is that pre 87 or post 87

tia,
RS

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1992 Camaro RS
Mods:
Custom chip, 14x3 Open element w/ K&N filter, MSD 6a, MSD GM blaster Coil ,MSD 8.5 SC wires, AFPR,Fuel Pressure gauge,A/F guage, 3-Row Al rad. , 180* t-stat,Proform 1.5 roller rockers, Hooker 1 5/8 headers, 3" Catco cat, 3" Hooker Aero Chamber cat-back, "Ultimate TBI" mods, Nitto 555R Drag Radials

Next

454 TB,intake,SLP Posi,3.42 gears
Al Driveshaft, Underdrive pulleys,
LT1 cam. 2400 stall Tq converter

Best Time: 15.279@89.02MPH
Underdog Racing

 

Looks like an 85 to me, with the longer grooves on the plenum.

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91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

 

Can't really tell from the picture. A shot from the side would help. The longer "fins" on the plenum were on '85-'89 TPIs (Mass Air Flow). You really want a TPI from a '90-'92 (speed density) for your '92 RS. Older TPIs will require modifications.

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'92 RS, ZZ4 10:1 350, Edelbrock 6085 heads, Crane 208/214 467/482 cam, GM/LT4 1.6 roller rockers, Edelbrock Hi-Flow base, runners & 52mm TB, SLP/Jet-Hot 1-5/8" headers, Catco 3" cat, Flowmaster 3" catback, Hughes 2500 stall converter, stock 700R4, Auburn Pro posi w/3.42, 17x9" SS rims w/BFG tires, Medium Quasar Blue w/white SS stripes, 48,000 miles....

 

No, the long grooves are only on the 85 cars. 86-92 plenums look very much alike, I think the main difference is the holes for the MAP bolts.

 

I thought 85-88 had the longer grooves, and 89-92 had the short grooves. Regardless, we need more pics to identify that TPI unit.

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West Coast GM Shootout 2001!
1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

Nah, 85 grooves are the same, Ive had an 85 and an 86. Come to think of it, I have a plenum off an 85 I polished, and an 86 plenum on my car. Same same. Its hard to tell from the pic what year it is, need a sideshot. I did notice someone mickey moused the fuel rail setup though.

por grammer... lokked terible

[This message has been edited by madmax (edited January 19, 2001).]

 

The '85-'89 are long, the '90-'92 are short I tell ya! It doesn't matter in this case. I think if the TPI is for his '92, then get the proper TPI for it.

 

Plenum looks like my '89...I have an '87 in the shop, but don't recall what it looks like...does it have the 9th injector? If so, it'll be pre-'89.

 

Kevin is correct. 85-88 plenums have the longer grooves. 89-92 have the shorter grooves. In looking at my upper pic, all plenums have an (1)EGR passage while 85-88 (left) also have the (2)cold start injector passage. The 89 plenums (center) eliminate the cold start passage, and then the 90-92 (right) have the MAP boss for use with speed density.

In looking at the lower pic, the plenum on the left shows the IAC passage that was only used on 85-88. All these have the longer grooves. The plenum with no IAC provisions and shorter grooves on the right were used on 89-92's.


UnderDog's pic shows an 85-88 system.

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1989 IROC-Z 5.7L

[This message has been edited by Omar (edited January 20, 2001).]

 

Great info Omar! I was mistaken on the '89.

Can I use an '89 plenum for my '92 speed density setup? If the MAP boss on the passenger side of the plenum is the only difference, can I still use the '89 if I need the MAP sensor? If so, what will I need to do to have a working MAP? Can I drill & tap my own hole? (not MY hole perverts).

 

Thanks Omar. I like to think I know TPI quite well, but some people just wont listen to me.

My dad is using an 89 plenum with his TBI to TPI converted 92 RS. He left his MAP sensor on the firewall and connected it to the 89 plenum. It works fine. 89-92 plenums are identical, except for the MAP sensor bracket and extra bung on the back passenger side.

 

Thanks Kevin. I know you know your stuff. I've learned a lot from you lately.

Now help me out...I understand that I can leave my MAP on the firewall, but what connects to the '89 plenum and where? Just a vacuum line? I have a '92 RS also.

Thanks!

P.S. - I actually still need clarification on the '89. I have a chance to buy an '89 plenum and I want to make sure before I do. The '89 plenum I have a picture of has long grooves. If that's the only difference other than the MAP, then I'm ok, but the long grooves threw me off from what Omar said. I think the short grooves denote speed density, ie: '90-'92 only.



[This message has been edited by Scott C (edited January 20, 2001).]

 

Scott, if you want to use that 89 plenum for a 90-92 speed density, you will have to drill and tap the #3 hole in my pic. If you have the means for that, then go for it. If you want a no hassle install, I would suggest waiting for a 90-92 plenum. If are unsure about the plenum in question, ask to see the passenger side of it and look for that #3 hole.

On a side note, I personally own an 89. It was owned by a good friend before me, and I know I am the first to molest the intake. I have the short grooves, no IAC in the front, and no MAP boss hole. About a year ago, I ordered a TPIS Big Mouth intake manifold, large tube runners, 52MM throttle body, and a ported plenum. If you have an 85-89 system, you can use an 85-88 plenum, since the only difference for 89 is the elimination of the 9th injector provisions. They simply plug up the runners. So I just realized by reading the proper literature that TPIS sent me a ported 85-88 plenum. While it doesnt matter for the functionability of the car, I like my items to match, know what i mean? Maybe I am being too ****. Either way, I have both at hand to compare and verify the differences.

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1989 IROC-Z 5.7L

[This message has been edited by Omar (edited January 20, 2001).]