A1 Transmission and PxS

core-rider

core-rider

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I'll be driving over to A1 this week to have a transmission and converter installed... I seem to remember seeing something about possible tune changes, but can't find a thread anywhere. I think it was mainly changes to line pressure and shift points. Any other things I should know?

My plan is to drive over Thursday, install Friday, and drive back that evening. I'm sure we will do a quick test drive, but 5-6 hour drive home with nothing but music and my over-thinking brain has me on edge! :ROFLMAO: :cautious:🤦‍♂️
 
core-rider said:
I'll be driving over to A1 this week to have a transmission and converter installed... I seem to remember seeing something about possible tune changes, but can't find a thread anywhere. I think it was mainly changes to line pressure and shift points. Any other things I should know?

My plan is to drive over Thursday, install Friday, and drive back that evening. I'm sure we will do a quick test drive, but 5-6 hour drive home with nothing but music and my over-thinking brain has me on edge! :ROFLMAO:
Click to expand...

When I installed my A1 transmission I asked Chris about settings etc in my US Shift controller, he mentioned to just leave it stock on the controller side, his build has the line pressures and such sorted out. So only things I ended up changing were shift points and lock up points. They rest I just loaded up a stock E4OD stock file for.
 
Raymond_B said:
When I installed my A1 transmission I asked Chris about settings etc in my US Shift controller, he mentioned to just leave it stock on the controller side, his build has the line pressures and such sorted out. So only things I ended up changing were shift points and lock up points. They rest I just loaded up a stock E4OD stock file for.
Click to expand...

I had to lower the base tune line pressures on my PxS because I already had a Level 10 shift kit, so maybe I’m good there then. Maybe just some shift point adjustments for fine tuning. I’m interested to try using the lockup features more in the future!


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Like Raymond said, the modified transmission will do it's own thing in terms of line pressures. I wouldn't change anything until you drive it, and then it will be shift points. If you're using timing retard on shift, you'll have to tweak the time/duration on that, but that's a fine tuning detail. It won't impact drivability.

Since ATO built my transmission, I haven't had a single issue with it. I mean nada. And that's with some pretty heavy towing and a lot of quarter mile passes. A well-built E4OD is a great transmission.

EDIT - I should probably include that the aforementioned transmission build was in ~2002.
 
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Okay... got the transmission installed yesterday and the only issues I'm noticing is shifting into Reverse or Drive it's rather aggressive and sometimes it will stall the engine also. Shifting into Overdrive is rather harsh as well and I did some quick line pressure tuning with Chris to try and simmer it down and make the 270 mile drive home. I ended up going back to my original line pressure settings and raising the shift MPH just a little in 3 and 4 which seemed to help more. I also wonder if it's because the converter is locked up when shifting into 4th.

I'm attaching pics of my line pressures and lockup strategies. Can y'all compare please? I feel like 4th gear and reverse line pressures are way high compared to the other gears, but that's how it was before the transmission change.

2400-2600 stall and Stage 1 transmission

On another note... Chris and the gang at A1 are a class act and great people! Would not hesitate to recommend them for a build.

Line Pressures.JPG


Lockup.JPG
 
I would load up the stock line pressure settings and go from there, also you're right, unlocking the converter during a part throttle shift will definitely make it smoother. I imagine with an A1 build you will have no problem locking the converter during the shift at WOT unless Chris says otherwise. I know on mine he said go for it :)
 
Raymond_B said:
I would load up the stock line pressure settings and go from there, also you're right, unlocking the converter during a part throttle shift will definitely make it smoother. I imagine with an A1 build you will have no problem locking the converter during the shift at WOT unless Chris says otherwise. I know on mine he said go for it :)
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Any idea what those settings are? I lowered them from the original PxS tune because they were harsh with my Level 10 shift kit installed and it did fine, but that was also on a 32 year old stock unit. I feel like the 4th gear and reverse gear line pressure graphs are way high initially when compared to 1-3, but that's how they've been for the last 3 years.

Also, yeah no issues with being locked up and shifting... Chris even said I could go to 4th locked up as long as I wait to hit the overdrive after I'm in 3rd gear.
 
Hmmm I thought they included a stock file, but maybe not. Let me find the US Shift stock one and see if I can post it
 
I did find my base file from Stinger… it looks a good bit different than mine and I’m not really sure why. May have to contact them to confirm it’s the right file.


