September 4, 2004**I searched the Forum for anything on this info and did not find anything. So, if the info is a repeat please delete/ignor!!**
After reading Envoy Fan's plee for the Westers I did a google search for info on this Westers. I came across an interesting read on another forum (not sure how posting links/info to/from other furums works here, so I will wait for an Admin/Mod ok). It had to do with a 04 Suburban with a 8.1L that has drive-by-wire, like our 4.2L I6, the owner was running an AutoTap and recorded the throttle blade position under exceleration. Results: No matter how hard you push on the go peddle, from idle to ~2700 rpm the throttle blade will only open gradually, no instant WOT from a dead start. Example from the posters AutoTap graph (actual graph is more detailed):
RPM * Throttle opening %
521 * 18
1391 * 28.6
1889 * 47.8
2270 * 72.9
2513 * 99.6
That is why we feel that sudden kick at between 25-3000RPMs, cuz right at around that time the PCM allows the blade to go wide open not before, this is also the reason it will not let you rev it past 3k, I think it is, in park. My guess is that GM set it up this way as part of the Torque Management and for better fuel econ.
The same owner installed a Westers PCM and this is fixed. The throttle goes to 99.6% as soon as you mash the go peddle. So, until we get a tuned PCM that addresses this, such as Westers, any mods you make will really have no major effect on the bottom end, since the throttle is not allowed to WOT until ~2.5-3k RPM's.
So I am with you Envoy Fan, we need to get a TrailBlazer/Envoy up to Wester!!!!
Sorry so long!