Tune questions....

[littleblazer]

So I have a couple of questions regarding a tune. I've been flirting with this idea since I've had the truck (whole 3 years) but my questions are as follows:
1. Is there any reason to not get the tune (being serious any regrets?)
2. whom to get it from? (PCMofNC seems to be the one to me)
3. Any telltale signs that it already has a tune? It seems to move pretty well for it's size. (pcm bolts don't appear to have been touched, ever. but who knows what happened in the 95 thousand miles before I had it.)
4. Off topic, whats the speed limiter set at?

 

[The_Roadie]

I only heard of one offroad buddy of mine who hated his tune and had driveability suffer because of it. He's the only one I know of who reverted to stock. PCMofNC is the place. It would require you to have some $500 software to look at the existing PCM tables and see if they've been touched. I think the speed limiter is 104MPH. I can't do that even downhill, so it's a bit irrelevant. But I *do* love my tune.

 

[jpimp]

I think the Rev limiter is about 3,000 rpm
So if you can rev past that in park you have been tuned.

 

[Blckshdw]

Only 2 regrets I've ever heard of (not terribly serious ones) are: First, getting tuned for a higher octane, and not seeing any tangible benefits (power or fuel economy) compared to a tune for 87 octane. This was one I experienced myself. And Second, getting a shift level 3, and feeling the shifts were too harsh. Everyone I know personally who's had a PCM of NC tune done, had a shift level 2, so that's what I went with, and I am quite happy with it.

 

[BrianF]

I too am looking for a tune. I am faced with the replacement of the SAI solenoid and pump, not wanting to waste 300+ dollars on a useless system I mentioned this to my wife and she was all for getting a tune.

PCMofNC is where I am going. I think I will stay with the 87 octane tune as I dont always have access to midgrade or premium in a pinch. Its a daily driver so what do people think of the level 1 shift firmness??

Any must haves to check off and get?

 

[Blckshdw]

The big thing is the torque management. I left mine set to "dealer's choice", so I don't know what they set it at, but that's what really woke this thing up and made it more responsive when you get friendly with the skinny pedal

 

[littleblazer]

So no major regrets as far as I can tell. I'm pretty convinced. The truck rev's in park to around 3000-3400 (depending on it's mood I guess ) however yesterday it went strait up to 4000. would a tune change the speed limiter... I mean not that I know that it stops at 105 or anything. (As Clinton would say, "I did not have sexual relations with that woman." )

 

[dmanns67]

PCMofNC is definitely the place to get your tune. I think they will be having a Labor Day sale which is typically $20 off of their tunea.

Like Carlton said, reducing torque management and increasing your shift firmness will really make it more responsive.

I contacted PCMofNC about torque management and they told me since I do not tow, they only left 10% torque management.

I opted for shift firmness level 2, 93 octane, 10% torque management, rev limiter increased, and speed limiter removed. I have only had a chance to hit 115 mph once. Would have not been able to without a tune.

A tune ia definitely the best performance mod for the I6 IMO. Wish it would have been the first mod I did to my TB after I bought it.

 

[HARDTRAILZ]

I love my tune. I had it retuned with tire and gear changes and went from level 2 shifts to level 3 and do not regret it. Its solid, but I do have some beef to move around so may not be for everyone. I also went to premium fuel and it did not seem to make a huge difference. I think it runs smoother and with my higher mileage i wanted the hotter burn and sometimes better fuel. It really was not much more money when I calculatedout my miles driven and extra fuel cost. I would not change it if I sent it for another tune. I did the newer fan clutch and the air pump died so eliminating those lights was well worth it, but the removal of torque management is the best part of all. Instant throttle response helps the drivability many times over.

 

[BrianF]

I know their site allows for the removing the egr. As I believe its just a function of the variable cam timing in the 6 cyl. Is this necessary?

I need this girl as a daily driver, road trips and the odd tow.

I am pretty pumped about getting this tune.

 

[KNBlazer]

I know their site allows for the removing the egr. As I believe its just a function of the variable cam timing in the 6 cyl. Is this necessary?

I need this girl as a daily driver, road trips and the odd tow.

I am pretty pumped about getting this tune.

We have an EGR?

 

[Texan]

I think that he is referring to the "SAIS" system as EGR. My 03 does not have this system.

