Not sure what stall is, but

The FSM clearly states:
The line pressure solenoid valve regulates the oil pump discharge
pressure to suit the driving condition in response to a signal sent
from the TCM.
The line pressure duty cycle value is not consistent when the
closed throttle position switch is ON. To confirm the line pressure
duty cycle at low pressure, the accelerator (throttle)
should be open until the closed throttle position switch is OFF.

Also,

Line pressure solenoid valve duty
Small throttle opening
(Low line pressure) = ~24%

Large throttle opening
(High line pressure) = ~95%

So wouldn't that mean you can get 5% more line pressure IF the drop resistor mod allows 100%?

 

At WOT, with the resistor connected I get a firm 1-2 shift, as expected.

At WOT with the resistor DIS-connected, I get a chirp of the tires on a the 1-2 shift.

Mr. Kojima, please explain this based on the premise that WOT line pressure is not affected by the resistor.

Thanks.

 

Thank you Ben.

Oh Gawd another engineer. I am outta here.

 

Stall pressure is when you step hard on the brake and apply full throttle until the engine RPM stabilizes, then you can read the pressure at this point.

The PL solenoid is controled by the transmission ECU which gets its inputs from the engine ECU which takes other thing besides the throttle switch into consideration and I suppose there might be a difference in programing on this MY from other Nissans.

If the PL is at 95% the actual line pressure at 100% could be higher than 5% due to the invalid time of the solenoid (time that the pintel is moving). So I might be wrong. That is different programing than other Nissans I have checked.

Mike

 

I thought that you made your last post?

Mike

 

I am probably wrong and stupid. I have not measured the line pressure of an 03 Maxima and made the assumption that it acts like all of the other many Nissans I have tested which is probably a fair assumption. I think I will go and kill myself :-).

Mike

 

Please do us all a favour.

Sorry Ice couldn't resist.

We have not been talking about 2k3 Maxima's we have been talking about 4th Gen Maxima's ie 1995-1999. At what point did you leave the conversation. I have kept inserting the 4th Gen in all my post.

 

I thought you made your last post?

 

Talk tech. or thread is going byebye.

 

Line Pressures for a 2K-2K1, which is the same 4spd I believe.

 

same as the 3k by one psi. In the old manuals they had a range which was much more useful for diagnositcs.

Mike

 

It really ****es me off to hear someone talk as if they know something when they actually know nothing.

Here is the graph out of the service manual on the line pressure. At WOT full line pressure is applied.

http://images.cardomain.com/member_i...780_1_full.jpg

 

There is nothing in that graph that says that WOT is full line pressure.

How did you come up with that?

Are you a friend of Sarah and Mike?

 

I say the video proves it...proof is in the pudding.

 

Just because the line pressure reches a maximum value at WOT does not mean that it reaches the maximum that the hardware can deliver.

 

Nothing like us geeks arguing like a bunch of little kids...

 

I'm not an engineer (I'm a scientist), but when I floor it with the resistor unplugged, I without a doubt feel a difference from the normal set up. I believe books, manuals, dorks, and graphs, but I'll believe in my 5 senses before any of those, and they are telling me there is a difference. Maybe you need to experience it to realize it. I drive a 2k3. I got to figure out how to hook up a WOT switch. Any step-by-step instructions would be appreciated. They don't have to be to detailed.

 

Hi, I'm an engineer too.

But I got a manual so I'll just have to sit on the sidelines and watch. But the track results of the 4th gen auto guys here with the drop resistor mod speak for themselves, as does Jime's video. Clearly the little drop resistor trick DOES change the shift response at WOT when disconnected vs still connected. Perhaps there might be a "disconnect" somewhere? (no pun intended )

 

Jime: I just watched your video and you sure do sound Canadian, A? I'm origionally from Montana and I haven't heard that accent in a while.

 

I am also an engineer

 

Reminds of Bob & Doug MacKenzie from The Great White North on SCTV, eh?

Hoser.

 

Hi guys. I have been reading this thread for some time but never responded. Jime is my dad and I have been in his car many times. I don't know anything about auto trannies nor do I really want to cause I'm a 5speed guy, however I can tell you this...

With the drop resistor unplugged the shifting so much harder than with it plugged in. Have you ever been in a car when you shift it feels like the dash is going to come off and fly in the back seat?

Well that’s what his car felt like with the drop resistor unplugged when I was in his car. It never felt like that plugged in, at WOT at part throttle or any time, PERIOD. With it unplugged the shifting was so much quicker, harder, faster it was unbelievable. The best way to do this is VIA the micro switch that he has detailed previously.

Trust me, what he is telling you is true. My dad is in "MY" sport. He was never involved in this until he starting coming to the track with me back in the day. He has run about 4/10ths faster than I have still (12.1 vs 12.5) so trust me, he knows what he's talking about. After over 100 passes at least at the track this year, we have proved that this mod works and works good over and over and over. I have pulled just as fast of a 60ft (on street tires too lol) and I use a stutter box and AWD to do it. Honestly his times would be 2-3ths slower without the drop resistor mod. Running 12.1 isn’t' easy or done by accident.

