Beginner G8 GT trans tuning

[04blackgmc]

Shift Properties -> Shift Time Inertia Adder -> Upshift - Special -> 1-2Sp.

3 left cells are higher than stock.

nope they arent..

looked at my stock tune they are all - over stock

[johnh]

Yep my discrete is disabled.

[Allmachtige]

nope they arent..

looked at my stock tune they are all - over stock

Any reason?

[04blackgmc]

Any reason?

They are lower than stock just like the rest of my special tables

[johnh]

So has anyone tried to improve the downshift via speed or intertia profiles? Since it seems we can't stop the timing pull, perhaps we could limit how long it takes via fast shift.

[8850]

So has anyone tried to improve the downshift via speed or intertia profiles? Since it seems we can't stop the timing pull, perhaps we could limit how long it takes via fast shift.

The downshifts can be made fast but still no way to reduce advance reduction recovery.

[johnh]

still no way to reduce advance reduction recovery.

This is a limitation of HP Tuners I suspect, there must be tables that control it.

[Allmachtige]

They are lower than stock just like the rest of my special tables

Ah your right, your right.

My bad.

I got confused with all the different files I have.

Last question: Your Inertia Factor Profile - Upshift tables for 1-2 and 2-3 have slight increase at ~4000rpm. Did you feel your shift was too soft at those rpms?

[04blackgmc]

Ah your right, your right.

My bad.

I got confused with all the different files I have.

Last question: Your Inertia Factor Profile - Upshift tables for 1-2 and 2-3 have slight increase at ~4000rpm. Did you feel your shift was too soft at those rpms?

just wanted a more firm feel when the car starts shifting at or above those RPM's btw 3-4 was increased slightly also.

[04blackgmc]

So has anyone tried to improve the downshift via speed or intertia profiles? Since it seems we can't stop the timing pull, perhaps we could limit how long it takes via fast shift.

i decreased the PD times through the main table
and also the shift time torque adder -downshift special as well.

[QuickSilver2002]

Here comes a possibly stupid question (been tuning for quite some time, but new new with auto trans).

I have a new G8 GT that I'm starting to play with.

I see people (on other forums...)talking about having tq mgt set to different % based on sport vs normal... From looking at the tables in HPT I don't see any tq reduction stuff that is specific to mode (normal, special...). I think most are talking about something with a cortex hand held....

I do see desired output TQ normal, special... under Shift Properties, but those tables don't even tell me what the axis is.

I have a lot to learn here.

Any suggestions on where to start would be greatly appriciated. Plan to do one of my first flashes on this car later tonight. First step is to remove it on teh engine side. The stock tq mgt is pretty limiting to say the least.

[04blackgmc]

cant cater TM to shift mods... but u can cater shift times to shift modes.
(with hptuners)
like on my car my normal mode is very much like stock but sport is not.

[QuickSilver2002]

cant cater TM to shift mods... but u can cater shift times to shift modes.
(with hptuners)
like on my car my normal mode is very much like stock but sport is not.

Thanks, that is what I figured.

[johnh]

Well I tried it out with Power DS TQM disabled. To tell the truth I didn't notice any difference in either the car or the scans (still pulled way too much timing).

I did try nailing it after downshifting with Manual mode...what a difference in power.

Ok we have to make them find the tables that control that timing pull...its a killer on downshifts. Only thing I could think of was blip the throttle to get it to downshift then nail it...but still...WHERE'S That table? It might be worth an email to Livernois or Vector to see what they say.

[04blackgmc]

Correct much stronger and no timing pull when u ds manually and punch it I do this then manually shift or kick it over them over again which will pit u back in sport

[johnh]

Well here's some scans (and tune).

One interesting thing I noticed is that I did a 3-1 shift and VSES came on, but that had good timing at least until stability control reduced the ETC. (stab on log frame 2800 or so). Need to look at 3-1 vs 6-2 and see what's different...

No difference from a 40 roll with Power downshift enable/disable and no stability control kicking in.

v87 and v88 tunes are same except for PD TQM enabled (87), disabled (88)

[johnh]

Hmm..I think the Shift Intertia profile might hold the key.

What gets me though is why the 2009.5 G9 GT (and camaro) the Downshift profiles are so dramatically different that 2009 GT?

[04blackgmc]

Hmm..I think the Shift Intertia profile might hold the key.

What gets me though is why the 2009.5 G9 GT (and camaro) the Downshift profiles are so dramatically different that 2009 GT?

yea they are ALOT different..thats sure.

[Allmachtige]

Well shane I like your latest shift times for special.

I can see why you enabled discrete shifts for 2-3, as it can be a bit rough when not under full throttle. However I don't see anything wrong with 1-2. I think I'll just re-enable discrete for 2-3 and let you all know how I like it.

[04blackgmc]

Well shane I like your latest shift times for special.

I can see why you enabled discrete shifts for 2-3, as it can be a bit rough when not under full throttle. However I don't see anything wrong with 1-2. I think I'll just re-enable discrete for 2-3 and let you all know how I like it.

glad u like it!