Let me start off by saying that I am not a tuner. I do understand most of the concepts pertaining to tuning. I am however very confused by a table in the auto trans shift parameters. I understand the concept and reason behind setting the desired RPM's for a WOT upshift.

Here's where I get lost....

What is meant by setting a downshift RPM point during WOT???? The concept baffles me. Who does this and why would you downshift during a WOT. I am probably reading too much into it. I understand the importance of setting the downshift RPM points at PT, but why WOT?

Please enlighten me.

Thanks in advance.

Randy

 

wow 28 views and no responses. I'm OK with being told it's a stupid question. I'd just like to know why.

 

I don't know of any WOT downshift tables vs. RPM. There's WOT downshift vs. MPH. And depending on vehicle speed, you WANT the trans to downshift when you hammer it.

 

Thank you. I apparently read it wrong. This makes much more sense.

 

maybe he was getting confused with the table that shows both up and down MPH speeds.

On my HP Tuners the table is named WOT shift speed VS shift where it's WOT throttle shift speeds, but in the table it also has down shift table where you adjust both so you dont lower your WOT up shift to lower than your down shift.

as for as the WOT shift RPM, there's no WOT down shift RPM.

No offense blue, but you may have married the tables together

 

On both the up shift and downshift at WOT tables---this is the easiest way to remember----( actually works for the PT shifting also)

In the "UPSHIFT "tables it will upshift at whatever MPH you put in
that TPS or any MPH HIGHER

In the "DOWNSHIFT" tables it will downshift at whatever MPH you
put in that TPS or any MPH LOWER

This works the same for both WOT shifting or PT shifting
**** it gets confusing because there is one exception---at WOT --the UPSHIFT MPH is just the 1st parameter the car must hit in order to command a shift--The second parameter being RPM (at WOT)

example---say at the 1-2 WOT UPSHIFT you have 40 MPH put in the 100% WOT TPS column---that is the 1st parameter ---and lets say you have the "UPSHIFT" at RPM for the 1-2 set at 6200 RPM's---more than likely at 40 MPH the RPM's are like 5000---so it has to hit the 2nd parameter of 6200 RPM's in order to upshift

This "SPLIT" between the MPH at 6200 and the MPH at 5000 is very important--typically on a stock engine you should have at least a 1000 RPM split between the 2 ---On a Silverado with less RWHP you can get by with a 500 RPM split---- BUT on a Modded C5---- cam/hds type car the split needs to be greater--sometimes up near 2000---IF the split is not big enough----It won't shift at WOT and skip over the shift point and hit the safety rev limiter---

 

I think I figured out I have less of a clue than I thought. :o

This is going to need some head scratching.