new commodore

Hi,

Have u ever tuned the new commodore before? When I tune them on dyno, they made more HP, but on street! They got beaten by stock ones in the 3rd gear (auto) any idea what is going on?? Note, in the 1st & 2nd they are ahead, and then get beaten.

thx.....OB

Post some tune/log files.

here are the modified tunes and some logs with changes, last one is the one for the tuned file (log#5).


Attachment 5139
Attachment 5138
Attachment 5137

here are the stock ones

Attachment 5141
Attachment 5140

...

please help

I looked at the files, but I don't know the answer.

I will have the car again today on the dyno, I will log the 1st, 2nd, 3rd trans. what do u recommend??

Your timing doesn't really look to optimal to me. I'm hardly a 6.0L expert but I can't understand why you would progressively pull timing at for example the .84G/cyl column as RPM gets higher above 3600rpm all the way to the limiter. Sure pull a bit at peak torque.. But you have to raise timing with RPM as the ol bang process tends to need more time to do its thing the faster the engine goes.

do u think I have problem with AFR, the engine doesn't accept (+) timing. If I shoot for 12.2 ~ 12.5 the car knocks a lot with stock timing.

Quote:

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Originally Posted by odd boy

do u think I have problem with AFR, the engine doesn't accept (+) timing. If I shoot for 12.2 ~ 12.5 the car knocks a lot with stock timing.

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Are you using knock muffs to confirm if its actually knocking. I wouldn't take what the engine knock sensors are giving you as gospel. I've heard they are over sensitive.

no I rely on the engine's sensors, I don't use muffs

Quote:

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Originally Posted by odd boy

no I rely on the engine's sensors, I don't use muffs

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My advice is to invest in a set. That way you will know for sure. Hell that's how it was done on old carby fed cars with dizzy's and vac advance.

I did a lot to the car yesterday, for testing I've disabled both knock sensors. I’ll do some tests on dyno tonight and give u the result. I will list down all modification I did when I get (+) results.

What fuel has the car been tuned for?

93 octane

It took some effort, the game was "knock sensors". They are over sensitive as macca said earlier. I had to cheat the ecu to make the car flying as a falcon by blind them. Thanks for your help.

Good job...:cheers:

Try using the 8 cylinder knock pids. youll find that theres generally only one or two cylinders doing all the knocking .dull them down till they all read the same when actually knocking add a few degrees and make it rattle at low engine speed (easy to do in a lugged higher gear.)Dissabling all the knock sensors is not the best way to do it.
Thats my two cents,
Cheers Shane