Using 87 gas mlg custom tune by Justin at VMP. I'd like one step up on shift firmness (assuming that correlates to shift pressure) and making sure it's set for 373 axle and 275/70/18, which I've found turn 608 revs per mile. I've set the tire revs to 605 with the other option being 610 and the axle ratio. I've also stepped it up one notch above zero on shift settings. I don't know enough about spark settings to mess with those. Has anyone else done any tweaking to their custom tunes? If so, are there any other recommendations? I do like what he's done, but the shift firmness he's set seems to only be felt under heavy throttle. I'll be GPSing the truck this weekend to ensure my MPH is accurate. I used his unchanged tune for a few weeks and just tweaked this morning. Normally at 70 mph, I'm just over 2K rpm's, but now I'm just under, thus the GPS test soon.

 

There is no reason to mess with anything other than the shift firmness to your personal preference, gear and tire size. Everything else should be left alone. I'm just wondering if Justin didn't make your shifts that aggressive since it's a gas mileage tune. Did you get any other tunes?

 

Good point, and yes, I also got the 87 tow and the 92 perf. How much percentage over zero can I safely take the shift pressures at 1-2, 2-3, 3-4? I do like the shift firmness he set "behind the scenes" under a heavy foot, but I'd like a little firmer under "economy' driving as well.

 

I set my trans firm to 1-2=10 2-3=10 3-4=5, I love the way it kicks in to gear. I have a 87performance tune from Justin.

 

a tuner is a poor way to increase shift firmness, do a j-mod or get a shift kit and save the pump in your transmission that much additional wear and tear

 

Just because you don't agree with it doesn't mean you have to laugh about it. Mature.

 

Adding shift firmness to shift firmness that already been added to through custom tunes?
There's a concept.
Thought the tuners knew what they were doing but I guess not?
I would have called the tuner to see what their thoughts were first.

 

Good post, 88!

What a concept - "Discuss your tune with your tuner"?

I'll add, if you can make small changes that seem to give you a better ride, good for you - but, talk to your tuner about what you've done. He may have further advice for you. You've paid him big bucks! Don't you think he's worth it?

- Jack

 

i consulted my tuner(vmp) several times untill he told me to just keep adding fuel till i felt it was right, well after doing that and several months when i finally got a wideband hooked up to it, it was still very lean....

 

Hmmmm, it's Christmas, let's all be charitable! lol

When you add a shift kit, valve body, plate/Jmod, the trans flows a lot more fluid quite easily. So, the pressure has to be decreased as the shifts become too firm. When the pressure is decreased the pump does not work as hard.

 

That's pretty cool I didn't know that the xcal allowed the addition of fuel?
Do you go into the menu and access an AFR section?
Elaborate if you can.
If that's the case I wish the gryphon came with that.

I was pointing out the manipulation of shift firmness by use of the programmer while using custom tunes.
So if the tuner sets up his tune with these shifts:
1-2 +10
2-3 +10
3-4 +7
you the user don't see these values because it's loaded as a file and all the arbitrary values should show this but do not.
So then a programmer jockey comes along and enters his idea of shift firmness cause they don't like what they feel:
1-2 +12
2-3 +12
3-4 +10
so now the total values of added shift firmness are:
1-2 +22
2-3 +22
3-4 +17
So a programmer is not really the best way to go to increase shift firmness as others and I have mentioned.
Look for a VB kit, shift kit, Jmod.

 

so you agree to adding un nessicary stress and most likely premature failure to the pump???




I am not sure how many threads we have to discuss that using a tuner (beyond what the custom tune has been set to) to increase shifts is a poor way to do it, and if you want a safe reliable way then a shift kit is needed...

 

I have asked VMP about adjusting the trans firmnes, he said you could go up to 25 psi with out any problems, I also asked PHP and they said you be ok at 10 psi with out destroying your trans, So I set mine to 1-2=10 2-3=10 3-4=5 since the 4 is the weekest gear I set it to 5. A tuner is a poor way to increase shift firmness why???? All Custom tuners do it so why is it a poor way? I think it's one of the best things you can do to the trans to wake it up. There are threads about this topic do advance search.

 

Bear in mind that when you add pressure using a hand held that you are adding to values that are already in the stock or customized tuning.
As an example, my 1-2 wot shifts with the stock tune were in the high 30 psi range.
With the valve body and more power, they are very firm shifts, but in the mid 20 psi range at wot and hight load.
The low speed/load shifts 1-2 are negative numbers to keep the shifts firm but comfortable.
Also, there are other timers involved in the shift strategy other than pressure which would likely be adjusted in a custom tune.

 

Wow. Thanks for all the precious feedback. Well with 10%, 10%, and 5% on the positive side for shift firmness, I'm happy so far. As someone said, you can't tell what Justin initially programmed; maybe they were negative or neutral with his gas mileage tune. With tire size set correctly now, I'm right on with the GPS.

Now I guess it's time to run a few tanks, then swap to his 92 performance at his "un-tweaked" settings to see if I feel any shift firmness differences and/or mileage and power differences.