He would never say anything that he can't prove or has proof of. He's an engineer and they are just that way. I'm not an engineer im a racer and have been to the track with him and my own car and can tell you straight up that this mod works, gives faster 1/4 times (been there saw it in person, cried cause it's faster than my talon still) and is a good mod for anybody to do. I have seen back to back runs with and without the drop resistor and it's readily apparent even when standing at the side lines. The trans DOES NOT apply as much pressure at WOT with the resistor plugged in and it does with it unplugged. There’s no arguing this. Go out to your car, unplug it like you saw in the video and step on it. You will see the difference. Feel free to apologize in this thread we will accept your apology.

Say what you want, but real world experience at the track, testing and racing is worth more than all the bench racing you can apply through reading books. Bench racing is just that, bench racing. We have gone to the track and tested everything you can think of, and more. Trust me he isn't here talking about this and replying this much unless he is sure of what he's talking about. Anybody that knows my dad knows that he knows what he's talking about, only talk about what he knows and does what he says.

Want more proof come to the track with us and whatever doubts you have about the effectiveness of this mod will be quickly erased after he runs a 12 second pass with you in the car and the A/C on for YOUR comfort. We can plug in the resistor if your stomach is just not up to it. Your choice.

 

A/C shuts off at WOT

 

I was kidding... Though he can probablly figure out how to stop that too...

 

I totally agree with both you and your father, as I have done the test myself. There is no doubt in the world that with the sensor unplugged you get a massive/hard shift from 1-2 and 2-3. The hard shifts are too much for every day driving (even too hard for a guy that likes hard auto shifts)...

 

Nice 7 paragraph post. Long winded? Crazy fingers on the keyboard can't stop typing? Sheesh, I about fell asleep reading it. Lets try to sum it up ladies and gentlemen and get to the point.

 

Better?

 

Thats why it's a message forum, your more than welcome to skip over certain posts if you don't want to read them. You obviously didn't read my post because it, like a few others, sums it up pretty well.

 

I should have some pics of my WOT switch setup for this mod this weekend. I will of course post them here...

 

I forgot that the ATECU can be reprogramed to reduce line pressure during shifts and it can easily be changed between models, etc of the same transmission. The ATECU can also work with the ECU to retard spark. Some models do this and others don't probably depending on the shift feel that was desired.

If you disconnect the resistor the line pressure won't be controled by the ATECU anymore and you get full pressure even during shifts.

So even if the WOT line pressure is at maximum, the shift pressure can be reduced.

Mike

 

i feel dumb after reading all this tech talk. dont even know what half the words mean... sorry i brought the subject up! Maybe in a couple years i'll be able to give some input after I finish my engineering schooling...

 

Next time don't go and get folks who think they know everything about Nissan transmissions come and try to convince everyone what we already know is wrong.

After all the dust is settled the truth still is that the WOT line pressure changes dramatically when the Drop resistor is disconnected. Not just 5% and it does it on all 4th Gen auto transmisisons. 5th Gens I haven't tried so I won't comment.

 

i respect the opinions of both of you guys, as it seems that both you know lots about cars in general. I'd be happy with half the knowledge! Thought that the magazine might help clear up my questions about the drop resistor, thats the only reason I asked them - little did I know they would answer in relation to a different transmission that apparently is significantly different from the Maxima tranny. Wish I could get to the track again and try the mod to see what kind differences it makes for me. That's probly the best way - but thanks for all the insight on how transmissions work, I'm impressed with your knowledge

 

I just pulled 5% out of the air. FSM said APPROXIMATELY 95% at WOT and I said "IF"(read assuming) 100% was maximum possible.

I too agree that the drop resistor mod can temporarily FORCE the line pressure >100%.

 

In this case, Ben and Jim no more than Sarah and the other character. These magazine people think they know it all because they are the "voice" of the world. One thing they can learn from this thread is to research before replying to something they are not clear about. Clearly the Maxima's auto tranny reacts differently than other trannies and there are differences between the 4th and 5th gens.

 

No the issue is that we have to be able to answer a wide variaty of technical questions on many different models and years of cars way beyond Maximas. It trying to provide a service and in the case of NPM, it happens to be free to the Nissan comunity.

The Nissan performance comuninty is generaly very happy there are people like Sarah willing to answer questions with more depth than the average enthusiast and not get paid for it, if she doesnt know the answer to a question, the people she asks for help are very good and well regarded, like the guys at JWT and other top tuners that she knows. I think we try very hard to provide good information. No we don't know everything, I am the first to admit to that, I even admited that I am wrong in this thread, but NPM definatly has experts in general and specific Nissan tuning on its staff. We have been looking for a Maxima editor for a long time but we have not found anyone localy who we can meet with that is reputable and that can write.

My issue with Jim is not that he doesnt know what he is talking about but his general character.

Mike

 

It's good that you can say you're wrong when you are corrected but Ben and Jim (both run autos) are running very fast times using this mod. I'll be running this mod next year when my car is finished and tested. There's times I haven't gotten along with Jim but I'm not going to use that to say he doesn't know what he's talking about. He really does know his stuff.

JWT, another story.

 

Being wrong is being wrong.

Mike

 

Let's all kiss and make up....

 

I'll kiss Sarah, you gays can have Mike.