cruze 1.4t questions

[[email protected]]

ive attached a log and what ive come up with as far as a tune, from tunes from the repository of what others have done on the 1.4t. One question i have is the throttle limitedeven though im wot, as u can see ive modded the driver demand tables with no real difference. Second is the afr is commanding very rich ill verify with my wideband tomorrow how ever even though ive modded the pe table again no change commanded afr. help is very much appreciated just looking for some advice where to start to clean this up some. This will be my first turbo tune up other than ls platforms.


thanks Mike

[luciddeath]

I finalized a tune on my gfs 1.4 trax.. if you want i can adjust this for you to test.. no charge.

[luciddeath]

try this out

[[email protected]]

thanks alot for the revision, i just started tuning with the wideband to make sure my fueling is safe. Lets see how this does thanks again.

[Jeff7577]

You are in Omaha? I'm in Lincoln and have a Cruze as well.

[jmardlin]

A quick question, is your intake still stock? If it is you just waste boost. Your boost will drop if its ported and you make a little more power due to increased airflow. At the bottom end of your driver demand table you can increase the values more. This will give it more power. Don't do anything with the low throttle parts of it because it can make it harder to drive. I would also put the reduced engine power dd table back to stock.

[[email protected]]

try this out

my cruze did not like that tune at all lol

[[email protected]]

A quick question, is your intake still stock? If it is you just waste boost. Your boost will drop if its ported and you make a little more power due to increased airflow. At the bottom end of your driver demand table you can increase the values more. This will give it more power. Don't do anything with the low throttle parts of it because it can make it harder to drive. I would also put the reduced engine power dd table back to stock.

yes everything on my cruze is stock will be deleting the cat soon and alittle bigger exhaust.

[[email protected]]

You are in Omaha? I'm in Lincoln and have a Cruze as well.

Yes im in omaha

[[email protected]]

recent log shows 35psi??? something is not adding up and the car feels very slow to accel up to redline... Ive been fighting to get the vve table tuned in with my wideband and tried with the factory stft and doing wot tuning with the wideband and it just wont pan out right. Idk y this car is so difficult Ive tried multiple other tunes others have sent me or Ive pulled from the repository and it still hits a wall and hangs at 5500 and don't accel much. Ive never had this much issues tuning anything . Heres the 35psi log and tune it was on...cruze log 35psi.hpl

[Dutch]

35psi is the manifold pressure. Subtract the atmospheric pressure (14.7psi) from it to get your boost pressure.

GM's service documentation says 22-23psi is the maximum boost pressure the turbocharger can produce, and you should be able to achieve that.

The reasons why you're not achieving the performance you want is because:
- You cranked the hell out the driver demand tables.
For safety reasons, the ECM is supposed to inhibit starting if these are too wild.
I'm actually surprised your car was able to start and drive with those settings.
You don't need to touch this table to achieve satisfactory performance.
- You didnt touch the Wastegate Base DC table.
- You probably made unnecessary changes to the VE table.

Occasional KR on these engines is normal. Do not panic if you see a couple degrees being pulled every now and then, especially immediately after flashing.
Do not attempt to mess around with knock sensor sensitivities, recovery rates, etc to try and achieve "zero knock".

It may take up to 2 ignition cycles and 200 miles (~322km) for the ecm to relearn the various noises made by the engine, especially as it accumulates wear.
Do not make changes to the spark advance or VE tables until this period has concluded, or you'll be chasing your tail.

I see a few things I dont like:
- You disabled piston protection, catalytic overtemp protection, and turbo overtemp protection.
- You tried to disable burst knock (you didnt actually disable it - you're supposed to zero out the multipliers. You merely increased the delay, so its effect will be delayed 10 crank cycles instead of 2).

Revert the above items to stock,
then go to Airflow/Turbocharger/Feedforward
and set the Base DC to this:
ff1.PNG

Because the quality control of the wastegate actuators on this engine are really wonky, you will probably have to tweak this table.

Go to TorqueManagement/TCBoostControl/BoostLimits
BoostMaxLimit: Set the entire table to 275 kpa
PressureDeltaFactor: Set as desired - 2.00 is the highest you should go. This increases the speed the ECM ramps up boost.
KnockAirmass: Set the cells at (0,3000) and (0,4000) to 0.85
Do NOT command more airmass over 5000rpm or you risk floating the valves.

KnockAirmass and Wastegate Base DC are your primary means of tuning boost.
I highly recommend you do not ramp up boost below 2300rpm because
- the knock thresholds below 2300rpm are dangerously high
- a special devastating mode of knock called low speed preignition occurs at high load/low rpms, and it cannot be suppressed through conventional means (pulling timing, adding fuel).

Then go to Fuel/PowerEnrich
and adjust EQRatio to something reasonable.
Especially with all the overtemp protections you do not need to run these so rich.

Lastly, go to EngineDiag/DTCs and disable the following codes:
- P0101
- P0106
- P0108
- P0234
- P0236
- P0238

so that the ECM doesnt throw you into "boost limp" (disabling electronic control of the wastegate).

If you would like more assistance please PM me.

[tunerpro]

You can command more airflow over 5000 RPM, but other cal changes are needed to avoid misfiring and charge reversion. The so called "valve float" syndrome.

Low speed pre-ignition is a phenomenon that mainly affects DI engines. This one is MPFI. But, any turbo engine will break pistons if they are pushed too hard, the wrong way.

[Dutch]

You can command more airflow over 5000 RPM, but other cal changes are needed to avoid misfiring and charge reversion. The so called "valve float" syndrome.

Low speed pre-ignition is a phenomenon that mainly affects DI engines. This one is MPFI. But, any turbo engine will break pistons if they are pushed too hard, the wrong way.

1) Yes, you could increase airflow to redline, and you really don't need to make additional changes to the calibration to do so.
Misfires under high load on this engine are generally ignition related, and from what I've seen, don't occur unless significant enrichment is commanded (such as with e85) and/or the turbocharger has been upgraded.
Surging, which can be mistaken for a misfire, can be caused by many tuning issues, one of which being the wastegate DC table not being set properly.
I do not know what you mean by charge reversion, but I suppose messing with the VVT settings could result in problems too.

What I meant by that comment is the valve springs in this particular engine are not well suited for sustained high boost applications.
When the engine is new-ish, they can do the job just fine. But as they accumulate wear, especially in the higher RPMs, they won't.

Given that the turbocharger struggles to maintain boost towards redline, tolerances for tuning errors decrease dramatically as RPM increase, the engine as a whole was not designed for sustained high load/high RPMs, and there really isn't that much power to be gained from this platform without considerable cost,
I dont feel it necessary to increase risk simply for marginally higher top end performance.

And since the OP is inexperienced with this platform, I felt it to be the best compromise to restrict maximum DC to 5000, and allow them to make additional changes at their own risk.

Personally this results in the best real world driving experience for these engines.

2) LSPI affects all small displacement engines, regardless if its multiport or direct injection.
Please do not load on these engines at low rpms too much more than what the OEM calibration has it set to. High enrichment and low spark advance will not save it.