This is an offshoot to a thread started in the dyno forum:

http://forums.maxima.org/showthread.php?t=347857

We are looking for some "good" consistent ignition timing vs rpm data taken from TS or JWT modified 96 ecus. This applies to NA ecu programs for stock MAF and injectors.

Runs are WOT in third gear from 2500 - rev limit. A minimum of three back-to-back runs should be made to establish data scatter.
Our ecus do not support a very fast sampling rate, so you should only be logging ignition advance and rpm in order to get the largest number of data points.

This is the result of several runs I performed on my vehicle with a TS and a spare stock 96 ecu.



If you want to, PM me and I will give you my email address. You can send me your data and I will compile it and post the comparisons on the same graph.

NOTE: Please use some common sense and do not carry out these test runs on roads with other vehicles or pedestrians present.

Watch the road in front of you, not the scanner display!!!

 

People this is great so we can finally determine which ECU will be better...This is ohow comparisons start! Anyone?!

 

Only back-to-back dynos or the track with a real consistent driver will tell which one will give better gains.
Ignition timing is only one of the two parameters that they change. You need good A/F control as well. Only the dyno will tell if that has been achieved.

 

While I haven't plotted WOT runs with my Harrsion OBDII unit, I have watched my timing far exceed 30 degrees in the midrange (3500-5500rpms) with it falling back to around the high 20s as I approach the 7000rpm limiter with my JWT ECU. My tests were done in 80 degree weather, high 29 baro, 1100', and 92 octane. I'll do some tests when I get chance.

TS buyers beware, both eng92 and Michael order extended rev limiters from TS and they didn't get them.

 

so what is the timing supposed to be on these ecu's? dave b if you could graph your JWT in action, that would be great!!! this thread was started primarily to see if eng92 and I were actually getting the timing we were supposed to b/c we weren't feeling the difference in ecu's that everyone on here is saying they feel according to the "butt dyno"....when we swap in our stock ecu's and run them back to back with our TS one's...but we need a graph to compare....so we have something to show TS...

so you see 30 degrees @ wot and it diminishes out to high 20's in the top end....wow....that would be a large power difference over eng92's TS ecu and mine then!

 

I saw 28 degrees at 6.5K in second gear with my JWT

 

I will try and graph the data as soon as I can. Unforunately it's raining today and snow will be moving in later today, so doing WOT runs probably won't happen until later on in the week. I also need to read up on how to log my data with the Harrison unit.

As for butt dyno feel, yes, I noticed a decent surge in power immediately especially in the midrange after installing the ECU. It got even better once the JWT ECU learned learned part throttle too. I think Neal and Mike noted the same experiences. It's pretty noticeable. It basically makes the MEVI feel like the stock manifold from idle to 5500rpms and then after that you immediately take a hold of the extended rev limiter and higher rpm entry upon shifts.

 

Yep, sounds like mine. I remember seeing 27-29 degrees above 5500rpms at WOT in 3rd gear. I remember thinking, "is this good or bad?"

 

Yes, one of the few mods I could feel

 

I never felt my ecu at all but ive seen my timing in the 40's and low 50's

 

Damn! That's crazy talk! is that when you're RPMs are at 8K +?!

 

I agree 100%. And I'm auto.

 

I always thought TS had more aggressive timing....although I don't know if eng92 or I are getting what we are supposed to as we don't really feel any difference over stock....others on the forums here are saying they feel a huge difference with the TS ecu....what we need now is graphs from JWT people (although it looks like we have a unanimous 27-29 degrees at WOT above 5500) and some TS graphs as well....from people who think there's is working right and gives a large kick over stock...

 

Here's my data from three WOT run in 3rd gear going from approximately 2500rpms to 7000rpms. It does appear the JWT does give more ignition advance at most anywhere in the rpm range. Conditions were 45 degrees, 1100', 30.10 baro, 60% humidity, and 92 octane.



Here are the raw numbers so they can be used as a comparion:

RPM Degrees
2400 40
2600 40
2800 35
3000 34
3200 35
3400 20
3600 20
3800 20
4000 20
4200 20
4400 22
4600 24
4800 24
5000 25
5200 25
5400 26
5600 27
5800 27
6000 28
6200 28
6400 30
6600 30
6800 30
7000 31

 

Is anyone else unable to see the images, I'm getting red x's.

