LS1 Tech has some excellent information on stand alone factory ECM's and the aftermarket now offers some very upgradeable systems. Depending on your end result there are many options. I've been research this extensively, with plans on building a car with a 5.3 engine.

Excellent build and thanks for sharing all the info!

 

I've been a member of Ls1 Tech for a long time. It's a great source of info.

The problem with a stand alone ecm is not the engine. It's all the other stuff ie. the BCM getting the wrong input from the trans, the braking system, the fuel tank, the airbags, the DIC, to say nothing of the emissions systems. I fear you are over simplifying this conversion. Even on Ls1 Tech almost all of the conversions are to older cars. Anything with OBD2 is extremely complex. I wish it were easier.

 

Oh, that's interesting, my application will be into an older car pre computer era. I was unaware it was all tied together, now I extremely impressed by your ambition, KUDOS to you!

I've been leery of simply adding the fuel injected LS style engine to a hotrod build.

 

Sorry, I miss understood your intentions. I thought you were doing a HHR V8 build. I would highly recommend an Ls engine into a classic hotrod. It''s a great powerplant....even bone stock. Tons of after market hop up parts and fairly cheap. And yes, a stand alone harness is what you will need for this sort of build. Best of luck on your rod.

 

No worries, all my buddies are teasing me to shoe horn one of my BB's into an HHR! Every time I watch my wife drive off, a can picture an HHR built like yours, lighting up the rears tires!

I totally agree, even at a bone stock level, my 5.3l Silverado hauls that 5000# truck around quite well, not to mention the drivability that accompanies it.

The same to you, best of luck with your build.

 

The FAST 102 intake manifold that I have is made to fit the Ls1, Ls2 and Ls6 engines of various years and displacements. Because of this there are mounting spots for sensors in several locations. Depending on your engine you may or may not use each location. My engine does not use the spot dead center just behind the throttle body. Unfortunately, to me it is a real eye sore right at the main focal point of the engine. To this end I have spent almost all day fixing this. I chucked up a hunk of aluminum and turned a cap that is held down by a counter sunk metric screw and painted the same color of the manifold. This makes the extra mounting spot almost invisible. Here are a few shots of the process.

 

Nice work!

So where's the sign up sheet for test drives when you're done?

 

It's amazing the extent some go to to please their own eye. Support this 100% "keep it simple stupid" is for the novice lol or simple minded folk. Awesome lasater. Doesn't matter how long it take IMO as long as it "right" from your perspective.
I've mentioned wheelies a few times. I REALLY want to know if this thing will see some serious track time...

 

I doubt if the rear end would handle wheelies. For that I probably should have gone with a 9 inch. Oh well. I will be running it at the drags......at least once to see what it will do. Because I know I will be asked over and over. I think it will pass a NHRA safety inspection with the full roll cage. I'm guessing it should turn low 12s to high 11s.

 

Sounds conservative but I'm thinking that your setup may weigh in about 4000lbs around 400whp with high 1s 60ft. Makes sure you do a good burnout :) and don't forget the camera. Rwd HHR burnout has "epic" written all over it.