Transmission Tuning (advanced tech)

[Pistol_91]

No not the base table, the actual table for each gear. 1-2 2-3 3-4 etc etc.
Yes if you make drastic changes above or below the stock value it can cause synchronization issues. For example I tried slowing down the 2-3 shift by 40% (took it to 1.4) to see how much of a change it will be and the shift flared and hung up and threw a CEL flashing light on the dash. Felt like I hit the brake pedal in the middle of the shift.

You have some play room with some minor changes inside the transmission but if you move some things too far away without moving everything else with it, you will have issues. 20% is a noticable change and no issues dropping it to .8.

Start slow if you're worried. Go to .9 or .95 and see how that effects things.

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[engineermike]

The inertia phase happens after torque transfer, so everything leading up to that point should leave it in a state of: torque is being carried by the oncoming gear but sync speed lines up with offgoing gear. The inertia phase simply pulls the engine speed down to sync with the oncoming gear. Torque has already been transferred over to the incoming gear, so all it really has to content with is engine inertia. It doesn't really care what happened to this point or how quick it happened, just that it happened.

Torque modulation happens during inertia phase as well, but more than just the value matters. There's also a torque modulation rate that generally allows it to rapidly pull a lot of torque quickly in alt1 but in alt2, if active, the rate of torque reduction and restoration is much slower and you don't get all the torque pulled you might have intended.

S550 inertia sub-phase times, at least in the past, have not been shown in hptuners. Only the multipliers were shown, so all you could see was the 1.0 multipliers in Alt0 and lower multipliers in Alt1 and 2, but all of these multipliers applied to the same base times for the sub-phases. So you could see all they did in Alt2 was change this to 0.2 for all sub-phases and the inertia phase would happen in 1/5 the time. In S650, they actually use different times for Alt0, 1, and 2, so the multipliers look totally different and are much higher for Alt1 and 2 because the baseline times are much lower. But I believe hpt shows all of these times for S650 but still not defined for S550. PCMTec has these defined for all of them.

 

[Pistol_91]

Mike you can see all the sub phases for the inertia phase now on HPT. They're in there for every gear and mode.

 

[Weezox]

Mike you can see all the sub phases for the inertia phase now on HPT. They're in there for every gear and mode.

I’m going to

No not the base table, the actual table for each gear. 1-2 2-3 3-4 etc etc.
Yes if you make drastic changes above or below the stock value it can cause synchronization issues. For example I tried slowing down the 2-3 shift by 40% (took it to 1.4) to see how much of a change it will be and the shift flared and hung up and threw a CEL flashing light on the dash. Felt like I hit the brake pedal in the middle of the shift.

You have some play room with some minor changes inside the transmission but if you move some things too far away without moving everything else with it, you will have issues. 20% is a noticable change and no issues dropping it to .8.

Start slow if you're worried. Go to .9 or .95 and see how that effects things.

Okay so I'd just be multiplying the gear change ALT 1 tables by .9 to start, this still keeps them far from ALT 2's .2s everywhere. I'll try it out.

I was looking over all the subphase base numbers, I wonder if the 300ms end time across the board for the 6>5 downshift (no other downshift has anything like this) is the reason the 6>5 always sounds/feels super wimpy when coasting to a stop. Maybe to protect the D to C clutch swap from 6>5?

 

[Pistol_91]

Btw when I'm talking about the inertia phase multipliers I'm referring to the first set under that tab. 1-2 2-3 3-4 etc etc. Not under alt 1. Alt 1 is set up differently with the sub phases. You don't need to touch those. It's the regular tables that have no sub phases in them.

You would think you'd change the alt 1 tables (which you could), but it's not necessary. Trying to dial in each sub phase takes forever. It's much easier to change the general multiplier in the regular gear shift tables.

 

[Weezox]

Btw when I'm talking about the inertia phase multipliers I'm referring to the first set under that tab. 1-2 2-3 3-4 etc etc. Not under alt 1. Alt 1 is set up differently with the sub phases. You don't need to touch those. It's the regular tables that have no sub phases in them.

You would think you'd change the alt 1 tables (which you could), but it's not necessary. Trying to dial in each sub phase takes forever. It's much easier to change the general multiplier in the regular gear shift tables.

Now I'm a little confused,

The first tab of Upshift corresponds to the "Normal" tab inside my file in PCMTec, I would be under the assumption that this would change the multiplier to the base "Inertia phase duration" for Normal Mode.

Is that not how it works? Do like ALT 1 and ALT 2 further stack those multipliers on top of the Normal table?

 

[Pistol_91]

Yes those are the tables. I'm not sure why they name it the "normal" table. I've never touched the alt 1 multipliers, I've only ever touched the "normal" tables and it definitely affects alt 1 upshifts. Mike may know exactly how it works together but I've only ever have changed those and changed the actual inertia sub phase times.

Edit - from what I've interpreted, the "normal" tables are for WOT or "higher demand" and the Alt 1 tables are everywhere else in between while you're in alt 1. That would explain why the changes work for me on my WOT shifts when I'm in sport mode.

Edit again - wait what year is your car? Mine is a 2020 and I do not have alt 1 or alt 2 tables under inertia phase duration... This may be the confusion here.

 

[engineermike]

I had assumed (but not verified) that the base multipliers were from base/alt0 shifts. I'm not sure if the alt1/2 multipliers stack on top of the base multipliers, but I would tend to think so.

 

[Pistol_91]

I had assumed (but not verified) that the base multipliers were from base/alt0 shifts. I'm not sure if the alt1/2 multipliers stack on top of the base multipliers, but I would tend to think so.

I believe they do. Whether I change base multiplier or alt 1 multiplier I get the same exact result.

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