JDM User Manual in English?

[svxistentialist]

I forgot you had asked this question.

Mike is commenting favourably on the habit of the Power mode to hang on to lower gears longer before shifting up.

In other words once the Power map is in play, the gearbox is less inclined to do its lazy thing and keep shifting into higher and higher gears on a light throttle opening.

I found my Plum was a much better drive with Power on all the time.

I have a 30,000 mile Road Test from the American magazine Car and Driver. They quote one interesting statistic, "Road horsepower at 50 miles per hour"

The figure??

12 hp.

I'll say that again; 12 hp at 50 mph!

Our lazy, genteel limousine comfort 4EAT at 50 mph is conspiring to deliver one twentieth of the total engine power output to the wheels at 50 mph, and then we wonder why it feels sluggish?

Down through the years we have had many contributors in every power mode thread jump in and say the bleedin obvious "Power mode does not give you any extra horsepower, it only affects the revs at which gears change up or down"

I respectfully beg to differ! When Power mode is in play, as Mike says above the gearbox holds on to lower gears for an extra 1000 revs or so with light throttle openings, no kickdown involved. This in turn means that the 50 mph test above is no longer measured from overdrive revs [we do all know 4 range is overdrive, right?] but in 3, and consequently we are enjoying the on-the-road power the engine delivers at those revs, not the paltry 12 hp as measured above.

Power Mode gives you access to more of your engine's horsepower on the road at lower throttle openings And before the man from the Ministry of the Bleedin Obvious jumps in and says, " You don't need this, just floor the boot and the gearbox will select Power and kickdown for overtaking" can I say that the whole point of the exercise is to make the gearbox hang on to the lower gears longer without engaging kickdown! If you can't see the benefit of that, please keep your "on demand" Power mode, and don't join in to this discussion at all, it's not for you!

Joe

[Trevor]

Again greetings Joe,

Surely the figure of 12 HP at 50 MPH was quoted by Car and Driver as complimentary, as it indicates efficiency in respect of rolling resistance and aerodynamics. I do not understand why it calls for exclamation. The power is available and will be delivered automatically, as would be indicated if figures were taken on a steep upwards incline.

You state:-

“This in turn means that the 50 mph test above is no longer measured from overdrive revs [we do all know 4 range is overdrive, right?] but in 3, and consequently we are enjoying the on-the-road power the engine delivers at those revs, not the paltry 12 hp as measured above.”


You are not correct in asserting that the engine will in fact deliver more power if the car is in lower gear. No more engine power is required and no more will be delivered. The figure will remain at 12 HP. That is aside from contingencies involved with differing drive chain losses. The car/engine will be more responsive towards acceleration when turning at higher RPM, but that is all.

Those wrongly arguing HP and Power Mode, as I understand it, were talking engine power as such, and in which case were correct. However as we both have pointed out, WHP is another kettle of fish.

Your inclusive statement as follows, was I trust not directed towards me:-

“If you can't see the benefit of that, please keep your "on demand" Power mode, and don't join in to this discussion at all, it's not for you!”

I have not said inferred, or stated anything which suggests I do not understand the benefits of power mode. Quite the opposite, as I have exactly shown that horsepower relates to RPM.

Cheers and off to get a beer, Trevor.

[Trevor]

Again Joe,

My understanding of what Mike has now stated, is that short repetitive pulses of say 250 ms, will not cause a kick down, whereas a longer pulse or pulses will. On this basis, continuous pulses not exceeding say 250 ms, will result only in constant power mode, which is what is desired .

A 555 timer IC could be used but a simple two transistor multi vibrator flasher type circuit would suffice. The best way to go would be to check hobby shop kitsets for something suitable, as this would take a lot of the hassle out of assembly and would be cost effective.

Edit P.S. I have had a quick look at a catalogue covering hobby electronics and a 555 timer kit which can be used to build all sorts of stuff is available here at NZ$30.00. A flasher kitset using discrete components, NZ$8.00

You may have to incorporate a driver transistor, depending on the current requirements. An IC regulator rather than a simple voltage divider would not go amiss. I hope you have the time to play, as have no desire to get involved.

