to mess with the stock plate. (I'd already made the change.
)
The heat issue: It does help, but eventually, the exhaust saturates the thicker plate too. Once this is done, it'll take the plate longer to cool off as it has more mass.
Weight difference is negligable.
I talked with my trusted GM engineer, and he said the C6 is certified for crashworthiness with the standard plate installed. Any change to this may change the energies transferred during an impact. For this reason, he suggested not to mess with the stock plate. (I'd already made the change.
)
Melting Slicks
Joined: Sep 2005
Posts: 2,670
Likes: 134
From: merritt island fl
C1 of Year Finalist (stock) 2019
2016 C1 of the Year Finalist
2015 C2 of the Year Finalist
I think we need to stop confusing chassis stiffness with body panel stiffness. The thicker tunnel plates will do virtually nothing to improve chassis stiffness, but they might help stiffen the body panels and reduce flexing. I'd guess most people that report "chassis stiffening" are vert owners, who don't have the body stiffening structure of the halo.
Anyway, stiffening the body panel can have positive results on the track, even if it is just because the driver FEELS more confident, not because of any structural improvement.
Anyway, stiffening the body panel can have positive results on the track, even if it is just because the driver FEELS more confident, not because of any structural improvement.
Last edited by davekp78; Jan 13, 2011 at 08:50 AM.
