Blow off valve comments

[nacelp]

> The following is based on my Skyline experience, with air usage
> measured by air flow meters before the turbos. It is not applicable to
> cars that soley use a MAP sensor and throttle angle for air measurement .
> To recap I put in a bigger intercooler and the standard Skyline duct
> that runs across the lower front of the car taking dumped air from the
> 2 blow off valves to the intake between the air flow meters and the
> twin turbo inlets was masking air exiting the lower 4 rows of the new
> IC.

It would have been interesting to do some before and after testing.  The air
is so turbulent immediately in front of the front bumper, that this making
might not have even been a problem, or having been "tested" before and after
would have shown how much effect got how much results.
  That's why I harp so on testing.  For a $140US if you can't design one of
you own, you can find out what is cost time effective for modifications.
  Mock somethingthing to go make a pass, if it works then you can go for it.
If it doesn't or generates huge problems the back to the drawing board.

> Having spent a good deal of money on this item it pained me to see some
> of effectively blanked off.

But without testing might have been perfectly fine.  Sometimes the cure is
worse then the disease.  Lots of times I done something that was borderline
genius, only to have it slow the car down.  But once I got into this testing
mode, life got way easier, less expensive, and the car faster.

So I decided to blank the inlet off
> altogether where the cross pipe entered the turbo inlet ducting, remove
> the cross pipe and vent to atmosphere. The dump valves were being held
> open at idle by the idle vacuum level, so after ages of pondering i
> made a set up of solenoids to control  when vacuum was applied to the
> dump valves. This set up worked perfectly. *HOWEVER* a much more
> serious problem occurred, which any similarly inducted turbo car will
> potentially suffer if the boost air is dumped to atmosphere rather than
> as standard into the air intakes after the AFM (s). On the overrun,
> after a period of boost running, the standard set up will recirculate
> the excess boost back into the turbos, through the IC, and back through
> the dump valves to the turbo inlet again until the turbos inertia has
> slowed them to the point of little or no boost. The AFM's do not see
> any more air entering the engine, as it is being recirculated.

How much code of the ecm do you have hac'd?.
Or are you trying to cover everything with mechanical cures?.

I mean no flames, just what I've found to be true after years of playing
this game
Grumpy

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