1982z28with18s

With my turbo setup I'm trying to run less than 26 degrees timing at wot, but no matter what I command it will only go as low as 26 degrees. I got the 2 bar tune from engineermike who had this problem also I believe and is using his ignition box to pull out timing.

I didn't have this problem with my old 1 bar tune, but for some reason this two bar tune has this problem. I've compared tables to my 1 bar tune and nothing is drastically out of what it should be though.

I've copied all the tables from the 2 bar tune into my 1 bar file, but that didn't help.

I'm running open loop and never hitting PE. Minimum spark advance I've set as low as 3 degrees and it will still run 26 degrees at wot.

Under part throttle/idle the timing is normal though.

I've heard of another person other than engineermike having this problem before, but can't remember who it was though. Also I believe Mike had this problem back when he had the 1 bar tune also.

Any suggestions?

JSK333

You checked the actual "Minimum Spark Advance" table. It has positive values beginning with 4400 RPM, up to 20* at 5200, and 23* at 5600+. Zero those out or put them at your new, appropriate mins. But if you mean you already did that...

Then what about the "Spark Coolant Temp Correction Bias" Constant? It's set to 20* stock. You could try zero'ing that out.

1982z28with18s

Yep already set the minimum spark advance to as low as 3 degrees, I could try zero though.

The bias is at 20, I've set it to zero. I've also tried putting in negative numbers in the spark correction vs coolant temp tables, but it didn't change anything.

JSK333

Very strange. Maybe we're dealing with another hidden table. Try emailing TunerCat and ask if they can find something that might be it?

I've seen timing go down to 0* when DFCO is engaged, so it's definitely possible to go under 26. But just not at WOT it would appear... the other weird thing is that the stock tables have some WOT values under 26, obviously, in the lower RPM sections. Are you getting 26* from 1000RPM up? Or just the high-end?

dookie454

Can you put 0 in all the WOT tables and run WOT starting from 1000rpm then tell us what the timing does?

I agree with sending Tunercat an email, but you might want to start from 1000rpm on up first then relay that info to them.

Does it matter if it's in closed/open loop or MAF/Speed density mode?

1982z28with18s

I'll show them an email, with my 4000 stall, I don't get to see a whole lot of 100% tps under 3500 or so.

I am only open loop, no maf. I haven't tried putting the wot tables low enough that it kicks in PE yet, still want to try that, just been too busy.

I'll shoot tunercat an email.

dookie454

Oh yea, I was thinking manual trans. I was thinking you could see something like 1-2 degrees of timing added for ever 500rpm being added automatically, or if there's a wall where it jumps up 5 degrees at some event (like RPM or MAP).

Just curious, about what psi do you start to require 26 and lower timing?

1982z28with18s

I run PUMP GAS 95% of the time so no reason to try to run high timing and take a chance of hurting the motor for the extra 20 or 30HP.

I usually like to run 16-18 degrees, very conservative and plan on running 11lbs on pump gas then 18lbs on good gas. It should go 135mph through my big stalled auto on 11lbs and pump gas.

dookie454

Makes sense, When I dyno'd I was at 38degrees total timing! I was wondering what was normal, I'm at 32 right now, occasionally I get some knock usually only in second gear? so Maybe I'll bring mine down to like 22-24. I did compare timing HP on the Dyno once and saw about ~2hp per degree of timing.. I only compared up to 4 degrees though.

When I do that I'll let you know how it went, or didnt went.

jchevy

Have any luck figuring this out??? Im having the same issure but I seem to be stuck at 27*.

Im also wondering, If I am showing 3* of knock retard, and showing 27* timing. Is that actual timing or is it 27*-3*= 24*

1982z28with18s

Datamaster on mine currently shows 14 degrrees with 12 degrees pulled out(knock sensor is pulling max amount, had this problem last year, not sure what is wrong with my knock sensor and havent had time to troubleshoot, just letting it pull it out so I can at least get my timing in the SAFE area). It is trying to command 26 degrees then pulls 12 so I end up with 14 degrees. I did bump it up to 18-19 degrees at wot for right now though.

dookie454

Your knock sensor only picks up basically full knock only at WOT? What if it decides to work again and doesnt pull anything out?

1982z28with18s

It yanks full timing all the time, I just have it tuned so it can't pull timing at part throttle. It's an issue I need to fix after the ltx shootout, I believe a new knock sensor will fix it, or I will be tracking down the wiring. Either way, I don't have time right now to fix it, it's been doing it since the last turbo setup so I doubt it will start working now.

dookie454

Interesting.

I know this isnt worth posting but I was getting ready to make some WOT runs with Datamaster logging to see what my timing did.. see if I had the same limit around 26 degrees but now my laptop freaks out when I insert the pcmcia card... locks up.. gets real slow...

I was going do to it all week and cant until this is fixed..

cause4panic

Silly question, how do you know whats its commanding vs. what its getting? Im assuming your looking at the logs for what its getting, then searching the table for what it should be commanding?