I have a question about the Speed Density system used on the 1990 - 1992 Camaro/Firebird. The vaccume port on the Upper Plentnum that the MAP sensor uses on the passenger side of the plentunm. What is the size of the hole, and the thread size used, and any special pipe fittings used for the vaccume hose. Any help would be greatly appriciated.

Thank You....

 

Probably not the answer you are looking for but when I went to SD I just teed off one of the existing air lines comming off the plenum o n my 89 car. As I recall the line is not very big. Maybe 1/8.

 

Yeah I'd thought about doing the same thing but was unsure if it would get in the way of the fuel rails or something. What I have here as you can see is a Upper plentum for a 1989 F-Body. I would like to convert it over to (SD) beacuse I found it brand new from a (Dealer) parts warhouse on EBAY who bought out alot of old GM stock. No offence to the 3rd gen community here, but I am Rebuilding a 1978 Camaro, and thought alot about building a TPI system from scratch using various companies like Edelbrock , Painless , etc to do it all. I love the 3rd gen Camaro/Firebirds, exelent cars...

Thank you for your reply, I'v posted on other various boards and this is the first reponse I got

Thank you....

 

[quote=Grizzly350;3150683]Yeah I'd thought about doing the same thing but was unsure if it would get in the way of the fuel rails or something. What I have here as you can see is a Upper plentum for a 1989 F-Body. I would like to convert it over to (SD) beacuse I found it brand new from a (Dealer) parts warhouse on EBAY who bought out alot of old GM stock. No offence to the 3rd gen community here, but I am Rebuilding a 1978 Camaro, and thought alot about building a TPI system from scratch using various companies like Edelbrock , Painless , etc to do it all. I knew a guy who had a 80's model Jeep and he retro fitted a TPI system off of a 1992 camaro, I can understand if the car is beyond repair or if your pocket book is not deepenough, but I don't like the idea of robbing a good car off it's heart.

Thank you for your reply, I'v posted on other various boards and this is the first reponse I got

 

Is there anyway you can shrink your text before you post, could be why you don't get any answers cause it's really hard to read when it's that big.

BTW if your going to tee off a existing line make sure you use that hardline that GM uses.

 

The MAP sensor needs it's own dedicated vacuum line, don't share with anything else. I ran into this problem with my TPI swap. I was using an '89 TPI with a '91 SD system and tried several combinations and wound up with MAP and the AFPR each having their own vacuum lines while the EGR, HVAC and accumulator have to share.