Discharge plenum – Vortech 1990-1995 5.7L TBI Truck/SUV User Manual

Page 17

P/N: 4GB020-010

22FEB02 V1.1

(LT. TRUCK (4GB V1.1))

10. DISCHARGE PLENUM

A. Thread the supplied 90

plastic fitting into the 3/4

NPT bung located on the discharge plenum. (The
fitting should be screwed in until snug, pointing
down & to the right at approximately a 45

angle).

B. Attach the discharge tube between the plenum

and supercharger with blue sleeves; secure with
clamps as shown.

C. Install the short 1" hose piece onto the 90

fitting

with hose clamps. Attach the supercharger by-
pass valve (vacuum pointing toward the outside
of vehicle) to the short hose.

D. The discharge of the bypass may either be routed

to atmosphere by using the supplied 1" K & N filter
(This installation will produce some air noise on
deceleration), or back to the supercharger air
inlet tube by using the supplied 1" x 10" hose and
3/4" NPT x 1" plastic fitting. If routing the air
bypass back to the supercharger inlet:

• Mock-up the steel supercharger inlet

tube into its approximate final location.

• Center punch and drill a 59/64" hole

into the inlet tube and thread with a
3/4" NPT tap. (See

Fig. 10-b for hole

position).

• Thread with the supplied 3/4" NPT x 1"

plastic hose barb into the air inlet tube.
Connect the long length of 1" hose
from the bypass to the air inlet.

E. Connect a vacuum hose to the bypass

valve and a vacuum source.

F. Connect the 5/32" vacuum hose between the

small fitting on the side of the discharge plenum
and the TEE that feeds the pressure normalizing
holes in the spacer block (see schematic page 5).

Bypass Valve Not Shown

Backside of Inlet Tube (Installed)

1-7/8"

Backside of Plenum

Approx.
Center
(Vertically)

Drill:

Tap:
(optional)

59/64"

3/4" NPT

Supercharger
Bypass Valve

Fig. 10-b

Fig. 10-a