Torque reduction on stalled up launch

[Sasha]

At the drags last night I noticed quite a reduction in power while stalled up on the line trying to launch. Is there a table in the ZF to reduce or remove this?

Also on a side note, is the indicated engine torque table tied in with the zf's shift characteristics somehow

[DarrylC]

Not an expert on either of these but look under the Transmission Torque table and at "Stall Time Limit". Mines standard and is set to reduce torque to ~90% by 3 seconds and down to ~10% by 12 seconds.

Yes indicated engine torque changes the shift characteristics. I had mine set at 500 ft-lb and the car was crap, vibrating under acceleration and with terrible shifts. Dropped it back to 405 lb/ft and she shifts real smooth and quicker.

Hiddeous, IH8TOADS or Jet will know a lot more about it. This is just what I have found by experimentation.

[Sasha]

stall.jpg Thanks DarrylC is this the table you were reffering to?

It has time at the top as an input value, but also time 0 to 5 seconds on the fixed horizontal axis.

0.0200000 is this a seconds value or a reduction value? Would setting this to 26 seconds give you 26 seconds of stall without reduction?

[JETURBO]

What your seeing is not related to the zf tuning

Look at engine torque management

And start clipping away.... I mean chipping away

[Sasha]

torque.jpg

Over here? What was Darryl referring to by stall time then?

[45T-XR]

The stall limit time will also give a similar result. It is actually what I messed up last time at the track. I'd flashed an early tune by mistake that has the stall limit time set to stock.
As you try to build boost on the line it will close the throttle. From memory when I was racing mine stock many moons ago, I used to stall the car up in second gear then click first then let the car go.

[Sasha]

Yeah it seems like a bit of a grey area that nobody is really sure about. I emailed support and the response I got back was "I honestly do not know"

The stall limit time table is there for a reason and surely someone must know what the numbers correlate to. There are guys doing 1.6 60's and even less! Are they all stalling up in second gear then clicking first....

[DarrylC]

As I said I am no expert but I was able to stall the car up to about 3000rpm for quite a few seconds. Anyway we discussed some of this here:

http://www.hptuners.com/forum/showth...-in-AUS/page39

Hiddeous and I put up a couple of tunes which will give you some idea.

I have seen the stall time reduction set to 80% from 4000 rpm up so will be interested in your outcomes.

I will find out how it goes on Friday/Saturday at the AFF Drags

BTW: Is it a comment thing or do the 'Fuel Cut Torque Ratio" and "Spark Torque Ratio Limit" tables work differently. The comments say set to 0.0 to disable in Fuel Cut one and 1.0 in Spark.

[Sasha]

Thanks heaps for that Darryl!

I enabled torque module switch and raised the torque reduction and clip torque figures for trans trunc and viola!

I had previously removed the fuel cut and spark cut torque ratio but it seems the transmission truncation needed to go in the opposite direction rather than disabled.

Disable and torque module switch off must default the ZF into thinking there is a drama and applying the maximum torque reduction.

Your input got me sorted Did a quick test on the street and stalled to 3,000 before turning the tyres and boost was well up there!

Also thanks to Jet for pointing me away from the ZF stall time table

[hiddeous]

Thanks heaps for that Darryl!

I enabled torque module switch and raised the torque reduction and clip torque figures for trans trunc and viola!

I had previously removed the fuel cut and spark cut torque ratio but it seems the transmission truncation needed to go in the opposite direction rather than disabled.

Disable and torque module switch off must default the ZF into thinking there is a drama and applying the maximum torque reduction.

Your input got me sorted Did a quick test on the street and stalled to 3,000 before turning the tyres and boost was well up there!

Also thanks to Jet for pointing me away from the ZF stall time table

This statement is very true. Switching off the torque module is a very lazy cut and past method of tuning.

[Sasha]

I was re-living / stuck in the BA days Hiddeous

[hiddeous]

Effects are just as bad in a BA. Considering the out of engine calcs based around torque it's madness to shut it off. My old ba would do some very odd things timing wise/fuel with the Trq Md shut off. Timing would drop coming onto boost and fuel would go lean on part throttle over run.

I tuned a ZF car that had the torque module shut off and would flare on a wo 1/2 and 3/4 shift. Trq Md back on a reduced trans shift and trans trunc on the spark side and not more flaring and perfect quick shifts.

Ford put it all in there for a reason!

[JETURBO]

No worries my pleasure

And people think I don't like helping others .......

[Sasha]

No worries my pleasure

And people think I don't like helping others .......

It's easy to throw a number out there, but to make someone stop and think about how they got that number......Are you sure your not a uni teacher Jet

[JETURBO]

no but ive taken many young lads from apprentice to tradesman and they hated everyday of it hahahahahaha

If you know an answer most definitely help people but never hand things to them as they will never appreciate the joy of working something out on their own

So ....... Post piks of the snapped tail shaft once u work out where it's max psi limit is :P

[DarrylC]

No worries my pleasure

And people think I don't like helping others .......

Jet, you are a very helpful person in the most prevaricative and obfuscated manner

[PSI 364]

Just wanted to thank you all for pointing me in the right direction for my turbo territory, was having the same problems and I made some small changes to the tables mentioned and re-enabled the torque switch. All I can say is it has made a huge improvement and shifts are back to being great. I am still new to HPT and Ford tuning (previously used another program on GM) but what I have learnt just from reading these forums the past month has been a great help, really appreciate you all sharing your knowledge and making me learn at the same time.

[Sasha]

So ....... Post piks of the snapped tail shaft once u work out where it's max psi limit is :P

Pics? I'll be sending you the bill

[JETURBO]

Hahaha that's the spirit sasha !!

I got a few broken ones so we can piece a few back together lol

[turbotrana]

So just looked up a workshop tune.

For ETC Torque Reduction RPM vs Requestor
Trans Trunc 6300
TCS 6300
Rpm Limit 6300
Trans Shift 6300
Rpm Guard 6300

For Clip Torque
Trans Trunc 1023NM
RPM Limit 1023
Trans Shift 1023
RPM Guard 1023

So basically this tuner just maxed out anything that could possibly cause torque reduction