# Aftermarket ECU, Where to start?



## Markj2222 (Jul 26, 2012)

Pretty much have been stuck at 220 whp with the stock ECU. 
None of the known tuners out there seam to be confident running a big turbo on a tune over 22 Psi (stock MAP sensor max)

I have a 3.3 bar sensor that will bolt in but the resolution goes to low and the fueling starts to stray pretty far.
The cruze has been running reliably with built internals for 3 years and im itching to turn it up!

*There are so many paths to take, im hoping to get some input on what would be an appropriate Universal ECU for the Cruze.
*What challenges do i face to get the ECU and BCM/TCM to communicate? Or is it best practice to separate the systems going forward?


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## Snipesy (Dec 7, 2015)

There is no plug and play ECM for the Cruze.


There are general purpose ECMs. But I don't know of any of that play well with GM, at least not post 2009. 

The ones actually worth their weight generally range into the $100,000 range. Usually those are used for sponsored race cards, F1, etc...


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## Markj2222 (Jul 26, 2012)

Already accepted that im not getting a PNP ECU. 
Lots of options in the <$2000 USD range. 

Ecumaster EMU BLACK
https://www.haltech.com/product-overview-elite-1500/
AEM Performance Electronics PR - EMS-4 Universal Standalone Engine Management System - March 15th, 2011
https://www.holley.com/products/fue...on/hp_efi/ecu_and_harness_kits/parts/550-605N
https://www.linkecu.com/products/wirein-ecus/g4-monsoon/

As far as im aware nothing out there will use the stock dash, Key system and BCM
Other considerations is i still want it to control the AC compressor, power locks, add remote start?
Show me the ECU's tailored for Daily's :wacko:


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## blackbird (Nov 6, 2017)

Having a decent amount of tuning experience, I can state reasonable confidence that nearly all the aftermarket replacement engine control systems will be a major pain if you're looking to daily drive the car. It will be pretty easy for a qualified tuner to get basic start, run, drive and even wide-open throttle tuning dialed in, but drivability almost always takes a hit and it generally won't be as good as a re-tuned/calibrated factory computer.

Many times you'll still have to retain the factory computer just to run and integrate with other systems. If you try to completely replace the stock computer there's a lot of little things that will add to cost and cause problems, for example how will it drive the instrument panel? With ABS and stability control still function correctly?


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## ChevyGuy (Dec 13, 2014)

The Cruze is a small data center on wheels. The BCM talks to the ECU and other modules. I have my doubts if you'll find a aftermarket ECU that will keep the BCM happy. If the BCM isn't happy, the car's not happy.

My take on this is that you're on the bleeding edge of mods. Either you have the skills to do it yourself, or you don't. Because I don't think anyone else here has done it to be able to guide you though the process. All I can tell you is that it's going to be more complex then changing the ECU on a older car where the ECU's communication with the rest of the car was much simpler. In the Cruze, most communication is done over the computer bus and not via dedicated wires that indicate status (start, run, etc.).


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## Blasirl (Mar 31, 2015)

Markj2222 said:


> Pretty much have been stuck at 220 whp with the stock ECU.
> None of the known tuners out there seam to be confident running a big turbo on a tune over 22 Psi (stock MAP sensor max)
> 
> I have a 3.3 bar sensor that will bolt in but the resolution goes to low and the fueling starts to stray pretty far.
> ...


I just read your signature.

Are you racing in the Snow?


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## Markj2222 (Jul 26, 2012)

Nuts, Sounds like a heavy trade off...

I guess i have to make the stock ecu work. 

The second path of least resistance would be to relocate my MAF sensor and get it back on a SD/MAF tune instead of SD only (current)
Right now its pre-turbo, but the readings go nuts when the bypass opens.

Question is would i get a better reading before or after the intercooler if i go post-turbo MAF setup?
Leaving it in the current configuration with a Bypass delete might keep the ECU happy too. Wonder how long my turbo would last with no bypass.


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## Markj2222 (Jul 26, 2012)

Blasirl said:


> Are you racing in the Snow?


No racing yet, it cant really run WOT continuously. If i hold it WOT i cook the turbo.
I run blizzak ws80's in the winter just to get around town. (Also they are cheap )


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## ChevyGuy (Dec 13, 2014)

Markj2222 said:


> Nuts, Sounds like a heavy trade off...
> 
> I guess i have to make the stock ecu work.
> 
> ...


I think I'd talk to a couple of commercial tuners and see what they recommend. There's a couple that the forum members tend to use.


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## lowgear (Apr 20, 2018)

I read awhile back (not here) that the mega squirt system can be run piggy back to the stock system. It can be used for engine upgrades while the stock ecu and bcm can operate all the rest. If it was me I would talk to some of the dealers that sell mega squirt it can't hurt for some info.


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## Sgp24 (Jan 23, 2020)

lowgear said:


> I read awhile back (not here) that the mega squirt system can be run piggy back to the stock system. It can be used for engine upgrades while the stock ecu and bcm can operate all the rest. If it was me I would talk to some of the dealers that sell mega squirt it can't hurt for some info.


I’m gonna email mega squirt here soon and see if that’s possibility. Considering an LNF/LTG swap and if a megasquirt can be supported alongside the stock ECU, it would kinda be fun to mess around with that and an LCD dashboard….given everything would play nice, as it’s starting to seem like it may not.


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## JustPunchItRonin (1 mo ago)

Ditch the mass air flow sensor and go full speed density and open loop. Run e85 and stop relying on the turbo so much and it's psi. You want to focus more on the amount of air that the turbo itself flows regardless of PSI and then start advancing your ignition timing. That should get you hopefully higher than that. But it's more just about airflow getting it into the motor making sure your motor can take it. Once you max out your turbo then how can you max out your fuel? Well knock resistance being what it is with e85 if you're running 80 or 85% ethanol then you should be able to advance your timing quite a bit. On my car I was able to advance the timing quite a few degrees and the meaty range between like 2800 and 5,000 and get a decent amount of power on the stock turbo putting me probably right around 210-ish if I had to estimate it. I haven't had a Dyno yet though to run it on


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