MPG is improving with PSI Powerbox

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Datatek said:
The gearbox ECU reacts to throttle position, revs and road speed not engine power.
Click to expand...

I am well aware of how a gearbox works thanks. The comment was made in reply to a suggestion that the extra torque allows you to run a higher gear. Automatic gearboxes select the best gear for a given road speed. No matter how much extra torque you have the gearbox will always select the correct gear. So to say the chip allows a higher gear to be pulled without the box changing down is ridiculous.
 
SpudH said:
I think there's a hint in the name 'torque convertor'
Click to expand...

What is that comment supposed to mean. The torque converter or fluid flywheel transmits the engine torque to the first motion shaft of the gearbox. At very low revs (tickover) the connection is fluid almost diconnected, from around 1000 RPM upwards it is solid with no slip. Think you had better read up a little more on torque converters.
 
Taken from Rave:

"To aid performance and driveability in the high range
economy mode, the EAT ECU has three adaptive shift
and lock-up maps. These maps delay upshifts and
torque converter lock-up similar to the sport mode if
the inputs from the engine indicate:
• A sustained high load on the engine, such as
occurs when the vehicle is ascending a steep
gradient or towing a trailer.
• The EAT ECU monitors the engine inputs and
selects the most appropriate adaptive map for
the prevailing conditions."
 
SpudH said:
Taken from Rave:

"To aid performance and driveability in the high range
economy mode, the EAT ECU has three adaptive shift
and lock-up maps. These maps delay upshifts and
torque converter lock-up similar to the sport mode if
the inputs from the engine indicate:
• A sustained high load on the engine, such as
occurs when the vehicle is ascending a steep
gradient or towing a trailer.
• The EAT ECU monitors the engine inputs and
selects the most appropriate adaptive map for
the prevailing conditions."
Click to expand...

That says the gearbox automaticlly selects the best gear for a given road speed. And delays torque converter lockup when pulling away under heavy load. Your point would be?
 
That says that there are adaptive shift patterns in the gearbox ECU which take into account the torque output of the engine (engine revs/road speed, or more particularily the change in revs, are a function of the torque the engine is producing) for a given gear in the interests of economy. Which is what i have been saying for a while.

We can go on like this ad infinitum, intelligent people argued for ages over whether the earth was round or flat, the Earth or sun was the centre of the planetary system or if the universe even had a beginning. Some who were absolutely correct in their stance at one stage found themselves on the wrong end of the outcome in the fullness of time, Einstein was one who actually changed sides in the Big Bang debate.
I'm merely reporting what happens in my own vehicle with or without the chip. With the chip fitted it accelerates either more quickly or at lower revs (as in when pulling away it only needs 2500 rpm instead of 3000rpm, downshifts less often on hills and gives better (calculated, not trip computer) fuel economy.
These are the simple facts that evidence my argument.
I have researched and tried to explain the technical reasons behind this 'have your cake and eat it' dilema. You can digest or ignore as you see fit. Your depth of knowledge is admirable and a of great value to this forum and I look forward to future threads.
Who knows, maybe it'll turn out I've been lucky and had the wind at my back more often or more likely I've modified my driving style without noticing.
Still believe I'm right though :)
 
SpudH said:
That says that there are adaptive shift patterns in the gearbox ECU which take into account the torque output of the engine (engine revs/road speed, or more particularily the change in revs, are a function of the torque the engine is producing) for a given gear in the interests of economy. Which is what i have been saying for a while.

We can go on like this ad infinitum, intelligent people argued for ages over whether the earth was round or flat, the Earth or sun was the centre of the planetary system or if the universe even had a beginning. Some who were absolutely correct in their stance at one stage found themselves on the wrong end of the outcome in the fullness of time, Einstein was one who actually changed sides in the Big Bang debate.
I'm merely reporting what happens in my own vehicle with or without the chip. With the chip fitted it accelerates either more quickly or at lower revs (as in when pulling away it only needs 2500 rpm instead of 3000rpm, downshifts less often on hills and gives better (calculated, not trip computer) fuel economy.
These are the simple facts that evidence my argument.
I have researched and tried to explain the technical reasons behind this 'have your cake and eat it' dilema. You can digest or ignore as you see fit. Your depth of knowledge is admirable and a of great value to this forum and I look forward to future threads.
Who knows, maybe it'll turn out I've been lucky and had the wind at my back more often or more likely I've modified my driving style without noticing.
Still believe I'm right though :)
Click to expand...

Ok Spud leave it at that then. The Earth is not flat, i find that hard to believe? It looks pretty flat in my atlas.:)
 
wammers said:
What is that comment supposed to mean. The torque converter or fluid flywheel transmits the engine torque to the first motion shaft of the gearbox. At very low revs (tickover) the connection is fluid almost diconnected, from around 1000 RPM upwards it is solid with no slip. Think you had better read up a little more on torque converters.
Click to expand...

Must be something wrong with the torque converters on my cars then, except at low throttle openings and light loads they slip like merry hell until the torque converter lock up comes in, boot it a 60mph, torque coverter lock up comes off and revs shoot up. Perhaps you have never driven an auto.
 
Datatek said:
Must be something wrong with the torque converters on my cars then, except at low throttle openings and light loads they slip like merry hell until the torque converter lock up comes in, boot it a 60mph, torque coverter lock up comes off and revs shoot up. Perhaps you have never driven an auto.
Click to expand...

The torque converter lock comes off or the kickdown drops a gear. Which do you think it is?
 
wammers said:
The torque converter lock comes off or the kickdown drops a gear. Which do you think it is?
Click to expand...


