View Full Version : Using a 94/95 plenum with an '89 engine

11-11-2014, 12:39 PM
Mine is a '91, but with a '89 engine in it, so I would assume that they would be the same. Anyways, I had bought a 94/95 ported blower/ plenum off another forum member. I'd noticed that there is different hose connections and things like that on the plenum. What would I have to do to adapt it--just use the current hose connections and other connections, and then plug the rest? It also looks like there's an EGR connection on the plenum, so i'm not sure if the 89-93's have it here or not.

Bear with me--my SC is in storage right now, so i'm just trying to plan right now--and also, I don't have a complete visual.

11-12-2014, 12:59 AM
If your engine doesn't have an EGR, you'll hafta put an EGR delete plate on the plenum to close that opening up.

David Neibert
11-12-2014, 09:54 AM
91 SC doesn't have EGR so you will need a plate to cover the opening. You can get the EGR delete plate from SCP or Spinning Wheels or maybe find a used one in the classified section. The hoses are done like you said.


11-12-2014, 01:58 PM
you could hypothetically also use some scrap metal drill holes in it and bolt that on the egr opening....using some rtv as well for a good seal.

11-12-2014, 03:09 PM
That's what thought, that there was no EGR. Thanks for the replies, guys! It would be pretty easy to fab up an EGR delete plate, so i'll probably go that route.

Next question--I guess the previous owner (SuperdadSC---hi, Steven...thanks again!) had the plenum ported/ polished, but I guess it must have been for the stock TB, since there's still a big step in the opening for my 75mm TB. I notice that to open the port wider, you'd have to grind away some of the material that exists on the square opening part of the plenum. Judging by the look of it, there shouldn't be a problem fully opening it up to the full 75MM, but I was wondering if any of you had any problems with weakening the metal too much. By the looks of it, even just beveling/ chamfering the opening up to the full 75mm would probably work to ease the TB port into the plenum, as the plenum obviously bottlenecks pretty soon through the opening anyways.

11-16-2014, 11:59 AM
I have an egr plate i will sell you cheap. How about $7 shipped?