My Side sills are burned !

Tomas

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Hello everyone

Today when I start my installation of new High flow cats to reduce the heat on the side sills I found that my side sills are burned. Inside the heat shields looks ok but outside on the sills the paint has start to bubble and crack. I also find that lots of rivets are gone and starts to come through the sills.
What to do about all this ?
Is it difficult to take away the heat shiels inside the side sills?
What is the yellow color code? What is the black color code for the sidesills?

When I now need to paint the side sills, Is it also good to find some heatpaint inside the sills to reduce heat a little more?

Anyone who has the some problems?

regards

Tomas

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Anyone who knows how to take the aluminium and heat shields away?
Just drill the rivets out? But how to put the rivets back?
341sidesill7.JPG
 

genXgts

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yep, yep, heat is not the factor there.

they yellow up when it's heat induced. I toasted them on my Blue GTS after one day at the track.

do a search and you'll find all sorts of tricks.

including POR15ing the inside of the sills, ceramic coating the inside and outside of the exhaust, including the cats.

when reinstalling the sills toss the OEM joke fasteners. Check the how to section on this site for a nifty rivet idea for the sills. I didn't get around to that on my exhaust project, I used Moroso Rim Screws, do a search for the part number if interested. Nice coarse thread and slightly oversized from OEM, perfect rebore to get the sills biting good to the car. Several on off cycles since then and not a problem personally.

good luck,
 

wcollera

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I took my side sills to get painted and my body guy said there was some rust under those bubles and that it was not from heat but poor prep work....He then went and primed it with some special porsche primer that they use in the rear bumper to help reduce the heat...not really sure of what the whole process was but sounded good to me!
 

95Viper

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The sidesills are not burned and the symptom is aluminum oxidation (corrosion) but the root cause is still heat.

The rivits are aluminum. The sills and shields are aluminum. People before talked about the rivits being another type of material and bi metal corrosion caused the problem, wrong.

The problem is that the rivits go from the outside of the sill (yellow paint is applied to the top of them in your case), through the insulation and shielding, to the inside of the sill. They actually stick out inside 1/4" or 1/2" towards the exhaust.

This means that they are completely exposed to the hottest parts of the exhaust. A lot of the rivits are fractions of inches away from the cat/muffler and pipes. Everything else has a heat shield and insulation between the hot/cold side.

During startup, the exhaust gets hot really quick. The rivits get hot first, really quick. The actual sill holes where the rivits exit, being protected by the insulation/shield are much cooler. It will take them precious minutes to heat up to match the rivit. Cool down? Same thing, outside cools first and rivits take much longer to cool down being saturated by heat in exhaust tunnel.

While all this happens, over and over again, the rivit expands and contracts with the heat, flexing the hole and breaking the paint/wax seal. Mineral deposits, salt, etc. picked up by driving, washing car, air, etc. work into area and begin breakdown. Corrosion easily works its way around hole and under paint. Bubbles begin.

Factory screws that hold sill on for my 95 **** too. Mine were black and were getting rust. Remove, flatten holes with screwdriver/punch/hammer/pliers, por15 top and bottom of hole with qtip, and buy new, silver ones used in newer Vipers.

How to fix? Drill out rivits. Strip. Drill out holes to remove ALL corroded material. It's like cancer so make sure you remove it now. Overdrill. Good bodyshop can fill holes. Paint inside with VHT, repaint. 96 or 97 Vipers went to rivitless sills and used glue so reinstall that way. Do searches because I heard of a place that specializes in this whole process. Reinstall with new silver screws, use high temp low strength sealant on screws and only tighten snug. Do not overtighten. Test first by trying one in hole with sill off and watch how quickly hole will strip. Sealant will hold screw if just snug.

Change exhaust with high flow cat or no cat.
 

dansauto

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The sidesills are not burned and the symptom is aluminum oxidation (corrosion) but the root cause is still heat.

The rivits are aluminum. The sills and shields are aluminum. People before talked about the rivits being another type of material and bi metal corrosion caused the problem, wrong.

The problem is that the rivits go from the outside of the sill (yellow paint is applied to the top of them in your case), through the insulation and shielding, to the inside of the sill. They actually stick out inside 1/4" or 1/2" towards the exhaust.

This means that they are completely exposed to the hottest parts of the exhaust. A lot of the rivits are fractions of inches away from the cat/muffler and pipes. Everything else has a heat shield and insulation between the hot/cold side.

During startup, the exhaust gets hot really quick. The rivits get hot first, really quick. The actual sill holes where the rivits exit, being protected by the insulation/shield are much cooler. It will take them precious minutes to heat up to match the rivit. Cool down? Same thing, outside cools first and rivits take much longer to cool down being saturated by heat in exhaust tunnel.

While all this happens, over and over again, the rivit expands and contracts with the heat, flexing the hole and breaking the paint/wax seal. Mineral deposits, salt, etc. picked up by driving, washing car, air, etc. work into area and begin breakdown. Corrosion easily works its way around hole and under paint. Bubbles begin.

Factory screws that hold sill on for my 95 **** too. Mine were black and were getting rust. Remove, flatten holes with screwdriver/punch/hammer/pliers, por15 top and bottom of hole with qtip, and buy new, silver ones used in newer Vipers.

How to fix? Drill out rivits. Strip. Drill out holes to remove ALL corroded material. It's like cancer so make sure you remove it now. Overdrill. Good bodyshop can fill holes. Paint inside with VHT, repaint. 96 or 97 Vipers went to rivitless sills and used glue so reinstall that way. Do searches because I heard of a place that specializes in this whole process. Reinstall with new silver screws, use high temp low strength sealant on screws and only tighten snug. Do not overtighten. Test first by trying one in hole with sill off and watch how quickly hole will strip. Sealant will hold screw if just snug.

Change exhaust with high flow cat or no cat.

Yes, but you must tig weld al back in the holes, body putty will lift, bubble and flake off. The best process is to strip the whole pc, grind out all the oxidation, tig weld the holes, sand, prime using self etching primer, seal using expoxy sealer then refinsih. I seal the inside and out to stop future corrosion.
 

95Viper

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Excellent point on the tig welding, it must be done this way and not just filled with putty.
 
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Tomas

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Hello Everyone

Now my painter has taking off old the old paint and its not looking good under the paint. The side sills have aluminum oxidation everywhere. It is lots of small holes everywhere. It is lots of work for a aluminium welder to get this good. What will new side sills cost?
 

Jeff Torrey

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Chuck Tator has replaced many of them under warrantee, including mine. They covered a percentage of the cost. So in the end it cost me $1750.00 for the set. The newer sets do not use heat shields or rivets. No problems with the new ones after 2 years and 30,000 miles.

He's out on vacation for 2 weeks.
 

John ACR

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Contact Chuck Tator when he returns from vacation.
914-763-3136
 

dansauto

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They can be fixed. I charge $1500 painted to match and guarenteed not to corrode anytime soon! It's a lot of work, as I have to grind all that out and tig weld al back in.
 

Neil - UK

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Re: My Side sills are burned !

when I had my side sills resprayed, the heat shield on one side was loose, and nearly falling off on the other side held on by a couple of tabs which looked like plastic
 

95Viper

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I heard they stopped the rivits in 96 or 97. There are still some way at the front and back holding the end pieces on but nothing like the rivits on the older ones.
 
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