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Comparison of what I believe is the base tune and current tune. Line pressure graphs look a good bit different and that might have something to do with my issues.

OG_LinePressures.JPG

Line Pressures.JPG
 
Don't forget Tuner Studio has a Compare function, it will highlight the differences between two tunes, then you can pick what you want and load the new tune.
 
Yeah already compared them, but it doesn’t show line pressure graphs or shift point graphs unfortunately. Looking at them closer I’m running about 40-45MAP at idle which both are very similar in those areas… no real reason to have anything on the graph below 20 MAP similar to the base tune. Think I’m going to try a drastic change of lowering the line pressure just to see how it affects shifting into drive and go from there.


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core-rider said:
Yeah already compared them, but it doesn’t show line pressure graphs or shift point graphs unfortunately. Looking at them closer I’m running about 40-45MAP at idle which both are very similar in those areas… no real reason to have anything on the graph below 20 MAP similar to the base tune. Think I’m going to try a drastic change of lowering the line pressure just to see how it affects shifting into drive and go from there.


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Sounds like a plan, just data log it and show Chris the line pressure to make sure he's good with it.
 
Well on the advice of Wesk at Stinger I tried going to TPS instead of MAP reference for the line pressure and still no good. I dropped the reverse line pressure percentage way down like it is with 1st gear and it still stalls going into drive or reverse. Only time it didn't was giving just a bit a throttle input. Went back to MAP reference just to test and it still stalled which would be slightly higher line pressures on the graph. Sent the datalogs and tune to Wesk to see if he can see anything in the logs. Kinda frustrating! 😕

I didn't drive around so not sure if the changes I made affect 4th gear shifts.
 
core-rider said:
Well on the advice of Wesk at Stinger I tried going to TPS instead of MAP reference for the line pressure and still no good. I dropped the reverse line pressure percentage way down like it is with 1st gear and it still stalls going into drive or reverse. Only time it didn't was giving just a bit a throttle input. Went back to MAP reference just to test and it still stalled which would be slightly higher line pressures on the graph. Sent the datalogs and tune to Wesk to see if he can see anything in the logs. Kinda frustrating! 😕

I didn't drive around so not sure if the changes I made affect 4th gear shifts.
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I wonder if some more idle timing would help the sensitivity to line pressure changes at idle? I'd try that as it will help the engine cope with the, potentially, increased load. What RPM are you idling at?
 
Could be tune related with the stalling in reverse. Big load changes can make things interesting.

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Raymond_B said:
I wonder if some more idle timing would help the sensitivity to line pressure changes at idle? I'd try that as it will help the engine cope with the, potentially, increased load. What RPM are you idling at?
Click to expand...
That's what I'm beginning to wonder... Just got back from a test drive and the lower pressure in 4th definitely helped. That was using TPS reference, but I think I'll go back to MAP for now. I may end up going back and using the base tune settings and tweaking from there. I did use compare tune again and this time it showed the line pressure graphs, so maybe I just missed them before.

You might be on the correct path with timing... it doesn't seem to be as sensitive to stalling once the transmission fluid get some heat in it. I'd thought it would have been less sensitive given the higher stall, but maybe my thinking is backwards. Idle is 750-800.

Did finally stall it up and on street tires with less than great surface I saw 2400ish, as well as heard the turbo start to spool up which never happened before, so there is some excitement there! Just need to get these little tuning issues ironed out and see what I can get done at the track!
 
Air and fueling will make the truck stall quicker than anything. When you put it in reverse, see where it falls to on the VE table. That area may need some work. Timing is quickest defense to holding idle speed though. I like to build a timing wall on my spark table. I also had a very aggressive timing correction curve for idle that would catch the fall very quickly. Not saying that is your issue but when you have all the idle stuff set up right it definitely helps.

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Just seems weird a trans/converter change would make symptom. I could see it with a tighter stall, but I went looser. Maybe because the transmission clutches are tighter? I’ll try adding some timing next time and see what it does.


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core-rider said:
Just seems weird a trans/converter change would make symptom. I could see it with a tighter stall, but I went looser. Maybe because the transmission clutches are tighter? I’ll try adding some timing next time and see what it does.


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Click to expand...

Hard to tell, have you taken data logs to verify the changes in line pressure, lockup, etc?
 
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