 

I have that problem occasionally as well. I was thinking it was a bandwidth issue during peak traffic periods and the pictures were not showing up as they typically comie from a different server.

 

Thank you Dave B.
Here is the original graph with your data added.



Did you go WOT from ~3400 on or right from 2400? I never see that much advance at that low RPM unless I am cruising at part throttle. Also TS programming doesn't start till 3500 rpm.

It looks like JWT holds it at 20 degrees from ~3.4-4.2K and then ramps it up at about 4 degrees/1000rpm from there.
TS on the other hand just takes the stock curve and adds an offset to it.

Looking at the data, there should be a noticeable amount of extra torque in the mid 3.5-4.4K range with the JWT.

Are there any other TS ecu owners with OBD-II scanners that want to contribute?

 

I would get cruising at at around 2500rpms in 3rd and roll into the gas and I was a WOT by 2800rpms or so. It's a mental thing because I usually don't go WOT at such a low rpm. That's probably why the timing looks so funky at the onset of the run. I did notice that timing can be quite high at part throttle around town in 3rd and 4th. I was seeing 35-50 degrees when cruising around at 1800-2500rpms.

 

From some timing maps I have seen, it seems to be fairly typical for the highest advance to be at partial throttle, high rpm. I guess because the danger of damage due to detonation (how's that for alliteration!) is low at partial throttle, and then timing is advanced less when increasing the engine load at or near WOT.

This may partially explain why sometimes it feels that a car feels peppier when accelerating at less than full throttle.

 

I agree. I don't fully understand everything about timing, but it does definitely seem like there's a lot more advance under part throttle acceleration and that sometimes that's why part throttle acceleration does feel pretty good sometimes.

 

Dave B
I noticed your rpm data is in evenly spaced 200 rpm increments. Is that something you specify, or is it fixed in the software?

 

I have some other graphs that may help to understand the shape of the timing curve. I took my maf data (at WOT) vs rpm and used it to create a crude engine volumetric efficiency vs rpm curve. When you overlay this on top of the timing curve, things make a lot more sense.

I will post the graphs once I clean them up a bit and get them online.

- EDIT -


Data for the above graph is all at WOT with the USIM and stock ecu.

VE really takes off at 3K. You can really feel the increase in torque at this point. Peaks around 4.5K which of course corresponds to our torque peak.

The rest of this post is from a PM that I sent Michaelnyden earlier this week.

"To summarize, your torque and VE vs RPM have the same profile. Peak torque and VE occur at the same RPM. Around 5.2-5.7K there is a small peak in the VE curve after which it drops rapidly. This corresponds to the same RPM where Nissan retards the timing slightly. The horsepower peak at this point is just a result of still having decent torque at a high rpm.
The rapid drop in timing between 3-3.5K corresponds to range of rapid VE increase. This drop in timing is necessary to keep the cylinder pressure from peaking BTDC. Timing is then ramped up slowly from 3.5-5.2K (approx.) Although VE is very high throughout this range, the timing must be advanced due to increasing engine speed in order to get complete combustion.
With the MEVI, your airflow in the upper end is completely different and I would expect a "properly" tuned ecu to have ig timing to reflect that."

 

good info.

 

Now I can see the first image and no others... I wonder if it is a bandwidth thing? I've never experienced this problem before though, ever. Just last night and now.

 

Same thing just happened to me.
I could not see them, I exited the thread, came back in and they were all visible again.

All the pics in this thread are coming from the CarDomain server. I suspect if that server is overloaded when you load the thread, the pictures will not not be visible. It seems to try and load them once and if that does not work it doesn't try again. You have to exit the thread and come back in again. The browser refresh does not seem to do it.

 

It's just a simple average between the three runs. The datalog seems to log the numbers at random. Sometimes every 100rpms, sometimes every 300 rpms, etc etc.

