I just picked up a 6.2 L9H and I've been tweaking the main spark table but haven't touched the VVT tables or the VCP Spark table. With a stock truck is it worth it to try and street tune those tables?
P.S. I've used the search a lot but couldn't find much for the truck engines.
Your motor has a pretty good VVT curve at full throttle already but you can really improve part throttle with some of the VVT advice below:
https://forum.hptuners.com/showthrea...-a-Kia-Sorento
https://forum.hptuners.com/showthrea...305#post507305
https://forum.hptuners.com/showthrea...318#post510318
https://forum.hptuners.com/showthrea...637#post501637
https://forum.hptuners.com/showthrea...593#post492593
https://forum.hptuners.com/showthrea...756#post491756
https://forum.hptuners.com/showthrea...648#post523648
https://forum.hptuners.com/showthrea...730#post506730
Thank you
I wonder why the early 6.2 (L92) spark and VVT IS completely different than later L9H 6.2s
different cam, different actuator.
The most hated, make the most power.
93 Ranger. 5.3 D1X. 1069hp.
I have done a bunch of L92, LY6, and L86 but I don't have a single L9H to compare. I'd be curious to compare the L92 and L9H.
The info I saw it looked like they had the same cam specs. 198/209 115 LSA. But if you are correct about the cam and accuator being different then comparing the VVT advance and VCP spark tables isn't the best idea.
Please be more specific which helpful person you are referring to when you say "you". Area47 said that the parts are different. I was interested to compare cam maps.
Yes, Area47 saying they are different. The only publication i could find both cam specs for L9H and L92 were on summit racing.
https://help.summitracing.com/app/an...tail/a_id/4847
https://help.summitracing.com/app/an...tail/a_id/4848
in reference to the difference in cam timing
https://www.performancetrucks.net/fo...m-swap-504902/
The cam actuator is actually different between the two engines.
The most hated, make the most power.
93 Ranger. 5.3 D1X. 1069hp.
Link to tune repository for 2013 Silverado stock 6.2Originally Posted by IARLLC
https://www.hptuners.com/repositorie...1377139343.hpt
Good info. So even though the L9H VVT has 52? of rotation, it only "advances" timing 8? total?
yrkz06, thanks for posting from the repository. On the road I don't work from a phone very effectively
AJK13, Yes. The cam is parked at 8 or 8.5 advanced. All of the numbers in the graph are the amount that GM is retarding it (from park position).
Now that I look at the L9H cam map I see a lot more room to improve it. The L9H looks a LOT like the LY6 curve and I bet it feels similar (nothing, nothing, nothing, then finally....WOW!) The L92 has a much smoother curve. When I start the retard of an LY6 just above idle (like and L92 and bring it up smoothly (like an L92) but leave the max at 10.2 (@6000), not as much as an L92 (12.3). For the L9H, since the cam specs are the same as the L92 I might copy the L92 map but go about 1 degree less (1 degree less retarded) throughout as the L92 makes more power with about 1 less than stock. Even without a dyno you can do back-to back tests using MAF numbers to see if your motor is sucking more or less air at each rpm point.
The other thing is outlined in several of the above mentioned forums, reducing the "over-retard" or "egr-retard" at cruise.
IARLLC, thank you for that info. I've read a bunch of other posts that discuss the 3 intake graphs under "variable cam". From what I understand "0" means the cam is fully retarded and "8" is fully advanced. I currently have the cam advancing around 3000 rpms to full advance at 6000 in WOT g/ps. I left the cruise areas alone. I also zeroed out the VCT spark table from .72 g and greater because i kept getting knock in the scanner. I just tweaked the high octane table in upper RPMs.
Oddly enough, my truck will blow the tires off from a stop and pulls hard to about 4000rpms. Then it just dies off a bit. I'll share my tune later when i get home.
If you?re talking about ?0? and ?8? in the VVT table, then it?s opposite of what you said in the above post.
?0? is full advanced, and any number above 0 are degrees retard.
Yes, like J-CUE said. On the graphs 0 is "park position" which means fully advanced (8.5 advanced). So 1 on the graph is 7.5 advanced, 2 is 6.5 advanced, etc, etc.
Generally speaking advanced gives better low rpm cylinder filling and retarded gives better high rpm cylinder filling. This is why the factory has 0 at idle then starts to retard (reduce advance) as it goes higher. If you compare to an L92 you see how they start to retard right off idle.
You guys are correct. I worded it wrong. This my current tune. I'm by no means an expert, just street tuning a bit
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