90 Corvette Pinging Update

[David A. Cooley]

This means the PR chip only disables EGR...
Not a performance improvement, but a detriment as it adds more detonation
since they didn't add more fuel.
Typical of a fly by night chip company.


At 08:34 PM 10/20/98 -0400, you wrote:
>Tonight I changed over to the stock chip.  At WOT, the stock chip pulls out
>5 degrees of advance at 5000 RPM just like the Performance Resource (PR)
>chip.  At highway cruise, the stock chip pulls out 1 degree of advance under
>light acceleration, the PR chip pulls out 2 degrees.  At 20 mph where the PR
>chip pulled out 15 degrees, the stock chip pulled out 3 degrees.  One
>blatant difference was the PR chip was indicating 0 duty time for EGR and
>the stock chip was showing 99.4% duty time.  I have spoken with PR and am
>returning the chip along with printed sheets of data from the PR chip and
>stock chip for this 20 mph case.  They are going to send me another chip as
>well as examine the data in the mean time.  So now I am left with the fact
>that both chips are retarding my advance on the highway under light
>acceleration and at WOT.  Should I suppose this to be normal?  The service
>manual indicates that the knock sensor is used to allow maximum performance
>which could be interpreted as "they run the engine right on the edge of
>detonation".  If so, a slight tip in of throttle may be too quick and the
>knock sensor has to respond.  I have also read that the front Corvette Y
>pipe has one pipe which crosses into the other internally where they meet
>such that one side of the motor is more restricted than the other.  My
>thoughts right now are that maybe this is leaning out one side of the motor
>and since there is only one oxygen sensor it does not detect this,
>especially if it is on the rich side.  Any comments on this or other ideas
>what to look at are welcome.  I also appreciate the comments I received from
>my original post.  Although I am using Sunoco Ultra 94 octane, I may switch
>brands to see if this helps the situation.  Thanks for any input in advance.
>
>Bob T
> 
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           David Cooley N5XMT           Internet: N5XMT at bellsouth.net
     Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
       I am Pentium of Borg...division is futile...you will be approximated.
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