whlimi

iTrader: (11)

I've been playing around with the ignition timing advance feature on the EU and I thought I would post up my map and get some suggestions/comments. I know there are quite a few guys here running the EU with a similar setup as mine. My main concern is not so much the advance at WOT but more so everywhere else on the map. Are you guys just advancing at WOT or are you adjusting all over the map including parts of the map that fall under closed loop conditions. I want to try and get the most out of this motor under normal driving conditions as well as under WOT.

Here's my map so far:

Under normal driving conditions I never exceed 4000rpm and 45% throttle. My adjustments have made the car feel much more responsive in that range but I'm not sure if I can safely go any further. This is a daily driver and will be driven during the hot Toronto summers (sometimes over 35* Celsius).

liqidvenom

iTrader: (6)

Mine looks pretty similar to that, when i get home i'll post mine up as well

95BLKMAX

iTrader: (10)

I would ramp your settings. I see that there are parts that you go from zero correction to 5, for example, at 4000, if you're accelerating at 20% throttle, then you punch it, there's a jump in ign timing from 0 @ 20% to 5 @ 25%.

The way I do my tuning is do the WOT timing advance for 80%+ at all rpm points, then ramp it downward to the lower settings you may have (zero in your case). Basically I would just eliminate those sudden jumps in ign timing advance that you have. Ramp them so that they are not so sudden (by this I mean both on the x and y axis). This will provide you with a smoother transition and you may or may not feel a smoother accelerating motor with less "hickups"

BTW, why in the world is 750 @ 0% advanced 1 degree and everything around it is at zero? lol

whlimi

iTrader: (11)

Thanks for the input. The reason 750 is advanced a degree is to raise the idle a bit higher. I tried messing with the IACV screw but I couldnt get it to idle like I wanted. The 1 degree advance made it perfect.

95BLKMAX

iTrader: (10)

Oh wow I see now lol. FYI (or for anyone reading this thread that may not know), to properly adjust idle via the IACV idle screw, you have to disconnect the plug for it, turn the screw as needed, the plug it back in).

I dont have an IACV so I adjust my idle off the TB's idle screw.

whlimi

iTrader: (11)

I've tried it all lol
The 1 degree advance gave me the best results.
As far as the actual advance goes, how much are you advancing your timing in the normal driving range? Are you ramping it up aggressively or is it pretty conservative?

95BLKMAX

iTrader: (10)

Well when I tuned maximaspd85's EU, I ramped it at about 2* per cell leading up to the full advance for 80-100%.

I notice that on your normal driving throttle area, you basically have timing advance fall flat on its face at 4000rpm with <25% settings. This isnt good, ramp it downward to about 2* (3* closer to redline) and hold it out to redline.

Reason Im saying this is so that (for example), lets say you're going for a fun-run against a friend from a roll. If you're starting at 40-45mph, you'd want to be in 2nd gear, which would put your RPMs at 4000-4500 just about. At that RPM range you are at 0* advance, then as you floor it, you jump on the map on to 5* (6* if from 5500). This jump could cause a hickup that can easily be smoothed out by just ramping it.

Tell you wat, Im gonna borrow your snapshot and edit it, lol. Give me a few minutes

whlimi

iTrader: (11)

I made some changes. Let's see if it's even close to what you were suggesting lol.



The timing is more aggressive than what you suggested but I'll change that.

95BLKMAX

iTrader: (10)

haha! thats looking more like it! Yea it is ramped quite agressively. This is what I came up with here...



Try either one out on a test drive. Do normal acceleration, sudden WOT runs from any RPM, etc... I dont think there will be much difference noticeable to the butt-dyno bet'n the map you just made and mine, however I would keep my map simply due to the more gradual incrementing of advance.

But you got the right idea going

whlimi

iTrader: (11)

Awesome. I will definitely load up that map and give it a shot.
Thank you.

95BLKMAX

iTrader: (10)

Standing by for butt-dyno normal driving results!

NameGoesHere

whlimi

iTrader: (11)

The power difference between my map and the one 95blkmax created wasn't really all that noticeable but that was expected because we had similar timing advance numbers except that his map was ramped gradually. Now here's the good part, acceleration did feel quite a bit smoother specially on the highway when passing. Love the fact that I can stay locked up in 4th and still be able to easily pass other cars.

