Optimum Spark Tuning for the E40 /LS2

[Gelf VXR]

CALC.POWER_RW pid from my experince gives garbled results.

There is another pid GM.TORGUECALC_DMA, if this pid provides consistant data then it can be mapped against SAE.RPM and GM.APCYL_E40_DMA in the same way GM.KR and SAE.SPARKADV.

This method can be used to monitor effects of changes made to timing on the calculated torgue map comparing before and after results, and in the same way tune optimum spark as if you where using a rolling road Dyno. Advance spark until no further increase in torgue, a few more degrees should see torgue reducing and the onset of knock, retard back a few degrees or to the mid point where max torgue was seen.

Of course you may want to use a RR to verify the results.

Also unless you have hours of Dyno time, WOT timing is all that is optimised, this method tunes the whole spark map and for street use.

Has anyone tried this?

[stigmundfreud]

not tried this but would be willing to give it a go on my ls1 (which will be different mapping)

got more details on what you are doing gelf?

[Gelf VXR]

not tried this but would be willing to give it a go on my ls1 (which will be different mapping)

got more details on what you are doing gelf?

I'm setting up torgue map with rows = SAE.RPM and Columns = GM.APCYL_E40_DMA, which is the same as the Hi octane map. Its probably a good idea to start the process by copying the low octane table over to the hi octane table. This way you should definately be seeing increases in the calculated torgue, so you know your on the right side of the peak torgue curve and hopefully no knock being logged.

B5101 and TORGUECALC maps
http://i5.photobucket.com/albums/y164/andysa1966/B5101.jpg
http://i5.photobucket.com/albums/y164/andysa1966/TORGUECALC_DMA.jpg

My plan of attack:

AutoVE smoothed to within +/- 2% average of both banks

Lowered PE throttle threshold and set my desired PE AFR (13.5:1-13.1:1)

Set up lean cruise (15.4:1) in low kPa cells in OL load multiplier table

Determine whether recorded knock is real or not. I believe that Monaro's in the UK are set up for use with low octane 95RON fuel, I always use 97/98RON

Start by logging the average calculated torgue of low octane map to get a base line reading, save into excel, increase timing incrementally up to the high octane map saving and comparing results with previous each step of the way, keep adding timing until torgue starts to drop and revert timing back to where peak torgue was seen.

Filters will need to be applied so to capture cells that are between cruise and WOT only, no deceleration cells required.

[stigmundfreud]

are you doing too much before completing ve or have you done that now?

Interested in lean cruise - did you go via the route richard did with the commanded table (COS) or did you enable lean cruise?

I think it would be interesting for you to go down to Vixpy's and get a base dyno run then do your changes and guage the result! I need to get back down to his to see how things are different now the cats are in place and I'm commanding 13.1 pe instead of the 12.5 last time.

The timing map I am running is the hsv one and I get next to no knock at all other than a 1 or 2 degree at 6200 but the count is low so putting it down to the fact the sensors go a bit crazy at high rpm.

[JezzaB]

What you will find on the dyno is that KR can be a long way from MBT (Mean Best Timing)

[Gelf VXR]

are you doing too much before completing ve or have you done that now?

I will be on my seventh logging session, I've only just started using filters, hopefully my BEN's will settle close to zero now. With BB logging, it will probably be an ongoing process of tiny adjustments.

PE and lean cruise shouldn't affect my BEN's, only in transtional states which I'm filtering out.

I don't have C03 or lean cruise enable calibrations. What I do have is 3 open loop fuel calibrations, in the load calibration I can set the commanded fuel to 15.4:1 in the low rpm and map cells. You can even set up PE in the higher cells if desired.

I want to tune spark advance map for my desired / commanded AFR's. If you change your AFR's, I believe you will need to retune your spark advance map to suit.

I have a base dyno plot for stock set up, all I've had fitted since is a wortec cat back without remap.

The knock I'm seeing 4-5 degrees at 1800rpm and 0.6 grams per cyl is at 95 kPa and questionably PE was not enabled??? PE map below

[stigmundfreud]

yes aware of the different ways you can command the afr but thought you had gone custom OS.

my personal view on things is to do each bit at a time rather than relying on filters. Ok it takes longer but you are purely doing one bit at a time. timing can adjust the afr readouts (which you know about) but I'd rather tune the ve. Then tune the timing after.

[Gelf VXR]

yes aware of the different ways you can command the afr but thought you had gone custom OS.

my personal view on things is to do each bit at a time rather than relying on filters. Ok it takes longer but you are purely doing one bit at a time. timing can adjust the afr readouts (which you know about) but I'd rather tune the ve. Then tune the timing after.


The options for custom OS is limited with the E40, I have upgraded to custom OS, this allows for FI and hi and lo octane tables with SD.

