Question: Looking for opinions on mod

[killain]

How do you all think of a beefed up tunnel plate ? I've seen them from $189.00 to $299.00 Some with a heat resistant coating, some made out of steel, others made out of 1/4 aluminum. Just wondering what you folks think? I don't race or autocross the 2003 coupe. Just a nice weekend car !

 

[gmjunkie]

How do you all think of a beefed up tunnel plate ? I've seen them from $189.00 to $299.00 Some with a heat resistant coating, some made out of steel, others made out of 1/4 aluminum. Just wondering what you folks think? I don't race or autocross the 2003 coupe. Just a nice weekend car !

If it ain't broke,Don't fix it!!

 

[killain]

I hear you Gmjunkie ! Thank you, I sometimes get what's necessary confused with what desired without really thinking it through. Thanks for keeping me grounded and on track !

 

[TooFast]

If you are installing headers, do you need to replace with a different one or will the stock one work on a standard C5?

 

[TheSearcher]

Heat insulation is a definite plus. I have Kool Mats installed in my car and I no longer have a hot tunnel.

 

[njlouc]

I agree with GM junkie.
That is a very specialized part for severe chassis flex usually in a racing environment. If you noticed a difference on the highway it would be suprising. The vette coupe is already very stiff, and the vert doesnt need any extra support on the same chassis.

 

[Hib Halverson]

If you noticed a difference on the track it might even be surprising.

Not to say an aftermarket close-out plate can make a contribution to the rigidity of the car's structure, but for it to make a practical difference, 1) it needs to be on a car that's modified for increased roll stiffness and lateral grip, 2) it needs to be on a car whose drive can actually run hard enough such that the car's structure to moves enough that an aftermarket close-out plate would be useful and 3) you'd need to be a very consistent driver and accurately measure lap times to see the difference.

Keep in mind that the way the aftermarket sometimes makes money, is it will develop a product that makes a useful contribution to a car's handing in a track environment and then, to turn the product and its development into a profitable enterprise, will convince people they need it in all driving environments, ie: normal street, included.

Sometimes a mod is useful in an everyday driving situation and sometimes its not.

IMO, aftermarket close-out plates are the latter.

 

[Mr. Lucky]

As someone who has done this mod, I'll offer a different opinion. Tunnel plates do offer practical every-day advantages. They provide lateral stiffness that is lacking in stock C5s ... even FRCs/Z06s. For example, my coupe feels more solidly planted going over uneven surfaces such as RR tracks or mid-corner bumps. The car also no longer exhibits the characteristic chassis groan when turning sharply into my sloped driveway entrance. If you get one with thermal coating, it also reduces the temperature of the center console.

Now having said all this, do I think they are worth the money? NO, but they aren't worthless.

 

[Hib Halverson]

I'm curious about your statement about "stock C5s...even FRCs/Z06es" lacking "lateral stiffness". There is no such term so maybe you mean stiffness in torsion or twisting. If that's the case, when you say the car lacks torsional rigidity, can you quantify that in some way? Have you tested the car's structure? If so, what is the stiffness of the car in torsion and, since you say it lacks stiffness, what is your benchmark for a car which has adequate stiffness?

As for the "chassis groan". I also own a 2004. I've driven it at an angle, across sloped driveways which are so steep the car will lift a wheel off the ground and my chassis doesn't make noise. Perhaps this groan you hear is not really a rigidity problem but a case of something loose or rubbing somewhere.

As for the console temperature issue, there is no question that a thermally-coated close-out plate will provide a reduction in temperature. Of course, you can also add thermal insulation on the bottom of the existing plate and achieve the same result for a lot less money, but...I digress.

What I'm really interested in is some kind of understanding, from an objective standpoint, if your belief that the C5 structure is weak in torsional rigidity.

 

[catbert]

Added weight.