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Discussion Starter #1 (Edited)
I've had a bunch of requests over time to document my Turbo Ecotec LNF swap. The Ecotec is a high output 2.0L Turbo 4 cylinder from GM. I bought a 0 mile complete drivetrain from a 2009 Cobalt SS in 09. The project has stalled many times because of my Air Force schedule since I started it and I don't predict it will be done soon unless I leave it at a shop. So far I have the motor mounted with axles in.

I chose this motor because it is a decade newer than the 2ZZ and it utilizes such things as a twin scroll turbo, direct injection, sodium filled exhaust valves, no lift shift, and launch control. It also can yield 30 mpg hwy. Plus Lotus has had a hand in it's development and used the earlier version (same block) in the Europa S and the VX220 turbo/Opel speedster. So I can use the Lotus dash, have stock Cobalt axles (fit perfectly- Lotus uses GM hubs), and have a wide range of European aftermarket exhausts that may work. I'm running the stock ECU and have a Europa S dash harness on the way. I fabricated new mount brackets and used stock mounts form the Cobalt- same mounting points as the 2ZZ. I'll post a pic of a typical Cobalt SS dyno with the factory GMS1 tune. It uses an integral oil cooler and I've eliminated the stock Lotus oil coolers for now. I may run an electric one out back but I've been told the campaigned cars do not use an additional external oil cooler.

The real reason for this swap is the torque and the fact that it has millions of dollars of development behind it, not a home built motor with varying results- even though I've had much success with and respect them. I sold my stock drivetrain at $2700 and bought the new drivetrain at $3500. I have since sold off my exhaust pieces and many other 2ZZ related parts and financially I'm at $0 invested on the mechanical swap, just a lot of hours. I still have thousands to spend but that's where I'm at. Currently I'm working on about 14 different clams so it's on the back burner. Plus I go back to flight training soon. I did buy an Exige body and hope to mount an intercooler in the trunk.

I'll take new pics when I get over to the car.


Again this is a random google pic of a GMS1 tune Ecotec. My exhaust may be a few feet shorter though and I plan to put a big wheel turbo upgrade which should bring me closer to 400hp...but I have a ways to go. The point of this picture is to show the wave of torque that is 'almost' always non existent in the 2ZZ no matter what mods.
 

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Very interested I your build. Before I bought my Elise my plan was to bring a 2005 Opel Speedster back with me from Germany. But work had me move back too soon to work out getting one home. The Opel Speedster is a Lotus Elise with GM Opel body panels but the Ecotec with turbo option. Like you stated much development already done on the Ecotec and was engineered for our cars already with many aftermarket parts available from Europe. I never did understand why the Ecotec was not the engine here in the states as OEM. I am not sure but I think better option for stronger trans also for people adding hp for a Ecotec then our weak trans in our cars
 

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Always great to see more options out there for people, thanks for taking the time to document.

I have a few comments:
- Torque is nice but if I could do it all over again I would trade torque for more RPM any day of the week. In these cars being so lightweight, with a wide track and short wheelbase it really doesn't take much torque to make them move. What do the gear ratios look like for the transmission you plan to use? I have the low revving Honda of the bunch and my redline is 7600. With about 1000 rpm less I would definitely want long legged transmission gearing.
- What is the car going to be used for?
- I would recommend an oil cooler of some sort if you plan to track the car. Lots of engines have integral oil heat exchangers, but if you plan to track a turbocharged car in a mid engine platform oil temps get up there quickly!

And a question on the electronics.
I noticed you mentioned using your stock ECU with stock dash. What stock ecu are you talking about? Cobalt ECU, Lotus 2zz ECU, EuropaS/Speedster ECU?
 

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Discussion Starter #6 (Edited)
Let me clarify something first. I do not claim to have any definitive answers or really claim to know what I am doing. This is just an experiment I chose to take on for fun out of curiosity. I was sick by the torque available on the 2zz and seeing as how the Ecotec was in the S2 chassis before there was an S2 Elise (vx220), I thought it was a logical option.

ADSM, I'm using the stock ecotec, edit. Cobalt, ecu and my stock Elise dash. I know that the Europa uses a similiar Lotus dash and the older ecotec ecu(same plug). The dash harness that the Europa uses connects the Lotus dash to the Ecotec ecu. I guessed that it may work in my car but I could always be wrong and need an aftermarket dash.
I don't really care about an extra 1k rpm with there being A lot of horsepower and torque. I plan to use the car for street and occasional track day but it needs to be completed first.
I'm not looking to win Alms, just miss the torque and I have a stock Elise to enjoy as well.
 

