Strange Problem

[pipen]

Hello from Europe,

I have strange problem on my Opel GT and maybe someone had some similar problem.

Few years back i have instaled big turbo (K16), car run perfect 403bhp/550nm. After i had piston no3 damaged i have forged my engine, instaled efr6758, ported head+st2 cams, werks intake manifold..etc.

After engine rebuild car does not work ok any more. Before i had 28psi boost, now around 20-22 psi. I dont get more even if i disconect WG. Map is same as it was before, so set to 28psi boost.

I dont have any air leaks and no dtc codes. Cant find any thing wrong on engine.

Torque went down from 550nm to 400nm, hp from 403 to 380hp.

Any help would be great.

Br,
Pipen

[ECaulk]

What pre-load are you using on the wastegate? I'm assuming since it's an EFR6758 it's an internal wastegate.

[pipen]

What pre-load are you using on the wastegate? I'm assuming since it's an EFR6758 it's an internal wastegate.

Yes it is internal WG. Preload is 5mm.

[ECaulk]

There is a chance you'll need more pre-load. Did you adjust the calibration or tune for the car after the install of the larger cams, turbo, etc etc?

[cobaltssoverbooster]

Borg Warner recommends a minimum of 2 mm preload which is equal to 2 flats of the nut. I wouldn't honestly go any tighter than 5 mills because there isnt much benefit after that..
Can you post a tune file to look over?

[pipen]

Borg Warner recommends a minimum of 2 mm preload which is equal to 2 flats of the nut. I wouldn't honestly go any tighter than 5 mills because there isnt much benefit after that..
Can you post a tune file to look over?

Here is the file.

Only thing i have changed is maps for cams and spark is stock.

[ECaulk]

Borg Warner recommends a minimum of 2 mm preload which is equal to 2 flats of the nut. I wouldn't honestly go any tighter than 5 mills because there isnt much benefit after that..
Can you post a tune file to look over?

I thought the max was 7 turns by Borgwarners chart, and now that I reread their charts the OP might have the medium boost canister instead of the high boost that he'll need to run +25psi

[Super Sky]

Warning : this is coming from a new guy.

I'm looking at a similar issue. I believe BW makes 3 different WG actuators for that turbo. Do you know which one you have?? I don't believe it will hurt anything so if you have it at 5mm give it another 5mm to see if it changes. Just unhooking the pressure feed to it may not tell us much. I believe earlier when Cobalt said 2mm equals 2 flats he is meaning 2 full turns or 12 flats. When I bought my 6758 setup used I believe the original owner had it set to 15mm. I don't know which actuator I have and it is not marked so I ordered a new one. I got the one for the highest boost level.

Larry

[Super Sky]

Just looked at BW's chart and it looks like you can go 10 full turns which equals 10 mm. Good luck. I will let you know how my "stiff" module works.

Larry

[pipen]

Here is also log from the car.

[dertobi]

loose both nuts on the actuator and check if the WG flap is actually closing correctly, had this on several LNF and LHU EFR conversions, the thread hooked up in the hole of the flap, wich made people think the flap is ready closed, but it was not.

[cobaltssoverbooster]

any reason you are commanding dals outside the table stability limit? should be able to boost very high without going over 255 dals.
if you command 255 and 95% you have a mechanical issue assuming you have raised the boost pressure max limits appropriately. currently sitting in an engineering class can't look at your file yet.

Post Update:

FILE REVIEW:
So again not sure why your dals are that high. there are multiple threads containing information about the 255 value instability limit.

From what i have seen in your file there isnt a limiting factor active.
I can tell you that some of your file does contain beginning errors that when corrected can make life with this ecu a little easier.

First your ignition tables. Make all four ignition tables match each other. i would try making max ignition a tad higher than 10* advance but do not exceed 14* without verifying boost and fueling first. Ramp it in smoothly. (smoothness is key with everything in this ecu)
As a second to this ignition correction, you should deactivate the advance modifiers to prevent the ignition from wandering away from the commanded main spark table settings.
i wont go into Optispark now since your still getting started with understanding the ecu. (from what i can see)

Your diagnostic section has the wrong map sensor cap data for the 3 bar sensor data you have loaded in. go into this section and make the MAP sensor range data match the Boost (CPPS) Sensor Data. This will prevent throwing unnecessary codes on the map sensor side.

