Re: more boost

[PDQSHIP@aol.com]

In a message dated 96-05-16 19:17:00 EDT, you write:

>>
>>For an implementation question on the 5000/200 turbo cars, why doesn't
>>anyone reprogram the ECU to make the wastegate frequency valve work
>>for you in raising the boost pressure? Kinda like the HKS EVC, only it is
>>standard equipment in all these cars. All that needs to happen is to use it
>>in the correct manner.
>> -
>>Dave Lawson  dlawson@ball.com
>
>
>The ECU WILL work the wastegate valve to raise the boost pressure if
>it THINKS it needs to be raised. If you just use the weaker spring,
>there is a BIG DEAD SPOT in your acceleration where the spring 
>"lets go" upto the time where the ECU realizes that there is not 
>enough boost, and then gets busy and takes it all the way to 1.7 bar.
>
>The smoothest action is when the spring holds the wastegate down
>to 1.7 bar, and the cpu decides that that's just right.
>( for 1.7 bar final boost that is, you can adjust the numbers for 
>your own target final boost )
>
>

.....   What you describe is the key to wastegate spring pressure...  You
want a very stiff spring rate to get you up to a boost level where the
computer can add more boostvia the WGFV....  To do this you really need to be
in the boost already (can't add pressure if you don't have any to add)....
 But once in boost the spring rate should be irrelevent, and the computer
should do all the control of the wg thru that valve, truly a good tweek.....
 So really the wg spring rate should only be enough to eliminate the "dead
spot" you describe, no more, and even that can be addressed with a stock
spring....  And that is hardly what ned or TAP or PW or a few others sell
you.....  Eprom mods....   Very few of the well known computer tweekers do
them, the exception list is REALLY shorter than many think.....

NJAP  (adding pressure)

Scott