noob here, need alittle help with my 8.1L

[CHEVYHD496]

i have a 2002 chevy 2500HD with the 8.1L/Ally. i just got efi live and am trying to figure out how to..
1) change tire size
2)remove torque management
3) and any other info anyone has for me!

thanks guys

[joecar]

Post your file... and welcome to the forum :cheers:

[CHEVYHD496]

thank you! looking forward to learning a lot! i also have a BBK 80mm TB for my truck but it didnt like to run with it. how can i adjust for that?

11469

[joecar]

Tire size: look at speedometer folder, use the Speedo Calculator.

Torque Management...? See the following:
Max allowed engine torque: B1901.
Engine brake torque management: B0401, B0402.
Traction control torque retard: B6603, B6604.

Also:
Set both PE enable tables B3615, B3616 to 60% below 3200 and 35% above 3200.

Edit: deleted comments relating to transmission tables.

[CHEVYHD496]

11480

i didnt quite understand the last part about the transmission shift pressure tables. i have updated alot (or to me anyways!) so i have attached my updated file. please look and see if it looks ok. thank you!

[Big Mike]

1) Re-enable RPM limiting via ETC and use it for your rev limit. Using ETC instead of cutting fuel (as you changed it to) works better on the 8.1's

2) Max out B6614

3) Set B3608, B3609, B3610 (PE delay) to zero. Then set B3611 to something very low, say -20. Doing all the will ensure it enters PE right away with no delay.

4) Even though you disabled axle torque limiting B6601, also greatly raise all the limits that go along with it. Sometimes just setting it to disable doesn't get them all.

5) Max out D2003 to go along with the rest of the abuse mode settings you maxed. Like above, just disabling some won't cover it all so its better to get all settings that pertain to it.

Once you have those covered, you make actual TM and torque reduction adjustment in table B6605. This is the table the trans controller uses to control torque reduction and will have the most affect on it. Be sure to only make small adjustment on this table because the trans needs time to re-learn the new adjustments and small adjustments have a dramatic affect on how the shifts feel and it's easy to go too far. Giving it time to re-learn also lets you identify whether the trans is happy after multiple drive cycles too, otherwise you'll think you have it working nicely and then the trans gets smart, learns the new reductions and begins to behave oddly. I worked on this table alone off and on for over a year on my own 8.1/Allison until I finally found the sweet spot and consistency.

By this point you really should have a WB on it as the 8.1's are set pig rich in PE stock and they need leaned out. You can lean it out a little without one but you're really shooting in the dark and can cause damage. Then you can also start on the high & low timing tables which is where most of you new found power will come from. You just have to be careful, use your head and log log and log some more watching for KR as they're VERY detonation sensitive.

Don't bother attempting to make transmissions adjustments in the PCM because they're not for the Allison and won't do anything. Once you've worked in the PCM for a while and are ready to make trans adjustments you do that in the TCM tune. Totally different animal.

EFI Live and tuning in general both have an almost unlimited learning curve but when it's working well it's one of the most satisfying and enjoyable endeavors you'll ever find. And when it's not you'll also find it has one of the best supports groups right here that money CAN'T buy to help you along. :rockon:

[joecar]

Oh, he has an Allison, I didn't properly read post #1, sorry :doh2:

[joecar]

Mike,

So he would reduce the values in B6605...? Would he set this table to zeros...?

When is Abuse mode active...?

Thanks. :)

[CHEVYHD496]

joecar, do i need to go back and change the tranny settings you had suggested? if so please send me the table codes again please. i will just put them back to stock for now. and where can i get WB 02?

[joecar]

No, those transmission settings are for the 4L60E/4L80E transmissions, you have an Allison so please ignore the transmission settings in the PCM file.

[joecar]

Wideband: there are various brands, this is old but see here: Wideband-Controller-Poll
(http://forum.efilive.com/showthread.php?13361-Wideband-Controller-Poll&highlight=wideband+poll)

if you have FlashScan V2 then get a wideband that supports serial comms (see the widebands listed in the V8 S&T software, goto F6:Devices and then F8: Serial I/O).

