Im looking at getting a TPI Unit off a Vette that is already Polished and the plenum is ported is why i want it, i also found one off a 1988 305 Z28 that the plenum is polished and ported as well, woukld these be a direct bolt up to my L98????????

------------------
1991 Z28 Camaro L98
5.7L T.P.I
Blk ext/grey lthr int
http://www.iroc-z.org/albums/KamaroZ91/


http://www.fbody.com/members/KamaroZ350/

 

Depending on what year the Vette intake is, it won't work right. Since the later Vette L-98 heads didn't have EGR passages, there is an external source, from the passenger side exhaust manifold. That means unless you delete the EGR from your system, and block off both EGR ends on the intake, you can't use it.

The '88 Z setup has provisions for the cold start injector (as does the Vette) untill '89.

'90 and later had provisions for a MAP sensor.

Seeing that you have a '91 Z, if you use the '88 setup, you will need to get the cold start block off kit (runner plug and fuel rail plug) and have to re-locate the MAP sensor.


------------------
If you live in Southeastern US, check us out!
South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
Whatever chip I feel like burning,
JET AFPR, Ported Plenum,
TB Coolant Bypass, Custom Cold Air,
SSM SFC, KYB Shocks, Boxed LCAs, Wonder Bar,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE

[This message has been edited by GMTech (edited March 10, 2001).]

 

I noticed that the upper plenium on 90-92 only have two holes on its front but, on the earlyer ones they had a triangular hole also I don't know what it is for but, when I tryied the 90-92 plenium on my freinds 88 it kept setting high gps (mass air) checked for leaks hoses every thing. so I put the older plenium back on and the problem whent a way. maybe it was just a fluke but, why do the older ones have that hole egr? idle air?

 

You got it, the middle triangular hole on the 85-88 plenum is for the idle air and the cold start injector. If you turn the plenum over you can see the passage from the driver's side hole to the front. The other passage on the passenger side is for the EGR.

------------------
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=-

 

What are the differences between these, what is the Gasket he's talking about? What is the difference between the plenum and intake? i thought they wer the same thing!

1)Port plenum; gasket matched to gaskets of your choice: $60 + exchange

2)Port intake; gasket matched to gaskets of your choice: $275 + exchange

------------------
1991 Z28 Camaro L98
5.7L T.P.I
Blk ext/grey lthr int
http://www.iroc-z.org/albums/KamaroZ91/


http://www.fbody.com/members/KamaroZ350/

 

ttt

 

The plenum in the box looking thing on top between the runners. The intake is the intake manifold, where the bottom of the runners bolt into.

Those prices don't seem all that bad, I would check out some of their other work before taking anything to them, unless you want to do it yourself. All you need is a dremel for porting and gasket matching the plenum, intake and runners, but I would look for an air grinder if you want to do the heads since they are most likely iron.

------------------
Kevin Irving
85 Trans Am WS-6, 305 TPI, custom burned '86 PROM with '87 "165"ECM, Accel Supercoil & 8.8 Wires, MSD 6AL, Aluminum Driveshaft, TB Coolant Bypass, Ported Plenum, Modified MAF, Syclone Fuel Pump, JET Airfoil

15.556 @ 86.65mph, Nov 10, 2000.... I know it sucks.. but it will get better!

http://www.geocities.com/transam85tpi/