echo999

Awhile ago, I asked you guys where the input to the boost solenoid comes from.
Everyone said that it would be ok to tap it off from the FPR. Looking at the
instructions that came with my SBC-iD, I truly believe that you shouldn't tap from
that location. You really should tap it somewhere after the intercooler, and before
the throttlebody. In fact, if you tap the wastegate off from the FPR on the fuel rail, the wastegate is not going to open up correctly... it won't sense the actual boost it is generating.

I'm thinking that you can have the throttle at 50%, and be creating like 5lbs of boost, but the intake manifold is only seeing 2lbs.

Example: I have a wastegate with a 4 lb spring. Turbo is generating 6 lbs of boost before the throttlebody, but only sensing 3lbs in the intake manifold. If I suddenly open the throttle to full, all 6lbs will suddenly be pumped into the intake. This will cause a 2lb spike before the wastegate can open up to relieve the pressure.

THEREFORE, I'm thinking that we MUST tap all boost controller type devices from BEFORE the throttle body. This includes wastegate and boost controller.

Ok.. flame on.


[Modified by echo999, 1:21 AM 5/10/2002]

DragII

if you have a boost controller, you can just tap off of the compressor.

intekragsr

what about people like me who dont have a hole on the compressor?

rioninja

I've had recent bad experiances tapping the wastegate from the manifold.
The BOV on the other hand, -has- to be tapped from there, because it only opens under vacuum. Before the throttlebody, there is never vacuum.

echo999

I'm thinking we need to tap the piping after the intercooler, and before the throttlebody.. This will ensure that the maximum boost ever seen before the throttlebody IS the max boost that the intake manifold will ever see.. EVEN IF the pressure is actually higher before the intercooler.

That makes sense Intekragsr.. BOV should be taken off the top list.. (will edit)

So Intekragsr, where do you tap your source for the wastegate?


[Modified by echo999, 1:22 AM 5/10/2002]

intekragsr

i tap it from the FPR

GruvyTune

I had a long conversation with the techs at Blitz and they turned me on to a really cool way of hooking up the solenoid. If you are running under 16psi this is THE way to go:

Even though you have an external wastegate, turn the setting to actuator and run manual settings by setting the duty cycle and gain to achieve your desired psi.

Now the kicker....leave the top port of the wastegate open and run the output from the compressor to the in port on the solenoid and the out port to the side port of the wastegate. works like a charm.

DragII

isn't that the "normal" way to hook up a MBC?

echo999

Heh.. reviving this from the dead...

SO, can someone explain how the deltagate works?

When I opened up the wastegate to change springs, I saw that the boost port
(top port) was covered by a metal plate (supported by the spring).

The side port opened somewhere underneath the the bottom plate pushed
by the other end of the spring..

Ideas?

I have the side port connected to my FPR vacuum, IN on the solenoid unit..
and I have the OUT on the solenoid connected to the top of the wastegate.

I have a 3-5 lb spring installed.. with the BC OFF, I boost 2.5lbs.

With the BC (Blitz SBC-id v2) ON, and set at 4 lbs, I boost 3 lbs.
Set at 6 lbs, I still only boost around 3 lbs...

What's wrong? Is my solenoid stuck open or something?