[Big Mike]

Mike,

So he would reduce the values in B6605...? Would he set this table to zeros...?

When is Abuse mode active...?

Thanks. :)Correct Joe, he wants to reduce the values. Those values are the timing values used for the various levels of TQ reduction the PCM uses to reduce TQ during shifts as the trans requests them. And usually setting them all the way to zero has negative effects on shift feel, ie they get way too harsh. The Allison's need at least some reduction on the shifts to function properly, comfortably and as intended. Generally lowering the entire data table initially about 20% (as a starting point) and then continuing to reduce it in 10% increments until you find where it works the way you like it is the best approach. Just be sure to allow at least a couple hundred shift cycles between adjustments both in normal mode and T/H before adjusting further as the "sweet spot" is easy to miss by going too far otherwise.

Abuse mode on the 8.1/Allison equipped trucks seems to act a little differently than other vehicles in that it's target parameters behave much in the same way as the DFCO parameters, in that if it hits ANY or all of them it will activate abuse mode. So I find it's best to be sure you're disabling them all to positively eliminate it from activating.

[joecar]

Mike, ok thanks :cheers:

[CHEVYHD496]

ok thank you guys, i will try and do that tonight to adjust those parameters and hopefully get it loaded to. im anxious to see how much of a change i will see

[CHEVYHD496]

put my new tune in and it seems to run rich. i also disabled the EGR but threw a P0405 code for it.i re-enabled the egr and no light. any ideas? also didnt really notice a difference in how it drove. maybe im just expecting way too much for as little as i have done. and thank you for yalls patience with me

[Big Mike]

When you disable EGR you also have to go into the folder- Engine Diagnostics--->Engine DTC Processing Enablers in the tune and set any and all codes related to EGR to "not reported". For example, the P0405 that was caused by you disabling the EGR needs set to not reported. And you'll also want to set P0404 to not reported while you're in there.

Post the current tune again. Shouldn't be any reason it's running rich unless you changed other settings from your first modified tune or the EGR code is causing the rich condition, which is certainly possible.

[CHEVYHD496]

ok, thank you mike.
11502

[Big Mike]

1) Why the drastically lower B6619? I don't know if it's enough to actually limit input shaft torque, even at your current setting but your number is way way less than it was stock. Change it back.

2) Max out B6610

3) Return all previously changed trans settings back to stock.


I'm going to say the seeming rich condition is due to the DTC's set for the EGR disable since you've made no actual fueling adjustments. Since they're really a medium duty engine the 8.1's have a thing where they'll fatten themselves up if there's any EGR codes to protect from possible elevated combustion temps thus detonation from the lack of EGR. Once you get those DTC's taken care of you can continue on.

[CHEVYHD496]

alright i did as you said mike. now on my stock tune i checked all th tranny parameters. nothing has been changed to the stock tune. on my updated tune, i changed the speedo and tranny calibrations for my tires. in doing so i thought i put in my correct tire size but was wrong. i then put in the correct tire size and recalibrated the speedo and all the tranny adjustments. when i checked it against my stock tune, i changed the tire size the first time to the correct size the parameters are slightly different. any ideas? also i changed the MIL and DTC settings for the EGR and it doesnt seem to run as rich anymore11511

[Big Mike]

The trans settings changed again because you used EFI's feature to adjust them with the speedo calculator. It won't have any negative impact because as you already know trans changes made in the PCM are for a 4L80E equipped truck (6.0) thus have no actual affect on an Allison truck because it's done via it's own separate TCM. I just never change those settings in the PCM simply for the fact that it add complexity when comparing tunes.

Of course you can tune the TCM too if you wish but I think it's in your best interests for now to continue working on the engine tune and get lots of logs before you start into the trans, because it's whole different animal that has it's own learning curve with it.

[CHEVYHD496]

wow thanks mike! i thought i messed it up!! i dont plan on messing with the tranny for awhile. you guys have been a HUGE help!