Again Cheers, Trevor.

[ItsPeteReally]

Originally Posted by svxistentialist

I have a 30,000 mile Road Test from the American magazine Car and Driver. They quote one interesting statistic, "Road horsepower at 50 miles per hour"

The figure??

12 hp.

I'll say that again; 12 hp at 50 mph!

Our lazy, genteel limousine comfort 4EAT at 50 mph is conspiring to deliver one twentieth of the total engine power output to the wheels at 50 mph, and then we wonder why it feels sluggish?

Err....., no Joe, you are wrong to infer that only 12hp is available. What they are saying is that to maintain a road speed of 50 mph all you need is the merest whiff of throttle, sufficient to deliver 12 horsepower to the wheels. The only conspiracy here is one between the driver and the throttle pedal.

If the driver opens the throttle, then he lets more air, and consequently more fuel, into the combustion chambers; the car then develops more torque, and more power, allowing the car to accelerate. How fast it accelerates will be a function of how wide you open the throttle and which gear the car is in.

An auto box will frequently be in the wrong gear as it has no idea of what the driver's future requirements might be. The more control the driver has over the box, the better. Access to the power shift map at all times might be an improvement some of the time, but it might be just a little too racy at others.

[svxistentialist]

Originally Posted by Trevor

Again greetings Joe,

Surely the figure of 12 HP at 50 MPH was quoted by Car and Driver as complimentary, as it indicates efficiency in respect of rolling resistance and aerodynamics. I do not understand why it calls for exclamation. The power is available and will be delivered automatically, as would be indicated if figures were taken on a steep upwards incline.

You state:-

“This in turn means that the 50 mph test above is no longer measured from overdrive revs [we do all know 4 range is overdrive, right?] but in 3, and consequently we are enjoying the on-the-road power the engine delivers at those revs, not the paltry 12 hp as measured above.”


You are not correct in asserting that the engine will in fact deliver more power if the car is in lower gear. No more engine power is required and no more will be delivered. The figure will remain at 12 HP. That is aside from contingencies involved with differing drive chain losses. The car/engine will be more responsive towards acceleration when turning at higher RPM, but that is all.

Those wrongly arguing HP and Power Mode, as I understand it, were talking engine power as such, and in which case were correct. However as we both have pointed out, WHP is another kettle of fish.

Your inclusive statement as follows, was I trust not directed towards me:-

“If you can't see the benefit of that, please keep your "on demand" Power mode, and don't join in to this discussion at all, it's not for you!”

I have not said inferred, or stated anything which suggests I do not understand the benefits of power mode. Quite the opposite, as I have exactly shown that horsepower relates to RPM.

Cheers and off to get a beer, Trevor.

Trevor,

It appears that I am now the one who was asleep and apologies on that, I read the Car & Driver test in a skimpy fashion, and misinterpreted the hp equation. They were in fact referring to hp used for volition, rather than hp output. HP used will remain constant relative to speed, tyre footprint, cd ratio etc. Wheel hp depends on the gear and the revs, and is my hobbyhorse here, if you'll forgive the pun .

The later remark was not at all aimed at you, in fact I am thankful for your intervention which shows you are thinking about what is being contemplated, even though you already have the JDM Power switch in your car.

Rather, I am getting irritated at the number of people who constantly interpolate to state the obvious, that only the shift points are changed, and no extra power is created. And like, this is news???

Just to take the discussion ad absurdam, to extremes of logic, you could be driving a 1000hp Veyron and if the gearbox and electronics only allowed use in the 1000rpm to 1200rpm level, will it still feel like you are driving a 1000 hp car?

No, it won't, because the gearbox is denying you use of the horsepower, which happens high up in the rev range. This is what the Normal shift map in the SVX does and is programmed to do. It shifts up to higher and higher gears on a light throttle, so you end up burbling round at 1500 rpm, with no power to the road wheels and no response from the throttle.

My remarks were for those who are happy to travel that way. They seem not to understand or see the benefit of Power mode in the TCU, which gives more responsive driving, much closer to a manual gearbox in style, at light to medium throttle without kickdown, or for that matter without physically changing the shift lever yourself.

