L99 Tuning?

[Pro Stock John]

I know guys like Padre have poked around with HPT inside the PCM and have been tuning their cars for quite a while.

I'd read threads on here going back about 1.5 years but would love to know what's worked well for folks...

Here is what I was thinking:

AFM delete - Goes without saying.
~Torque Management - Reduce by 50%? Also have to play with timing tables?
~Fans - Make the car easier to hot lap, cool the car down, turn fans on sooner?
~Idle - Raise it a little for the under drive pulley?
~Shift firmness, increasing line pressure, how much have you guys done?


Thoughts:

~Will be tuning on the dyno for longtubes, cats, stock exhaust, ud pulley, cai, ported tb
~Tell me more about adaptive learning?
~Any cool ideas out there for downshifting, like when the downshifts happen/don't happen?

I'm all years (Padre!!).
~Torque converter lock-up mess with that?

[Padre]

Transmission->Torque Management:
. disable it by putting the enable RPM at 8000+. Done, no worries about % or timing.

Engine->TM->General:
. Probably not needed if the Tranny TM disables it all, but just in case:
. Set All Max Torque gears to 6042, all cells.
. Trans input and output max to 6042.
. Brake Torque Limit to 6042, all cells.
. ETC Limit, disable.

That's about it on TM.

For now, don't mess with the TCC, except:

Transmission->Auto TCC:
. Zero out all TCC Desired Slip cells.
. Disable Use DoD Slip (probably not necessary if you've disabled AFM/DoD, but just in case).

For shifting, change the Special tables. This way, at the track, launch in "M" (not "D"), so that you use the Special Tables (not Normal). Makes it easy to see what your changes do.

Also, consider just adjusting the high rpm columns, so that it mainly only changes WOT performance and normal driving is the same.

You may adjust:
. increase the pressures a little bit, in increments, say by 5.
. Shift Time->Upshift Special (gear shift in M), reduce by small percentages (e.g. multiply by 0.95 or 0.98), and see how it feels. This can be more or less aggressive by gear.
. General->Inertia Factor Profile. Don't change much. Look at intertial profiles from other tunes (e.g. the CTS-V) and experiment a little.

For spark correction, you need to do some logging. For consistency at the track, you need to be aware of IAT and ECT.

For ECT:
. Look at columns 158*, 176, 194, 212. Zero them out.
. For columns 230*+, multiply by 0.5.

For IAT:
. Leave every colum below 77* as is.
. For the 86*+ IAt columns, you can either zero it all out, zero it out to a certain point (e.g. 122*), or shift all the columns from 86-248 to the right 2-4 columns.

After you make those changes, log it to see where you are getting KR (while looking at IAT and ECT), and adjust till you're comfortable.

Obviously, if you are getting really bad IAT and ECT, you need those protections, but in a comfortable range, you should be OK.

With your logging, once you are sure you're not pulling timing because of TM, IAT or ECT, then look at your logs of KR. Go to those cells in the HIgh Octane Table and subtract accordingly (smoothly, by also adjusting adjacent cells).

Rinse and repeat.

Padre

[white ZL1]

I did the same as you, read and read and read and read. Especially on the HPT forums. You can find a wealth of info on LS3's and the A6 there.

Delete the AFM if you want. Maybe keep it active in just 6th gear, or 5th and 6th. Or you can shut it off completely in Sport and keep it active in Drive.
Tons of options there.
Getting the MAF curve and wot fueling, in conjunction with spark, is critical to torque calculations for the trans. Going pure MAF mode makes tuning much simpler.
The A6 is where it's at though. The car really is a totally different animal if done right. Working shift time and shift pressure together in order to get minimal learning can be tricky but makes a huge difference. Making small changes to shift time in Sport mode, then copying them over to drive works well. And small changes to line pressure in each gear seems to minimize the learning.
Even bumping part throttle shift MPH in Sport makes the car quite a bit more fun to drive. And I'm not talking much...1-2 mph in first and then a few more mph in subsequent gears.
Two schools of thought on trans torque management. Some say deleting it is better for the trans, some say TM allows the clutches to engage quicker since you're pulling timing (torque). Delete it all, or keep some. HPT even allows you to keep some TM at part throttle and delete it all at higher torque/rpm. With the little changes I talked about making to shift time and pressure, I found pulling 30% out at part throttle to make for nice quick shifts without them being to harsh. Then you can pull as much at WOT as you want.
You'll also quickly find out the tc lockup is different on these cars. TCC line pressure starts low and then ramps itself up and down based on some desired slip tables and torque values. It also doesn't follow the stock tables very well. Sorta confusing.

[Tampa Tuning]

Hey John,
Its Phil'sC5Vette from the LS1tech and Corvette forum before I became Tampa Tuning on CF.
Its payback time. You've helped me and everyone else on LS1tech, so Id be happy to give you one of my bolt on tunes for no charge.

Just Email me your tune, and Ill convert it to a Tampa Tuning tune and you'll love it. Do the compare function to see what changes have been make.
www.TampaTuning.com

Phil

[Pro Stock John]

Hey Phil thanks very very much for the offer, I do of course recall you as a longtime LS guy.

Actually a local place Speed Inc. will tune it for an article, I'm just looking to understand what all can be done to the L99.

Is torque management universal, meaning if you delete it in sport it's gone for drive mode? Padre, you have a lot of runs on your car, do you have zero TM at WOT?

I heard that AFM is universal, so I cannot remove it in sport and keep it in drive?

