1) Can I make the part throttle 1-2 shift happen later?

2) The 1-2 shift pressure setting was at 20 psi. Does that mean it raises the pressure from the stock setting to 20 psi during the shift? Or is the pressure at 20 psi whenever the engine is running?

3) The 2-3 shift was set to 10 psi and the 3-4 shift was at 4 psi. Is there just one pressure setting that changes based on the shift? Or are there different lines for each gear shift (1-2, 2-3 & 3-4)?

4) At what point would the line pressure be considered too much? If I understand this right, having too much line pressure can cause premature seal and gasket failure.

5) What do other Predator users recommend for settings to get firm shifts? How about hard shifts?

 

1. Yes
2. During the shift
3. There's one main valve body for this.
4. The problem isn't seal and gasket, I've yet to hear of a single case of this. The problem is running the pump dry from too much flow. That's why this is an advanced setting... they assume you know what you're doing with it.

 

1. Isn't that a function of the LOAD vs. RPM? Which setting in the U7146 Predator would that be? Or is that adjusted through a custom tune only?

2. Thanks.

3. If I understand this correctly, there only one line pressure and it varies depending on which shift is happening. Thanks.

4. The more I learn, the less "advanced" those things will be. That's why I come here.

 

PP,
When you figure it out, can you explain it to me? I figured out how to retard the timing a bit so I can use regular gas and that's about as far as I've gone.

 

My question I posted on DiabloSport:

I have a U7146 Predator and was looking at the Shift Pressure setting. It shows 20 psi and everytime I click it to the right, it increases by 5 psi. Is this the absolute pressure it will use (25 psi), or does this mean it will add 25 psi to whatever it normally uses?


The reply:

This is the absolute pressure. This is the actual amount that your shift pressure will be set at, not the amount of increase.


More from a different reply:

The Performance tune that is included in the Predator has already firmed up the shifts and made them more aggressive.

-------------
... just posting it for the other knowledge-hungry people like me.

 

Follow up:

Isn't 20-25 psi line pressure way too low to perform the shift in a 4r70w? I thought I read somewhere that the line pressure at idle is around 50-75 and when engaged, it is around 160-210.

Anyone?

 

Yes, its too low. 10-20 psi over the stock amount results in a very nice, firm, shift.

 

Bummer. I got the same reply in a post I made on another message board. The DiabloSport representative said it is the actual pressure setting, not what it will add. It doesn't make sense. Hopefully he/she will reply with an explanation.

 

Here's a suggestion (please, not to be taken the wrong way). Invest in a Ford factory shop manual. Its more expensive than a basic Haynes manual but it will give a lot of information on the car, plus maybe a couple of books from Amazon covering the theories. Diablo, SCT, Superchips and others provide the tools that can be applied to your vehicle. If you go beyond the basic included tunes, its really beyond their support scope to give the detailed automotive knowledge for them. An analogy: You can get a hammer from Home Depot... but Home Deport doesn't show you how to frame a house.

 

A follow-up...

I guess what I'm saying is they don't have the huge support resources that the sites may give the impression of. None of the chip companies are massive companies. Some of the companies they sell to are much bigger than they are!

 

Point well taken. I actually surfed Amazon a few days ago for Ford tuning related books. Do you recommend any of them?

I was under the impression that the factory shop manuals are much like the Haynes manuals, primarily pictures and step by step instructions but without the underlying reasons for setting certain adjustments. If they give more than 'what' and include some of the 'why', then I'll go that route. After all, one of the reasons I chose the Predator was to have a tool I can learn with.

 

Update to finish off the thread:

I searched and searched some more and I did come across some stuff that indicates that the pressures during the shifts are in the neighborhood of 160-200 psi. Also, a friend of mine who has a Predator set his Shift Pressures to 0, which would mean stock pressure, and his car shifted like it did when it came off the factory floor. If the displayed value for Shift Pressure was the actual pressure it shifted, as the email from tech support claims, I can't see how a shift would occur at 0 psi.

 

I had a similar thread on another message board. The response I got from DiabloSport about the displayed value on the Shift Pressure setting changed from:

1) The actual pressure
2) The amount to add shown as a percentage
3) The amount to add shown as a PSI value

The second response came after I asked how can the shift complete with just 4 psi, which is the default setting of the Predator's Performance Tune. The third response came after I posted a photo of the Predator screen with the Shift Pressure edit mode showing "stock" on the left end of the scale and "firm" on the right end of the scale, the indicator was somewhere in the middle and it showed 25 psi.

*sigh*

I'm happy with the Predator. I just wish their tech support folks knew their product a little more. Ken at Ford-trucks.com has been the best resource by far!