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Tail o'the Dragon Action!
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108 Posts
Discussion Starter #1
I have a GT that I just did a DOD delete and top end overhaul (a lifter was beginning to tick with 235,000 miles). I already have the GXP catalysts installed. I purchased a new LS3 cam from GM because you can't beat the price/quality (yes I know I left a lot on the table, but I was economizing).

My short term goal is to get equal or close GXP performance with my 6.0 ASAP. I can then make incremental changes to gain what I can. I realize that I am down .2 liters of displacement to the "real" LS3 and that some fine tuning will be required. My question is this: I have HPTuners and 35 years experience repairing EFI, but not the tuning part of it. What is the best approach for me,

1. Disable DOD and start tweaking (seems like a lot of tweaking to me) or
2. Disable DOD and copy all the tables from a stock GXP to my tune, then tweak from there (seems like less hassle if it is possible).

Thanks in advance,
Pat
 

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You're overthinking this. No need to copy all tables from GXP for max power. With that mild cam all you will really need to do is disable DOD and tune WOT for optimum power. The old stickies at the top of this forum should have all the info you need. You will need a wideband O2 or go to a dyno equipped with one.

Not sure if you know this, but these cars have no WOT feedback, so they are running off fixed tables that are tuned slightly rich from the factory for safety to account for differences in manufacturing. Leaning this out to optimal is the only way to gain power, and even so, the gains are modest, on the order of 10-20 hp or so. That's it. After that you should take a look at WOT timing, so if you are willing to commit to run premium (93 octane here) you can definitely add some more timing over the stock GT map.

So what I'm saying is copying the GXP tables is sub-optimal - the best thing you can do is the above at the dyno or the track. Doing the same to a stock GT or GXP would also yield benefits.

In regards to the rest, I seriously doubt you will have to do anything else.... It has been a while for me now, like 6 years, but my first cam was relatively mild, but bigger than the LS3 by a fair bit, and all I did was the above for a while. Rarely the car would stall coasting to a stop. So eventually, like a couple months later, I went through the idle procedure and fixed it. Then I changed my trans shift points.
 

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Tail o'the Dragon Action!
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108 Posts
Discussion Starter #4
Gentlemen, thanks for the help. Jgeorger, that is the kind of direction I was looking for. Wide band in hand, I will jump in!

Thanks again,
Pat
 
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