ER34 AA51G VE indexing

Discussions concerning the M7790 cpu

Moderator: Matt

Post Reply
SeriouR
Posts: 18
Joined: Sun Apr 22, 2012 8:47 pm

ER34 AA51G VE indexing

Post by SeriouR » Fri Sep 24, 2021 6:59 pm

Hi,

I am having an issue with my VE indexing. In the log it will show what I think is the correct ATPS value but on the VE fuel table the cursor is always way further to the right at a higher ATPS value.

What is causing this?

I have a R35 AFM in a 3.31 inch tube so I have used the VQ generator and only changed the floor end of the curve (Idle AFRs essentially)
Can I set my fuel maps to estimated AFR and change the afm curve to suit the map with WB readouts?

Any other input on the tune so far? I have scaled new afm, load scaled fuel map, set K/TIM, setup fuel map, minor timing changes (knock heard)

Im running a high flowed factory turbo, 3 inch exhaust from turbo back (2x high quality resonators), blitz intercooler, turbosmart wastegate with 14psi spring, 720cc injectors with latency data (data has been input and not changed)
Attachments
Nistune_31.csv
(546.86 KiB) Downloaded 9 times
220921.bin
(64 KiB) Downloaded 9 times

Matt
Site Admin
Posts: 8755
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Re: ER34 AA51G VE indexing

Post by Matt » Sun Sep 26, 2021 10:42 am

From factory there is no VE index reporting from consult. So that makes things a bit tricky

The ATPS value we pull from the ECU for R34 is doubled when we do the maptrace in the VE window. This is why you don't see an exact match on the table vs the ATPS. That was based from experimenting with values in the VE map compared to where the cursor was (so it wasn't a 1:1 match)

Looking at the tune
1. Increase boost sensor limit counter to 255
2. You have disabled O2 feedback and knock sensing?
3. Bit of an interesting bump with 14ms around 70degC upwards in the Crank Enrich table
4. Set Alpha/N table all to 255
5. Latency table also interesting. Would recommend keeping it straight
6. Estimated AFRs are rubbish. Ignore them. I would remove this view, but some customers want it in there still. Leave the VE table alone and only adjust the fuel map in 'filtered values' view to achieve desired AFRs

We have some training notes on our website, but the basics for fueling are
1. Adjust TIM so that you have stoich at cruise, with near 0% trims (with O2 sensor enabled)
2. Adjust K constant to adjust the load cursor, that on full boost you use the entire map
3. Then you can adjust the fuel map to achieved desired ratios (around 11.5:1 on boost)
4. Adjust latency at the end to achieve a good idle

SeriouR
Posts: 18
Joined: Sun Apr 22, 2012 8:47 pm

Re: ER34 AA51G VE indexing

Post by SeriouR » Mon Sep 27, 2021 9:43 am

Hi Matt,

Thanks for your speedy response. I did read that the VE values were doubled in the Neo tuning guide just wanted to make 100% sure before really getting into it, thanks for the clarification. If you could give some feedback on the responses below that would be greatly appreciated.

Looking at the tune
1. Increase boost sensor limit counter to 255 - I thought this was already done, will change
2. You have disabled O2 feedback and knock sensing? - I have disabled the O2 feedback after I dialed the K constant/TIM. Should I re-enable while tuning or after tune is complete? Also from reading the documentation again I saw Neo ecu you do not disable closed loop areas with the "O" key but rather just increase the figures in filtered view mode, is that correct?
The knock sensor wiring is bypassed with resistors as im using a knocklink listening device with donut sensors in the factory locations. Is it worth re instating the factory sensors once the tune is done and checking operation?

