? about D2801

[whackem04]

Does this say it will lock the convertor during an upshift? Why would you want this?

[joecar]

Yes it does (at part throttle).

At WOT the TCC will be unlocked, see D1007-9 and D1001-6.

[whackem04]

why would you want this?
how do you get knock in the engine from the torque converter and how can i fix?
its real annoying!

[joecar]

The cars (F-car, Y-car) come with D2801 enabled... probably for improved accumulated fuel mileage...

Immediately upon the trans shifting into a higher gear, the engine sees an immediate load increase... this immediate load increase is large if the TCC is locked, and it is small if the TCC is unlocked (if the TCC is unlocked, the TC slips and allows the engine rpm to stay higher... this is the same as the engine seeing a lesser load)...

If the vehicle is heavy (trucks), then the large load increase will probably cause knock...

If the vehicle is light (cars), the engine probably won't knock regardless of the TCC being locked or unlocked (during a shift) since the vehicle is a lighter load.


BTW: at WOT the TCC will stay unlocked (i.e. even during a shift).

[whackem04]

so i should leave this disabled?
ive tried to get the tcc to unlocked when i increase TP in the 4th gear but it doesn't like to unlock unless the TP is held in that position for at least 2 sec.
any more insight would be great.

[joecar]

Post your .tun file and any .log files.

[whackem04]

i have more. thanks

[joecar]

If you're trying to unlock the TCC in 4th using D1009, then this table is interfering with D1006/D1003 (and vice-versa)...

set D1009 to 100%, and instead edit D1006 (remembering to keep D1003 above D1006).


BTW: you may also want to set D0961, D0962 to 100% otherwise these tables will similarly interfere with the PT up/down shift tables.

[joecar]

Set D2801 to the same setting as stock... if your truck is heavier then the stock setting of D2081 would be disabled.

Edit: corrected.

[whackem04]

ok i already changed and will try tomorrow. thanks

[whackem04]

it still does the same thing. do you think my TC could be bad?
if so what stall speed? i want fuel mileage.

[joecar]

I don't think it's bad... your calibration may have some reason for doing that.

[whackem04]

i guess i would have to go back to a stock tune and see if it happens then?
no other idea why it would do that?

[whackem04]

in still having the TC problem and dont know what do do next.
The other thing my TC does is if i let the truck sit in park running for say 5 mins, i drive again it takes like 5 mins for it to lock down again. I'm still scratching my head.

[whackem04]

Anything?