Power Mode Switch Installed, Very Pleased

[Myxalplyx]

Power mode makes the car more responsive? I thought power mode only delayed shifting of the transmisstion until higher in the rpm range. Am I missing something?

"The car's computer has shift-point "maps" for normal and power modes, dictated by how fast the driver presses the pedal to the metal. If you stomp on the accelerator, the computer chooses the power mode, indicated by the POWER light on the dash, and the engine eagerly revs right up to the red line for maximum speed and power. Above 5000 RPM, the exhaust system emits a satisfying, race-car like growl. "
http://http://www.epinions.com/auto-...39729903-prod2

[svxcess]

This Power Mode switch mod sounds like a potential Reading tech session.





Almost as much fun as doing alternator wiring mods in the middle of the night at Lafayette That's me and Zeppelin and I have forgotten the other member's name at the moment.



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[Nomake Wan]

Originally Posted by It's Just Eric

before I start yanking wires...it it the same pinout for the obd2 cars?

Yes. OBD-II did not change the harnesses for the computers, it only changed the diagnostic connector (which is not what you're plugging into ).

Originally Posted by Myxalplyx

Power mode makes the car more responsive? I thought power mode only delayed shifting of the transmisstion until higher in the rpm range. Am I missing something?

"The car's computer has shift-point "maps" for normal and power modes, dictated by how fast the driver presses the pedal to the metal. If you stomp on the accelerator, the computer chooses the power mode, indicated by the POWER light on the dash, and the engine eagerly revs right up to the red line for maximum speed and power. Above 5000 RPM, the exhaust system emits a satisfying, race-car like growl."

Whoever wrote that has never driven an SVX with this mod in place (or alternatively, a stock JDM SVX). I know I keep saying it, but that's because it's the only way to say it...

The only way to understand is to just do the mod. Then you'll understand what we're all talking about, and why it's way different from what you get from mashing the gas.

Originally Posted by svxcess

This Power Mode switch mod sounds like a potential Reading tech session.

Seconded! That would make a lot of SVXers happy, I think!

[svxistentialist]

I'm really pleased to see you guys engaging with this at last.

I have been extolling the virtues of this, as has Phil, since way back in the Noughties.

Until Nomake Wan actually wired his up, nobody in the States would believe how much better the car drives with it ON.

What is not too obvious to most I suppose is the actual laziness of the so-called on demand Power mode that US and UK cars are saddled with. The "map" engages Power mode based on a number of factors. It measures how quickly the TPS is rotating, the faster you crunch the pedal, the more likely the Power light and Power mode will come on.

Mitigating this is the fact that the map will not engage Power mode at higher speeds. If you are going fast enough, maybe 70 or 80, you may find it impossible to engage Power mode, because the software has decided you don't need it. If you are going slower, say 40 or 50, a sharp bang on the pedal will bring it in.

These factors are what led me to disliking the on demand system. The "learning mode" meant that if you spent a lot of your time in slow traffic, the software had learned that you wanted high gears and slow shifts. Then when you badly wanted the car to overtake in a hurry, it was reluctant to kick-down say for applying 1/2 or 3/4 of the throttle. Then you got mad at it, and floored it, and it both kicked down, engaged Power mode, and set off like the proverbial Bat out of Hell.

So to me the regular Power on demand has only two ways of traveling, slow and sluggish or drive like a mad b'stard. Nothing in between. No let's keep the momentum up, no "I want to overtake NOW", no push in the back when I push the pedal.

As Nomake says, the SVX is WAY more responsive with the permanent Power switch.

Joe

[immortal_suby]

I don't get torque converter lockup anymore with the power mode mod. Is it just me or is this what you guys are seeing also?

If this is the case, I will install a switch. The mod is great, but no lockup = high tranny temperatures and poor mileage.

[svxistentialist]

Matt

Nowhere in the WSM or another 4EAT manual I have does it directly say "When Power mode is on, lock-up is not obtainable". However, I believe you are correct, and it will be interesting to hear back from Nomake and others with the switch installed to see if their lock-up engages.

The stated reason for Power mode [in the manual] is for climbing hills and for rapid acceleration. To me this implies that when Power is on, by definition the torque convertor needs to be engaged to give its benefit to the acceleration, or torque multiplication in the case of climbing hills.

Having said that, I ran my car for 3 years with Power permanently on, and no ill effects. Phil in England runs his the same. If you feel the need to add a switch [ it would be advantageous for long highway runs at steady speed] then do so. Power mode is mostly noticable for quick driving on back roads or for rapid overtaking. If a lot of your miles are steady speed highway, it will certainly help economy to switch it off.

Joe

[Nomake Wan]

How will I know when it's locked up? In the years I owned my Legacy, and now my SVX, I never knew how to tell when it was locked up. Also, if there's a signal that the TCU sends for "Torque Converter is now Locked," someone (Phil? ) should tell me. A lot easier for me to just scan a computer readout.

However, I will note that I did this mod back when I was in New York. I have driven the car across country, and did so on one seized brake caliper (which has since been replaced). I still managed something like 27 MPG on average across the US. So gas mileage, as Phil has said before, is really not a concern with this on (though the urge to go fast may hamper this). High transmission temperatures I cannot comment on, since I have no gauge. The light has never come on, though.

