Torque converter unlock

daviesbike · #1 26th February 2012, 04:25 PM

i was just wandering how exactly the torque converter works and why it seems to feel like it drags the clutch untill around 2.5k rpm is this all in aid of getting a smooth ride and gear change ?
and also the fact that tip is not quite as controllable as id like, ie when doing 30-40mph i would like to stick it in 5th if i want to with out it being over ridden.

am i alone in this or do others share my views ?

Singh · #2 27th February 2012, 03:24 PM

No your not, I want my car in fifth when doing the 30-40 MPH mark too but it is always in fourth. You need to get the TCU mapped, contact Grizz - I think he can sort this. I drove Amanda's 950 nm RS 6 that he has done and it was brilliant being able to put it into fifth at 30 MPH.

sloss · #3 28th February 2012, 06:17 AM

That's a sure fire way to overstress the engine and just possible to break the crankshaft

The computer will probably stop it damaging itself but re-mapping to allow that is IMHO just plain silly.

Too low revs can also mean that the oil pump may not be producing enough....

Leave that stuff to Engineers who know.......

Singh · #4 28th February 2012, 08:47 AM

This is a popular mod with RS guys Sloss, people have ran it for the past 7/8 years and hundreds of thousands of miles with no issues, big tuners such as MTM were running it even longer, it is no different to putting a manual gearbox'd car with enough power/torque into fifth at 30 MPH.

sloss · #5 28th February 2012, 12:01 PM

Sounds OK then

prolly the sophistication of injection and electronic ignition help. Cranks broke years ago if you tried to accelerate in far too high a gear it starts to vibrate you give it more gas and the stress becomes too much. Not in their thousands I add but it did happen and back then we had 3 bearing cranks without fancy damping assemblies.

I do get annoyed at my RR which won't go into top gear until about 52mph and you have to sit behind someone at 50 while wasting 800 revs or so.

Singh · #6 28th February 2012, 12:12 PM

Yep, it is safe. The modified TCU wouldn't allow you to accelrate hard in fifth from third as it will drop it down a few cogs, it is only if your sitting at 30-35 MPH, which is easy in a big torqey V8 and will allow it achieve better MPG. I like to follow 30 MPH speed limits so I am essentially wasting revs and fuel sitting in fourth, and am sometimes tempted to drive at 38 MPH as it does bug me. I understand what your saying Sloss, but no crankshafts have gone bad at all as far as I am aware, and TozoM8 who is considered a ZF gearbox God over in the US, actually says this mod helps prolong with box/TC if anything, torque etc is limited in certain gears and some sophisticated tuning is built into the software, I can't pretend to understand it all though.

sloss · #7 28th February 2012, 12:27 PM

modern technology has me beaten most of the time nowadays......

HPsauce · #8 28th February 2012, 12:38 PM

Quote:

Originally Posted by Singh

I like to follow 30 MPH speed limits so I am essentially wasting revs and fuel sitting in fourth

Me too. I didn't realise you could do this remapping, would it be possible on my PF S8, or is that a soldering job with a new chip?
I spend a lot of time in 30 and 40mph limits, which I usually observe using the cruise control* and it's always in 3rd or 4th sucking fuel out of the tank.

(on the same roads in my Focus I just stick it in 5th and it potters along quite happily around 1200 to 1500 rpm and that's only a 4-cylinder 1.8)

* another niggle - cruise only works above 25mph so is useless in those new-fangled 20mph areas.

Singh · #9 28th February 2012, 12:48 PM

I would contact MRC Tuning in Banbury as they are very good with software and have done many of these TCU maps, Ranj is booked in with them, we are going to see exactly what his car is doing with the Revo remap, and possibly get MRC to wipe it and put their own on, as I am 100% certain it will be much much better then the Revo remap, they will do the TCU at the same time too.

Adrian E · #10 28th February 2012, 03:31 PM

Quote:

Originally Posted by Singh

I would contact MRC Tuning in Banbury as they are very good with software and have done many of these TCU maps, Ranj is booked in with them, we are going to see exactly what his car is doing with the Revo remap, and possibly get MRC to wipe it and put their own on, as I am 100% certain it will be much much better then the Revo remap, they will do the TCU at the same time too.

I'd be interested to hear the results of this too, since mine is the exact same vintage of engine and box.