911 Pressure valve

[Bazzer]

Could somebody tell me whether or not my 1977 911sc could benefit from fitting a pressure valve inside the air box.
I have seen variouse articles saying it makes sence to fit one but was'nt sure if this included fuel injection models or was aimed at the carb type.
Any help on the above including fitting if required and the best place to obtain one would be most appreciated.

Cheers Baz

 

[bones]

As your SC is equipped with fuel injection I'd recommend you fit one of these A.S.A.P it's not uncommon for the engine to backfire back out of the engine through the air box and wreck it, your wallet will certainly complain if this happens! Buy one from Type 911.co.uk for about fifty squid.

 

[flat6buster]

Someone told me that there is a later type of airbox that does not have this issue - is that true?

 

[bones]

The air box is the same it's the CIS that has been adjusted to prevent backfiring.

 

[Bazzer]

Hi Bones, thanks for that, how do I know if the cis has been adjusted and what is this?.
Cheers Baz

 

[bones]

it applies to cars post '81.

 

[Bazzer]

Thanks phill, I will get one prior to putting mine back on the road when the weather clears up, would like to list all the bits I have replaced like you but the page ain't big enough!!!.
Cheers Guys Baz