95BLKMAX

iTrader: (10)

And that was exactly the objective here. Glad I could help

chillin014

iTrader: (67)

subscribed. Anyone know much of an improvement can be made at WOT over the stock 3.0 timing?

95BLKMAX

iTrader: (10)

A whole lot. Especially for you running that 3.5 engine. Put it to you this way, the 3.0's timing curve takes a dip right at high 2000s, troughs at ABOUT 3400 to ~15* then slowly ramps up to 24-25* to redline. On the Z33 ECU for example, there is no trough, timing stays flat from the high 2000s and ramps up to about ~26*. And even still, it can use some more advance and still make useable power.

Look around for eng92's timing graph ubber thread. These comparisons were on it.

nismology

iTrader: (8)

The stock 3.0 timing is a reflection of the USIM's characteristics. So it's not "bad", just not optimal for every IM/engine combo.

whlimi

iTrader: (11)

Is this the thread you are referring to?
http://forums.maxima.org/all-motor/3...questions.html


Based on those graphs, stock 3.0 timing starts declining at around 2900 rpm (~23*), hits a low of ~13* at around 3850 rpm and then starts ramping up till it hits 23* again at around 5100 RPM after which it continues ramping up right to redline. So between 2900 RPM and 5100 RPM there's a trough like you mentioned. Now in order for someone with 3.0 timing and vq35 motor to get a map similar to the z33 ecu, they would have to advance timing significantly in some areas of the map. For example at 3800 rpm the z33 timing is ~27*. We would have to add 14* advance to get the 3.0 timing to 27*. Currrently im advancing that portion of the map by 8* which brings me to about 21* total advance. Any thoughts on timing advance for this specific area under WOT? Is it safe for the 4.5 gen with 3.0 timing to eliminate this trough by advancing the timing in that range by as much as 14*?

EDIT: found the thread you were referring to:
http://forums.maxima.org/all-motor/3...on-timing.html

DandyMax

iTrader: (7)

It's probably safe but really the best way to set your timing is to get on a dyno and advance timing to find optimal power. There's too many variables at play to just copy another car's info IMO. Have you datalogged your total timing curve to see what you're currently actually running? I'd do that first personally...

Also, another note: I don't quite trust that the "stock" A32 curve is as low as 13 degrees around that "trough". I have several datalogs off the EU from my stock 98 A32 ECU showing that trough at around the 20 deg mark. And 13 degrees seems intuitively too low and ultra conservative to me. Given the head design and geometry of the VQ etc there's no need to be below 20 degrees around torque peak on an N/A engine.

Maybe in a few days time if I get a chance I'll post up a couple graphs, including my measured stock timing and also the setting I used on my cammed 3L engine from the dyno runs (but your optimal may well be different, given you have a 3.5 and different IM setup etc etc).

whlimi

iTrader: (11)

Below is a graph of my stock timing when I had my car dynoed. It's based on a two run average.



Based on the graph, I hit a low of 15* at 3500 after which point it begins to ramp up. At around 5300 RPM is where it comes out of the trough and for the rest of the graph it's somewhat linear except near redline where it peaks to 30*.
So between 3300 RPM and 4500 RPM there seems to be a lot of room for improvement but like you said, only a dyno will show what the gains will truly be. I'm only applying this theory to a vq35 swapped 4th gen because we know the z33 ecu is running between 26-28* advance in that RPM range on the same motor.

My setup comes alive at around 4500 RPM and that's where stock timing advance breaks into the 20s. I guess I'm just curious as to how the motor will pull if that trough was never there .

Below is a graph of my timing with adjustments made by the EU and as you can see the trough is still present just not as defined as before.



I'm hopeful that there will be significant gains once timing is in the 30* range in the RPM range concerned.

EDIT: Sorry about the giant graphs

liqidvenom

iTrader: (6)

what are you guys using to pull the stock timing info?

an obd tool or is there something in the EU that lets you see what the stock timing is + what ever adjustment you are making?

i havent checked my EU in about 3 mths so i cant remember

whlimi

iTrader: (11)

I'm using the EU data logger. It lets you see total ignition timing as well as ignition adjustment.

Nealoc187

iTrader: (23)

You should be tuning using airflow rather than throttle position. Tuning in the way you are does not allow emanage to compensate for different atmospheric conditions.

sparks03max

iTrader: (7)

+1 Most of the tuning software I've been around (HPtuners as a majority) will use airflow over throttle position for setting those parameters. More accurate that way for every day driving all year long albeit more confusing to work with.