What is different between SD and MAF plenums? I need to convert a MAF plenum to SD. What do I do?

 

You need one more port for the MAP.

 

^^^ He's right. 1/8" npt will do just peachy. Put the map sensor as close to the plenum as possible using hard tube.

-- Joe

 

where do i drill for it? any pics? do I need to plug the hole in the bottom?-Mike

 

Mine comes from the pass side rear of the plenum.
Extra holes should be plugged otherwise its a vacuum leak or use the existing hole if it will work.

Good point Joe on getting it close to the plenum.
I have mine on the fenderwell with a 2 ft rubber hose and I was thinking it is causing some slight delay in readings and reactions.
I' m gonna hard tube it and mount it closer!

 

Anyone have a pic of the back of the SD plenum where the MAP sits? I have that plenum on now but I'am not to sure how things are hooked up.

 

Maybe these will help. Engine was hot so I couldn't disconnect anything to get better shots, but I doubt you'll need it.

The location of the MAP. The SD plenum has mounting pads and holes for the MAP bracket, so locating it isn't too much of a problem if you have this plenum.

 

A shot from below. The circle highlighting the short factory vacuum line from the plenum to the MAP.

 

The SD plenum has a hole on the bottom for the MAT sensor. I haven't touched an MAF plenum, so I don't know what hole you're talking about, but you may be able to reuse it for the MAT.

 

Thanks for those pic's, that helps a lot!! I wonder if I guy can still order that short vacuum line?

 

The big blue book says:

10105294

Unfortunately, GMPartsDirect.com and NewGMParts.com don't have it.

 

Now I am really confused, Does anybody have a pic of the rear pass. side of a S/D plenum without all the stuff in the way?

The MAF plenums have a whole in the bottom towards the rear for the MAP or MAP sensor. Do I need to plug this?


-Mike

 

The plenum for a MAF setup will not have a port for an MAP sensor.

As I said before, the SD plenum has one hole in the bottom for the MAT (Manifold Air Temp) sensor, you may be able to reuse the hole in the bottom of yours for this purpose if that's not what its for.

On the passenger side of the plenum, there are 2 ports near the rear; the rearmost (circled above) is for the MAP sensor.

 

This will help a lot, MAF plenum on top and MAP on bottom.

 

So now, The two fittings on the MAP are the same as a on a MAF except instead of one 1/4" and one 1/8" they are both 1/4" and I need to add one 1/8" fitting just to the right of the two fittings that are on the MAF plenum now. Anything else? Do I need to take out the sensor on the bottom and plug it? Thanks guys! --Mike

 

Dude, I keep telling you the SD plenum has a hole on the bottom near the rear for the Air Temp sensor, and you can reuse the hole for this purpose if the MAF plenum doesn't have a separate hole for it already.

 

whats that black plastic thing connected inline on the vaccum line coming off the SD plenum. I got rid of that on my setup now that I am running a HSR.

 

Dude, I keep telling you the SD plenum has a hole on the bottom near the rear for the Air Temp sensor, and you can reuse the hole for this purpose if the MAF plenum doesn't have a separate hole for it already

Got ya- anybodt have a pic of the underside of a S/D plenum? Is there mounting bosses on the underside of the S/D plenum. I seem to remember seeing a thread on converting Plenums but I can't find it. I did a search as well and nothing.

 

The plastic thing is a check valve....it keeps your vacuum powered accessories (i.e. air blend doors for the A/C) from losing vacuum when you nail the throttle and manifold vacuum drops.

 

well, I dont have A/C anymore so is that check valve even needed on my car at all? like i said I ditched it.

 

Dude,

They all have the MAT there.

Only thing you need to run s/d is a fitting for the MAP.

Why has this thread gone on this long?

-- Joe

 

BECAUSE I am slow AND stupid as well.

Seriously, I am converting a mass air plenum to be used on a S/D car and I'm getting paid to do it. If it was mine I wouldn't care If I cobbled some half-butt set up that I had to redo and test fit. Since it is for someone else I want to make sure it is perfect, complete and trouble free. That is just the way I am. Thanks-Mike

 

Drill and tap a 1/8 npt fitting behind the runner on the passenger side, then drill and tap a 1/4-20 hole to mount the bracket for the map sensor.

Whats our cut out of the payment for helping you?

-- Joe

 

Well, If your running a 9 bolt I was the guy who donated the rear to T/A performance for the stud girdle/cover. OR I could buy you a beer if I ever see you around.
Hey, need some work done? I'll cut you a healthy break!

 

No, I'm running a 10 bolt.

I'll take a beer.

And though I left mechanics to persue law enforcement, I still do my own work.

-- Joe

 

All that horsepower AND now your chasing the cops!

Just could resist.
Edit: But now I will drive slow when in Mass!

 

I have an SD one that I want to sell, if you need one.

 

Formulaman, check your pm's Thanks Joe-Mike