AlloyTec 4L60E

[B-REX]

I am hoping someone can give a little advice here. this is my first post so please be patient.
I have been tuning a holden VZ Commodore with the AlloyTec 3.6 litre V6 (HFV6) and 4L60E for a friend and have got good results but have a few questions.
When in "Performance" mode the transmission seems to "disengage" at closed throttle when decelerating (below 60 Km/h) which gives no engine braking and then re-engages with a "thud" when the throttle is pressed again. This occurs even with the stock tune but is exaggerated with the new "higher speed" shift tables. Is this a normal feature of "performance" mode? Can it be adjusted?
I cannot find any tables for the transmission calibration that effects this at all.
There is also a "rolling" idle speed table that appears to do nothing.I am trying to keep the minimum engine speed higher during deceleration to reduce the thud when the throttle is reapplied. I can only change the idle speed when decelerating using the "Commanded idle speed vs VSS" table.
Is there anything else I can try?

Thanks

Richard

[driftnpow]

Gday Richard, ive been playing with the alloytecs for some time, autos havent touched on at since i did my day course, but ill try my best to help you out, (just going thru my HpT bible)
firstly the "rolling idle" table affects the allowed speed that your car can do when the car is statonary and you put it in gear when you lift your foot off the brake and your foot not on the accelerator - walking pace-clutching creep with the engine at idle.
The thudding you are experiancing can most likely be sorted out by goint to your shift pressures under shift properties in your trans config, and selecting the appropriate table to suit your desired drive mode.
For this maybe shoot Chris or Bill a pm for detailed expert opinion
but yeah i do know you can adjust your clutching pressures, shifting speeds and shift timing all thru that area, maybe plug around in your help file cause that can answer alot of your questions.
Engine wise outta curiosity what have you found out so far?

[B-REX]

Driftnpow, thanks for your reply.
The tune that the VZ owner wanted involved holding the 1-2, 2-3 and 3-4 shift points to 30, 55 and 90 km/h which means when you accelerate to 40 km/h and release the throttle the engine revs fall to 730 rpm and there is no engine braking at all and it is still in 2nd gear.
As you know there are 5 idle tables for the Alloytec which are Idle v Engine temp P/N and In Gear and Idle v VSS P/N and In Gear and Rolling. The first 4 idle tables all do something but the "rolling" table seems to do nothing.
It gives desired idle rpm v speed v gear which I could use to control the rpm slump off throttle and virtually cure the problem I mentioned in my first post but I cannot get it to make any effect.

I have reset the shift pressures to standard but that did nothing. The gearbox is not actually shifting at the time the noise occurs but feels like it is "freewheeling" and the "thud " occurs as the driveline takes up again when the throttle opens.

I would like to know whether anyone else cannot get the "Rolling" table to have any effect.

The car is only run on 91 octane fuel so not much has been done to the spark timing table but all torque limiters and reductions have been removed and PE changed. Inlet VCT tables will be next on the list to see what it will do. Quite a lively engine now. The driver is very happy

[driftnpow]

Ok seems like ya goin from engine config tables to transmission, id disregard the idle parameters, as i stated earlier really thats to do with engine idle and "in gear/rolling" is basically adjusting settings for when your sitting at the traffic lights in gear and lights turn green and u lift off the brake, nutshell easy to leave stock! The rolling table does work to answer that question, be it manual or auto.
Your transmission issues is only resolved in the transmission settings and nothing to do with engine. Now shift points this is done in auto shift speed tab, these tables you have upshifts for the first 3 rows... downshifts bottom 3 rows, then throtle ya position, the cells are in KPH in our case. if you are wondering what "hot" table is thats when overtemp is detected in the trans it will switch to those tables - id leave them
start with that at least you can command the shift speeds that your customer requires.

im just reading up on the clutching side of things atm

[B-REX]

Driftnpow, It possibly comes across that I am confusing engine and trans tables but no. I have been tuning my blown LS1 A4 for a while now and can get the trans and engine to interact exactly as I want using the throttle cracker and throttle follower tables to control deceleration (engine braking) and throttle takeup. It is driveability and refinement I am trying to achieve on the AlloyTec and please correct me if I am wrong but the rolling idle table should come into operation at 0 throttle when rolling.
So whether I just lift my foot of the brake from a standstill and the car starts rolling or I am already moving and I lift off the throttle, the rolling table should take effect shouldn't it? Or does it only work from a standstill? I can set 1500 rpm on the Rolling table in all gears but the actual idle speed when rolling stays at 730 rpm which is the setting of the commanded idle v VSS In Gear table.