I've read that the earliest the fans can be commanded on is 192F (something like that). I think I've read that the fans current come on at 210F. I don't want to mess with timing vs IAT, but I'd like to have the car consistently cooler in the lanes while waiting to make a hit. Seems like a lot of timing is pulled somewhere between 185-190F. Anyone have their fans on sooner, and have some thoughts on this? This and torque management are my most important items, I like to drag race a lot.

[Padre]

Yes, I have pretty much no TM at all.

Neither TM nor AFM can be controlled by Sport Mode.

In HPT, you only have values for fans down to 192* (put the value at 91, which turns them on max).

If you buy a 3-bar tune, it expands that field to lower temps so that you can put it to 91 at those temps.

I don't have that and still manage to cool mine down to 165* between runs (EWP, manual fans on, 160* stat, and HEX vents).

I would go ahead and do a 160* thermostat also. No reason not to. I've read all the debate and just did it, and it helps my overall setup.

Padre

[Pro Stock John]

Thanks for the reply!

Yeah I don't care about mileage, I care about cooling the car off between runs at the track. So how will the fan(s) work if I put it at 91? Let's say I start a run at 185, go WOT, the fan(s) won't be on then right? Then I brake and come around for my slip. Will the fan(s) be running harder than stock? Is typically just one running unless I flip on the A/C? So would the car cool off quicker by leaving it on after doing the stat and the tuning?

[Padre]

I think the number 91 is a % which indicates 100% on (kind of like the throttle reads 88% for WOT). Does this mean more wear on the fans, I suppose so, but shouldn't be an issue. If you look at the stock tables, it ramps up from 192* (partial) to 210* (full=91). I just changed the "ramp up" values to full=91.

I think the only thing to worry about with running the fans more frequently is draining the battery. I can manually command the fans on in HPT, with ignition on, motor off, and this cools down quick (with my vents and EWP especially). But I also get a battery saving warning after about 15 minutes or so.

When you go WOT, I believe the fans are turned off, but I could be wrong. I have manually turned on the fans in HPT and left them on during a run and noticed no harm or gain.

Padre

[Tampa Tuning]

Your idle should be ok with bolt ons even with the reduction pulley. If you bump it, I wouldnt do much.

When you dial in the MAF, you can zero out the dynamic airflow tables.
On the acceleration based table/ accel threshold, zero that.

Correction your open loop gains table

Correct your Power Enrichment EQ Ratio, the enrichment ramp in and the PE Delay

Disable the CAT Over temps and the DoD

You may have to actual decrease your timing at WOT when you lean it out some.

Even though you turn off the DoD, I like matching my high octane main spark advance with the high octane DoD table, and the low with the low.

Half the minimum final spark TqMgt table
Max out the Max Torque tables
Disable the tip in limiting

Im going to keep the tranny stuff my in house secret

Ive go enough shops calling me for tranny tunes because they cant figure them out

[white ZL1]

Originally Posted by Padre

Neither TM nor AFM can be controlled by Sport Mode.

Go to Engine -> Fuel -> COT, Lean Cruise -> and select Disable PRNDL you can turn DoD on or off in Sport and Drive separately. Sport is D4 and Drive is D6. I had mine set like this for a few months. DoD was only active in Drive and 6th gear.

Originally Posted by Padre

I think the number 91 is a % which indicates 100% on (kind of like the throttle reads 88% for WOT). Does this mean more wear on the fans, I suppose so, but shouldn't be an issue. If you look at the stock tables, it ramps up from 192* (partial) to 210* (full=91). I just changed the "ramp up" values to full=91.

System -> Fans -> then look at Fan Desired % vs ECT, Fan State vs Current State, and Fan Output Control vs Current State....
Fan Output Control vs Current State shows you what fan kicks in for a given state. State 1 kicks on fan 1. State 2 kicks on both fan 1 and 2.
Now go to the Fan State Transition Desired % vs Current State and you will see what percentage controls each state. 0>1 happens at 50 and 1>2 happens at 90. Fan 2 shuts off coming back down at 50, and fan 1 shuts off at 25.
Take this and move over to your Fan Desired % vs ECT table. At 203 degrees, I have a value of 50 in there....so fan 1 kicks on. At 210 degrees I have 89 and at 214 I have 91, so at 212 I would see 90 and the 2nd fan kicks on.
These cars are not like the Vettes, the numbers in the Fan Desired % table are not the actual % or speed the fan is operating at. They are either on, or off.

Padre...you might want to check your fan operation. One of Chris' posts on the HPT forum says that if you have your first fan set to kick on in the 192 degree cell, that (depending on the OS) it might mean your fans are set to always be on. Your Fan State never drops below 25 so you're fans will always think that you want them on.

[Pro Stock John]

Thanks guys, I'm still re-reading the posts don't understand it all but am trying.

White, are you saying our fans are on and off, not different speeds?

[white ZL1]

Yes, they are discrete fans. Not PWM.
The only thing I can't remember is if one is the low speed and the other is the high speed, or if they both have a low speed and then high speed.

[Rhino79]

The fans are not just on/off. They are variable speed for both engine temp and ac activation.

[white ZL1]

My 2011 are discrete fans that have set on and off points dictated by the logic I described above. I can hear, even feel, when they kick on and off while parked and/or idling. I can also see on the DIC when they kick on that the coolant temp starts dropping fairly rapidly, then turn off at the temp I have them set to turn off.