Quick question, is there any way(other then with a nissan consult) to increase the timing on a 95+ maxima? Rumor has it the maxima comes out of the factory retarded approx. 5 degrees. So if the timing could be advanced 5 degress it would yield some decent gains(maybe 10 HP?).

I know there are things to retard the timing, could the same unit be used to increase the timing?


BTW I put some denso iridium plugs in today, the car feels good with them. I also ordered a apexi S-AFC, I am hoping to squeze out anotehr 10 WHP with the SAFC. Hopfully I will get my 250 WHP by this spring, we will see..

 

From my search results, I saw that people got their timing advanced at the dealer a few degrees. You can also get that OBD-2 thing and hook it up to a laptop and change the timing.
Check out this thread for some timing information.
http://forums.maxima.org/showthread....advance+timing

 

Since the VE is almost identical to the VQ, I am sure the way we do it would work the same for you guys, you have all the same sensors,etc...believe it or not. Alot of people dont want to believe it, just like I said the VE transmission would work on the VQ and people wouldnt have to hunt down the I30 trans to get VLSD. But on another note, I think we use the crank angle sensor, I havent done it, so I wouldnt know...here is a write up on how to do it though...

http://www.prism.gatech.edu/~gte671n/mymax.html

 

Donald you numnutz! haha 3-gen VEs have a cam angle sensor that we can rotate to advance/retard the baseline timing. 4-gen + have a crank angle sensor that cannot be moved.

 

No, the VE timing is adjusted by the crank angle sensor.

 

Hmm is that sensor mounted on the crank or cam?

 

It's mounted right on the end of the cam. But why is it called the crank angle sensor?

 

I don't know what the manual calls it but it's a sensor mounted on the end of the cam. Thus it can't be reading off the crank. It might be sending a modified signal to the ecu to give it the crank's position. ie. crank rotates at 2x the cam's speed or vice versa. I forget which.

 

I apprecite your help here, but.. I have reason to beleive once the nissan consult is un-plugged from the car the factory timing settings will go back to normal. I have been told this by several nissan techs, a few of which do quite a bit of tuning on there own.

Now if I was to get the software for a lap top application I could possibly keep the laptop pluged in(under the seat). If the software truely worked I could keep the lap top plugged in all the time We will have to see about this, any more info on this matter, anyone?

dmontzmax, Jeff and Aaron, sounds intersting, I will be standing by to here if you get this figured out amoungst your selves. I will look into the ideas you shared too, thanks for your time.

 

Well, there is nothing to figure out. On the VE, you advance and retard the ignition timing by turning, what all manuals call it, the crank angle sensor.

As for the VQ, I haven't heard of anyway to advance the timing yet.

 

After reviewing your page there is no way this will work on a 95+. Our CPS is located on the bell housing of the tranny and another one is right below the crank pulley.

 

Ethan, the ONLY way to advance the timing is with a Consult-II, since it is ECU controlled. You might find a piggyback computer that can "trick" the signals to the ECU and force it to add advance, but the ECU might also adjust/counter the changes over time. An OBD-II scanner can not modify anything except clear fault codes stored in the ECU.

According to what I've read and hopefully understand from the ESM, the Consult can make permanent changes to the timing. It will not revert back to the original settings.

However, the "timing" people with 5th gens have changed is the BASE ignition timing, which is going to do nothing but maybe make the throttle slightly more responsive. It's not like the old distributors that advance the whole curve. As the throttle is depressed, the ECU adds advance, which will offset the slight base timing increase the Consult changed.

I'm hoping I'm wrong, but unless we can get a Consult-II and a Max on a dyno, I doubt it. Otherwise, JWT is who you MUST NAG FOR AN ECU.

 

Great info! I spoke to my friend who owns the local nissan dealership. He had a long dissusion with Jim Wolf about a 350Z ECU and other things. Cams will be out by spring(or so they say) and they are working on a 350z ecu. If they can get a 350z ecu to work I am sure they will be able to get a max/alt ecu onto the market.

 

Thanks. However, I would still love to be wrong and if you can persuade/bribe your Nissan friend to let you borrow his overweight game boy size Consult-II for a few dyno runs, I'd really like to hear how it goes. It's VERY simple to operate and extremely portable. I'd love to buy one someday, but at ~$4K, I don't think that's going to happen.

JWT is the key. We just need to show enough demand to offset the huge R&D it would require. However, having VQ30DE, VQ30DE-K, and now VQ35DE engine applications is far fethced. I'm hoping you 3.5L guys will luck out with the 350Z!

 

FYI, I had my timing advanced by the Consult II a few months ago, and wasn't sure if it would reset itself, especially after resetting the ECU via unhooking the battery. I took it to a dealer while in AZ to get my 60k tune-up (at 70k miles...) and the timing was still up at 17. Dunno if this applies to the 2k2 & newer, but so far so good on my 2k.

 

Woo Hoo, another thing the VE has (the ability to adjust timing).

