I've been wondering the same thing. My anti-GM brain says that anything's got to be better than what I've been dealing with.....ECU's with no AC control.....spending 2 entire days at the dyno every time I have an engine that needs tuned because there's always some screwed up parameter in the ECU that won't let us get where we need to go. The re-occuring VATS problem that many have had come back after years of running fine....Which I've had happen to me.
I'd be very curious about this option also.

 

It would be a waste to use one of those. They are still a delphi or denso ecm that is still exactly what gm is..

The stock computer is more than capable to do ANYTHING we could ever want or need.

User error and user unfamilurisms are the only issues with the oem computers.

They can make anything run and run excellent if the "Tuner" knows what he is doing.

Those computers are MEFI ecms, they are more of a headache than the gm ones, as you basically have to start over from scratch... Where gm already had alot of the tables correct..

 

It would be a waste to use one of those. They are still a delphi or denso ecm that is still exactly what gm is..

The stock computer is more than capable to do ANYTHING we could ever want or need.

.

While the hardware may be delphi or Denso, that's not the big issue, it's that the software running it is so much more versatile.

There are some serious limitations with the Gen IV ECUs... the AC control is not through the engine ECU, it's through the BCM. Therefore you lose your AC controls. The Gen III ECU's will not control VVT. Also the Gen IV cannot control (with high resolution) 3 Bar MAP sensors (the best they can do is the 2.5 (255kpa) sensors), and I am looking for more than 22psi of boost. So I wouldn't say that they can do "Anything".

I need:
VVT control
Throttle by wire (which can be programed non-linearly)
AC control
Boost capabilities (up to 25psi)

This system will also do (which is nice)
Cruise Control
Gauge Control (of engine parameters such as RPM, coolant temp)
Fan Control
and a few other cool things

I have spent more than "a few" hours tuning many different vehicles (with both OEM computers and aftermarket), and while the current generation of GM ECU's may be the best that GM has put out, they don't hold a candle to what's been coming out of Honda for the past 20 years. with a factory Honda ECU from the 90s with aftermarket tuning, I can set up launch control, 2 step soft rev limiter, no lift shift. I can swap to a 3 bar sensor and program for up to 29psi of boost... The list goes on and on

Right now, this system looks like the cat's meow to me. I was considering going the Motec route, but this, in combination with the ISIS system looks to be the best bet for my vehicle control.

If I am wrong with my criticisms of the Factory Gen IV ECU, please let me know, but I've researched this pretty deeply

 

$$ ?

 

I need VVT and AC controls, and if you read on this post series:

http://www.ffcars.com/forums/showthread.php?t=231681&highlight=compressor

It shows that on the Gen IV (Which I will be using for the VVT, and higher cam/crank resolution with 58 tooth wheel), the AC is controled through the BCM. and they offer "black box" solutions like window switches and the like.

Yes, MOST people don't need the VVT controller, but I do. VVT is an AMAZING tool that most people don't utilize. And there are aftermarket companies which develop cams to utilize this tool.

So here are my questions. since you know so much more than I do...

I am controlling a Twin Turbo LSX block using the 58 tooth wheel, and Gen IV sensor pack in speed density mode.

Can a stock GM computer (without any other black boxes)

---------These are must haves that I will need

-Control Throttle By wire?
-AC control (compressor cut on/off)
-increase RPM with compressor engagement
-support 3 bar sensors?
-support VVT (and if so, how is cam phasing determined?)


---------These are "nice to haves" which aftermarket ECU's can provide.

-provide cruise control
-provide a throttle plate RPM limiter?
-provide a throttle plate speed limiter?
-provide "no lift shift" capabilities?
-provide "launch control" capabilities (through an engine RPM rise time table)
-provide wastegate control.

I would also like to utilize DOD, but this is a "would be cool if we could" feature.

Help me out here. I obviously am hearing different things from different people. So give me a Yes/No on all of these, and point me to a tuner who has experience with big turbo LSx Gen IV tuning.

 

Temperacerguy, did you decide the Mast setup is a good way to go? I'm looking at and LS engine swap for my mustang and essentially need a from scratch hot rod setup.

Thanks.

 

Temperacerguy, did you decide the Mast setup is a good way to go? I'm looking at and LS engine swap for my mustang and essentially need a from scratch hot rod setup.

Thanks.

Cheby engine swap into a Mustang? :no: ....please tell me you mean a Mustang skid-loader.......or demo-derby car.

 

If you can show me a Ford product with long runner EFI, stock idle, aluminum block, 500rwhp, naturally aspirated on pump gas that doesn't require a $4,000 set of Glidden race heads I'll buy it! Ford is way behind the LS curve in that dept. Supposedly someone is developing "LSX" heads for SBF so we will see...