 

if you cant see the pic. right click the red x and click properties and copy the link and paste in new IE window. and itll work

 

wow...that is a lot of advance with the JWT vs. the TS...the JWT must dyno higher I would think...peaking at 31 degrees...is that safe??? I guess it is, cause the timing never pulled back as you can see in Dave B's graph...though it was done in incredibly cold weather...nonetheless...that is quite a bit of extra advance over the TS!!!


when you guys are datalogging, are you doing it in graph mode or meter mode?

 

I always use meter mode because I start the logging just before I start my first run and then I let it continue logging till I have three or four runs in. I then just hotsync the data into my computer and use PDBexport to convert it into something excel can use.

 

I got two runs in with my Auterra. Unfortunately the road wasn't long enough for me to hit the rev cut (JWT 7200RPM)

edit: done WOT in 3rd gear. Temp 50 degrees Humidity: 54% Wind: Calm Pressure: 30.02 in , 260ft elevation, Unocal 76 91 octane.




Run 1
RPM Timing
2213 24
2588 26
2963 25
3350 22
3738 21
4150 20
4525 21
4888 23
5213 25
5475 26
5763 27
5988 28
6200 29
6363 29
6513 31
6625 32
6725 33
6850 33
6938 34



Run 2
RPM Timing
2600 26
2963 25
3350 22
3738 21
4150 20
4525 21
4863 23
5175 25
5475 27
5725 27
5988 29
6163 29
6350 29
6500 31
6625 32
6738 33
6863 34
6963 34
7063 34

Cardomain's acting funky so if you cant see the graphs go here:

http://www.cardomain.com/memberpage/741438/2

 

Excellent data VeeQueue, Thank You

Can I get you to email me the raw data .pdb file(s)?
email address is dharrington@nordockinc.com

You may have already, but the rpm data needs to be corrected to correspond with the engine speed at which the timing value is taken.

example.

Your .pdb file format is
sample PID value units
1 12 2213 RPM
2 14 24 deg
3 12 2588 RPM
4 14 26 deg

A reasonable approximation is just an average of the rpm samples on either side of the timing measurement.
-> RPM for sample 2 is (2213+2588)/2

If the rpm is not corrected, it shows up as a left or right shift of the curve on the graph. Email me the files and I will process them and add them to the graph.

One question: Did you get the MEVI before or after the JWT? The reason I ask is that I would imagine JWT would have a slightly different timing map to correspond with the change in MAF that the MEVI produces.

-EDIT-
I answered my own question. You have a lot more advance above 6.5K than Dave B. That would make sense as the MEVI produces a lot more AF in the upper rpms over the USIM and you need the extra time to burn it.

 

I too have the MEVI. Probably the reason he is seeing more timing is his nearly 1000' lower elevation (more O2) and maybe his motor wasn't hot as mine. I had actually done about 6 back to back passes because I kept getting the log parameters wrong. My coolant temps were sky high on my last three runs which were logged. My poor car got beat on pretty bad that day.

As for the log fills you requested, my Harrison unit doesn't use that .pbd format. I simply used a .log which gives me a run down like this:


1 2213RPM'''24deg'''
2 2588RPM'''26deg'''
etc.

 

If air density was the issue, I would expect to see a timing offset if his airflow was significantly higher than yours as it would apply throughout the rpm range. The curves should share the same profile but just be vertically shifted.
The curves are actually very similar from 4-6.5K. You actually have a little more advance between 4-5K. Once you hit 6.5K yours sits around 30-31 degrees while his continues to climb to 34 @ 7K.

Once you start seeing differences in the upper end like this, you may need to start comparing maf vs rpm data. Do you two have different intakes?

I will post all the data later today.

 

they both have CAI's with the stock resonator it looks like...so same intake...

 

veequee....I would love to see you re-dyno with sean church once you get all those fuel related problems ironed out...!!!

 

I purged my open scan data files already. However I did save my first run but its already converted to .CSV format. The table looks the same.