 

 

I'm looking to getting my timing advanced next Saturday. One of the guys I work with has a friend who is a Nissan tech. I asked him to call him the other day for me to see if he would do this. The call was made and the tech said that he has done this to several max's. Not sure what year he was referring to but he said the factory timing was at -1 and they advance it to +2. I believe that is an increase in timing from 14 to 17. He also said that the timing advance will hold after the Consult II is removed. This is pretty much in line with all the other info I've read at the org.

 

Does anyone know the factor timing setting on a 4th gen? So the general rule of thumb is to advance the timing +3? Thanks.

 

This may be a dumb question, but does advancing the timing cause any sort of problems? I mean, what is the reason that the cars don't come from the factory with the timing advanced? It wouldn't cost Nissan anything to do it.

 

Check out these threads. They have a ton of info.



http://forums.maxima.org/showthread....advance+timing

http://forums.maxima.org/showthread....advance+timing

http://forums.maxima.org/showthread....advance+timing

http://forums.maxima.org/showthread....advance+timing

 

You should have just waited and got a G35 with all the money you're throwing into your Maxima j/k

Seriously though, I've been told that the S-AFC does nothing for our motors in NA form. Apparently the MAF/ECM is smart enough to adjust the A/F to compensate for the added air flow from mods and the injectors are easily within spec even with all the NA bolt-ons. Advancing the timing will work in terms of gaining power, but you need something that you can adjust the timing at various rpms, just not overall. Seeing that todays cars are pretty damn smart, I don't see much of a gain advancing the timing (maybe 5fwhp?). With the amount of money spent for the equipment and dyno time, advancing the timing seems pretty pointless.

After thought, I'd bet Nissan dials back the timing slightly just to compensate for our lower octance fuels. We're so lucky in the States. We get both crappy gas and crappy roads.

If I were you, I'd spend my money elsewhere and/or buy a 2nd car that will offer you the extreme performance you desire.


Dave

 

You're right, there is tons of info. After 2 hours of reading, I think that I am beginning to get it.

 

 

Make a device simular to the timing adjuster that Steeda offers for the modular mustangs. That would allow you to advance or retard the timing.

 

I have a 3.5VQ with my timing advance the 3 degree by my dealer. A month or so later I took it back for something and had them see if the timing was still advanced. sure enough it was still advanced..

my .02

 

For those of you who insist on the dealer advanced timing technique, please read what ice2k1 said above. He makes a good case and I would like to hear what others have to say about it.

 

Okay with the VE this is what happens. As Icy said, you can only change the BASE timing. BUT the ecu will base it's timing curves against this base timing. Imagine a graph of the timing vs rpm. If you overlay the timing curves of the base timing curves over the advanced base timing curves, the the advanced one will mirror the old curve perfectly but will be x degrees advanced/retarded at every point(x=whatever you had the base timing advanced to)

Of course the trick is not to advance the base timing so much that timing curves run into a situation where the knock sensor chimes in. If it does, the KS will really pull back the timing x degrees to make absolutely sure the ping goes away. That will hurt performance, not help it. But since the Consult appears to only to +/- 5-6 degrees, that should be within the safe range. Maybe + 5 or more, might be too much.

 

Ethan, what part number are the plugs? I looked at their website and could not find a part number for a 2002 maxima.

 

IK16



Thanks for the explanation Jeff.

 

That is true for timing sytems that use distributors with vacuum advance. However, for distributorLESS ignition systems that are ECU controlled, I don't believe it is.

Distributor timing systems:
The BASE timing is set at idle, say 15*. Then as the motor accelerates the vacuum created is used to advance the distributor which adds additional advance to the 15* according to the amount of vacuum created at different RPMs. Therefore, the BASE timing value of 15* will be compounded on throughout the timing curve for all RPMs as Jeff explained.

DistributorLESS timing systems:
The BASE timing is set at idle, say 15*. Then as the ECU reads it's crankshaft position sensor, TPS, MAF, 02, etc.. it calculates based on ALL sensor inputs AND current advance, what the MAXIMUM advance can be. Therefore, the BASE timing value will be 'overtaken' according to what advance the ECU calculates.

In the distributorless timing systems, the ECU will try and maximize the advance throughout the rpm range. So, if the BASE timing is raised from 15* to 20*, when the ECU calculates according to its sensor values the advance necessary at a specific RPM, say 5000rpms, it will compensate/override the 5* delta added to the base timing.


Example:
The base timing is set to 15*@650rpms and the ECU calculates a MAXIMUM actual advance of 20* at 2000, 30* at 3000, 40* at 4000, 50* at 5000, and 60* at 6000rpms. So, then you INCREASE the base timing to 20*@650rpms. Now, you have 20* of advance from 650-2000rpms giving you a better pull until 2000 RPMs. However, once you hit 2000rpms the ECU calculates the same MAXIMUM actual advance, so you're back to 20* at 2000, 30* at 3000, 40* at 4000, 50* at 5000, and 60* at 6000rpms.

I believe the advantage of raising the base timing from 15* to 20* in this example will ONLY be beneficial from 650-2000rpms, however in the 'real world' it's until the ECU calculated advance exceeds the base timing.

