1-2 Shift Flutter

[Jackpine]

Originally Posted by RedFX4

I just went into the custom programming and it showed that the shift points were set to 5000rpm with max revs set to 5400. I distinctly remember seeing pass this though. Maybe its as you said and I'm just seeing the flywheel freewheeling. Does it usually default to 5000 when you select the customize feature?

Also I was goofing around on the gryphon and noticed it logged my max rpm at 5383. That is a little high for my liking if the TC starts ballooning at 5400.

Long story short, I have the 1-2, 2-3 shifts set to 5000rpm, and the 3-4 set to 4500rpm. I might increase the 3-4 later depending on how it drives. Max revs I have set to 5350.

IF you do a WOT 1-2 upshift with the shift set at 5000 and the max at 5350, you may not get it to complete unless you back off on the throttle. A brief burst at or even above 5400 will not hurt anything. Personally, I'd either set the max at 5500 or move the shift points down to 4900.

- Jack

[RedFX4]

Ya I set the shift points to 5000 on the tow tune and it still revs to 5200 for whatever reason. Yes I selected done after and it re-uploaded the tune but there was no change.

Finally burned off my 88 octane tank and filled it with 91. Retarded the engine by .5 degrees and lowered the shift points to 5000 for 1-2, 2-3 and 4900 for 3-4. Runs like a charm. I really think you need that load of hauling a trailer on the tow tune settings for it to work properly. Performance tune shifts better to. Far less harsh, more like a lightning now.

I'll just run the 91/93 performance tune until I get and custom 87 performance tune from php.

Thanks for all your input "JackandJanet". Appreciate the help. I'm new to the whole tuner scene if you couldn't tell already.

[Jackpine]

You can expect it to rev to 5200 if you set the shift at 5000. The clutch bands release at 5000, and since the engine is no longer seeing any "load" the rpms rapidly increase (remember, you still have your foot on the floor). Then, after the new gears move into place, the bands lock up again, bringing the rpms down. The unlocked torque converter softens this a bit, but you probably still feel a "lurch".

This kind of thing doesn't happen on a manual transmission, because you let off on the gas as you push the clutch in, adding it back as the clutch is released. Ford actually tries to mimic that a bit in an automatic with something called "torque reduction" that's applied during a shift. However, they overdo it in the name of a very soft shift and Bill reduces the torque reduction value.

This is why you need the max rpm set higher, by about 400 above your highest shift point. If the rev limiter is hit, the engine fuel and ignition (I think) is immediately cut, which causes the rpm to immediately drop. Then, the PCM senses a low rpm and tries to put you back into the lower gear, causing the process to repeat until you ease off on the gas.

Glad you like the way it's working now though.

- Jack