Timing not staying on commanded value. Drops from 12 to 11/10 around 5200rpm.

[johnminer]

I'm not sure what info you need for the car, if you need other info let me know:
Car: 1997 Camaro
2001 LM7 with 223/223 114+5 cam
4l80E with 3200 rpm billet single disk circle D converter
2 bar SD tune, still setup according to the HOW TO section in the help section. Haven't re-enabled the DFCO/MAF OFF/ETC....
80lb Siemens Deka injectors
78/75 vsracing turbo on the medium waste gate spring (6ish PSI)
BR7EF plugs (came out of box at .23 and put them in)


I had a question about what is pulling timing from the commanded timing. I'm commanding the car to hit 12degrees of timing at .92 g/cyl and up. The car pulls okay,but around 5200rpm the timing drops from 12/11.5 down to 10.5/10 and it seems to make the car stumble a little.

I know the IAT temps are not the reason for the timing being reduced as it was 45 degrees out during these 20-100ish pulls. I thought it might be the ECT Spark reduction table, but my car wasn't above 204 where I have it pull -1 degree of timing. I did change that table anyways and moved the ECT spark reduction table to the right and now have it pull -1 degree starting at 220. Haven't logged since.

I've got the VE table within 0 to -4% error in boost areas and the car is also hitting the commanded 11.4 AFR.

I think the problem may be somewhere in the torque management area???

Thanks for the help!

[nkautz]

Looks like torque management to me

[mowton]

Try setting Burst Knock retard to all zero's, at those rpms it will be pulling 2...could be the culprit without seeing more details in the log.

Ed M

[johnminer]

Looks like torque management to me

What should I change in torque management? I don't know much about that area in hptuners. Thank you!

[johnminer]

Try setting Burst Knock retard to all zero's, at those rpms it will be pulling 2...could be the culprit without seeing more details in the log.

Ed M

Thanks Ed! I'll give that a try too. Hopefully after I get out of work tonight I can go log another run or two.

John

[nkautz]

If you have an automatic you probably don't want to completely disable torque management because it can be hard on the tranny. I don't have any experience with automatics but here is the process I used on my 6-spd for completely disabling torque management:

From a post by RWTD

Quote "

Okay, to COMPLETELY remove torque management, follow these instructions below. Keep in mind, zeroing out the torque management on the trans will likely result in a sloppy 1-2 shift at WOT. Oddly enough, some of the newer classic Silverado/Sierra trucks already have the Torque Reduction zeroed out on non-tow/haul mode. Also, yhere is some redundancy in doing some of these below, but I listed everything, regardless.

Engine, Torque Management, General:

Maximum Torque
RPM vs. Gear - Max out
vs. RPM - Max out

Max Torque
Max Torque - Max to 640
Tip In Torque - Max out
Trans Input Max - Max out
Trans Output Max - Max out
Front Axle Max - Max out
Front Propshaft Max - Max out
Rear Axle Max - Max out
Rear Propshaft Max - Max out

ETC Limits
ETC TPS Max - Max out

Spark Retard
vs. Torque Reduction - Zero out

Torque Loss %
vs. Spark Retard - Zero out

Engine, Torque Management, Abuse:

Drivetrain Abuse
RPM > - Max out
Speed < - Zero out
timer vs. Trans Temp - Zero out

Trans, Torque Management:

Abuse Mode
Enabled - Set to Disabled
RPM - Max out
TPS - Max out
Speed - Zero out
Torque Reduction - Zero out

Torque Reduction
Normal - Zero out
Performance (aka Tow/Haul mode) - Zero out

" End Quote

[johnminer]

Thank you guys for the help! I was going to change the tune in two steps, but I went ahead and zeroed out the burst knock and I also changed more of the torque management settings. I'm not sure which actually fixed my timing issue, but it stays at 12 now in boost.

Ed, will the car still register KR with the burst knock settings set to zero?




The timing is now fixed, but the car is still stuttering around 5,500 rpm. You can see it in the log I posted in the dig and 2nd gear pull. It does it in both 1st and 2nd, but it's more noticeable in 2nd. Could this be spark related? I'm only at 5 PSI running 11.4 AFR with 12 degrees of timing.

I'm running BR7EF plugs as it seemed like a safe plug to go with (Not sure). I didn't re-gap them out of the box and left them at .023 This is my first forced induction car and I've read about spark blow out, but that seems to happen at a lot higher PSI then what i'm at. Am I using to cold of a plug for my psi? Thank you!

[mowton]

Yes, normal KR is still active. The burst knock is a feature which "anticipates" on coming knock and intervenes with preemptive spark retard. Shutting it down will not effect the knock sensors reporting/spark retard.

If you are like me and an ex-engineer, put back the burst knock (easier of the two) and see if the timing changes...Inquiring minds want to know :-)

Ed M

[johnminer]

Yes, normal KR is still active. The burst knock is a feature which "anticipates" on coming knock and intervenes with preemptive spark retard. Shutting it down will not effect the knock sensors reporting/spark retard.

If you are like me and an ex-engineer, put back the burst knock (easier of the two) and see if the timing changes...Inquiring minds want to know :-)

Ed M

Ed, The weather turned to crap today. I was looking forward to going to the track this weekend, but that will have to wait. After the weather clears up ill try setting the burst knock back to stock and do another pull.

Thanks for the help!