12-02JWT Acura 1994
Sample PID Value Metric Units Metric Value English Units English
1 12 3038 RPM
2 14 0 deg
3 12 2213 RPM
4 14 24 deg
5 12 2588 RPM
6 14 26 deg
7 12 2963 RPM
8 14 25 deg
9 12 3350 RPM
10 14 22 deg
11 12 3738 RPM
12 14 21 deg
13 12 4150 RPM
14 14 20 deg
15 12 4525 RPM
16 14 21 deg
17 12 4888 RPM
18 14 23 deg
19 12 5213 RPM
20 14 25 deg
21 12 5475 RPM
22 14 26 deg
23 12 5763 RPM
24 14 27 deg
25 12 5988 RPM
26 14 28 deg
27 12 6200 RPM
28 14 29 deg
29 12 6363 RPM
30 14 29 deg
31 12 6513 RPM
32 14 31 deg
33 12 6625 RPM
34 14 32 deg
35 12 6725 RPM
36 14 33 deg
37 12 6850 RPM
38 14 33 deg
39 12 6938 RPM
40 14 34 deg
41 12 4950 RPM
42 14 0 deg
43 12 2550 RPM
44 14 0 deg
45 12 963 RPM
46 14 15 deg
47 12 875 RPM
48 14 15 deg
49 12 925 RPM
50 14 15 deg
51 12 950 RPM
52 14 15 deg
53 12 950 RPM
54 14 15 deg



If you really need a .PDB I can maybe do another run during nightime asap "when the coast is clear".

 

Here is the revised graph with all the timing data received to date.
I averaged both the stock and TS runs to give me a single data set for each. The graph was beginning to look quite cluttered which has a tendency to obscure some of the trends.



Comparing TS and JWT (VeeQueue), the amount of advance is pretty much the same from 4.5-6K.

It is the amount of additional advance from 3.5-4.5K that peaks my interest.

If I had to guess without seeing MAF vs RPM data for a VQ w/ MEVI, I would say that this is JWTs programming to bring some of the midrange torque back because of the reduced airflow with the MEVI in this rpm range.

I would imagine, running the JWT MEVI program with a USIM may result in some pinging in the 3.5-4.5K range depending on fuel and CC conditions.

Is there anyone out there with a JWT programmed for a USIM???
(with an OBD-II scanner of course)

 

that extra midrange/low end looks promising...!!! I you could just combine the timing from veeque's 3500-4500 and dave b's from 4500 to 5200....car would pull like mad....we just have to figure out the extranious variables that caused 2 cars with the same ecu's to have quite different timing...considering your intakes are the same...what are your other mods and what years do you guys have?

 

Since they both have JWT ecus, I will have to make the assumption that their AFRs are pretty close. Is any dyno data available to support this?

As timing is predominately based upon injector pulse width and engine rpm, if the AFRs are the same then the difference should be MAF. Of course this assumes they are both running a stock fuel pump, FPR and injectors.

Is it possible to get you two guys (Dave B & VeeQueue) to do some more WOT pulls logging MAF and RPM?

 

My mods are:

MEVI w/5200 switchover
JWT ECU 7000rpm limiter
HKS intake with stock resonator
WSP non-mandrel y-pipe
2001 Maxima muffler

I'll try and do some MAF vs RPM runs, but the weather once again isn't cooperating and it won't be until Tuesday that I can get some runs in.

I've seen a lot of JWT AFRs and they're all in the 14:1 range from 3000-7000rpms. This is with the sniffer O2 and also the wideband O2 (further proof that the Dynojet "sniffer" O2 is quite accurate). IMO, 14:1 is quite lean up top. We could probably see a little more power in the upper rpms if they were to dial the AFR back to around 13:1 above 5000rpms. A lot of people suggest the SAFC to dial back the AFR up top, but the word is adjusting AFR via the MAF will screw up JWT's programmed timing. These word's are straight from JWT.

With the JWT, I immediately noticed the increase in midrange power. It made my MEVI drive exactly like my car did with the USIM. WIth the addition of the JWT ECU, I went from consistent high 14.6s@95mph to consistent lower 14.4s@98mph. I'd say half the gain was because of the increased the power and the other was because of the increased rev limiter.

My all time best is currently a 14.31@99.34mph. With the MEVI and the mods listed above, no JWT ECU, and the addition of a b-pipe, and an UDP, my best was 14.65@95.6mph. With the USIM, B-pipe, UDP, and mods listed above (no MEVI/JWT), my best was a 14.60@96.0mph. As you can see, B-pipes and UDP aren't worth squat on these cars hence the reason I don't run them anymore.