I spend 5 weeks at a time away with work, plenty of time for theory. I am still only at the VE stage. My thinking is miles ahead lol

I wont be touching my timing, I'll need to log and see what results the TORGUECALC pid gives before i set down that route

[stigmundfreud]

Oh yeah I forgot to replace my low timing table, I'll do that tonight. Looking at the lean cruise option too but getting good mileage anyway.

You certaintly have been doing a lot of theory stuff!!! Weird about the low down knock though!

[Gelf VXR]

Oh yeah I forgot to replace my low timing table, I'll do that tonight. Looking at the lean cruise option too but getting good mileage anyway.

You certaintly have been doing a lot of theory stuff!!! Weird about the low down knock though!

How did your MOT emissions go?

[stigmundfreud]

How did your MOT emissions go?

sailed through, well, 1.03 at idle and 0.99 at 2898rpm. I need to work a bit more on idle but it got through. HC and the rest were ridiculously low too so room for a cam one thinks.

[Gelf VXR]

I think my first MOT is imminent, I will reload the stock calibration for the MOT.

[stigmundfreud]

I'd go as you are (once you are happy with your VE) and if it fails then use the free re-test on a stock map.

I used Trevor Carr's over in Poulton near Fairford. Thorough but not a rip off "needs this doing mate" kind of place.

I take it you are using the stock timing at present?

[Gelf VXR]

I'd go as you are (once you are happy with your VE) and if it fails then use the free re-test on a stock map.

I used Trevor Carr's over in Poulton near Fairford. Thorough but not a rip off "needs this doing mate" kind of place.

I take it you are using the stock timing at present?


Still in India, my flight leaves in 8 or 9 hours time, then another 18 hours to get home, phewwww

[joecar]

sailed through, well, 1.03 at idle and 0.99 at 2898rpm. I need to work a bit more on idle but it got through. HC and the rest were ridiculously low too so room for a cam one thinks.Mike, good job... :cheers:

Your HC/CO being ridiculously low is an indication that your NO is thru the roof
(HC/CO and NO have the inverse relationship to each other wrt AFR)...
you are lucky they don't test for NO over there (unlike where I am)... :cheers:

[Gelf VXR]

torguecalc does not give any decent results!!

[stigmundfreud]

torguecalc does not give any decent results!!

just an estimation! Though I've just bought a FPIK so will do a before and after barometer check

[ringram]

Guys Jezza is right, trying to get timing right without a dyno visit is almost pointless. I know, I spent months and loads of cal updates trying to find what was good. I thought I had it nailed... I was wrong.
In a lot of cases even though I had no KR, max torque was with lower timing (but not always) than I was running. In some places I was 10* out!
Use the bidirectional controls and a spreadsheet and find someone with a dyno that will hold a sustained load. Use runway highlighting and alter spark until you get the highest torque reading on the dyno then move to a new cell.
You can use area blending so you dont have to do every single cell, do like every 3rd or 4th, you will find it pretty hard anyway.
A roadrunner is excellent for the older ECU vehicles. Newer ones will have to be done manually. With a spreadsheet then alteration later (while the dyno cools down, hehe).
Im not even going to bother touching spark unless Im on the dyno from now on.

[stigmundfreud]

I'm sure with dyno time I could do far more with it but tbh am happy with the tune and I aint to the pocket money to pass to vixpy for a day of dyno time ;)

[Gelf VXR]

torguecalc does not give any decent results!!


Not supprising really, does'nt get referenced in the tune tool calc_link pids, but GM.TRQTRANS does!! Unfortunately abroad again and will have to wait four weeks to log this pid.

[hymey]

Mean best timing is the fancy terminology for "Lets stick a few degrees till it starts to knock then back a few off". I have spoke to numerous members who are running quite low amounts of timing to obtain maximum torque. The dyno is the best way to tune for timing but I must say I got my car with 5 rwkw of its best power output seat of the pants simply by finding a steep hill and loading up the car and logging. Listening more than watching KR. Just watching rpms and creeping up timing till its audible then go back a few degrees.

An old trick was to test and tune at the strip and add timing until terminal speeds stopped increasing.

The dyno is the best place to check timing. In all my previous cars(mainly turbos) I was able to add timing until knock was audible through a headset. Funnily enough I always found that when knock was just audible through the headset I was getting max torque. Going back 2 degrees would lose torque slightly.

I am running more timing than your LS2 map although my car is an L98 with lower comp. I am running 24 degrees at max torque and 26 total. There was no knock at all. I didnt push the envelope further as I only had limited dyno time and I believe I would of pulled more if I increased timing further due to the fact the car kept responding very well to timing increase.

Cheers

Joel

[Gelf VXR]

Given up on this idea now, see below

http://forum.efilive.com/showthread.php?t=7912