Better Exhaust Gaskets

[DaveW]

I was looking for a supplier of higher-performance exhaust gaskets (I don't like the standard laminated steel ones - they always seem to burn out) and came across this manufacturer. I ordered a couple of the RF8006 3" ID gaskets to use on my cat-to-RB dual-tip catback flange, and on the intermediate flange of the catback. We'll see how they work.

Here's some info from their site:
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Remflex Exhaust Gasket
Remflex's unique flexible graphite material has been proven for more than 30 years in industrial applications, where temperatures routinely exceed 2,000 degrees—day after day, week after week, year after year. Now, we're bringing this technology to enthusiasts of all kinds to eliminate exhaust leaks for good! Whether you have an old pick-up that needs a manifold gasket, or a race car with custom-built headers, you can be assured that Remflex exhaust gaskets will work properly the first time, every time.

The Remflex Performance Promise
Seals Warped Flanges:
Remflex exhaust gaskets come in a standard 1/8-inch thickness and are designed to crush 50%. This allows them to fill gaps in the flange surface up to 1/16-inch!
Won't Burn Out:
100% flexible graphite construction means Remflex gaskets are good for up to 3,000 degrees F—far exceeding that of any vehicle's exhaust system temperature!
No Re-Torquing Necessary:
Remflex exhaust gaskets rebound 30%, creating an optimum seal that eliminates the need to re-torque!
The Science
Remflex gaskets work because they solve the two main problems associated with sealing an exhaust flange: Warping, and gasket failure.

Warped Reality
A common misconception is that, if you spend a lot of money for high-quality headers with thick flanges, leaks will not be an issue. In truth, a thicker flange does help, but it can't solve the problem of warping altogether. Constant thermal cycling, especially in high performance and/or high-load environments, causes warping of header flanges and cast iron exhaust manifolds--even the exhaust flange of the cylinder head itself.

Once the sealing surface is warped, leaks are imminent—and once there is a leak, pitting of the exhaust port sealing surface usually follows. A new set of average gaskets won't fix the problem—but Remflex gaskets, with a 50% crush built in—can seal gaps as large as 1/16-inch. And unlike traditional gaskets, they won't shrink, so they never require re-torquing.

If you can't take the heat…
Curiously, the number one cause of exhaust gasket failure is heat—the very thing exhaust gaskets are supposed to withstand. That's because traditional exhaust gaskets are made of composite materials—blends of natural fibers and synthetic compounds that are bound together using rubber. Simply put, it's only a matter of time until the extreme temperature in the vehicle's exhaust system burns the gasket's composite materials away, resulting in an exhaust leak.

You've no doubt experienced the pungent odor that arises from the engine compartment after you install a new set of the top-brand exhaust gaskets. That's the smell of the rubber binders in the composite materials that begin to burn out almost immediately. And once the rubber overheats, it begins to shrink, as well has harden. That's why you are instructed to re-torque the gaskets regularly, and why an exhaust leak will develop if you don't. Remflex exhaust gaskets are made from 100% flexible graphite and can withstand up to 3,000 degrees F—so they are not affected by exhaust system, and won't burn out, shrink, or leak. Not now, not ever!
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[Herblenny]

Interesting.. Whats the cost on these?

[David Jerome]

What was cost on these. I have looked a couple times before and never really found any other options to usual gaskets.

[DaveW]

Originally Posted by Herblenny

Interesting.. Whats the cost on these?

$10.40 each x 3 =$31.20 but no shipping cost since the order was over $25 (Amazon.com).

Other places had them for as little as $6.79 (IIRC), but shipping costs were too much.

On another note, the one possibility for these to not work well might be blowing out with backfires, since they are thicker, and maybe not reinforced enough. I'll update my opinion on them after I get and install them.

[Chadwick]

What site did you order them from?

Thanks,
Dan

[DaveW]

Originally Posted by Chadwick

What site did you order them from?

Thanks,
Dan

I ordered from Amazon.com because of their free shipping for orders over $25. Other places had them cheaper, as I mentioned above, but too much shipping charge.

