MAX-IMAL

How many of you have the car running without heatshields using the RB components? How hot gets inside the car?

Rattaan

Do you mean no heat shields between the exhaust and underside of the car? or just between the exhaust and the road? I wouldn't suggest trying the first there unless you want to melt your carpeting, and possibly cause yourself a fire hazard. I don't think it's as big a deal beneath the pipes as the majority of the heat goes upward anyway. Why do you ask out of curiousity?

MAX-IMAL

curiosity, right now I'm working on a tranny swap, and basically all the noises when i'm driving comes from the heatshields some parts are loose, just want it to now while im at it If I should take them off.

Rattaan

I wouldn't take off any shielding between the pipes and the underbody. Any shielding below the pipes should be ok. If the upper shielding is loose, find a way to re-fasten it down tight with new bolts. Better safe than sorry.

Rattaan

I wouldn't take off any shielding between the pipes and the underbody. Any shielding below the pipes should be ok. If the upper shielding is loose, find a way to re-fasten it down tight with new bolts. Better safe than sorry.

Rattaan

Just look for a way to refasten the ones between the pipes and the underbody, the rest should be ok to come off. I have my lower shielding off too, I just try not to park over dry grass too much

Rattaan

Just look for a way to refasten the ones between the pipes and the underbody, the rest should be ok to come off. I have my lower shielding off too, I just try not to park over dry grass too much

Rattaan

Just look for a way to refasten the ones between the pipes and the underbody, the rest should be ok to come off. I have my lower shielding off too, I just try not to park over dry grass too much

scathcart

If you are referring to the hideous aluminum ones that line the underneath of the car, get beant, and rattle, take them off. Catalytic covertors retain a LOT of exhaust heat which can seriously heat up the floor pan, enough so to melt the underlay and possible catch fire, but without a cat, this retention of heat is no longer localized.

Now, heat from the exhaust pipes will still travel upwards, yes, and soak into the floorpan, but while moving, the airflow under the car will sevrely help to reduce this effect. I am only stating this to lead into my next point....

I was curious as to the effects of removing the heat shielding as I did not want to damage the underlay, bubble any paint on the floor pans, catch fire, etc etc. So, after installing a free flowing exhaust, I left the heat shields on, removed the passenger seat, and idled the car for 30 minutes at 3000 rpm. I did this instead of driving as this would allow maximum heatsoak (through minimum airflow cooling).
I pointed the ol' Infared heat gun at the bare floorpan and got a reading of 89 degrees fahrenheit... not bad, not bad.
I then took off the heat shielding and repeated the test under indentical circumstances. The infared gun gave a reading of 131 fahrenheit. Hotter, but not near hot enough to cause worry.

Then curiousity hit me (as if it hadn't already). I reinstalled the cats, and redid the tests with and without heat shielding.
With heat shielding and stock cats, I got 118 fahrenheit... a little cooler than a straight pipe without heat shielding. Then I removed the heat shielding.... and got 192 degrees after 15 minutes. Too hot for me to be comfortable, so I ended the test early, and reput on the straight pipe without heat shielding.

As an aside, there is a temp sensor in the passenger side floor pan that lights up a dummy light if the floor pan gets too hot, signaling a clogged cat. You can read about it in the owners manual. I have never seen it go off, on any car, even during my test, on other cars without heat shields, etc.


So, to sum it all up:
No cats, no heat shielding.

Hopefully these results will end any argument over the subject.

scathcart

Negligible affect on the actual interior temperature. The underlay of the carpet acts as an insulator from floorpan changes in temperature.
See my above post for actual floor pan temps.

drft_180sx

That's some great info, Thanks Sean.

Also if your cabin is getting warm, you might want to check the inner and mibble shift boots.
Mine were really worn out and a lot of heat was entering the cabin, although i had a exhuast leak in between the stock manifold and pre cat pipe.

MAX-IMAL

OK thanks alot scathcart great info, i'm gonna take them off.

Wankel7

Good luck with the tranny install Max!

James

DEZERTE

IM running mine, I had no shift boot for a while so i could see straight down to my drive shaft, and hot air would blow up into the cockpit from the exhaust being there, thank God no fumes. But heat isnt an issue, especially after I got a boot.
*edit, i dont know if this matters, but all my insulation/sound deadening/carpet is not present.

poor college student

we have heat shielding for our exhausts???? hahaha, i either never noticed, or they were gone be4 i got the car... but then again... i never had cats...

91_fc

wow. nice writeup on that! btw, has anybody tried the insulation wrap around the headers and straight pipe? this is what im considering. the place where the heat sheild gets bolted down got rusted and boke off. now its making lots of noise so im just gonna get rid of it.

scathcart

Heat wrap does work very well... if you wrap 2-3 times, you can generally grab onto the pipes while the car is running. They will significantly reduce engine bay temperatures, which in turn decreases heat soak into the intake manifolds, which boosts power. As well, wrapping the exhaust helps keep the exhaust heat in the exhuast pipes, which will slightly add to power as well. Lastly, the wrap will decrease much of the Tinny, rapsy sound associated with the thin piping of headers, giving the car a deeper, less-fartcanish sound.

Now, the downsides.... Exhaust wrap severely decreases the life of the exhaust. Even with stainless steel, corrosion sets in almost instantly. ALL header manufacturers consider their warranty void if any header wrap is installed. As well, the exhuast will offer no actual muffling to the exaust, just remove the tinny sound. Lastly... its pretty tough sometimes to cover up a nice, bright, shiny stainless steel pipe with white/flat black "fabric". Wrap definitely does not have the "bling" that RB headers tend to be associated with.

All above said, I run header wrap in all of my header installs, and have been extremely happy with the results.

91_fc

it shortens the life of exhaust components? i didnt know that. by how much would you say?

Rxmfn7

iTrader: (4)

It decreases the life of exahust piping considerably. If not SS, or whatever high-quality ceramic coating the RB header is made of, Id estimate almost 50% life-span compared to non-wrapped pipes. If good high-quality SS or comparable, its not quite as bad. I for one didnt bother with heat-wrap on my RB header. It was already much lower and not as restictive as the stock manifold, so I dont think it retained as much heat.

91_fc

so what would the life expectancy be if i bought the RB header and prescilencer and wrapped them in insulation tape? at least 5 years?

scathcart

Too hard to guess, depends on too many things. I would be happy with 4-5 out of any wrapped SS header, and 2 years out of non-SS header.

91_fc

oh ... sorry i left that out! if i were to drive her ... well pretty hard. when i drive i usually like to push her, so im guessing that would probably cut another year of the lifespan.

I Hate Ricers

Hey, what about doing a weak-sauce wrap job.
Like, you know, wrap the same lenght of header with 1/4 the wrap...so spaces are left between winds.

Would this take a few degrees off the engien bay?
Reduce a little tin maybe?

(as i re-read this i start to realize how stupid of an idea this sounds like hehe )