I know these are are engine parameters but I have posted in the trans tuning section as they relate directly to the engine/trans interaction and effect trans tuning.

[driftnpow]

Sounds like were getting a little off the transmission here, but your LS1 is cable driven from the sounds with the throttle cracker, electronic throttles do not have this! instead they allow the idle airflow by being slightly open at all times. on decel they turn back past this naturally cracked position to fully closed but then go back to the slightly open position to resume idle airflow, if you ever see the TPS on the scanner the percentage is usually 15%.
Engine braking is only ever going to occur when clutch is engaged, in gear and your in decel, which you already understand and even better you have first hand experiance with the A4's.
now cause i havent played with it software wise i can somewhat picture what is happening with your customers car, the hydralic pressures for the clutch sounds like its dropping off too early on decel then its pressuring up at lower speed, resulting in no engine brake then the thudding, if its thudding when accelerating, dare say its slipping too much then at certain rpm/speed its then fully engauging. but thats my view and keep in mind i havent played with the A4's as yet. but if what im saying is of not much help i do recommend shooting chris and bill a pm!

[B-REX]

Driftnpow,
Thanks for your advice. I need to be able to explain myself clearer.
The problems are simple.

With the new shift settings the car shifts 1-2 at light throttle at 30 km/h.
As you accelerate past 40 km/h then lift off the throttle (still in second gear) the engine rpm drops from over 2000 rpm to 730 rpm. When you re-apply the throttle (gently) the revs jump back up to above 2000 rpm and the thud is heard / felt.

This is what I am trying to eliminate.

When you manually select 2nd gear and do the same the revs only fall by 200-300 rpm and there is no "thud".

How can I set it to do this in Power mode?
I was hoping the "Rolling" idle table would hold the revs up to achieve the same result but I have found that it did nothing. So what else can I try?

PS I have PMed Chris but no reply yet.

[driftnpow]

How ya goin Richard, had much of a play this weekend. Yeah i think Chris and the boys may be lil flatout with pushing out a new beta release, but yeah if you bare with him he should be able to give ya reply with the best possible remedy.
Yeah ive been out and about today myself, just working on stablising fuel trims.... playing with cam settings greatly throws them off. atm round town im getting about 10lt/100km which is alright i guess, but open stretch been getting to low 8's, my mates sv6 was seeing open road figures as low as 7.5, which is staggering but im stoaked all the same - need time to pull in his STFT's as they like to swing like a dunny door, way worse than mine.
ill be working on it for some time still as its a never ending battle but once im happy ill rig up the wideband again for some WOT/PE work - chugs a little on PE, so i do think it needs some attention.

[driftnpow]

Gday Richard, any developments on your customers gearbox config?
Yeah, i havent had much time to look at auto gearbox configs, but still busy playing with the fueling/maf and ign timings on my ute, slowly but surely getting there

[Pwayne]

Hi,
I was informed that the HPtuner software did not include tranny tuning yet for alloytec. I got mine and sure enough nothing under the transmission section.. How are you guys tuning your alloytec tranny?? I have on 05 Cadillac CTS with 3.6 liter alloytec, and latest version of HPtuner software. Thanks.

[driftnpow]

HP does include tranny tweeking, its down to what operating system is running in your vehicle and weather or not its got supported parameters at current time, there are availible parameters for us to tweek but dont ask me on autos as i drive a manual.
As you may be well aware GM using bosch based systems these days in conjunction with the alloytec series and yeah this makes development for Chris, Bill and the rest of the HP team more difficult.
But yeah if your tranny isnt supported this current time ive fired up a thread for alloytec family in the requests section.
Cheers, Bryan

[Pwayne]

Thanks for the quick response. It looks like they have included the 4 speed auto but not the 5 speed yet.

I'm a new tuner. I'm hesitant (scared) to tweek the 4 timing tables for different combinations of intake cam/exhaust cam angles. Do you have any tips or tables that might apply to my 3.6 alloytec?

[driftnpow]

yep on timing... ill get another thread cranking for you in the V6 engine forum for ya!
as for the 5 speed ahhh dont think its supported or it maybe... i havent had time to sit down with a mate who got an sv6 with an auto 5... but yeah again autos in general, im still clouded in general im only confident on gear change speeds if it gives ya idea lol