cooked a side sill

**stuntman** · 07-06-2015

www.Heatshieldproducts.com has all of their technical data & MSDS of all their products on their website. If you have further questions, email them and the owner (whose an engineer) will surely answer and help you out.

I have not asked HP yet, but i'm skeptical on wrapping, ceramic coating, or insulating cats in general. I used Heatshield Armor on the pipes before and after the cars and used HP StickyShield on the chassis & side sill side of the uncovered HighFlow Cat. I plan on eventually removing all of the factory heat shielding both on the chassis and side sill and replacing it with HP StickyShield.

FYI the biosoluable silica insulation in HeatShield Armor is rated to 1,800*F continuous & 2,200*F intermittent, which (other than covering the cat) should withstand most any FI application; while the Aluminum side on the outside of the insulation is rated for 900*F. It reduces radiant heat by 70%. After a quick drive, I used an infrared gun and shot the bare exhaust and got 260*F, and the HeatShield Armor registered at 120*F -this was near the rear diff. I will post a full review in the near future.

The HP StickyShield is rated for 1,100*F continuous & 2,000*F intermittent and reflects 90% of radiant heat when given a <1" air gap (which my HFC have).

**dave6666** · 07-07-2015

All this hi-tech and expensive insulation but the most effective fix of all is free. lol.

**daveg** · 07-07-2015

Also, it appears he has an issue on one side and that needs to be resolved first.

**Sybil TF** · 07-07-2015

My stock cats had a load of black crap that came out when we replaced them. Replaced with hi-flows. 2 years later went catless and the hi-flows had a considerable amount a black crap that dumped out if you shook it...

**stuntman** · 07-07-2015

Increasing air flow and venting is huge, but for those like me who don't want to punch homes through their side skirts or buy replacements to put holes in and then have to paint them, good insulation is an effective option.

**uvbnbit** · 07-11-2015

Band clamp after cat is bit loose. But, couldn't say if heat caused loose or loose caused heat. I had few weeks prior went through all and checked clamps while I had sills off checking for leaks. Looks like hottest area was at front of resonator?
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The last pic shows crack in heat shield same spot as most burnt area, there again, caused by heat or vise versa...

**dave6666** · 07-11-2015

I took this pic about a month ago for Lou Belanger when he was setting me up with parts to build another set of side pipes. I noticed the identical pattern.

**Glen97** · 07-11-2015

I had a hi flow cat fail on the right side of my 97 gts. It ended up being a bad up stream 02 sensor.

**uvbnbit** · 07-11-2015

Did some idling diagnostics. Sill off of course. Temps at bend at front of sill, 185, cat 385-422, front of resonator 285. All after about 10 min idle. O2 voltage looked good, STFT, LTFT seem ok too. Fuel pressure key on, engine off 50psi, 46 psi after 8 mins? Injectors all clicking consistent. Exhaust seems equal at tips. Will try some drive time readings later...thanks for replies. Leaning towards the slow, 1hr, idle parade with no air flow as culprit, but will be modding sills for more flow. Not capable of designs like Dave, but vents front and back gotta help..

**WDW MKR** · 07-11-2015

The SpeedTactics sill vents are nice. Easy to install and they blend well.

http://www.speedtactics.com/dodge_viper_gill.php

**challenger** · 07-11-2015

Here's what I did for vents. I used leaf guard gutter stuff to make them.IMG_8049.jpg IMG_8051.jpg

**dave6666** · 07-11-2015

Looks good, but put the pretty side of the rivets to the outside?

**challenger** · 07-11-2015

Originally Posted by dave6666

Looks good, but put the pretty side of the rivets to the outside?

they are allen head bolts. I just finished this today.I might paint them black in front and red in the back??

**stuntman** · 07-12-2015

Your resonators look a bit toasty. I'm a bit surprised they look worse than the HFC and that the heat damage is that far back.

**uvbnbit** · 07-13-2015

Originally Posted by stuntman

Your resonators look a bit toasty. I'm a bit surprised they look worse than the HFC and that the heat damage is that far back.

My thoughts too. When I pulled the sill, I was expecting the cat to be burnt up.

**dave6666** · 07-13-2015

An interesting thought as both your car and mine show a heat signature on the muffler downstream from the cat but not so much the cat itself. And that is, that cats are designed to run at extreme temperatures. They are by design exothermic reactors. Mufflers are on the other hand likely not designed to see such heat. At least not the inexpensive mufflers that would be found in our cars.

So, continuing on with that thought, if the cat is designed to run hot safely and the muffler is literally just a few inches further down the pipe, would it not be safe to say that the muffler is seeing elevated temperatures from the exit of the cat? And that if the muffler is not designed to deal with this level of heat (or at least contain the heat) that the radiant heat damage would be more so than the cat? Which is also physically much smaller with much less radiant surface.

Part of my basis for this thought is on a conventional passenger car or truck you don't see the muffler 5" from the cat.

**stuntman** · 07-13-2015

^Good hypothesis, but OPs exhaust is ~1' after the cat, not 5", but it could still be true. The burn pattern on the resonator is interesting how its heavy only on the first 2/3 of the resonator while the last 1/3 looks fine.

Uvbnbit - your cat back is a B&B? I would remove the resonator and look inside.

**dave6666** · 07-13-2015

Saying 5" had nothing to do with his car per se. Mine is 5". On my trucks it's 5 feet.

**uvbnbit** · 07-13-2015

Dave, what muffler is it you have there on your set up? Part of a Belanger kit? Smaller diameter for exterior (of it) flow?

**dave6666** · 07-13-2015

I believe my old ones are Dynomax. They are 4" diameter. My new ones are 5" OD. They are Walker according to Lou.

This is the loot for my new set of pipes. You can see the mufflers are slightly larger than the cats on the new setup. I'm also doing slip joints on the header turnouts and the side exit kicks so that I can change items more readily. My other pipes are fully welded.

**uvbnbit** · 07-13-2015

Thanks, I may have missed it somewhere else, but why you changing? Sound? Experimenting? Because you can and like playing?
Just curious.

**dave6666** · 07-13-2015

Kind of all the above. Sort of. My existing mufflers are from 2007 and I'm certain burned out. The car is just freakin loud. So I decided new mufflers would be in order, and it was suggested I switch to metallic cats too. Lots of people were consulted to finalize my plan even though ultimately it's Lou's standard Gen 1/2 3" side exhaust kit. But he wanted to reduce the muffler to 2-1/2" ID and my tuner said 3". It's almost like managing a cat fight trying to get the different opinions civilized lol.

**uvbnbit** · 07-14-2015

Again, thanks. We ran catless for 6 yrs. 5 of those with the Roe. Yes, noisy, but we liked it. Exhaust fumes-no likey. Constantly cleaning, even wet-sanding rear bumper-no likey. Moved O2's to collector helped, new O2's helped. But still had fumes, stains over time. I think new/tuned PCM would be only resolution. So, instead I put the metallic hi-flows on 2 yrs ago and really like it. No fumes, stains, etc. Car even feels more "torquey"= more Likey.
At this point, I'll paint the damaged area, add vents, and keep close look on it. NO MORE 1 HR, slow PARADES! lol.
-chip