THIS is why you dont use RTV
 

TL;DR Dont use RTV for header to TP/HFC connection, it WILL leak.


So I got some Resonated Test Pipes from someone on the forum, brought them to my favorite shop (at the time) to have them installed (I didnt want to deal with the demon bolt). The shop calls me a few hours later to ask if I brought gaskets for the header flange, and I said that the RTPs didnt come with them. The guy from the shop said that they would use either RTV or fabricate a gasket, and I told them either one would be fine as long as it doesnt ever leak.

I picked the car up and loved the new louder, deeper sound and extra HP. However, I began to notice that my car had a loud HISS whenever I was decelerating. I rode in a friends Z who had Long Tube Headers, and his had a similar, albeit less loud hiss. It got louder and more frequent until I finally got under the car to see that the shop had used only RTV, and that it was completely blown out. They have only been on for 3 months.

I ordered Z1's metal gaskets on Black Friday (see here: Z1 Metal HR/VHR Manifold 3 Bolt Gaskets) and finally got the chance to install them today.

Here is the obivous leakage:
http://www.the370z.com/members/losts...214-111452.jpg
http://www.the370z.com/members/losts...214-105808.jpg

So at the end of the day, if you are going to do anything with headers, test pipes, or HFC's, dont be cheap, spend the extra $40 and get gaskets so you only have to do it once.

that no where near enough RTV to seal the header and i bet the shop didnt let the RTV dry properly before giving it back to you(it needs 2-3 hours to dry properly)

im using RTV to replace a gasket that burnt up and im not leaking

at the end of the day, don't let someone else work on your car, you're just asking for something to go wrong

Metal gaskets are best.
 

Nissan uses metal exhaust gaskets on the car from the factory because they work best. Using RTV or a metallic cardboard style gasket does not provide the same heat resistance or durability as the OEM style metal gaskets.

luigi - You can tell they used a good amount, but it had all blown out, and most of it was stuck on the header side hence why this pic looks like there is none

verda - the factory components use a donut style gasket, which most aftermarket ones dont. I was just sharing an experience with a shop as well as giving a word of advice for those who might try to save a few bucks.

OEM dont have gaskets at all on the cats, just FIY



it looks like it was globbed on in some places and it wasnt spread evenly throughout the header
do you know which RTV they used? and do you know if they allowed it to dry properly before letting you drive it away?

like i said i have no problems with RTV on my header and test pipe(i used RTV ultra copper)

I only have a cat back on mine so far so I know that all of the factory gaskets for CBE are flat stamped metal gaskets for all of the 2 bolt flanges. But I haven't yet had the front of the cats disconnected. So next year when I get Motordyne ART test pipes I'll also be ordering the metal 3 bolt flange gaskets from Z1 to connect the test pipes to the exhaust manifold with no leaks.

Funny my car says other wise.

I purchased these from Z1 Motorsports for my HFC install. They worked as expected. Ahh ... just read the last sentence on your post. These will work great!

Z1 Metal HR/VHR Manifold 3 Bolt Gaskets

http://www.the370z.com/members/stino...4-img-0636.jpg

the factory cat has a stamped two bolt gasket on the bottom, and a stainless o-ring on the front. to anyone who says they didn't have rear gaskets, either they were removed already or were stuck to the pipe and you didn't notice.

The colour of that RTV tells me it's a high temp for water or oil. If it was the correct stuff, if would look copper coloured, not red. Still, I agree with the OP, use a gasket!

I have had no issues with red RTV when it comes to sealing exhaust flanges, even on boosted cars where the exhaust back pressure before the turbo can reach 20+psi. I do however let it sit overnight every time I use it. I think this is very important.

With the turbo kits I use Berk Technologies gaskets, rated to 2000 deg F. These have worked great when installed properly.

Ummmmmm... Yeah they do... How else does it seal?



And my bet is that the RTV didn't have time to harden. Red RTV sets stronger than the copper stuff too from what I've been told

Regardless of if RTV "can" work, the metal gaskets from Z1 WILL work and aren't so expensive that people should cheap out. Just my 2 cents.

I agree, but before Z1 had theirs out, RTV was a good second choice

Aren't the directions put in on, tighten only a little, wait a few hours, then tighten to spec. After 24hrs its gtg. I can't see a shop doing this!