Have seen electric (Jet, B&M) shift improvement products as well as mechanical (Jet, TransGo) shift improvement products for the 4L60 transmissions. Wondering if someone could explain the how the electric systems work and whether the mechanical systems make the shifting VERY harsh.

Looking for something more from my tranny but my Tahoe is a daily driver and weekend family car so the shifting can't be TOO obnoxious. Read some posts earlier about Torque Management. Does that mean quick firm shifts, w/ chirping of the tires here and there is out of the quesiton?

Product/Brand recommendations/experiences appreciated.

 

A shift kit of any kind on firm will create some TQM issues. This means a shift even less desirable than stock. I have a HPP3 and a TransGo Shift kit and have experiemented with many combinations of the two. I have also experimented with the B&M shift + and an Trans Interceptor from AutoTrans INC.

I would still say the mechanical shift kit is superior in shift feel than an electronic line pressure device. I have run the Transgo with the "3 washer" race setting and it will bark the tires at WOT any time you want. The only negative is the TQM reaction...delayed engagement, negative timing, and cylinder fuel cut. I have since restored a "1 washer" setting in which it is slightly firmer and quicker than stock.

The electronic shift improvers work OK for street use but don't seem to speed up shift engagement at all. Some of these also have very harsh PTO shifts.

Richard

 

Is TQM only a truck/suv problem?

Also, what does PTO stand for?

How does a torque converter factor into this? I know that the launch is improved, but does it also change shift characteristics? I thought I read that the TC maintains higher RPM through the shift.

Thanks again for the info.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Is TQM only a truck/suv problem?</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">No, It's a year problem. As you progress through the years the TQM issues become larger. A 99' truck vs. an 02' truck will react very differently to elevated "measured torque" levels. This is an issue just as prevelant in the F and Y bodies.

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Also, what does PTO stand for?</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Part Throttle Operation

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">How does a torque converter factor into this? I know that the launch is improved, but does it also change shift characteristics? I thought I read that the TC maintains higher RPM through the shift.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Exactly...The converter keeps the motor from "seeing" the lower HP/TQ rpm range thus allowing for faster initial acceleration -launch- and better sustained power during shifting. The rated stall speed/rpm of the converter is the point at which hydraulic lock-up (differing from hydro-mechanical lock-up) ocurrs or nears 1:1 on the input shaft. The higher the stall the more quickly the motor will reach the "optimal"
rpm range.
While shifting the motor and trans are disengaged and re-engaged and the amount of rpm the motor drops is lessened with a higher stall converter. As the load under the stall rpm is not "seen" or realized by the motor.

Richard

 

Last question. Any links to torque converter installation procedures? I have vague memories of changing one, back in the day, but may as well go to the source.

Again, your help is appreciated. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />