Nick,
I already had the msa Premium exhaust kit installed. I did noticed there is some detonation when i let the gas pedal go and more pronounced if i go down a hill. Is this normal?? Both of my 72 round 3 screws SU CARBS are tuned and balanced correctly. If i lean the mixture i will have detonation at the intake. Are the gasket sold by MSA good enough? My original stock system was 2". THis one is 2.5"

I would notice when the car was cool I would get some pooping but once it warmed up all was well.
I would stand behind the gasket provided by MSA


Sent from my iPhone using Classic Zcar Club mobile

So these gaskets are really of good quality? The popping is only on deceleration and becomes more accentuated when the car goes down a hill with the foot off the accelerator.

So these gaskets are really of good quality? The popping is only on deceleration and becomes more accentuated when the car goes down a hill with the foot off the accelerator.

Personally I would probably find a better brand because if I'm not mistaken MSA sends a cheap cardboard type gasket.
I haven't had any leaks but maybe look for a better brand gasket for 2.5 inch exhaust and you'll probably be better off in the long run if it's a daily driver.


Sent from my iPhone using Classic Zcar Club mobile

Odds are you have blown out a section of your gasket. Dave Rebello and I were just discussing this. He recommends a for exhaust red/orange high temp etc in replacement of the gasket. I did ask him about a copper racing gasket and he has not tested them. They are about $50


Sent from my iPhone using Classic Zcar Club mobile

Sorry. Type error. RTV not ect


Sent from my iPhone using Classic Zcar Club mobile

https://zcardepot.com/engine/engine-rebuild/copper-racing-manifold-gasket-intake-exhaust-240z-280z.html


Sent from my iPhone using Classic Zcar Club mobile

19 hours ago, Nick0227 said:

Personally I would probably find a better brand because if I'm not mistaken MSA sends a cheap cardboard type gasket.
I haven't had any leaks but maybe look for a better brand gasket for 2.5 inch exhaust and you'll probably be better off in the long run if it's a daily driver.


Sent from my iPhone using Classic Zcar Club mobile

Where do i get these high quality 2.5 diameter gasket?

Edited April 27, 20177 yr by jalexquijano

I have the MSA stock manifold kit and really love it.  Sounds much better than my twice pipe setup and bolted up nicely.

i love it too!! but have some popping on deceleration when letting the gas pedal go. Im afraid i can damage the engine and hence i have been advised the unión gaskets are not of high quality. Where do i get the nissan quality gaskets?

The popping on deceleration is unburnt fuel leaving the combustion chamber into the exhaust system & combusting (burning) due to the heat in the exhaust. I solved mine by removing all of my smog gear, capping off the air galley and leaning out the carbs.


Sent from my iPhone using Classic Zcar Club mobile

air galley? lean more tan 2.5 turns clockwise  which is the starting point?

The air galley is the device that the smog pump pushes fresh air into the exhaust manifold with.  Most of them are leaking or damaged by now.