lucas287

SO much of the clunking/hard shifting can be attributed to the programming. The TC stays locked through shifts at part throttle and combined with the Driver Demand table commanding high negative torque at low speeds it feels clunky. If you have DOD enabled, that commands a different amount of slip too, which can cause shuddering. I've been able to tune my 8 speed to be a very compliant and happy transmission. It's quite remarkable when you realize how sensitive the programming is. I can make a simple MAF-fueling adjustment and it changes that way it shifts. Torque-based ECM/TCMs are very finicky and I'll GM left a lot to be desired when it comes to driveability. I say all this, because you might be chasing your tail. The transmission itself is quite robust. The programming just sucks.

If you're under warranty, yeah I'd pitch a fit about that.

You're telling me that a blown L86 doesn't have enough torque to pull that trailer with 3.23? I've pulled ~5k many times and I've never struggled and I'm not blown. Sure, maybe not in 8th but that's the beauty of having 8 gears. Drive in 6th or 7th! If it were my money, I'd do the following. Buy HPTuners and modify the tow/haul map to lock out 7th or 8th. And then upgrade to LT4 injectors and fuel pump and convert to e85. After a good tune you'll easily pick up 40-50 lb ft down low.

Definitely won't sound like crap! I had some flat stock (1x.25") laying around so I cut a small square and used that with a hose clamp. I went back and forth many times and couldn't really notice a SOTP difference. It does let a lot more deep tone through at idle though. I had this for nearly a year before scoring a local deal on a used Corsa cat-back, which makes me grin every time I drive

Yep, agreed. Overall volume at WOT is the same. At idle it'll sound a little deeper. Just clamp it open yourself and you'll get an idea of the sound difference.

Sorry to derail the thread. The main issue is still the oil consumption...let's try to solve that problem!

I, too, am very experienced here. I, too, drive around with a laptop in front seat. No need to patronize - just offering an opinion and counterpoint.

Maybe so! Hey @JONBLARC7 did you ever get yours to stop black smoking at WOT? Ran across a thread over on HP Tuners where you were trying to nail down EQ ratios to remedy it. were they direct injected?

@truckguy82 this isn't helpful, but really just for comedic relief. Nothing beats the oil consumed in this episode of Roadkill 9 miles to the quart! https://www.motortrend.com/news/roadkill-cleetus-mcfarland-toyota-hilux/

I 'think' if this were the case it would be blue-tinted smoke not black. Just sounds like a big fuel dump, meaning the EQ ratio might be a bit rich. BB likely tuned it on the safe side if you don't have a wideband.

did you notice any difference in ride quality with just the shackles installed?

I'll take it! $20?

I appreciate your efforts on this! Traction on the street with all season tires is practically impossible with a RWD truck and any sort of power! There's only a couple ways to mechanically get faster: 1) better tires - think drag radials 2) traction device that manipulates downward force - like caltracs With those two you should be able to hammer down and not lift at all. But, of course, there's many nanny settings in place that will either limit throttle opening, and, or, spark advance to keep you from getting full power. All these reasons were a big factor why I bought a 4wd

@Grumpy Bear I've often challenged your viewpoints of positive caster because my general experience with caster is mostly positive. At some point, though, it does have diminishing effects. My gut tells me frame angle is mostly overlooked when considering caster spec on a truck. Combine that with dropped rear ends and leveled front ends and we are creating unintended consequences to caster angle. What are your thoughts on this:

RFB is indeed fickle. I always stand on the floor and watch/talk to tech and sometimes it just isn't going to make a situation much better. I think it is a very useful diagnostic tool. If you RFB 4 tires and 1 is excessive...replace it. Without the RFB you probably just would've lived with it. Also, just FYI I've had tires that took very little weight to balance but were still not round. You can balance a cube right? Doesn't mean it will roll very well though. The RFB machine quickly discovered it was the tire we least suspected due to weights.

Right there with you! I feel the OE setup has a stiff spring AND a stiff sway bar. Hardly ideal. That's why when I go Thuren King 2.5s I'll be requesting 600 lb springs and put my sway bar back on!

