Fred Allen Burge

That the 01 + pathfinder/QX4's have a VQ35DE with VTC's but have a 360 tooth rear crank trigger wheel (like the VQ30DE but unlike all other VQ35DEs), a 4 tooth front crank trigger wheel (like the VQ30DE but unlike all other VQ35DEs), and a regular 2 wire cam position sensor mounted to the timing cover (like the VQ30DE but unlike all other VQ35DEs)?

My suspicion is that one could swap the 01 + pathfinder/QX4 timing gear/cover setup onto a VQ30DE and use the pathfinder/QX4 computer and harness thus creating the worlds first VTC equipped VQ30DE. I'm not sure what would be needed in terms of cams/cam gears. Heck, I'm not even sure there would be any great benefit to this given the .5L difference in displacement and differing timing needs of the two motors. Nevertheless, it's fun to think about all the possibilities and talk them out.

Anybody wanna try this? Anybody see any glaring problems? Will this revolutionize the world of VQ's forever? Will Osama Bin Laden ever be caught?

allen

hightuner

iTrader: (1)

Hahah dont know about ousama ouistiti

but all those new VTC'S idea sound great to me !

IceY2K1

iTrader: (3)

Very interesting.....

VTC would allow agressive VQ35 cams to idle with a killer top-end.

95mtlMAXSE

how about that ey ...whoever figures this stuff out is great

hightuner

iTrader: (1)

Looks very interesting , i decide to browse the FSM on Phatg20

it seems that nissan made 2001.0 and 2001.5 model / both have Vtc tough

anyways downl the pdf if you want

http://www.phatg20.net/modules.php?n...ownload&cid=76

nismology

iTrader: (8)

Stephen Max noticed posted this info over a year ago. Nothing ever came of it though.

hacim105

iTrader: (6)

yeah here is the thread

http://forums.maxima.org/showthread.php?t=412405

SR20DEN

iTrader: (7)

This has been discussed dozens of times behind the scenes and even talked about here some. People read about these things, think it's interesting and then forget about them ten minutes later.

It is however refreshing to see more people figuring things out for themselves.

IceY2K1

iTrader: (3)

Just like the 00VI/350Z IM....everybody talked about it...many forgot...finally Krismax/vasmoly stepped up and now many have followed the lead and even come up with their own solutions.

We need to keep these discussions alive and up front...

Jeff92se

iTrader: (82)

How about discussing them period? hehe

IceY2K1

iTrader: (3)

...........

Tatanko

iTrader: (34)

I'm feeling rather hesitant to ask this, but could this help (if figured out) with some of the issues of being unable to keep VTC's when swapping a 3.5 in?

allen222

WOW, I've refreshed the SR20DEN


allen

allen222

I think the best way to get the VTC's working for you 3.5 swappers is to simply use the 3.5L's computer (Maxima, Altima, etc.). Travis is using them in his 3.5L swapped Sentra cars, I don't understand why you guys aren't. The extra cost isn't outragous, the extra wiring work is offset by not needing to swap timing gear around. Maybe I'm missing something though.



allen

SR20DEN

iTrader: (7)

Most of them are just too afraid of the unknown and refuse to do anything unless they can follow someone elses work. You can run the VTCs without the 2k2 ECU if you really want.

liqidvenom

iTrader: (6)

the cost isnt outragous, but having to swap in e-gas and all the other things that comes in the sentra from the factory kinda makes doing this in one a bit easier then if u did it to a 4th gen.


if bolting on the timing stuff from a pathy might be doable to a 3.0 to possibly yeild vtc then i dont see why the same cant be done to a 3.5 motor in a 4th gen to give us vtc.

DandyMax

iTrader: (7)

I guess perhaps many are scared of/don't understand the wiring, but personally wiring does not bother me in the least and when I get around to doing the VQ35 swap, you can sure as hell bet it's gonna have VTC's in some form or another.

Although to be fair cost is also a factor, more so for some than for others.

allen222

I'd love to hear more, please PM if you feel the it's necessary. I'd like to get them working with my standalone if possible.

I hear that, my whole project is still well under 5 grand.

allen

scrhale

Can you elaborate on this? It is not that I am trying to call you out, but I haven't heard of running VTC without swapping in the ECU. I remember asking if you can do it with EU and everyone said no.

Also, can anyone throw out random guesses on the CONS of running a pathfinder ECU? Codes, incompatibilies, etc etc.

