what do you guys think?
is it gonna kill the stainless steel like it does to mild steel(cracks,rust,corrosion)?
just want to keep the underhood temp low , its getting crazy hot in here in the summer
Don't do it. Get them ceramic coated and use a thermal barrier sheet under the intake. Jegs has 'gold' sheets. Vent your hood- scoop, vents, cowl,lift, etc.
Crap I wrapped mine a while back, so even if they dont get too wet it ruins them?
It most certainly lowered my IAT by a good 40-50 degrees over the unwrapped, this was just checked with the handheld live data scanner while cruising down the highway.
How long you think they will last? I am in Texas and it rains... oh wait... not anymore it doesnt.
Ive wrapped my borla header twice over the last eight years and it is doing great. I also put a thermal blanket around my intake manifold. Also cowl induction hood, there was a significant drop in underhood temps.
I had three cheap remote thermometers from radio shack taking various readings but cant recall the actual drop in temp.
I personally wouldnt go that route.. just dont like the idea and i can only think of what will happen with Moisture/mud/whatever trapped under there. I would (and did) go with ceramic coating...
I made a 2.5" mild steel crossover tube for a GM 6.5 Turbo Diesel, had it ceramic coated inside and out. Then used a header wrap over that, to also include the donut areas where it attached to the factory exhaust manifolds that I also had ceramic coated. I used the same ceramic coating on the exterior of the turbo housing (exhaust side) and a 3.5" mandrel bent down pipe, wrapping the downpipe and using a blanket on the turbo housing.
It worked awesome, a noticeable power increase, considerably lower under hood temps, egt's were lower due to larger mandrel bent 4" exhaust system, etc. When I pulled everything off to sell the truck, it was still in very good condition after 75k miles of hard use, including Minnesota winters (read tons of road salt and chemical).