Experiment: LSJ using E67

[Zoidborg]

I have a supercharged Cobalt and a 2.4l HHR. I recently discovered that the E67 controller in my HHR has supercharger controls (under Torque Management in the Engine group). Upon further research I found that the E67 is used to control some supercharged applications, most notably the supercharged 4.4L Northstar V-8 with VVT!

So I then compared the pins on the ECM connectors between the 2.4L HHR and Cobalt to the Cadillac STS with the LC3 supercharged Northstar and found enough commonalities to guess at a good connector configuration that could be used with the LSJ. Based on past experience with "creative rewiring", I have a high degree of confidence this would work.

The E67 has several tantalizing advantages over the P12, I think. First, it is a fully modern controller that is faster, and it fully uses GMLAN rather than Class 2 (like the P12). It offers two tables for MAF calibration, allowing higher frequencies to be read than the P12 and better resolution for lower frequencies. The fuel cutoff (if you've ever revved a 2.4L) is far more gentl than the P12's. The E67 has the Cylinder Charge Temperature adjustment features, which can help better approximate the charge air temperature inside the cylinders. The more sophisticated VE and speed density systems can greatly enhance airflow estimation (though tuning it can be a pain).

The only big thing I see missing is that the boost gauge is driven by the P12 controller via a pinout; I cannot see if there is a similar pinout on th E67. And besides that there would be no way to properly set the output voltages corresponding to the charge air boost/vacuum pressures. The gauge on the new Turbo Cobalts and HHRs use an ECM pinout also, but the dial's different scale means different voltages on the output wire for different pressure/vacuum pressures. I once obtained a gauge for the new SS and tried to use it in my supercharged SS, but it did not read the correct values. It was clear that the needle moved to the same physical location as it did on my gauge from the superchaged car.

Here's the thing that is truly interesting: a "hybrid" LSJ engine incorporating VVT. I'll bet you could use the new VVT 2.2L as a basis to do just that. Just consider that the 2.2L engine gained over 10 HP when it went to VVT in efficiency gains (mostly) from using VVT technology. Of course, this introduces the cam offset variables into the VE equasion, turning it from a 2-variable system into a 4-variable system. I have created a Mathcad worksheet that should be able to calculate the correct values for the full equasion (15 coefficients!), but it requires a good amount of log data to perform multivariate polynomial regression with.

I put this out in case anyone here has ever considered this. I have the Excel spreadsheet I created that details the connector pins for the ECU. The VVT idea is a pie-in-the-sky kind of thing; I think it's worth looking at even without a major hardware change like that. But I'm a crazy tech head who enjoys problems like this.

Right now I don't have an extra ECU or the desire yet to rewire my ECU connectors in the engine bay (I'm already working on a big rebuild project), but if anyone out there had the time and the inclination, I'd be happy to lend any information I've gathered on the subject. I submit this for your consideration as an intellectual exercise, but hopefully at some point it will be a real endeavor. Enjoy!

[Zoidborg]

I've discovered more, and I am more convinced that this can work. The only hardware difference I've found that requires work is that the LSJ crankshaft sensor would have to be replaced with the sensor from the LE5.

The LSJ sensor produces an AC signal, but the LE5 produces a 5V pulsed signal. An extra wire for the CKP 5V Reference would need to be added into the harness. and the connector on the LSJ harness would need to be changed for the one on the LE5 harness. However this is not too difficult; if that is all I'd need to change on the harness, that's not bad at all.

I've edited the above post to replace the Excel file with the latest updated version.

[dont_blink]

And how is the E37 going to respond to not being able to pick up the cam sensors that the LSJ doesn't have? It has one on the exhaust yes, but it is not the same style as the two used on the cars that run the E37.

[divingsolo]

There is also a difference in the Crank reluctor wheel..the LE5 is a 58x...the LsJ is only 24x i think. Someone tried to use a 2.4 short block with a LSJ head in a Cobalt. He had to pull the reluctor off his LSJ crank and put it on the LE5 to make it work.

[Zoidborg]

First the cam sensor: you can select within the E67 variable camshaft section (Beta HPT) the number of active cams. By comparing the VVT engines such as the LC3 and LE5 with the LD8 (4.6 Northstar in the DTS) it is apparent that if no cams are variable the sensor input for the one cam sensor is accepted on the Intake cam sensor connections matching the LE5 configuration. My hope is that selecting the variable cam is enough. Some DTCs may have to be changed as well.

The crank reluctor wheel switched in 2006 LSJ engines to the 58x type (according to GM Powertrain), so I think dealing with that should be as simple as installing the 5V pulse based detector from the LE5 in place of the A/C signal detector that is used in the LSJ. The service manual diagnostic section lends some support to this hypothesis. I wonder drivingsolo if the engine in question was from a 2005? That would be good to know to help find out for sure. An interesting build in and of itself, it sounds like.

There are a lot of uncertainties in this whole deal, but so far it does look pretty well worth trying out at least. The most trouble has been so far trying to determine based on available information from various E67 engine calibration files (HPT files) combined with the P12 LSJ's configuration what the best settings are for the LSJ+LE5 configuration. Much voodoo math involved.

[Zoidborg]

My Cobalt SS/SC has been sitting for a while, but I'm bringing it back to rebuild into a DF Kit car, very excited about it! I've started thinking about some of the ideas I had in the past especially for the engine management and VVT.

I'm thinking I could replace the engine head (maybe block also) with the LAP 2.2 VVT one. The cylinder bore is the same; in theory I could use the forged crankshaft, rods, and pistons from the LSJ in the LAP block. Mainly it would then allow me to use the E37 that drives those engines, or maybe a 2009 or later E67. Biggest item is to get the higher fuel flow maximum, which for those E37s and newer E67s is 127 lb/hr instead of 63 in the old P12 running the LSJ.

I need to find out though if anyone has run supercharger sensors and/or controls (boost control solenoid, coolant pump) using an E37. HP Tuners has the tables for supercharger in both airflow and torque sections, but are there pins assigned to the controller connectors to take in the SCIP reading and output boost control solenoid signal or coolant pump signal? These are the big questions for whether the E37 can be used or if an E67 will have to be used.

[tunerpro]

GM uses a common code base for all of their operating systems, so, while you may see the supercharger control settings in an E37 application, it doesn't mean the E37 hardware supports it (it does not).

So, the E67 is probably your best choice since you know it has hardware support for the controls. There's a couple more hurdles though:

The LSJ cars are this funky mix of Class2 VPW comms and CAN bus. In fact, the P12 ECM sits on both the Class 2 network (for reflash, comms with the BCM, DIC, etc.) and also a CAN network (for the brake controller, etc.). The E67 supports class 2 based vehicles, but requires reflash over the CAN bus, and who knows if it can speak the correct language to the brake controller, DIC, BCM, etc.

The software support for the supercharger controls is not likely complete. Let's say you use a 2006 LE5 Cobalt calibration. Yes, it uses an E67, and, yes the E67 has the hardware support for the supercharger controls. Are all the software pieces hooked up? HPT only exposes a very small number of the actual calibration tables and constants, and just because you can flip a switch in the editors to say it has a supercharger doesn't mean it'll work. There may be missing OS support on the Cobalt E67 OS.

Personally, I think this is a very cool, ambitious project, but unless you can get into the guts of the ECM OS code (something hpt doesn't allow), you're not likely to succeed.

[yellz06]

It can be done.. just how bad you want it.

[bk2life]

Mainly it would then allow me to use 2009 or later E67. .

It can be done.. just how bad you want it.

yes. yes. yes.

Any updates?