 

My build has been put on the back burner. There is a serious health problem in my family that's going to need some attention for the next six months, so all my "Fun stuff" is going to have to wait.

As for what I figured out. I'm still waiting to see if "wait 4 me" can tell me if a factory ECM can do all the things that I need. I don't see that it can, but he obviously knows far more than I do. It turns out that alot of my misconceived notions about 3 bar sensors were about a GM bastard ECM that controls the GM LNF motors.

That being said, I still don't think that there's a GM computer that can control both AC controls, and VVT (or DOD)

 

OK, let me just point out a couple things.

No lift shift is an entirely seperate animal from the ECU. It will require either a computer controlled trans, or a dog ring box and a seperate computer linked to the shifter and the FBW for downshifts. This is an area of high $$$$$ solutions. My recommendation would be to stay away from it unless someone offers, and you can afford one of the new twin clutch computer controlled Getrags. I don't believe they are available in "crate" form at any price right now.

I agree with you that VVT is a great thing. It doesn't really boost the top output, but helps the low end torque HUGE. If you were normally aspirated I would see the need, but why would you think you need this with a twin turbo setup? If the turbos are sized properly and the engine is tuned correctly, you will have WAY more power than you know what to do with without the use of the VVT throughout the ENTIRE RPM range. More stuff to go wrong. IMHO, with twin turbos, ditch the VVT. I understand that you are trying to get rid of any turbo lag at the low end, but turbo cams and VVT cams can be VERY different and I don't think you will find many builders that combine these two technologies. Although, if you insist, you must find an experienced builder in this area, as trial and error WILL be very expensive here.

You might want to think it over and do some serious research since it appears you now have some time before going forward.

Just my .02

Hope everything turns out OK for the health issue.

 

The engine builder/designer on this project will be me. I have built hundreds of custom performance engines in the past, and used to be quite involved with the import/rally car arena. Much of the technology of the LSx engine has been incorporated with imports for many years and is considered "common knowledge" in the import scene. Unfortunately there is a great divide between the Import and domestic scene and very few engine builders/tuners ever cross over so the knowledge stays where it is. I admit, my experience with domestic building/tuning is extremely limited, and I am learning as I am going. My last true domestic performance engine build was a chevy 383 which I put into the back of a Fiero in '92. (thank god GM finally evolved that design!)

Actually, No Lift shift is easily incorporated into the ECU. I have used it on Hondas, Mitsubishis, Toyotas and with GM's LNF engines in the past. In fact in the Mitsubishi Rally Cars we have used it in combination with the Anti-lag features with GREAT results.

I am WAY oversimplifying the programing here, but basically when you press the clutch in, the ECM plays with the timing and fuel curves to reduce the output of the engine so that the RPM's drop while allowing for the throttle plate to remain open. The only reason you do this is so that the turbos can remained spooled (as there is no pressure wave bouncing off the throttle plate), so when the clutch is disengaged in the new gear, you are at full boost at a lower RPM. If you incorporate this with anti-lag, you can introduce fuel into the exhaust manifold causing the turbos to further maintain speed (in addition to a really cool flame popping out the exhaust.. oh and there is that whole destroying the turbo shaft and turbine issue with extended use....)

As for VVT. Again, I have used it with GMs, Toyotas and Mitsubishi Rally cars (all Turbo 4s) in the past with great results. I have designed cams for them in the past and can easily get custom grinds made if I need to (however it seems that there are other companies out there that already make performance VVT cams for the Gen IV engines). The expensive part I feel will be lobe separation angles. With the DOHC engines I have played with in the past, we could easily just adjust the cam gears. With this engine, it's either going to be a very expensive trial and error (yet getting very good at cam swaps on the engine dyno). Or a best guess and leave it (cringe at the thought)

Power is not my main concern here. If it was, you can relatively easily get 2000 HP from the LSX, and I could do it with Carbs. I am going for efficiency and drive ability. after market ECMs allow for quite a few features that make them quite attractive (the above as I previously mentioned, as well as launch control, traction control, different "personalitys" of engine control). The debate I am having within myself is whether to go with all the bells and whistles of an aftermarket ECM at the expense of complexity, or to go with a re-tuned stock ECM (if possible) for simplicity.

I am an engine builder to the core... that is where my heart is with this build... to me, the rest of the car is just engine dressing to showcase the work in the engine.

And thank you for the best wishes with the health issue... the prognosis is good, but it will be a rough 6 months.