Guys like Mike in NJ push the boat out, and actually do something to improve the SVX driving experience. Then you get others who seem only to read the last post or two, then jump in and point out that no extra power is magically created, and that the car accelerates well in kickdown. Well read my lips here. We know that. Some of us have read the Owner's Manual and have passed the driving test!

The one thing Fuji Industries could have done to help communication would have been to call the faster shift map Sport mode rather than Power mode, then maybe a few more might see the light.

Joe

[svxistentialist]

Originally Posted by ItsPeteReally

Err....., no Joe, you are wrong to infer that only 12hp is available. What they are saying is that to maintain a road speed of 50 mph all you need is the merest whiff of throttle, sufficient to deliver 12 horsepower to the wheels. The only conspiracy here is one between the driver and the throttle pedal.

If the driver opens the throttle, then he lets more air, and consequently more fuel, into the combustion chambers; the car then develops more torque, and more power, allowing the car to accelerate. How fast it accelerates will be a function of how wide you open the throttle and which gear the car is in.

An auto box will frequently be in the wrong gear as it has no idea of what the driver's future requirements might be. The more control the driver has over the box, the better. Access to the power shift map at all times might be an improvement some of the time, but it might be just a little too racy at others.

Thanks Pete

I did not notice your post till I had replied to Trevor. You are quite correct, and I apologise for my error and misinterpretation of what was being measured.

Too racy?

There is such a thing? I know what you mean. I suspect your car is UK and you don't have the Power switch? As you say, the auto box needs a lot of logic circuits and good software to be able to predict all situations a driver might be in, or evaluate driver inputs well enough to give a good approximation of what rate of progress the driver would like to proceed at.

When Power mode is on, you can actually proceed at a genteel rate using throttle control if you wish. I found it the best experience, best driving mode. Other may disagree.

Joe

[svxistentialist]

Originally Posted by Trevor

Again Joe,

My understanding of what Mike has now stated, is that short repetitive pulses of say 250 ms, will not cause a kick down, whereas a longer pulse or pulses will. On this basis, continuous pulses not exceeding say 250 ms, will result only in constant power mode, which is what is desired .

A 555 timer IC could be used but a simple two transistor multi vibrator flasher type circuit would suffice. The best way to go would be to check hobby shop kitsets for something suitable, as this would take a lot of the hassle out of assembly and would be cost effective.

Edit P.S. I have had a quick look at a catalogue covering hobby electronics and a 555 timer kit which can be used to build all sorts of stuff is available here at NZ$30.00. A flasher kitset using discrete components, NZ$8.00

You may have to incorporate a driver transistor, depending on the current requirements. An IC regulator rather than a simple voltage divider would not go amiss. I hope you have the time to play, as have no desire to get involved.

Again Cheers, Trevor.

Thanks Trevor

The suggestions are appreciated. I will call on your help with the electronics when I have the fresh transmission installed. If it works as well as expected, then perhaps a simple kit could be produced for those who are less savvy with wiring and electronics.

Cheers man

Joe

[Trevor]

Originally Posted by svxistentialist

Thanks Trevor

The suggestions are appreciated. I will call on your help with the electronics when I have the fresh transmission installed. If it works as well as expected, then perhaps a simple kit could be produced for those who are less savvy with wiring and electronics.

Cheers man

Joe

Joe, we can not be accused of not digging deep in order to investigate all things involved Over to you to do the donkey work.

All the best with your efforts, Trevor

[oab_au]

Originally Posted by b3lha

I understand what you are saying Trevor, but the presence of a cpu chip must surely indicate that at least some of the functions are controlled by a program stored in firmware? Such a program must read the input ports, process the information, and set the output ports to control the gearbox appropriately. I believe that if we were able to download and disassemble the program then we might gain some insight into how it all works.

A bit late to here. What you say Phil, is the way it is. The CPU uses inputs and out puts, the program software decides what the response is going to be for each input, and how it is going to drive the output. This can be varied to suit the models that it is fitted to.

Doing it this way saves hardware changes that cost more to change. But as we know there are circuit board changes, as with the way the front speed sensor is routed to the TCU for the diff multiplication, before it is sent to the ECU, on the Aust, UK models, as compared to the JDM/US versions, feed to the ECU first.