[Cp1]

hmmm interesting... though as an alternative i picked up a big 12"x30" sheet of exhaust gasket material from napa for about $25. which is composed of high temp fibre material with a metal core sandwiched between and have had great luck using it for all of my exhaust gaskets everything from block to manifold, manifold to turbo, turbo to downpipe, downpipe to midpipe etc. the only draw back to using this is that you have to cut it yourself which if your not good at using tinsnips can be a pain in the ass. for me no problem but im sure a lot of people could really go either way.

Either way is definitely better than the near $100 that mazda charges for each gasket down there!

[DaveW]

Originally Posted by Cp1

though as an alternative i picked up a big 12"x30" sheet of exhaust gasket material from napa for about $25. which is composed of high temp fibre material with a metal core sandwiched between and have had great luck using it for all of my exhaust gaskets everything from block to manifold, manifold to turbo, turbo to downpipe, downpipe to midpipe etc. the only draw back to using this is that you have to cut it yourself which if your not good at using tinsnips can be a pain in the ass. for me no problem but im sure a lot of people could really go either way.

I bought a sheet of what NAPA had (FelPro ProRamic 2499), supposedly to be used for exhaust gasket applications, like you did. I gave both it and the Remflex material a test with my heat gun (~1400F). The Remflex material was unaffected. The FelPro material smoked, smelled like burning paper, and turned brittle and black. Maybe the NAPA stuff I bought was not the same as you bought. What was yours called? Did it have a part #?

On the subject of the Remflex gaskets, here are my results:

I installed two of these in my RB dual-tip CB (one between the stock cat and the CB, and one in the CB middle joint). The Remflex instructions say to compress the gaskets ~50%, from the initial 1/8" to 1/16" thick. This took ~40 ft-lb of torque on each of the 4 bolts involved (2 stock rear cat nuts, and 2 7/16" RB mid-flange bolts), even though the contact area was much less from the RB flange to the cat flange.

After driving ~35 miles,with several full-throttle power applications, I rechecked the gaskets and bolt torques. The gaskets seemed perfect, with absolutely no sign of leakage or distress. The bolts had loosened a few ft-lb, so I re-torqued them (despite the Remflex claim that re-torquing is not necessary) to the 40 ft-lb and used wicking Loctite on the nuts.

So far, so good.

[cewrx7r1]

I am using a FC turbo exhaust gasket which was cut in half to reduce flexing between both ports like the FD gaskets are. Cheaper and works fine with my GT35R on my 13B-REW FD engine.

If you are burning exhaust gaskets, you propably have a manifold that is not truely flat.
I had to have both faces of my A-Spec manifold trued because they were not flat. I have seen this same problem on other single turbo manifolds.

Don't blame the messenger!

[DaveW]

Originally Posted by cewrx7r1

I am using a FC turbo exhaust gasket which was cut in half to reduce flexing between both ports like the FD gaskets are. Cheaper and works fine with my GT35R on my 13B-REW FD engine.

If you are burning exhaust gaskets, you propably have a manifold that is not truely flat.
I had to have both faces of my A-Spec manifold trued because they were not flat. I have seen this same problem on other single turbo manifolds.

Don't blame the messenger!

The current gasket problem I mentioned was with gaskets that I got with a used RB dual-tip CB. These gaskets were used up. However, the flanges ARE quite flat on this unit - I checked them with a flat plate and feeler gauge. I have also seen burned-up laminated steel gaskets on other applications. Most exhaust gaskets, including the laminated steel ones, IMO, have a couple of shortcomings - they compress with heat and loosen, causing gaps and flange rocking motions (particularly bad with 2-bolt flanges), followed by exhaust leaks and burn-out, and they also have very little compliance or tolerance for uneven flanges (as you pointed out). Also, because they compress, they are one of the leading CAUSES of warped flanges. I, personally, have not had much problem with exhaust gaskets burning out, but these (the Remflex) just sounded better in all respects.

I didn't mean to infer that no one should ever use the other gasket types - they obviously work well in many applications - I just wanted to bring what I thought was a good, maybe sometimes better (especially in the case of the VERY hot FD exhaust), alternative to peoples' attention.

As I said, so far so good. YMMV.