If your tuning the maf sensor you need to set the entire base table to 1.0 first. This base table is a modifier to the maf curve table. In order to adjust the maf curve table you must deactivate the 3D modeling table for the maf which is the table named 'base'.

under the camshaft section set all of the main cam and cat cam factor tables to 1.0 (leave the knock factor tables set to 0). This forces the warm tables to run all the time. You don't need wandering cams unless you live in extremely cold environments. I ran mine in Reno and Florida where the car has seen as low as 8*F and it runs just fine strictly on the warm tables. I see your cat warm-up cycle is disabled but the cat cam cycle is not. to disable copy your main warm cam tables and paste them into the cat warm cam tables. every time you make a cam change you need to make sure the cat table is the same in case a catalyst test is triggered. This makes the airflow from cam changes consistent and predictable making for smoother airflow calibrations. I have also been able to consistently increase gas mileage when using this method because of the consistency when referencing the airflow.

90% load is quite high and more often than not it experiences some decent amounts of boost. I would recommend you commanding a richer pe to prevent engine failure.
Another issue you will have is your cat over-temp tables. the way it is set up is to add fuel when the calculated egt exceeds a threshold value which cannot be adjusted. Thing is the egt value is calculated not actual which means its god awfully useless. To disable and prevent tuning errors turn this system off by commanding both tables as a value of 1.0. If you wish to keep the feature in the long run finish all other tuning and then return these tables back to stock and call it a day.

Mechanically speaking: if you leave the turbo wastegate unplugged that sucker should shoot straight to the moon unless the back pressure forces the gate open. There is a way to test if the gate is being pushed open but i don't ever post the methods to do so since its easy to exceed the factory fastener load capacities. (basically its an extremely risky test and i don't want that burden placed on me) If you cannot successfully build boost without the wastegate disconnected its time to look for leaks. This means you may have to pull the turbo to inspect the wastegate door for sealing qualities aside from inspecting other leaking point areas as well. I personally leak test all intercoolers in a bath tub and have a pvc cap with a tire valve stem in it so i can pressurize the unit with either an air compressor or a bike tire inflator. The stock intercooler is notorious for separating at 24 psi.


Hope these tips help you make a smoother and more predictable tune. Without being there in person i cant really put a finger exactly on whats causing your low max boost.

[pipen]

Thank you for you file review.

About dals. I always thoat if you charge 28psi that shoud be around 300%, 100% as atm presure. Seems i am wrong. Didnt get any unstable boost for now.

Ignition tables are stock for now. Didnt want to tune them till rest of the car works ok.

I dont understand what you mean about map sensor. Linear and offset seems ok to me. I dont have any dtcs for it. Can you explain more?

I have done presure test on the car. Conected ruber hose to turbo inlet and tested to 14 psi and than to 28psi. All joints/seals covered with foam, no leak. Only thing left is turbo it self.

[pipen]

Check that MAP. I see what you mean. Will set map and boost same. Thank you.

[cobaltssoverbooster]

it was kind of designed to work that way but we ran into issues a long time ago. The dal table seems to have stability issues around 255. coincidentally 255 is the pressure cap for the factory map sensor. This seems to be hard coded limit of the table. Although programming wise it is physically possible to exceed the value, result wise the ecu becomes unstable. It is always best to run the lowest dal value possible to attain desired boost. best method is to start low and command up on the wgdc % without letting it exceed 95%. at 95% lower the wgdc back to 80% and raise the dal by 5 and try hitting max boost again. For whatever reason the ecu produces smoother operation this way. I haven't even begun to test the reasons why. I ended up selling my vehicle before i tested a bunch of stuff i was curious about. This result information was mostly gathered by GMTech. MikeM did some minor testing on it with Randy and i have another Friend that doesnt frequent here much anymore Eric that told and showed me logs of this instability issue causing power issues in his kappa chassis.

I dont have anything to back up the why, i just know this has been an issue for a long time.

[pipen]

Ok, found my problem.
WG gets forced open by exhaust gases.
Tryed relocating WG actuator but no luck. Did someone had any similar isues with ZFR6758 on sky?

[dertobi]

which actuator are you running, the ZFR come with efr mid boost actuator if I remember right couldnt run much more than 1.6 bar boost with it....high boost worked always for me up to 2 bar (30PSI) and higher.

[pipen]

Runing stock Actuator. Pobably mid boost one. It opens at 20 psi.

Did any of you mesured exhaust manifold presures? I get 31 psi in exhaust manifold with 20psi boost. After that wg opens and all fun is ower.

[dertobi]

so you have roughly 11psi pressure difference across the actuator... pretty exactly what you need to open a non preloaded mid boost actuator.
change the actuator to a high boost one and you should be fine