Doubling up grimspeed exhaust gasket?
 

So I know the grimspeed gaskets are 20% thicker than OEM, but I can't get the connection between a motiv overpipe and motiv high flow cat to seal for the life of me.. tried oem gasket, grimspeed gasket, grimspeed gasket with copper spray, tried doubling em up, both with copper spray and it seemed to seal.. any disadvantage of doubling up on 2 "thicker" gaskets? is it like a condom where its just no bueno to double up?

A gasket works on pressure. There's no reason 2 wouldn't work

Now, how does that work ...... ??


humfrz

2 flanges pushing against the gasket?

Oh ........ I reckon ma brain is still asleep ....... I was thinking that you were saying that .......oh, never mind ....... :bonk:


humfrz

OP, I reckon you could safely put together as many gaskets as you want to in an automobile exhaust system ...... just as long as they don't leak.

However, don't try that on a head gasket or a plate on a boiler .....:eyebulge:


humfrz

Just use OEM gaskets. I went back and forth for like a month with Grimmspeed gaskets.

OEM, sealed up perfectly. If you're paranoid (like i was) use a little RTV with the OEM gasket.

For header to block - Grimmspeed gasket is great. Forrester XT gasket is better (and cheaper).

Remflex crush gasket is the ticket. I also have the Motiv overpipe and the front pipe and the Remflex gaskets have been leak free for the last 50K miles. I also use them between heads and header, header and overpipe and midpipe to axleback.
This is the one I used for the overpipe to front pipe: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1


You just have to enlarge the bolt holes on the gasket a tiny bit, since the bolt pitch is slightly smaller on our cars.

Thanks for the suggestions guys, any suggestions for a bigger gasket for perrin 2.55" gasket? (for those eliminating the donut for 2.5 CBE systems) I was going to get the 2.55" gasket and a grimspeed one and go to a machinist and say here, but thanks
@SpectreRT so the XT ones are better than the grimspeeds huh? makes sense being turbo I guess

I'll try both your suggestions if the grimspeed double gasket setup wants to leak again

Forrester XT gaskets are metal and triple layered, yet somewhat flexible. Perfect for crush sites.

I second the remflex gasket... they work wonders.

Generally when people have sealing issues with our gaskets it is either due to misalignment, torquing order, or warped flanges, and is rarely due to our gaskets. Our gaskets exceed OEM spec, so I would have to disagree with you that the FXT gaskets are better. Our gaskets are made out of stainless steel, have 5 layers, and a fire ring. So they are equally flexible, and the fire ring is specifically designed to take the crush and seal the joint. So if the gasket it misaligned, pressure won't be put on the fire ring, and the joint won't seal.

I would advise against doubling up on exhaust gaskets. When you double up you change two sealing joints to three. So instead of adding an addition point where a leak could occur, I would just and solve the actual reason for the leak. AS stated in the above post, the main culprit for leaks is misalignment, torquing order, or warped flanges. Misalignment and torquing order can both usually be solved by loosening the joints before and after the joint you're trying to seal. Instead of completely tightening one and then then other, do them all in steps. Generally this will be enough to seal any exhaust leak. However, if the flanges have warped from welding, there might not be much you can do short of flat sanding them, other than using a generous amount of copper RTV on the fire ring, and giving it time to cure before starting the engine.

Chase
Engineering

I used the Grimmspeed gaskets for my header and it was the first time I ever messed with a header. Excellent quality and (evidenced by the fact that they are sealed nicely and not leaking at all) they must be forgiving too because it was a bit of a learning process.

I heard about using the GS gaskets from other users on this forum

Had no problem on the header, just OP/FP.. @GRimspeed do you guys sell any 2.55 gaskets for the perrin? loved the quality of your gaskets vs that one