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'07 CTS 3.6 Sport, 6-Speed
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189 Posts
Discussion Starter #1
Now that people are offering a tune on the 3.6 CTS I remembered I could hook my OBD II scanner to the CTS. I bought the scanner for a different car but it works on the CTS - should have done this awhile ago.

Well, I put it in monitor mode and drive. Sure enough the ignition timing ONLY goes to 24 degress before TDC under full throttle? WTF? I was running 93 Octane fuel so I can't imagine it was pulling back timing due to knock.

Maybe I don't understand the readings but IIRC most engines will like around 36 degrees BTDC for max power. Seems like there is free power up there and the PCM is not going after it. Maybe emissions?

My scanner does not read the variable cam position - I sure hope they are cranking to max duration at high rpm but for some reason I doubt it.

I sure can see how a tune would help here.

I'm in a bad mood so I will also say not only does this engine not make enough power for its size but the mileage sucks. Caddy is still targeting old folks with the power and torque curves of this motor. I have the manual and I expect manual trans cars to pull hard to the red line but this one does not. BTW, I had a 3.2L CTS before this and it did pull hard to the redline. I had a BMW before that and let me say that this car is not a BMW. The BMW was nearly as fast and got [email protected] which is mighty impressive in my book.

Having bashed the caddy I will say it is the best overall US car I have ever owned. They just need to keep improving FASTER. The BMW engines now don't even have a throttle plate due to the variable duration AND lift cams. GM is WAY behind.
 

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Premium Member
2006 STS V8 AWD, '95 Ford Ranger
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28,969 Posts
The amount of ignition advance required by an automobile engine is a good measure of the combustion chamber design. An engine that requires a lot of advance has poor combustion chamber turbulence. I'd be more interested in a graph output by a combustion chamber pressure transducer vs. crankshaft rotation.
 
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