Both in some circumstances, but it's easy to see when the lock is off on the torque converter, you just have to play with the throttle and watch the revs rapidly go up and down with little or no immediete change in road speed.
 
Datatek said:
Both in some circumstances, but it's easy to see when the lock is off on the torque converter, you just have to play with the throttle and watch the revs rapidly go up and down with little or no immediete change in road speed.
Click to expand...

And in the process drinking fuel which is made easier by fitting a chip to gain power. The lockup is there as an economy device to give a solid connection to the gearbox, very much like a mechanical clutch. If you use the extra power at a road speed at which the gearbox cannot change down, you use extra fuel to give you your extra power, and extra fuel reving the engine past an econamical connection to the gearbox. Basically all your extra power is just warming the trasmission fluid in the torque convertor.
 
wammers said:
And in the process drinking fuel which is made easier by fitting a chip to gain power. The lockup is there as an economy device to give a solid connection to the gearbox, very much like a mechanical clutch. If you use the extra power at a road speed at which the gearbox cannot change down, you use extra fuel to give you your extra power, and extra fuel reving the engine past an econamical connection to the gearbox. Basically all your extra power is just warming the trasmission fluid in the torque convertor.
Click to expand...

Really? so all cars with more than 136bhp are wasting their time just heating up the transmission fluid :doh::doh::doh::doh::doh::doh::doh:LOL
 
SOD the chipping and the bitching just get em remapped, i know feck all but understand mine is remapped...official mpg i think 22 and 28... i get 25 for school runs and the shops and m'way 37ish and acceleration is great if i need it :)
 
Datatek said:
Really? so all cars with more than 136bhp are wasting their time just heating up the transmission fluid :doh::doh::doh::doh::doh::doh::doh:LOL
Click to expand...

One day you will come up with something sensible. I await that day with baited breath. Answer no they don't because they have a convertor suitable for that power output. Would you fit a Fiesta clutch in a Cosworth? Maybe you should confine your comments to something you know about.
 
wammers said:
One day you will come up with something sensible. I await that day with baited breath. Answer no they don't because they have a convertor suitable for that power output. Would you fit a Fiesta clutch in a Cosworth? Maybe you should confine your comments to something you know about.
Click to expand...

Merely taking what you say literaly. End of story
 
Datatek said:
Merely taking what you say literaly. End of story
Click to expand...

Nothing wrong with doing that because that is what literally happens. The lockup clutch engages when the pump speed and rotor speed are the same, this gives a 1 to 1 coupling, the most economic state, all the speed of the primemover is going through the torque convertor into the gearbox. So if the engine is doing 2500 RPM the first motion shaft is also doing 2500 RPM. If you are travelling at a road speed too high for third gear when you put your foot down, and the RPM of the engine increases the gearbox will not change down. But because the pump speed is now greater than the rotor speed the lockup clutch drops out, this gives slip or a sort of reduction gear. Were say the engine speed is 3500 RPM and the first motion shaft speed is 2500 RPM slip occurs until the rotor speed matches the pump speed again. This is obviously not instantanious so until the road speed increases to syncronise the pump and rotor the extra 1000 RPM is absorbed by the transmission fluid this causes friction and heat build up. Torque convertors can be destroyed by this heat as the internal parts warp. On hard acceleration obviously the more power you put into the convertor the higher the RPM differential will be, therefore the fliud has to absorb greater amounts of power until things equalise so more slip, and more heat is generated. Some four speed auto boxes have a switch for towing which cuts out top gear,this leaves only 1 to 3 available, this is to cut the slip that would occur pulling heavy loads in top gear, thus causing high heat build up in the transmission fluid, and premature convertor failure. Simples.
 
wammers said:
Nothing wrong with doing that because that is what literally happens. The lockup clutch engages when the pump speed and rotor speed are the same, this gives a 1 to 1 coupling, the most economic state, all the speed of the primemover is going through the torque convertor into the gearbox. So if the engine is doing 2500 RPM the first motion shaft is also doing 2500 RPM. If you are travelling at a road speed too high for third gear when you put your foot down, and the RPM of the engine increases the gearbox will not change down. But because the pump speed is now greater than the rotor speed the lockup clutch drops out, this gives slip or a sort of reduction gear. Were say the engine speed is 3500 RPM and the first motion shaft speed is 2500 RPM slip occurs until the rotor speed matches the pump speed again. This is obviously not instantanious so until the road speed increases to syncronise the pump and rotor the extra 1000 RPM is absorbed by the transmission fluid this causes friction and heat build up. Torque convertors can be destroyed by this heat as the internal parts warp. On hard acceleration obviously the more power you put into the convertor the higher the RPM differential will be, therefore the fliud has to absorb greater amounts of power until things equalise so more slip, and more heat is generated. Some four speed auto boxes have a switch for towing which cuts out top gear,this leaves only 1 to 3 available, this is to cut the slip that would occur pulling heavy loads in top gear, thus causing high heat build up in the transmission fluid, and premature convertor failure. Simples.
Click to expand...


wammers, that is the nuts m8!
i take me hat off to ya. you know your stuff bloke..
my box is playing up at the mo and been told its the torque con, my dse is chipped and i also have front fogs wich were on when i purchased the car (wich i have since learnt block air to the auto trans cooler) so with your description i'm thinking its a mixture of both chip (cos i got a lead foot lol) and front fogs blocking cooler causing exssesive heat in the said converter..
 
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