Wastegate
Bleeder T mod
Purpose:
To create more boost than stock (11psi). With this mod on a stock Supra, expect about
15-17 psi of boost, which is about 60-70 HP!Note:
do the BCC before doing this mod to
prevent fuel cut!
- Parts Required:
two 1/4″x1/4″x1/4″ vacuum Ts (available at auto parts stores), knife,
2″ long 1/4″ diameter hose (optional).
- Time Required:
5 minutes.
- How it Works: By bleeding off air from the actuator, the wastegate stays closed longer, which
builds more boost than stock.
- Disclaimer: This modification puts additional stress on the turbos, clutch, transmission,
etc. These components may wear out prematurely. Obviously this modification will
void your warranty (however, it is easily reversible). A boost gauge is essential to
monitor boost levels. The general consensus is that you should not run more than around 18
psi on a regular basis.
Steps
:
- 1. Locate the black, 6″ hose that goes from the vsv to the
brass actuator. Figure 1 shows the general location: front, left side of the engine bay,
just above the alternator.
-
- 2. Figure 3 shows a close up. Cut hose 2 in half. Insert a
vacuum T (fig. 2) into the two hose ends that were just created by cutting.
- Note: there are two ways to insert
the vacuum T:
As in fig. 4 (this is the
classic method, creates approx. 15psi on a stock motor).
As in fig. 5 (this creates
additional 1-2 psi of boost because most of the airflow coming out of the actuator goes
straight thru the open end of the T). I recommend using a a Manual Boost Controller
to limit boost if this method is used.
-
- Note: An
alternate/better way is to disconnect hose 2 from the actuator. Connect a 2″ long,
1/4″ diameter hose to the actuator. Connect hose 2 to this new 2″ hose via the
vacuum T. This method doesn’t require cutting the factory hose, making it easier to put
the car back to stock condition.
-
- 3. If desired, attach a 12′ long 1/4″ diameter hose to the
open end of the T (as shown if fig. 3) and run hose into the cockpit (if desired). A
simple valve can be attached to this hose that can be used as a Manual Boost Controller.
-
- 4. To gain approx. one more psi of boost, cut hose 1 in half and
insert a T (fig. 6). Note that you can’t use this in conjunction with the Manual Boost Controller
unless you run another hose and valve off this T as well. On my car, I just keep the T on
hose 1 capped unless I go to the drag strip.
Note: some people
have found that 1/4″ vacuum Ts aren’t tight enough. If a hose blows off the T then
use a 5/16″ T instead, and/or consider using hose clamps.
To create the maximum amount of boost (for the drag strip,
etc.), simply disconnect hoses 1 and 2.
Fig. 1
-
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Comments/suggestions? Email me
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