Scaling Injectors 09 E38 ECM

[Yasei]

I'm using it in my Z06 with the custom OS for the increased airflow limit.

It won't work on an E40 PCM if you move more than 67.7 lb/min of air.

Ok, thanks! You're running MAF, but how about SD? I assume this scaling workaround should work...

E40 Custom 2.5bar OS (SD only)?

E38 Stock LS7 OS in SD mode (this would be EFILive actually)?

[DSteck]

I don't know what you're asking.

[Yasei]

I don't know what you're asking.

I'm asking if this IFR-limit workaround works for E40 2.5bar COS in SD-mode (because you mentioned the air flow limit of the MAF for E40)? And if it would work for a stock LS7 OS in SD-mode (because you mentioned that you're using the E38 COS)?

[DSteck]

No on the E40. I don't know about SD on a standard E38 OS.

[Yasei]

Just tried this with my E38 LS7 stock OS and looks like it works. Couldn't drive the car due to it's being off the road for winter, but stationary it looked fine on LTFTs (on the throttle and idle).

Did you try it on a E40? Do you know why doesn't this workaround work in a E40? Just asking this for a friend who needs to scale his map for a boosted E40...

[DSteck]

Because the E40 is limited to 67.7 lb/min no matter what you do. Even in SD it doesn't seem to work. I ran into this on a supercharged Trailblazer SS and had to scale it the hard way.

The operating system has nothing to do with the trick working. It's a matter of whether the operating system can handle the airflow.

[Yasei]

Understand! Thanks!

[Sébast19X]

In preparation for my supercharger install, the install of 75 lb/hr injectors, and the ECM limit of 63.5 lb/hr injectors I thought I would mess around with scaling the stock injectors to see what happens. To make it easy I just divided the stock values in half and then changed the values in the "flow rate vs voltage" table to multiply the flow rate by 2 for all voltages. By doing it this way I assumed that I wouldn't have to change every table that involves airflow. Below is the only tables changed.

Like this


I went out and did some data logging afterwards and all seems to work just as before, AFR is still spot on. What do you guys think? Any downsides to tuning for bigger injectors this way? Sure would make life easier. I'm just not sure if when I install the 75 lb/hr injectors and adjust the tune like this if it will get past the coded limit of 63.5 lb/hr.

Is this table work on a 2006 Z06 ? I have done this for 120 lbs injectors, S/C car making over 880rwhp at 18 psi boost on a mustang dyno. The car idle ok, fuel trim seems good and the MAF are not screwed up imho.

But again, maybe I'm forget something, I didn't scale the tune. Ok the g/cyl on the timing table peg, but it use the timing on the last cell 1.36.

Seb

[DSteck]

Post the file, and I'll tell you if something's out of whack. Also, how could it work without a problem when the car is moving way more than 67 lb/min of airflow to make 880rwhp?

Everybody I've talked to (and I've tried it myself) says the voltage multiplier doesn't work.

[Sébast19X]

Hi Dave, probably the same, but I have used the IAT temps multiplier.

Also I have applied the 2.5 bar .

I will post the tune and the log tomorrow, I have not the laptop in hand now.

Thank you

Seb

So I'm resurecting this threads, because I have received the 2 Greg Banish DVD for christmas, and the z06, i have done it in september and it run fine since ...
So in the DVD I'm watching Greg scale the tune to run bigger injectors. Of courses, I have no probleme to scale.

[TimC]

Watch that scaling with the auto trans. My trans started slipping as soon as I scaled mine. I scaled all the axes and did everything right. Has anyone else had luck scaling an A6 tune?

If no one has done it I recommend converting your fuel system to return style with a boost referenced regulator. Then turn the base pressure down to a point where the injectors flow 63.5 lb/hr. I'm making 575 at the tires uncorrected with 48s so you should have plenty of room with 63.5 effective-flow-rate injectors.

[DSteck]

TimC, if you cut the IFR in half and multiply the stoich value by 2, torque reporting is unaffected. You just need to be sure you have headroom for the airflow.

[TimC]

TimC, if you cut the IFR in half and multiply the stoich value by 2, torque reporting is unaffected. You just need to be sure you have headroom for the airflow.

I did not try that method. I used 80% and scaled all the airflow and torque axes by that amount. Have you had success scaling tunes on automatic transmission vehicles? I looked for info on it but found none.

I am currently bumping up against the 67.7 lb/min limit so I will have to scale soon. I also need more fuel pump or bigger injectors/less base pressure. Fuel pump capacity is probably affecting my maf chart so I'll hold off on scaling till I get that taken care of. 600rwhp is my goal and I'm almost there.

[DSteck]

I did not try that method. I used 80% and scaled all the airflow and torque axes by that amount. Have you had success scaling tunes on automatic transmission vehicles? I looked for info on it but found none.

I am currently bumping up against the 67.7 lb/min limit so I will have to scale soon. I also need more fuel pump or bigger injectors/less base pressure. Fuel pump capacity is probably affecting my maf chart so I'll hold off on scaling till I get that taken care of. 600rwhp is my goal and I'm almost there.

Yes, I've successfully done A6s with big injectors using the stoich trick.

[Yasei]

What exactly happens when you bump into the 512g/s limit in SD-mode (E40 or E38)? I'm running E38 stock OS (not scaled yet) in SD at ~760whp and dyn air is way past 1.36g/cyl (and airflow way past 512g/s). Have not noticed any problems with the car.

Have you really had a need to control the spark advance beyond 1.36g/cyl to max power?

[DSteck]

In the E40, in SD mode it would just stay at 67.7 lb/min no matter what I did. The thing ended up leaning out. I scaled it, and it was fine.

[Sébast19X]

Post the file, and I'll tell you if something's out of whack. Also, how could it work without a problem when the car is moving way more than 67 lb/min of airflow to make 880rwhp?

Everybody I've talked to (and I've tried it myself) says the voltage multiplier doesn't work.

Ok this is stock file, modded one for injectors that flow 120 lbs at 58psi, and the second dyno run.

Seb

[DSteck]

120lb injectors at 92% duty cycle should be moving considerably more than 86 lb/min of airflow. Your file is inadvertently scaled on the MAF. Just looking at the values in your MAF table, I can tell they don't jive.

By the way, your MAP sensor values are incorrect. It's reading 207kPa right off the bat.

[Sébast19X]

120lb injectors at 92% duty cycle should be moving considerably more than 86 lb/min of airflow. Your file is inadvertently scaled on the MAF. Just looking at the values in your MAF table, I can tell they don't jive.

By the way, your MAP sensor values are incorrect. It's reading 207kPa right off the bat.

The customer run an adjustable fuel pressure regulator, and the setup are at 43 PSI. So the injectors act more like 102.5 lbs/hr. The map sensor value are incorrect because it are the stock map sensor. The customer don't want to buy the ZR1 MAP. So anyway I don'T need the MAP reading since we are usind MAF.

Seb

[DSteck]

You really should use a correct MAP sensor, or at least fix the calibration values in the tune. Barometric pressure impacts other parts of the tune.

The fuel pressure regulator doesn't have much to do with it. Those injectors at 92%, assuming fuel pressure keeps up, are supporting about 150 lb/min of airflow. That's a far cry from what the scanner shows, which means the MAF actually is scaled down.