Belly Pan Danger –Belly Pan Owners Must Read

[aardvarcus]

Justme1969, yes the vehicle is still emissions legal and yes I did cover up the catalytic converter. I need to correct that. I can’t think of a good way to cut cooling holes in the .060 aluminum without removing the pan given the danger of cutting the exhaust when trying to cut the aluminum, so I will need to dismount the center pan, cut some cooling holes, and put it back. I will try to make that a project this weekend.

Elhigh, good tip on the exhaust wrap near the tank, I will look into that. I think a combination of wrap and openings for cooling will be the best benefit.

[Frank Lee]

I'm nervous about wrap; seems it leads to premature exhaust system corrosion.

[justme1969]

I would stay away from wrap also just go to u-pull it and find front wheel drive v6 cars.
Sooner or later you will find the heat shielding from exhaust laying inside car or on the ground. Im thinking late 90 early 2k buick and chev v6 had a y collector that wrapped over Trans so theres going to be plenty.

[jedi_sol]

Perhaps it might be better to just give up a little aero for the sake of safety?

Otherwise, look up Mcrew's Q45 belly pan build thread. I believed he used a mesh screen around his exahaust to still allow heat to dissipate through the mesh, but the screen also acts as an something for air to flow over. Essentially best of both worlds.

http://ecomodder.com/forum/showthrea...q45-11402.html

[mcrews]

THanks Jedi sol!!!!!!!!!!!!

on the rear pan, you will see that I also left a slot in the middle where it attached to the rear lower fender.
I think op could have done something similar to 'pull out' the air.
Since the front of the rear pan was not completely sealed, then air was able to flow thru.
Let me start my next sentence with.....I AM NOT AN EXPERT ON "MATERIAL".
But I cant really imagine that the aluminuum doesnt build up more heat than coroplast.

[mcrews]

vent from closed off space:


here is a pic of the rear vent slot

[oil pan 4]

I was searching belly pan posts several months back and found one like this, a few years ago one of our ecomodders warned about heating the gas in the gas tank, it happened on his car.
One of the reasons I have no interest in belly pans. Go air dams.

[justme1969]

I am firm believer in belly pans because when I modified the front spoiler on the POS. I lost 1.2 mpg. hiway.
These are speeds over 60mph and make up 75% of my normal use.
Most modern cars are somewhat aerodynamic in thier front FASCIA already and split the wind fairly well. Air damming forces more of air mass to go over and about remaining 3 surfaces and causes highly charged air pocket before car to enlongate and spread out.
Slice it like a knife if you doubt this take a pencil and a dinner knife and pull them through about 5" of water and observe your results. just remember the 1200 activating degrees inside the catalytic converter. I read a post somewhere that they used an over wrap cat to develop hydrogen probbably in unicorn files.

[freebeard]

Or, you know, you could drive a VW Beetle. It has the gas tank in the upper front and the exhaust in the lower rear.

[aardvarcus]

I got a chance to work on this yesterday. I popped out my engine under tray and then took the screws out of my center section. I did not see any evidence of heat around the cats or the rest of the exhaust causing issues, but trying to be safe and not sorry I went ahead and cut out the areas under the cats and other low hanging exhaust parts. This is the piece with the rectangular holes and the small circles. Next I took the previously offensive back piece and trimmed it to stop before the muffler. I then drilled holes through it with a hole saw right under the exhaust. Then I cut the areas between groups of holes out with my saw. I also tried to bend up small lips in all the aluminum holes, to keep from having sharp edges to grab road debris. I then reinstalled these pieces.

Well I drove my one hour commute to work this morning and got out and felt my gas tank. The gas tank was not hot, but it was slightly warm. I felt other areas of my cars undertray above the belly pan that I could reach, and they were slightly warm as well. The aluminum tray was slightly warm as well.

I believe that because there is warm air blowing around above the belly pan, anything that is above the pan is going to be warm. I will be checking my tank temps a few times on my drive home from work this afternoon, as I have everything I need to remove the rear pan section with me in the car.