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Assuming when you are saying "ecotec ecu" you mean the vx220 ecu then you may have a shot of making it work.

If you are saying stock cobalt ecu that won't work. There is a lot more to the dash than making sure they physically connect. The dash is driven by the can bus so its a lot more complicated than a standard dash which consumes raw signals for things like rpm, speed, coolant temp, fuel level, etc

My personal suggestion would be to run all cobalt wiring and stock cobalt as ecu and adapt it to the chassis. This would allow you to run off-the-shelf sensors for thr cobalt and most importantly run HP tuners software which is fantastic. For the dash either run an aftermarket unit or do some electroinc wizardry to take the signals from the ecotec and packetize in the correct format to be consumed by the stock dash (that is what I do with my Honda swap)
 

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Discussion Starter #8
On the previous LSJ ecotec from Secant-
"We are using the GM Ecotec ECU but have modified it and adapted to work with the Lotus - so no engine lights come on and everything works". Irrelevant as it was an earlier motor but they "adapted" the Cobalt Ecu to talk to the stock dash, wether it was splicing in a ecu plug or swapping the harness and then flashing the Ecu?

ADSM, I do have the BCM and main wiring harness of the Cobalt SS in place, just not the forward harness to the dash. I know that they are both using Can, but the dash as an 05, is using a Lotus specific Can and maybe I could talk to someone like CharlieX to get it to communicate.
I don't mind upgrading the dash but I'm still left with splicing a new connector at the ECU or installing the Euro forward harness with the Lotus dash connector and the Ecotec Ecu plug. If someone is a specialist at swapping the ECU plug I'd gladly go that route and upgrade the dash to one that can talk to the Cobalt ECU.

Plus the Cobalt SS is DBW...
 

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Yup Secant is going about it the same way I would... which IMO is definitely the best way.

Have the engine computer run figuring it is a Cobalt. The beauty of this is that your whole drivetrain is a Cobalt take out. Which means procuring parts, upgrades, etc is all super easy. You can walk into a local autozone, and be good to go :)

Additionally the HUGE benefit of this is being able to run HP Tuners. An HP Tuners license and cable is probably like $600 but allows the end user to tune anything and everything. Using HP Tuners you can do things like tune fuel, ignition, knock. startup, idle, airflow, parameters as well as disable DTCs (which is what Secant has done). Using HP Tuners for the Ecotec (and Hondata K-pro for Honda swaps) is one of the biggest reasons to swap. IMHO the tuning solutions for the 2zz in the Lotus leave A LOT to be desired. Those that have cracked the ECU keep the info to themselves, and the standalone options are so-so (although getting better).

As for the dash converter. You pretty much hit the nail on the head. The Cobalt may run a CAN dash however the protocols are different. Therefore you would either need a box that takes the Cobalt CAN output and converts it to Lotus, or a box that takes the raw signals (rpm, speed, etc), digitizes them and converts them to Lotus. I have done the second option with my swap, although Hondata makes a converter box which does the first option. Both of these options require a pretty electronically savy person to do the job. I could make a converter box to take the raw signals, however I would need the car in front of me to measure the signals and programs specifically for them... and unfortunately you are far away :(
 

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Discussion Starter #10
Yup Secant is going about it the same way I would
or was. I think they have been defunct since 2010 or at least there hasn't been any action online. Reading over the old Sector swap, they completed the whole swap in less than two days.
 

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I don't mind upgrading the dash but I'm still left with splicing a new connector at the ECU or installing the Euro forward harness with the Lotus dash connector and the Ecotec Ecu plug. If someone is a specialist at swapping the ECU plug I'd gladly go that route and upgrade the dash to one that can talk to the Cobalt ECU.

Plus the Cobalt SS is DBW...
Dash aside in general I think you will need to integrate the 2 harnesses to achieve what you want.

Some things will need to get integrated at a bare minimum like power feeds, switched ignition sense, fuel pump relay, main relay, fan control, starter.

Then there are some more things which you will likely want to integrate:
OBD-II connector, reverse lights, AC (if applicable)
 

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Discussion Starter #12 (Edited)
So I could run the other Cobalt harness for those items and it's dash or one that's compatible. I noticed some GM light plugs on my Elise already. It does run a digital boost gauge with this option...
"option replaces the boost gauge in the A-pillar, and allows the driver manipulation of traction control, stability control, and the engagement of Competition Mode, as well as information regarding the car's engine torque and horsepower, g-force, boost, wideband air fuel ratio, barometric pressure, temperature, and battery voltage"
 

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