I'd be happy to share my latest calibration too. Literally haven't touched spark or fueling at all. I've tried many variations of cam timing too, but I'll just share a tune that's basically stock except Driver demand, DFCO, PE, and lots of trans changes. I actually have had great success in LOWERING the values in the Driver demand table. I left the top row alone to ensure I would get 100% pedal when I want it, but the rest has been greatly reduced. On the stock settings it was just far too aggressive and jumpy. I didn't mind it because it felt real torquey! But it got old quick because it was unpredictable and not very smooth. I studied up on the Corvette driver demand tables and started with just copy and pasting right over. The result was very nice, but it was a bit too subdued! Since then I've finessed it and I think it's almost perfect now. You can easily modulate the throttle and with DFCO completely disabled it makes for very smooth transitions. On the trans side, I keep the TC completely unlocked until 6th gear, so right around 30 mph. I also tried many many combos of shift scheduling and found that I just like the stock schedule the most. I dont think it was ever the problem. I think the goofy lockup schedule, jumpy driver demand, and aggressive DFCO made it so clunky and awkward as you transition from accelerate to coast to accelerate. I really look forward to dialing in my MAF tables and VE because I'm sure it'll get EVEN better. Didn't mean to type all that, I'm just excited that you're getting to make significant changes in driveability and want to share what's worked for me.
Do you have a 2017 Denali 8 speed? It can be tuned, just costs a bit more than the 15-16's. But yeah factory GM tuning on the 8L90 is garbage. There are many contributing factors to the clunkiness (in my opinion and experience) 1. The trans tune sucks all around. Primarily the TCC lockup schedule. 2. Driver demand settings make transitions from light throttle to zero throttle abrupt. 3. The 6.2 has zero cam ****** until .14g cylinder airmass. These three areas are big contributors to the poor driveability of the 6.2/8 speed.
I've spent a considerable amount of timing tuning the calibration on my 8L90. I've compared it to Corvette files, Denali files, Sierra, Yukon, etc.. Pretty much all the truck-based stuff is the same. The Corvette calibration is entirely different. The TCC lockup schedule is more intuitive than the truck-based schedule. Also, the shift scheduling is more performance-oriented instead of lugging like the trucks. Shift times are much quicker in the high torque/rpm areas. Even the TCC desired slip tables are different. All in all, yeah the trans tune was pretty much garbage from GM. Between changes I've made to the trans side and some minor changes to the engine side, it drives a lot better. But yeah, what @CamGTP said is spot on. No dealer will ever do that. And the cost for you to make changes to your '17 is a bit steep. @WS6FirebirdTA00 has a 2017 with an 8 speed so maybe he can advise on what the process is.
Pretty sure the LT1 and L86 use the exact same cam, LT4 is different and the 2019 DFM motors might be different. But any LT1/L86 from 2014-2018 should have the same cam. Should slide right in no problems - same base circle. This guy did it. He's got install videos too:
I probably wouldn't go circle d route for their 8L90 stuff. General consensus over on hptuners forum is they don't quite have it figured out. Plus, there's underlying problems at play with aftermarket converters and the 8l90. It's difficult to ACTUALLY command zero slip in this tranny. You can bump the line pressure and command zero and for some reason it slowly decreases pressure until it slips then it slowly applies again. Wash rinse repeat. There's a couple long threads with much more detail about it. I'm still playing around with my tune but once I have it driving where i like it (subjective i know) i can send you the file for your tuner to have a baseline.
I personally think you just need to tune it. I have HPTuners software and I've made my 8L90 very livable. Perfect? No. But much improved? Yup. It's not all trans related too. Some of it is due to the driver demand tablets demanding negative torque. That exacerbates things greatly. Some of the things I've done to help the clunkiness: Adjust negative torque at low speeds on driver demand tables, I disabled AFM and their corresponding TCC slip modifiers, zeroed out TCC slip in 7th and 8th, completely unlocked the TCC from 1st to 6th, changed the entire part throttle shift schedule, fine tuned downshift speeds, and adjusted the base line pressure during TCC lock in 8th gear. Those changes plus my traction bars make my truck so much more enjoyable to drive.
replied! uploaded a couple vids to the Samsung cloud showing that it's unmarried and works great. This link is only good for 24 hours but I can repost them if someone wants to view after tomorrow. https://s.amsu.ng/3Cchksfxc7FN
I bought this tuner several years ago and it has served me well. Used it on my '00 Silverado and I just took it off my '16 Silverado. Works great! It tunes a laundry list of GM's, way too many to list. Pretty much everything from '99 to '16 with a handful of '17s too. It does all the standard tuner things,...disable AFM, change tire size, gear ratio, and, of course, MPG, 87, and 91/93 tunes. I found it hard to show that it's completely unmarried and ready to be used on another vehicle. You don't need to purchase a license or anything, it's ready to go. $200 shipped OBO
Meh. Sounds like marketing to me. I'd be much more concerned about their understanding of virtual torque, driver demand, injection timing, cam timing, etc.. That's really where the driveability gains come from. When you combine that with making simple changes to the TCC lockup schedule and ignition timing during part-throttle shifts = totally different truck.
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