Haha all good Yeah I will ALWAYS get balanced and road force sorted out to my liking within the first few weeks going forward. Discount is real easy to work with if you're polite about it. On my wife's CX-9 I told them up front that I want ALL FOUR tires under 10 lbs RFV and we went through 9 Michelin Premier before switching to Falken CT60 and finally got all four under 10. Smooth as glass ever since. It helps if you rotate at home because I tell them, "look, if you get these perfectly smooth - you probably won't see me until it's time to replace them - because I do my own rotations at home". In short, yes, I hear you! I am very particular when it comes to tires and balancing. Anyways, I digress. I might try to find some of the same springs on the cheap and swap 'em out just for fun. If you feel up for it - try taking off your swaybar. Takes about 5 minutes. It makes a difference in NVH for sure. I've had engineers turn blue in the face with frustration telling me "there's no way it changes the ride" or "that's not how it works"... I agree - "in theory" but the reality is that it changes the ride.

Yeah for sure hard to differentiate and give credit when multiple variables changed. I also have the Roadmaster Active on the rear to help with axle wrap since my traction bars didn't work out (they bind the articulation of the rear and make it worse). The roadmaster feels pretty good overall but I've got them cranked to their max to prevent axle wrap which makes them quite stiff/bouncy. Still better than stock shocks/no roadmaster though. Currently running 275/55R20 Michelin Defender LTX. I gave up fighting Discount on them. One tire took about 4 oz and the rest took 6+ to balance. Have had them road force several times and tried different locations etc.. I even have intentionally done some wicked burnouts to round them out but I think it's just a sidewall stiffness variation. So that definitely contributes to the ride quality on the highway. And the 55 sidewall isnt doing me any favors either. Plus Michelins are pretty stiff anyways in my experience. Long term plan is King 2.5s all the way around tuned by Thuren. Probably stage 2/1 front to rear. Then I'll put a set of Black Rhino Chase 17x9 and P285/70R17 probably Toyo Open Country. Between the sidewall increase and the Kings it should be a transformed ride quality. Just looking for a bandaid between now and then. Might just go back to no sway bar for now. I've had it off 3 or 4 times experimenting and there's no denying it smoother without it.

@Yondu have any longer term thoughts on the front Tahoe springs? I'm considering doing this too! This ox cart ride has gotten old real quick.

Did you ever test this? Theoretically the digressive valving of the Bilstein's should help offset the lack of a sway bar.

Crud! Good catch man. Considering I've never touched the reverse table that makes sense. I've played with 1-8 quite a bit and never liked KPA so I switched all of those tables over. In any event I cut the values in half for the first two columns as a test and it feels no different. So therefore I dont think there's anything from a tuning perspective that can be done to help. But i have had the dealer flash "the latest calibration" before and then downloaded it into HPtuners and compared to before and haven't spotted any differences. So maybe their updates change something I dont have access to??

If you're unfamiliar with HP Tuners this will look a little complex to you. Here is the base pressure for reverse compared to 1st gear. As you can see it calls for ~ 8 times the pressure of 1st gear, which has the highest psi of any forward gear. With that said, I haven't experienced this issue with my 8 speed. Sorry that no one can figure it out either! Sometimes mine is pretty laggy and then it clunks but never that long of a delay. I'm going to experiment by greatly reducing the first two columns to see what happens and report back. If it engages quicker and with less force, then I'd consider it a win.

@SRT8dan you're spot on. No differences at all between the long block on the LT1 and L86. Even the same throttle body actually. Just comes down to intake manifold and the full exhaust. Sure there are minor differences in tuning, but I'm sure they're very minor. I wish the L86 had a variable intake manifold like the newer Hemi's do - best of both worlds.

I must be lucky because my stock '16 L86 stat usually runs 175*-180* @ 70 MPH on the highway regardless of ambient temp. It doesn't act like it's stuck either because I get heat pretty quick even the last couple days when it's been bitter cold. Warm idle it'll creep up but I've only seen over 200* maybe a couple times. And this is confirmed via OBD, not the useless gauge on the dash.