3. Bit of an interesting bump with 14ms around 70degC upwards in the Crank Enrich table - Very slow to start when this is not increased. Starts perfect when cold. Is there other things I can look at?
4. Set Alpha/N table all to 255 - I did have this table set all to 255 have only just changed it as I read in documentation to leave it on turbo vehicles that use VE tables. I also thought it may be throwing off the VE indexing for some reason
5. Latency table also interesting. Would recommend keeping it straight - Injector latency's are what the injector manufacturer supplied. I will alter the table to make it straighter
6. Estimated AFRs are rubbish. Ignore them. I would remove this view, but some customers want it in there still. Leave the VE table alone and only adjust the fuel map in 'filtered values' view to achieve desired AFRs - The only reason I was going to use this is to ensure my VQ map is correct. It does appear my actual AFRs are quite close to the calculated AFR in the fuel maps with some exceptions. Is MAF calibration of the VQ map not necessary?

We have some training notes on our website, but the basics for fueling are
1. Adjust TIM so that you have stoich at cruise, with near 0% trims (with O2 sensor enabled) - Yes this is how I did it
2. Adjust K constant to adjust the load cursor, that on full boost you use the entire map - Yes this has been adjusted with some foresight to run 18PSI at the boost sensor
3. Then you can adjust the fuel map to achieved desired ratios (around 11.5:1 on boost) - I have done this but I do worry it does not get rich enough in boost transition. Thoughts? This is something my actual tuner will help with
4. Adjust latency at the end to achieve a good idle - Is this the only way to get idle mixtures correct?

Matt
Site Admin
Posts: 8755
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Re: ER34 AA51G VE indexing

Post by Matt » Wed Sep 29, 2021 2:56 pm

2. There is no disable of the O2 flag in the fuel map for the R34 / WC34 RB25
The O2 sensor flags were disabled in feedback/DTC filters. You can disable during dialing in K/TIM or otherwise leave it enabled and aim for 0% trims whilst achieving 14.7:1 AFR at cruise to establish base mixtures
3. Make sure your battery is good, as that is a large number to have there. Sounds like its compensating for another issue
4. Even VE vehicles we set this to maximum when tuning ourselves (non VE have this 255 from factory, but VE by default dont)
5. AFRs in the fuel map dont equate to real world values. Some tuners will modify VQ map to make this happen, but we don't do that or recommend it

Yes discuss mixtures with your tuner going onto boost. Ours is just based from our experience
Yes only latency will really affect idle. There is a TTPMin table added to RevH/RevI feature pack updates which can also assist

SeriouR
Posts: 18
Joined: Sun Apr 22, 2012 8:47 pm

Re: ER34 AA51G VE indexing

Post by SeriouR » Thu Oct 14, 2021 2:57 pm

In regards crank enrichment, i have done a log on startup it appears to be starting at 10 volts. The battery is a brand new larger AGM battery and i have run a 50mm2 for both positive to starter motor and negative to the factory engine bay point.

I converted it back to the factory AFM for testing so only change is the injectors. These have had only TIM dialed in so cruise mixtures are good. I also tried adjusting the whole injector latency table to a more linear arrangement and giving it a couple more degree crank timing but it still seems starved of fuel on startup.

This tune setup was just to make sure everything was initially operating correctly before afm was changed.
Log is of startup.

I also noted that when cold start is done the rpms drop to 900 odd rpm within 30s seconds and after 1 min normal rpm observed where as i hear people saying high rpm should go on for 2 to 3 min when cold.
Attachments
Nistune_43.csv
(173.95 KiB) Downloaded 2 times
ER34 ERF528 06052021 fuel ammend.bin
(64 KiB) Downloaded 3 times

Matt
Site Admin
Posts: 8755
Joined: Sun Jan 29, 2006 1:45 am
Location: Adelaide, Australia
Contact:

Re: ER34 AA51G VE indexing

Post by Matt » Fri Oct 15, 2021 9:07 am

Crank enrich is way too high. See the purple line (compare mode with AA51G stock). Its flooding with 20ms of fuel during crank
Attachments
2021-10-15 08_36_32-Nistune [ER34 SKYLINE (RB25DET) Feature Pack 2.0  (Version_ 1)].png
2021-10-15 08_36_32-Nistune [ER34 SKYLINE (RB25DET) Feature Pack 2.0 (Version_ 1)].png (146.79 KiB) Viewed 66 times

Post Reply