Quote:
Originally Posted by KingLT1
Agree but when I tweaked his tune, I found 40-50wtq by adding 3-4 degrees midrange, but lost 15whp peak pulling timing from 29-30 down to 27. This was when it made around 800whp... So, I don't think it had too much timing (23 degrees) in the 3-5k rpm range if torque jumped that much. If I added that timing and it gained little torque I would have pulled it back out. Generally, you don't need as much timing around peak torque as Ted mentioned. But if it responds like that then the engine is happy. The setup has since been retuned by someone else, so this might be meaningless to share.
Edit*
Want to touch up on my prior post. Another reason why I suspect mechanical issue being culprit is because the mentioned valve guide wear could have been allowing excess oil into the cylinders and that could cause detonation. Be curious to know if any rods are bent. Far as tuning, look up all the vehicles equipped with a LT4 and compare the differences. The Cadillac BW is tuned for 30 degrees peak (Seems Crazy!!). Then let's circle back on oil...GM has recommended like 3 different oil weights for the 6.2 engine. 0-20, 5-30, 5-40. So, there isn't no way Amsoil caused it.
My final opinion is premature valve train wear allowed oil to contaminate the cylinders and potential metal in the oiling system.
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Thanks for sharing.
Peak torque is where things can get ugly in a hurry, I purposely leave them a litte low there becuase in the event you get some bad gas it won't tear it self apart, it is easier on the engine components where we are doubling factory rated HP and Torque.
Torque is Mean on parts due to cycle time if that makes sense.
Example, I once destroyed a manual transmission (cleaned the teeth off 5th gear) in my Diesel truck by installing an overdrive on the back of the trans, and operating the truck at Peak torque 1400 rpm vs 1800 rpm on the highway.
The higher torque at lower rpm spreads out the power strokes hammering the parts like a giant sledge hammer.
This roughly illustrates what I am talking about.
Typically the extra torque is useless on a street tire anyway,
(spinning ain't winning).
As we get further from peak torque we need to roll in more timing to keep cylinder pressure up and carry the torque and is not where the destruction occurs.
Im 61 this year, I started working on and tuning engines of all kinds starting at 5 years old thanks to my Grandfather, Tool maker and Genius and in my eyes.
I share the 56 years of engine tuning experience to help people understand why I do what I do.