SR20DEN

iTrader: (7)

The VTCs are driven via PWM and the waveforms look nearly identical to what drives fuel Injectors. All anyone has ever needed to do is drive them with the extra injector drivers on the EB or EU. The only real problem is drawing the correct map, which won't look anything like an injector map. You also have to be careful not to over drive them because they're 7 ohms which is a lower impedance than the Greddy units are rated to run without resistors. And they're also driven by the ECU on a very low duty cycle, once the desired angle is reached.


I also need to mention that they'll be 'blindly' driven in this form. Because you'll have no way to determine the angle at which they're being run at. It will be difficult to use them in between full on and full off.

scrhale

Throwing out my last question: ... Engines > me

Does the DEK has the same/simular timing equipment was the VQ30DE? I always have the DEK swap on my mind. A DEK with VTC just sounds hot. Thanks.

nismology

iTrader: (8)

There's one itty-bitty problem though. Where would the 3.0 ECU get it's cam position signal from? Maybe cutting off the teeth of the 3.0 cam gear, attaching it to the front bank VTC sprocket somehow, and retrofitting the 3.0 cam sensor on the 3.5 timing cover??

Edit: Nevermind, that wouldn't work...

eng92

iTrader: (3)

That would contradict what is indicated in the FSM.

If those little scope screenshots they have are of any significance, the period of the VTC pulse signal is something close to 4ms. The period of an injector pulse signal is independent of duration and is always equal to 2 crank revolutions (for engines using sequential injection) At 6000 rpm, the injector signal period would be 20ms.
Therefore in 2 crank rotations, the injector would be pulsed once, while the vtc solenoid would be pulsed 5 times.

The EU/EB cannot interpret the VTC signal correctly because it is not crank angle based. The input circuits on these units are only set up to trigger on one pulse every other rpm. They do not recognize the four or more other pulses that follow it before the next injector period begins.

I presume from what you are saying that you have already successfully done this. This would mean that the vtc solenoids still function correctly with a much longer and varying signal period. (60 ms @ 2K down to 20 ms @6K)

This is good news if that is the case. I should have a scope up and running this weekend so I will be able to directly measure cam timing changes.

SR20DEN

iTrader: (7)

I didn't say wave durations or frequency. If you look in the ESM you'll see the wave shape, similar to a square wave, is what drives the solenoids.

Fred Allen Burge

If you were to use the Pathfinder/QX4 timing setup it has a cam position sensor mounted very similar to the VQ30DE's.

Fred

nismology

iTrader: (8)

Understood. I just thought he was referring to using the Gen II 3.5's VTC's with the EU.

DandyMax

iTrader: (7)

That IMHO, is the main challenge/drawback to using the sub-inj method.

IceY2K1

iTrader: (3)

AEM EMS has VTC control with feedback....not for the faint at heart though.

DandyMax

iTrader: (7)

And there's always Motec.

Even more "not for the faint at heart."

IceY2K1

iTrader: (3)

I'd prefer the AEM EMS for both cost and user friendliness.

I haven't tuned one yet, but my boss at work just bought a 800+hp Supra with one already installed. I'm hoping to get to play with it.

Jeff92se

iTrader: (82)

What makes the AEM EMS "more difficult"? I guess the tuning? I thought AEM prided themselves with plug/play installations with the use of the oem stock maps to get you up and running? I'm ignorant in these things sorry

IceY2K1

iTrader: (3)

The P-N-P units that include base maps aren't that bad, just 3x or so the price of the EU, but far more capable.

The race/universal AEM EMS units are what I referring too.

DandyMax

iTrader: (7)

Cool! Sweet deal if he'll let you... How well do you know him? I'd be asking for a test drive too. haha

IceY2K1

iTrader: (3)

Very well...he's an exotic car guy/collector, I'm the one who found the Supra advertised locally and told him to test drive it so he'd know what a turbo car powerband was like. He left a deposit, but hasn't paid in full yet.

He doesn't know much about Jap stuff and he listens to what I regurgitate from all my car mags/websites. I don't care to drive it, just hope to tune it.

DandyMax

iTrader: (7)

Sounds like you'd be perfect as an engineer on a race team, since it seems you enjoy the behind the scenes tuning, computer work etc more than the driving.

Me I'd rather drive, although I can do the other stuff too. lol

krismax

iTrader: (15)

I have a SCC mag where it shows JWT using a nitrous commputer to control vtc on a car . maybe i can find the mag ....