Belly pans and exhaust heat.

[Kraig]

I would like to make a full belly pan for my Festiva this winter out of coroplast. What have people been doing to protect the plastic from exhaust heat?

[MetroMPG]

Dan (krousdb) just kept the exhaust exposed: cut the plastic about 1 inch away from the pipes on his Del Slow Camino, which seemed to not burst into flames as a result.

basjoos also left a gap from the plastic, and then bridged the two sides with aluminum flashing and sealed it with aluminum tape, if I'm not mistaken. His car has also failed to burst into flames.

Edit: Phil Knox' Toyota Pickup is also decidedly not on fire, and he sealed his underside with thin sheet fiberglass, if I recall correctly.

Which isn't to say that it can't happen. (If it does, please post pictures.)

I just made the front 1/3 of my undertray (coroplast ) on Sunday and stuck to a similar 1-2 inch gap (left open for now).

PS : There should be pics of both cars' bellies in the archive (if they didn't break the links due to the theimagehosting screwup).

[tomauto]

Well I would say as long as the plastic and the exhaust piping do not touch...You will be fine ...It should be safe, I mean, Honda does put there catalytic converters in the engine bay. I know for a fact that catalytic converters reach temperatures of over 800 Farenheit (just to get ''lit off'')

[krousdb]

No fires on the Del (butt ugly) Slow. On the VX I will soon be working on one and am considering the aluminum flashing and tape route that basjoos used. As an experiment, I tried to burn some coroplast with a lighter. It did catch fire but burned itself out fairly quickly. The stuff just melts and isn't really that volitile. I suggest that you try to light it on fire and observe. You may get some idea what would happen.

That being said, Im not sure that my exhaust woiuld get hot enough to ignite coroplast. The cat is on the EM and far away from where the coroplast would be. I keep forgetting to check the exhaust pipe temp when pulling into the garage after the drive home. I have an IR thermometer for that.

[SVOboy]

I kinda miss the look of the sol these days!

[Kraig]

Thanks for the replies.

[lindermant]

Using an IR thermometer, I've recorded readings no higher than 169 degrees F on the portion of the exhaust shown (hangs lowest at the front of my car just aft of the cat).



Eventually I'll get around to putting a scrap piece of coroplast up against it after a long trip to see what the effects are. I'm wondering of a strip of exhaust wrap would do the trick and allow the coroplast to snug up against it?

[krousdb]

That is great info. Coroplast won't burn at 169F, I'm quite sure about that. The exhaust tape sounds like a good idea. If you decide to do that let me know if that drops the temp further. I plan on installing my pan this week. Maybe I will go out and get some of that tape.

[lindermant]

I'm going to order some exhaust wrap from Summit today - I'll keep you posted kdb on the temp delta once I get it installed.

[lindermant]

My thermo-tec exhaust wrap came in the mail on Friday - bummer the package didn't contain the needed exhaust clamps to keep it in place... I should have it installed later this week and I'll take photos and post up when done.

kdb - I took a temperature reading this morning when I got back from work and it was 191F (the highest reading I've ever noted). Weird that it was so high with ambient temps in the low 70's

At any rate, I'll be sure to post temp readings once it's installed!

[MetroMPG]

Thanks for the update. Please keep us informed.

I just finished my full undertray this afternoon. My cat is immediately aft of the 90ish degree bend in the pipe where it comes down from the manifold and bends underneath the car.

I left an opening in the coroplast there, but enclosed everything aft of it using the basjoos aluminum bridge (TM) + tape technique.

I also have a remote temp sensor (though it only goes up to 50C) which I plan to insert into the undertray in various spots to see what's going on while I drive.