[Big Mike]

You're doing fine so far and as you work with the software you'll constantly learn new things and it's powerful features. I bought EFI Live nearly three years ago and I still learn something new almost every time I tune with it.

And you're more than welcome to any and all help and I thank you for yours too as I see you're in the Marines. It's guys like you that allow us to enjoy our great country and our individual lifestyles. Can't thank you enough for that. :wave:

[CHEVYHD496]

thank you again mike! i have enjoyed it tremendously. could you please try and explain to me the B6612 TC, ETC pedal torque limiting table? then after that i think i will try and tune for my 80MM throttle body.

[Big Mike]

The table does exactly what it's description implies in that it limits torque output for a given throttle blade request position. Based on this I think you can see it will control throttle blade angle based on the requested angle (from the pedal) and how much torque it will allow. So it's basically a torque limiter and it uses throttle blade position to control it. I haven't found that the actual data in the table correlates with anything specific such as a torque or blade angle percentage from zero to 100% so you just have to adjust it as a percentage, see how it responds and work your way up from there. I've also found that greater changes can be more safely made in the 70%-100% range than in the 0%-60% range before throttle sticking may occur, as the description warns about. I know going too far on my own truck causes the throttle to stick so I had to work with this table making small changes at a time until I got it as high as it would safely go without sticking.

However I've also found that guys running '01-'02 PCM's can often max this table out with no throttle hanging issue and your '02 may be the same. So you could try (as an initial test) maxing it out but just be very very careful on your initial test drive and do so in a safe place because if the throttle sticks it can be very dangerous for obvious reasons. If it does stick; immediately applying the brakes will cancel the throttle input request and bring things back inline until you adjust the table again. I can also say the sticking usually doesn't manifest itself until you go past 50% pedal position so be ready for it when you do the first time. It may seem fine in stop and go traffic...but then stick once you run it up a little.

If you find yours works fine maxed out great, you'll notice the response it adds, but if it causes the throttle to hang you'll have to go back to square one and then sneak up on it making small changes each time.

[CHEVYHD496]

when you say maxed out mike you mean set all columns/rows to 100%? i read and read the discription and couldnt quite figure out what it meant

[Big Mike]

Oops, sorry about failing to mention that important detail. I even had trouble in the beginning knowing whether to zero it or max it and I still forgot to clarify it for you. So yes, to remove any limiting it's causing you want to set the entire table to 100%, not zero. But again be careful on your initial drive and good luck.

[CHEVYHD496]

i'll give her a shot. thanks mike

[CHEVYHD496]

started at 90% and no problems thankfully. but also didnt really notice a difference. so later im going to take alittle more torque reduction out of B6605 and maybe go up to 95% on B6612.

[Big Mike]

If increasing B6612 that much had no negative effects go ahead and max it to 100%. It should be safe now. Then continue to lower B6605 until you like how the shifts feel. Then you can start working on logging, fueling and timing and that's where your power will ultimately come from.

[CHEVYHD496]

well big mike, i changed it back to stock. at about 2000 rpm at 70-75mph the throttle stuck just alittle bit. so i guess im just gona have to play with it. but now my tranny cooler took a dump (135,XXX miles) so i have to fix that before i can really start messing with my tune. just my luck lol

[Big Mike]

Sounds like you have the same kind of luck I do so I fully feel your pain. :grin:


Going to replace it with a stocker or update to a bigger one?

[CHEVYHD496]

a bigger one of course big mike!! i also had it next day air with expedited (be here tomorrow) and it was still cheaper than GM!

[CHEVYHD496]

got the truck up and running. thank god, just in time for the morning drive to work! hopefully get some more tuning done!

[CHEVYHD496]

still need to do some data logging, will post the log soon, but what do i need to look at to adjust for my bigger throttle body and long tube headers?

[Big Mike]

I would start with getting a WB since you planned to anyway. Most everything you do at this point you will find you'll need to re-do once you have actual WB data. Of course you can do plenty of logging to see where you're at currently paying special attention to fuel trims and KR thus you can make some small changes in the fuel and timing areas. I know Joe has posted all the good links and PID lists to include many times so perhaps he'll do it one more time. :grin:

I'm curious why you wish to go to a larger TB as I've never seen much benefit [on an 8.1] on a N/A (or even boosted) application. The stock TB is not the first restriction in the intake system and will out flow the stock intake and camshaft easily.