Just tell me what to look for and I'll look for it.

[svxistentialist]

When lock-up happens, the engine is connected directly to the transmission with the torque converter left out in the cold. So the road speed becomes directly related to the revs.

When the torque convertor is working in the system, you can rev the engine and the revs go up, but the car speed stays the same[it will start to accelerate, of course, but there is a mis-match between revs and speed]

How you will notice it is when traveling at maybe a steady 60, when lock-up engages the revs will drop, then stay steady. I think they drop possibly 200 or so, but if anyone thinks different, please correct me.

Joe

[immortal_suby]

I've been monitoring my tranny temp for 7 years and even with the stock cooler(heater) bypassed and 2 external coolers run in series it is certain that my tranny will increase in temperature until lockup occurs. Once lockup occurs, the temperature will begin to drop. On an extended trip the system will hold a steady temperature of 90-100 degrees F above ambient temp with lockup.

But - since I don't have any experience running without lockup at highway speeds for extended distance I can't say what the temperature will climb to. I suppose if the cooling system is adequate, and you have the increased airflow of highway speeds on your side, then the system could keep up and the heat produced would not cause an alarming increase in temperature. Since you have been running like this for 3 years and have not had any problems it is probably safe to assume this is correct. Or perhaps there is a difference in your JDM transmission and TCU to account for this.

I have to assume gas mileage would suffer somewhat on the highway since you would be running almost 300rpm lower at the same speed with lockup. That small difference may not be enough to even notice at the pumps unless you were on a very long drive.


I am not trying to discredit this mod - I love it! I just need to take a long drive to see what kind of temperature increase this might cause before I install a switch.

[Crazy_pilot]

Originally Posted by immortal_suby

I don't get torque converter lockup anymore with the power mode mod. Is it just me or is this what you guys are seeing also?

If this is the case, I will install a switch. The mod is great, but no lockup = high tranny temperatures and poor mileage.

I THOUGHT I noticed that once...Told myself I was just seeing things. I don't drive enough at consisten speed to really see lock-up, but he time it happened I switched from power mode to regular at around 60 MPH and the RPM's dropped from 2200 or so to 2000.

[Myxalplyx]

So let's say we have four scenarios!

1) Power-braking an SVX up to stall speed and letting it rip (No power mode),

2) Just stomping the gas pedal, allowing for the 'Power Mode' light to come on,

3) Power-braking an SVX with a power mode switch turned to the 'On' position,

4) Just stomping an SVX with a power mode switch turned to the on position,


Which scenario would you say you would get the best 1/4 mile time? Just a guesstimate since it has not been tested.

I'm thinking the ability to power-brake with a power-mode switch turned to the 'on' position should be nice.

[svxfiles]

Originally Posted by Myxalplyx

So let's say we have four scenarios!

1) Power-braking an SVX up to stall speed and letting it rip (No power mode),

2) Just stomping the gas pedal, allowing for the 'Power Mode' light to come on,

3) Power-braking an SVX with a power mode switch turned to the 'On' position,

4) Just stomping an SVX with a power mode switch turned to the on position,


Which scenario would you say you would get the best 1/4 mile time? Just a guesstimate since it has not been tested.

I'm thinking the ability to power-brake with a power-mode switch turned to the 'on' position should be nice.

I was cautioned by an engineer whom I hold in the highst regard,OAB!
not to power block fully, when drag racing!
He opinied that WOT power block would only add extra heat to the torque converter, and not provide lower times.
Having done both, WOT PB, and 2300-2400 RPM PB, and having no noticeable differances, I would agree, and just bring up the RPMs to 2300 or so and HAMMER DOWN!!!


BTW, READINGS COMING!!!!!!!!!

[svxcess]

As with all things of an electrical/electronic nature on this network, I am awaiting a comment or other excellent insight by Trevor.

He has been very silent on this issue so far...

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[It's Just Eric]

I will say..personal preference...I HATE the way the auto works in twisties. Nothingis less satisfying than going through a corner at speed, and gently rolling onto the throttle at the corners exit only to find the transmission decided it wanted to save me fuel. Hearing that obd2 cars can have the power mode done, Im putting in the switch TOMORROW

I would imagine that in a drag racing scenario...having power mode already engaged at the tree would save a bit off the 60'..seeing as the car no longer takes a moment to decide what shift map it wants. Also, you neednt MASH the pedal down...you can gently get on the gas...giving better controll of traction off the line (for those with, say, fwd cars or supercharged 4.44's) and even going as far as to allow the car to shift before a million bajillion rpms, where power isnt at its best

It snt really a make the car go faster thing (other than eliminating the split second it takes to push the pedal and have computers react and engage mechanical elements accordingly) its more a throttle feel and controll thing. Kevin, given the mods already done to your car's drivetrain, and your methodology when it comes to modding...id just ground the pin. Drive it a while. if you like it, put in a switch, and if not, jsut yank the wire

[svxcess]

Maybe I should let you install one of these in my car at Reading. I already have a spare switch installed in the console. I was waiting to see if it would work on the OBDII


Keeping your hands busy on the inside of may car may allow for a few less fingerprints on the outside


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