Is this mod allowed ??????

rick978 · 11-13-2014, 01:47 PM

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.

HandOverFist · 11-13-2014, 02:05 PM

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.

Jim Caughlin · 11-13-2014, 02:24 PM

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.

rick978 · 11-13-2014, 02:25 PM

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

Rory McNeil · 11-13-2014, 02:30 PM

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.

Dyno · 11-13-2014, 08:13 PM

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

Dragsinger · 11-13-2014, 08:37 PM

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.

Don Anderson · 11-13-2014, 08:40 PM

Quote:

Originally Posted by dyno

i believe that if you run a fuel cell the stock tank mustbe removed.

x2

Bill Diehl · 11-13-2014, 09:34 PM

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

7423 · 11-13-2014, 10:44 PM

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

11-13-2014, 01:47 PM	#1
rick978 Junior Member Join Date: Aug 2014 Location: Methuen Ma. Posts: 30 Likes: 0 Liked 1 Time in 1 Post	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.

11-13-2014, 02:05 PM	#2
HandOverFist VIP Member Join Date: Oct 2013 Location: Gulf Breeze, FL Posts: 1,655 Likes: 8 Liked 33 Times in 16 Posts	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. __________________ Rich Taylor I/SA - 321

11-13-2014, 02:24 PM	#3
Jim Caughlin Senior Member Join Date: Mar 2002 Location: Woodburn, Or Posts: 635 Likes: 70 Liked 693 Times in 208 Posts	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.

11-13-2014, 02:25 PM	#4
rick978 Junior Member Join Date: Aug 2014 Location: Methuen Ma. Posts: 30 Likes: 0 Liked 1 Time in 1 Post	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

11-13-2014, 02:30 PM	#5
Rory McNeil VIP Member Join Date: Jun 2007 Location: from Vancouver BC Canada, now in Nova Scotia Posts: 1,257 Likes: 244 Liked 939 Times in 259 Posts	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. __________________ NHRA 6390 STK M/S 85 Mustang

11-13-2014, 08:13 PM	#6
Dyno Senior Member Join Date: Dec 2002 Posts: 870 Likes: 918 Liked 605 Times in 177 Posts	Re: Is this mod allowed ?????? I believe that if you run a fuel cell the stock tank must be removed. Last edited by Dyno; 11-15-2014 at 01:31 AM.

11-13-2014, 08:37 PM	#7
Dragsinger VIP Member Join Date: Jul 2008 Location: Liberty City [East Texas] Posts: 1,759 Likes: 5 Liked 99 Times in 60 Posts	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. __________________ Larry Woodfin 471W

11-13-2014, 09:34 PM	#9
Bill Diehl Member Join Date: Dec 2013 Posts: 311 Likes: 2 Liked 9 Times in 8 Posts	Re: Is this mod allowed ?????? Can the fuel cell be mounted in the front of the car?

11-13-2014, 10:44 PM	#10
7423 Senior Member Join Date: Dec 2006 Posts: 640 Likes: 0 Liked 1 Time in 1 Post	Re: Is this mod allowed ?????? Why use a fuel cell? Any issues with the stock tank?