panda_1

iTrader: (4)

What In Tarnation Is It?

Matto357

You simply disconnect a connection in the engine bay, and it makes your shifts much much firmer. Only in an Automatic tranny though.

In a 2k it's mounted to the front of the right hand side strut tower. You will probably pull an SES if you try it out.

PearlWhtMaX2000

iTrader: (5)

more details on how to, and if it is worth it

panda_1

iTrader: (4)

<~~~~~ 5 speed.

Ironlord

All it does is make EVERY shift at full line pressure. IT can alledgedly drop a tenth or two in a quarter. You WILL get a SES light if you unplug. Not suitable for everyday driving, i'm a 20 y.o. and I ended up plugging it back in cuz the banging shifts were annoying.

KCMichaelM

Then you'll have trouble finding your resistor

PearlWhtMaX2000

iTrader: (5)

i have an auto how would i do this?

KCMichaelM

Attached to the front of your left-front strut tower is a resistor. This is a white block about 5 inches long. There is a single connector on it, 2 wires. You can unplug this, and it will cause your transmission to shift with full line pressure. This is cool is you're racing but it kind of annoying at slow speeds. It is easier on your transmission to shift this way (although it feels harder to you) becuase the discs and clutch packs in the tranny take a lot less slipping and wear.

It will light the SES light. This light is resettable by unplugging your ground wire to the battery for 30 minutes.

I will say it's pretty cool to feel how this shifts, just annoying at slow speeds.

RBa

iTrader: (2)

Def not worth it since you'll be damaging your tranny everytime you shift..

This is almost equal to doing neutral drops.

PearlWhtMaX2000

iTrader: (5)

ic ok thanx is it at all bad for the car?

KCMichaelM

Nope... You are not damaging your tranny. As I posted, it actually creates longer life for the wearable clutches/discs in your transmission. The gears in the tranny are plenty capable of withstanding shock. It saves wear on the parts replaced during an overhaul, like brake band / disc+clutch packs etc...

RichSpidizzy

Is this the same on an 02? I think I've seen the resistor your talking about on my car but I thought it had something o do with the power steering (the resistor, not the mod)

KCMichaelM

It is one and the same...

panda_1

iTrader: (4)

just a little...

† ErV †

and you couldn't be further away from what really happens when you mess with the line pressure/sensor.

KCMichaelM

Quoted from Nissanperformancemag.com... I have an extensive automotive background (though I can't say I rebuild auto trannys) and this makes perfect sense to me. I have also asked several transmission experts about this, guys that I trust very well. Please tell me what part of this explanation you feel is incorrect, I always keep an open mind:

Q: Recently on Maxima.org someone posted about a 'drop resistor mod'. When a sensor is disconnected, it allows the full line pressure in the auto tranny which makes shifts faster and more abrupt. I tried this myself and it makes an enormous difference in shift times. Is it harmful to the transmission?

A: Full line pressure will be slightly easier on the transmission because it reduces slippage (typically 2-8% for autos) and shift overlap (being in two gears at once when upshifting) due to stronger application forces being directed via the servos to the bands and clutches. This locks up the bands and clutches harder and gives firmer shifts. By reducing slippage, it also decreases the amount of heat produced by the clutches and bands and locks the clutch in the torque converter up harder in the higher gears to increase fuel economy. The heat produced by slippage contributes to wearing out the seals, bands and clutches in an automatic more quickly. However, since the transmission controller is programmed to give full line pressure at wide open throttle, this mod just gives rough shifts at part throttle. It's similar to using an HKS ALC (Automatic Line Controller) box. Other ideas to improve shifting with an auto tranny could be to shim the PL solenoid regulator springs to increase peak pressure or to shim the shift accumulator springs to firm up and speed up the shifts. Or you can just swap in a manual!

RichSpidizzy

OK, then I'm confused. I always though that white thing (im assuming the resistor) had to do with the power steering. Can someone post some pics of the drop resistor so I can be sure I know what we are talking about?

KCMichaelM

Sorry, my hood is iced shut so no picture right now The drop resistor is right on the front of your front left strut tower. It's the only 5-inch long white block in that area. It is just behind the battery about a foot. Out of curiousity, where did you hear this had something to do with steering? I cannot speak as to why Nissan mounted it here, but it partially regulates the line pressure in your tranny.

I will say again, even though I argue this doesn't hurt the transmission, I do not use this mod because it really produces annoying shifts (for my liking) at low speed. That, and you will always have a SES light.

RichSpidizzy

Aha! behind the battery..... I was thinking of the wrong thing. I was thinking of a connector on the passenger side strut tower.

This is the thread and specific post that made me think you were talking about the power steering thing: http://forums.maxima.org/showthread....76#post2570237

† ErV †

ok there was a whole thread around that article. search for it if you want it, i didn't find it neccessary to bring it up. yes there is no denying it does good by reducing slippage, however, this is an *uncontrolled* shift. ever thought about just how much force is being put down with every shift and at what point it actually becomes harmfull? but proclaiming that it is completely harmless or is the right thing to do is not proper, considering data on its effectiveness and safety of use is incomplete to say the best.

also please keep in mind that your transmission is linked directly to some very expensive components called driveshafts/cvs and linked to an engine connected to rubber mounts. every vibration is felt by these parts as well.

making sense in theory is one thing, letting it loose is another. i am acceptive of the wot switch approach, but driving with it unplugged all the time... apprehensive.

KCMichaelM

I will agree with that... I think it is very useful for racing but unnecessary for daily driving. I too know some members here have installed a switch that temporarily removes it from the circuit, I like that approach as well. Thanks