Have Dyno numbers for you!!

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Justin

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Those numbers = OUCH! I don't suppose you have pre and post tune numbers for a 6.2? If I ever get the damned transmission working right, I will be getting a programmer/tune. I was hoping for well over 300 RWHP stock, and hopefully, at least 20-30 RWHP gain after tuning? Any special instructions to the dyno guy to do this? I'm guessing traction control off and trans in manual running up in 4th gear?

Colorado Springs is around 5000' elevation which has 80% of the air density that you have at sea level, that's 20% off right there.

In addition, TRUE rwhp is always lower than what people assume they get when comparing to DynoJet numbers. This dyno he used reports actual power output, not the 18-20% inflated number of a DJ.

Unless your 6.2L is a 2wd, which most are not, you'll have a very tough time dynoing it. Transmission gear doesn't matter either aside from overloading the dyno via the torque multiplication there is no such thing as a 1:1 ratio with the 6L80E. 300+ at the wheels with any dyno shouldn't be a problem. The 2007+ 6.0L trucks regularly put out 295-300rwhp after tuning.
 

Fast55

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I realize that altitude makes a huge difference, that's why I was expecting 300+ RWHP from my 6.2 even stock (I'm at sea level). My truck is a 4X4 LTZ that has 2WD available unlike an Escalade, so I wasn't expecting any issue with dyno'ing it even stock? I was under the impression that 4th gear was 1:1 and only 5th and 6th were overdrive gears?
 

Justin

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I realize that altitude makes a huge difference, that's why I was expecting 300+ RWHP from my 6.2 even stock (I'm at sea level). My truck is a 4X4 LTZ that has 2WD available unlike an Escalade, so I wasn't expecting any issue with dyno'ing it even stock? I was under the impression that 4th gear was 1:1 and only 5th and 6th were overdrive gears?

There is no 1:1 gear on the 6L80E, but that doesn't matter much anyway as there is still multiplication going on via the differential and the ratio of the tire diameter to roller diameter. You should have no problems with your 2wd tahoe, other than the fact that the stock tune won't run to nearly high enough of an RPM to make peak power, manual mode is overridden at the low speed of 5200rpm in 3rd gear and above.

1st Gear Ratio 4.027
2nd Gear Ratio 2.364
3rd Gear Ratio 1.532
4th Gear Ratio 1.152
5th Gear Ratio 0.852
6th Gear Ratio 0.667
Reverse 3.064
 
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COTahoeLS

COTahoeLS

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Colorado Springs is 6300' elevation.

5.3L Flex but was using 91octane with 90K mile old wires/plugs (which I changed today destroying the old wires).

---------- Post added at 10:19 PM ---------- Previous post was at 10:17 PM ----------

Justin-

Do you want me to send you a copy of the dyno sheet scanned via email? I won't post it here.

-E
 

Justin

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Colorado Springs is 6300' elevation.

5.3L Flex but was using 91octane with 90K mile old wires/plugs (which I changed today destroying the old wires).

---------- Post added at 10:19 PM ---------- Previous post was at 10:17 PM ----------

Justin-

Do you want me to send you a copy of the dyno sheet scanned via email? I won't post it here.

-E

Sure, feel free to email to [email protected]
 

Fast55

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There is no 1:1 gear on the 6L80E, but that doesn't matter much anyway as there is still multiplication going on via the differential and the ratio of the tire diameter to roller diameter. You should have no problems with your 2wd tahoe, other than the fact that the stock tune won't run to nearly high enough of an RPM to make peak power, manual mode is overridden at the low speed of 5200rpm in 3rd gear and above.

1st Gear Ratio 4.027
2nd Gear Ratio 2.364
3rd Gear Ratio 1.532
4th Gear Ratio 1.152
5th Gear Ratio 0.852
6th Gear Ratio 0.667
Reverse 3.064


Ok, so leave it in 2WD high, traction control off, and run it in third, or up to the 99 mph cutoff in 4th? If I buy the programmer from you is it possible to leave it stock and get rid of the limiter to get a good baseline before I do a scan and send it for you to tune? I have no doubt I'll be impreseed with the results, I'd just like to get real before and after numbers if possible.
 

Justin

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Yes, that wouldn't be a problem to bump up that tap up/tap down shift point.

These newer vehicles really seem to dyno well, despite the often lackluster performance on the street, so it should do well for you.
 

Fast55

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Ok, I think I'm going to go with what I have for transmission operation. I've now had it to another dealer and they bless how it's working after the latest software flash although it still occassionally "flares" or seems to momentarily almost hit neutral on the 2-3 shift at very light throttle, especially when not fully up to temp. It seems Ok if I'm deeper into the gas. I will need the programmer and cable or whatever, and then I get a dump that is sent to you for a "custom" tune based on this info? Do I call you or someone else with shipping/payment info? Let me know, I'm done waiting on the cheaper handheld (autocal?) solution.
 

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