Just my .02, which aint worth much!

 

Icy. My ve doesn't have a dist. It uses a crank angle sensor mounted on the exhaust cam. You can move it CW or CCW to advance/retard the base timing. I'm pretty sure it affects the whole curve on my VE because if you move the base timing too much, it will ping when you drive it. So at least in my case, the ecu is NOT evaluating what the max advanced timing can be at all times. It's going on a preset curve based off the base timing and if the ecu sees something bad though the sensors(ie.. ks), it will change it(ie.. retard). I believe MY ecu uses the tb/maf/head temp/water temp/crank angle sensors to help tell where on the timing map to put the timing at for a given rpm/temp/load/throttle position. But it can't pull a non-preprogramed timing map and make it so in the ecu. It can only pick a point on one of the present timing maps available. ie.. cold start, part throttle, full throttle etc.... blah!

I see what you mean but how can the ecu determine EXACTLY what the maximum timing advance the engine can use? It would have to keep advancing it until it pings and then pull it back(no logical). And then keeping do this until it learns what that max is per given gas/temp/driving habit etc....

Hmm okay after writing that, maybe the newer ecus ignore the base timing and just points to a particular point on the timing map based on the sensors. THAT makes sense but why even have a base timing anyway? And why have the ability to adjust it though the consult?

 

The ECU still uses base timing but now it has 2 sensors to read engine rpm. In the FSM it says the CAS behind the crank pulley is what the ECU uses to adjust fuel/timing curves. Thus it is the reference signal, I believe it uses the POS signal from the one on the flywheel or camshaft to note when #1 is at TDC. If one was to offset the REF sensor let's say 3*BTDC then the ECU would see 15*BTDC but actual timing would be 18*BTDC.

All one has to do is mark the timing ring in relation to the crank pulley and pointer @ TDC. Then bias the timing ring's TDC mark to 3*BTDC. It is the same princple as an adjustable cam gear/sprocket. Here is what a steeda timing adjuster looks like below. I believe that the timing ring on the UR UDP might be removable. So all one has to do is take some measurements and re-drill the timing ring's mounting holes to allow you to offset the timing to the desired setting.

http://www.steeda.com/store/-catalog/UDTACombo.htm
http://www.steeda.com/-hotnews/press/timingadjuster.htm

 

Interesting. I don't know how your VE works then. I just threw the distributor idea around for comparison sake. Actually, I was reading up on how ignition distributors work and there is typically two spark-advance mechansims: 1)A speed-sensitive centrifugal advance mechanism and a load dependent vacuum-controlled device. So, ignore my other post.

That may be true, but again I don't know exactly how advance mechanisms work on Nissans. However, according to my 4th edition Bosch "Automotive Handbook", todays ECUs process engine-speed and load signals before using them to calculate the precise ignition angle within the ignition map. Other signals such as engine temperature, trailing throttle, or full-load operation are processed to derive correction factors used to regulate other vehicle specific functions. The Ignition Maps are 3D with x and y as the load and engine speed, while z is the advance angle. Also, it is possible to program each point in the map independently from every other point. Thus the optimum ignition timing can be selected for every operating condition, but limited by such things as exhaust emissions, pre-ignition limit and driveability. The Knock Sensor is used to retard timing for each cylinder where knock is occuring, allowing the others to perform.

Actually, according to SCC that is EXACTLY what the Subaru WRX does, so fuel octane is a HUGE performance factor.

However, for Nissan lets replace "maximum" with OPTIMUM. I see how that could mislead you. Each point on the 3D map is independent, so I'd say the "base ignition" value is the floor. The hills and valleys make up the overall OPTIMUM advance value, ie the base ignition value is a component.

That's pretty much what I believe happens, however each system is designed differently. I believe that the ECU uses the base timing as a component of the optimum advance angle. However, a change in the base timing will just cause the ECU to choose a slightly different path on the 3D table, but still result with the SAME optimum advance. As far as I can tell, the base timing is used for idle-speed control, since according to Bosch the speed is determined by the intake-air flow, the excess-air factor(A/F ratio), and the ignition timing. Supposedly, below the idle speed the ECU reacts to further decreases in engine rpm by advancing the ignition, thus increasing torque and preventing engine speed from decreasing further. I'd also assume that the base timing value is a backup for "limp-mode" incase of sensor failure or possibly during open loop mode for cold starts. As far as to why is it possible to adjust it with the Consult, I don't know for sure. I do know that someone on the board was told by a Nissan tech that they retarded the timing to prevent pinging(which would support YOUR argument), however I doubt that's true since there are adaptive procedures that focus on the ignition-timing map and the fuel vapor flow from the charcoal canister to provide optimum engine operation regardless of the type of fuel being used.

Again ALL of the above is based(read plagerized) from the BOSCH "Automotive Handbook", which is NOT specific to Nissan ECU design and could not be correct. However, I've found that what Bosch specifies as "typical" or "generally used" is almost universal by the time it publishes the information, since they are the leader that everyone follows on ECU and fuel system designs.