Is this mod allowed ??????
 

we run a 89 fox body in stock elim n/sa . my question is with the stock fuel tank removed and a fuel cell installed in the spare tire well it leaves a big open area under the rear of the car .also we do run wheelie bars .i read on another thread that theres alot of air being caught now by the rear bumper of the car .are we allowed to block this off under the car ?or fill the bumper with foam ????
thanks rick r.

Re: Is this mod allowed ??????
 

Rick - I had an idea recently of running the factory fuel tank plastic cover along with the tank support straps for this very reason. I have no idea as of yet if it will work as intended. Sure would be nice if I had access to a wind tunnel lol.

Re: Is this mod allowed ??????
 

You might get away with it (because no one will see it) but doing modifications to affect aerodynamics is not legal. An example that people often try to do is blocking off the backside of the grille, etc. These get booted any time they are caught.

Re: Is this mod allowed ??????
 

it makes sense that that bumper is acting like a parachute . i thought of putting an empty tank there with the cover but would have to modify it for the bars same with just the plastic cover .i might try to fab up a piece that attaches to the rear floor and bends down towards the bumper dont think the car will catch to much air by this but will stop the bumper from grabbing it also make sure its removable in case its not legal i guess its time to put the reading glasses on and go through the infamous rule book thanks again

Re: Is this mod allowed ??????
 

Not really sure how you would mount the factory gas tanks plastic cover, as it is sandwiched between the stock gas tank and the mounting straps. Without the stock gas tank, there would be nothing for the cover to be held in position with.
As for how much air would get trapped behind the rear bumper cover, I don`t know, but when I had my 85 Mustangs tank out, it sure looked like a big "parachute" to me. And the 87-93GT rear bumper cover hangs further down by a considerable amount.
I would really be suprised if NHRA Tech would allow any non factory paneling or other methods of trying to smooth out aerodynamic drag.

Re: Is this mod allowed ??????
 

I believe that if you run a fuel cell the stock tank must be removed.

Re: Is this mod allowed ??????
 

Rick,

just something to look at,

consider keeping the factory tank and adding a sump area to allow only running a few gallons. Maybe add an extended pickup tube from pump to sump. Doing so also gives the option to add more fuel if some temporary ballast is needed.

Re: Is this mod allowed ??????
 

x2

Re: Is this mod allowed ??????
 

Can the fuel cell be mounted in the front of the car?

Re: Is this mod allowed ??????
 

Why use a fuel cell? Any issues with the stock tank?