[CHEVYHD496]

i will need to get WB but need to wait abit since i just had to replace the cooler. the TB i have i got at a VERY LOW PRICE. just want to put it on. i already ported the intake throat to match, but really just want to learn as im building a 550ci raylar/turbocharged BBC gen 7 to put in my truck. is there a link for a tutorial to adjust for the bigger TB? thanks big mike!

[Big Mike]

Sounds like a very exiting project and one I'd like to hear updates on as it progress's since there's so few guys doing big work with the Gen7's. So don't keep it a secret as it comes together. :rockon:

Since you want to get started on learning by adding the bigger TB the main things you're going to need to work on is the desired airflow tables [B4307] and [B4515] along with possibly some others (basically any that have a direct impact on airflow) until you find what the engine wants with the increase in TB area. Most likely you'll discover you need to reduce the stock numbers since it's already equipped with enough TB.

There's a great idle tuning tutorial in the tutorial forum that you can familiarize yourself with what PIDs to log and how the tables correlate with what you need to know and do.

[CHEVYHD496]

thanks again mike! here are some pics, still got a ways to go, but hey work in progress!1157811579115801158111582

[CHEVYHD496]

1158311584115851158611587

[joecar]

Thanks for the pix.

[L31Sleeper]

Turbo it !!!

Does this setup have a Allison trans controller ??
I wasn't sure if the 0411 could control that trans.

-Justin

[ScarabEpic22]

All Allisons have their own TCM, the 8.1/Alli combo is unique, it uses the LS1 PCM for the engine but the A40 (I think?) TCM controls the Allison.

[CHEVYHD496]

on table b6612, what exactly is the TP % ? example: at 8,000 rpms and 100% Torque Limit, the TP% is 100%. so does that mean the TB is open 100%, closed 100% or the TB blade angle is 100%? still trying to wrap my head around this table! thanks yall

[Big Mike]

You're basically correct. The data is the commanded TB blade position for the requested torque limit based on RPM. Example, if the PCM calls for a TQ reduction of 50% at 4000 RPM the TB will be commanded to the indicated position percentage shown in that cell on the chart regardless of what the actual throttle pedal request is. On your stock tune as an example that would be an actual blade position of 13.11. So you can see why you want these numbers as high as possible without running into throttle hang issues.

[CHEVYHD496]

so big mike, could you post your tune for your 8.1 to give me something to look at? im gona try and play with the B6612 table tomorrow again. think im gona max it out at 100% and see what it does, if nothing or negative results i will then start back from stock and do small percent increases. then gona learn auto-ve! and i do appreciate the patience you have had with my un-knowledgeable self!

[CHEVYHD496]

i set B6612 to 100% across the board, it didnt stick on me but if i am in the fuel hard then take my foot off it seems like it cracks the throttle open itself for a second. im gona run it for the day then decide. is there any other tables i should mess with to get this one to work?

[Big Mike]

No one to date (that I'm aware of) has figured out why changing B6612 has a detrimental effect on some operating systems. I believe it has something to do with things/tables we don't have and the DBW own systems sanity check, so currently there's no way around it. Believe me if there was I'd have that one maxed out.

It's kind of frowned upon to post a tune as a sort of "cheat sheet" that someone spent a lot of time on so I won't post one here, but I would email you one with some timing and fueling mods in it so you have an idea since there's so little 8.1 info around and basing changes on other engines will usually lead you down the wrong learning path with an 8.1. Shoot me a PM with your email.

[azcagiva]

FYI dart has just released some new iron heads for the 8.1 as well as a carb style intake. You might want to look into using the carb intake, I am sure it will outflow the stock 8.1fi manifold. You could use a plate and mount your bigger throttle body on it, that and adapting it for injectors you could build a lot of power and really get the most out of those raylar heads.

-John