This is a US TCU (courtesy of Tomfiles). You can see the Rom that holds the programing. The number shown is the version that the US one has. Have you looked at any of the other TCUs to see what the ROM number is?

http://www.subaru-svx.net/photos/files/oab_au/41413.jpg

Pin 4 is connected to the CPU as an input, although there is no wire connected to it.

Harvey.

[Trevor]

Originally Posted by oab_au

A bit late to here. What you say Phil, is the way it is. The CPU uses inputs and out puts, the program software decides what the response is going to be for each input, and how it is going to drive the output. This can be varied to suit the models that it is fitted to.

Doing it this way saves hardware changes that cost more to change. But as we know there are circuit board changes, as with the way the front speed sensor is routed to the TCU for the diff multiplication, before it is sent to the ECU, on the Aust, UK models, as compared to the JDM/US versions, feed to the ECU first.

This is a US TCU (courtesy of Tomfiles). You can see the Rom that holds the programing. The number shown is the version that the US one has. Have you looked at any of the other TCUs to see what the ROM number is?

http://www.subaru-svx.net/photos/files/oab_au/41413.jpg

Pin 4 is connected to the CPU as an input, although there is no wire connected to it.

Harvey.

We know all this Harvey. You tell us nothing. As usual you are simply adding confusion in an effort to display your alleged knowledge.

[b3lha]

Originally Posted by oab_au

This is a US TCU (courtesy of Tomfiles). You can see the Rom that holds the programing. The number shown is the version that the US one has. Have you looked at any of the other TCUs to see what the ROM number is?

http://www.subaru-svx.net/photos/files/oab_au/41413.jpg

What interests me about this picture is the 4 contacts with a box drawn around them to the left of the ROM chip. Is this perhaps a JTAG or some other interface that can be used to download the contents of the ROM?

Phil.

[svxistentialist]

Thanks for the picture Harvey. It will be interesting to compare this to the UK and JDM version.

It looks like we ought to loan a couple of boards to Steve, and see what he can do.

Anybody Down Under got spares so Steve can connect up and investigate?

Joe

[Trevor]

Originally Posted by b3lha

What interests me about this picture is the 4 contacts with a box drawn around them to the left of the ROM chip. Is this perhaps a JTAG or some other interface that can be used to download the contents of the ROM?

Phil.

Phil,

I have zoomed right in at what you are looking at, but it appears to be a marked position for a component not actually fitted. I can not make out actual contacts or anything protruding from the board.

The marking however could well indicate a position for a plug socket, with the key towards the outside of the board. Realistically, I can see no way that the photo can be off use within the context of this thread.

Edit P.S. IMHO I do not think you will get any answers from the ROM. The key will be in the associated interface, as the functions required are not those which are likely to be included as part of ROM.

Regards, Trevor.

[oab_au]

Originally Posted by b3lha

What interests me about this picture is the 4 contacts with a box drawn around them to the left of the ROM chip. Is this perhaps a JTAG or some other interface that can be used to download the contents of the ROM?

Phil.

Yes it is a pin head, but it goes directly to the CPU, comes out underneath the CPU chip, so I can't tell where it goes from there. It is a masked programed ROM and it's pins are replicated in the socket for the E/PROM beside it.

So there is a JEC unit, built on this board, for some other car that uses the same TCU, that has a PROM on it, instead of the ROM. This would be a good unit to find and convert.

Harvey.,

[Trevor]

Originally Posted by oab_au

Yes it is a pin head, but it goes directly to the CPU, comes out underneath the CPU chip, so I can't tell where it goes from there. It is a masked programed ROM and it's pins are replicated in the socket for the E/PROM beside it.

So there is a JEC unit, built on this board, for some other car that uses the same TCU, that has a PROM on it, instead of the ROM. This would be a good unit to find and convert.

Harvey.,

Magic and X-rays combined to exactly describe what can not be seen. The assumption being that the knowledge is not available to recognise tripe presented with a BS topping.

What is more the description has been ignored and what can be seen has not been seen.