 

[KNBlazer]

I think that he is referring to the "SAIS" system as EGR. My 03 does not have this system.

My EXT neither...

I only heard of one offroad buddy of mine who hated his tune and had driveability suffer because of it. He's the only one I know of who reverted to stock. PCMofNC is the place. It would require you to have some $500 software to look at the existing PCM tables and see if they've been touched. I think the speed limiter is 104MPH. I can't do that even downhill, so it's a bit irrelevant. But I *do* love my tune.

Mine is set at 95mph...it appears it was an Enterprise rental truck...

 

[BlazingTrails]

My TB cut out at 110 from the factory, which is weird because most trucks cut out at 99 or 100 mph. I remember My 2005 Envoy stopped at 99 mph. same year.....

 

[Mounce]

My 04 will go past 105. Although, once it hit around 90 it was a slow crawl from there to get to 10_ however far I went, I can't remember it was over a year ago.

 

[limequat]

No EGR. AIR showed up in 04 or 05.
There are no external indications a PCM has been tuned, unless the Tuner deliberately marks it. If it was done in person, it would be through the OBD port, so the PCM wouldn't be touched at all.

Not all tunes are the same. I've seen tunes done to ONLY raise the rev limiter.

I've had customers that only wanted to disable AIR or only disable passlock.

I used to think tunes were pointless. Then I saw some of the bonehead decisions that GM made with the P12 computer.

 

[littleblazer]

PCMofNC is definitely the place to get your tune. I think they will be having a Labor Day sale which is typically $20 off of their tunea.

Like Carlton said, reducing torque management and increasing your shift firmness will really make it more responsive.

I contacted PCMofNC about torque management and they told me since I do not tow, they only left 10% torque management.

I opted for shift firmness level 2, 93 octane, 10% torque management, rev limiter increased, and speed limiter removed. I have only had a chance to hit 115 mph once. Would have not been able to without a tune.

A tune ia definitely the best performance mod for the I6 IMO. Wish it would have been the first mod I did to my TB after I bought it.

That's actually another question, I don't want to eliminate the torque management since I do tow a boat quite a bit, in the summer. And then I also have a receiver mounted box that I have about 350lbs worth of pool supplies inside that I tow around from May to September, I know its not like towing, its more like it's in the truck, no wheels, but you know its back there.

 

[Blckshdw]

That's actually another question, I don't want to eliminate the torque management since I do tow a boat quite a bit, in the summer. And then I also have a receiver mounted box that I have about 350lbs worth of pool supplies inside that I tow around from May to September, I know its not like towing, its more like it's in the truck, no wheels, but you know its back there.

Go on their website, and start a PCM tune order, you'll get to the order sheet, and see all of the options available. You can tell them how much you tow, and other factors to consider, and they'll adjust the tune accordingly. If you have questions, simply shoot them an email, and fire away, they are a very friendly staff. Countless members here have peppered them with questions about what does what, what people should order, and how options affect different aspects of the truck.

 

[Mooseman]

I had a tune done first year I got the truck and I know I can feel the difference because I just recently went back to a stock PCM (just for kicks and giggles).

What I would recommend is having the fan error codes disabled so when your fan fails (and it will), you can switch to a regular, more reliable and cheaper 2008 non-electro-viscous fan clutch.

If you have a SAIS and plan to eliminate it, then those codes can also be disabled.

Upping the shift firmness is also highly recommended. I had a level 2 done and I liked it at the time EXCEPT when I installed the shift kit in my tranny recently, it made it too firm. That's one of the reasons I put a stock PCM to compare. It did make it a bit less firm but not that much difference. I will be going back to the tuned PCM because I miss the performance.

Because I tow, I let them decide how much torque management to put in.

Another thing you should request is to eliminate the PWM in the torque converter clutch engagement. What this does stock is gradually engage the clutch so you don't feel it so much. All that does is create heat and increase wear on the clutch. I didn't request it at the time but when I put in my shift kit, it eliminated it directly in the tranny. I love it. Feels like another gear and you know when it's engaged.

 

[SmokeyMcBlazer]

Once I get the lifts and such installed, I'm gonna be looking at one of these tunes for sure.

I'm sure I'll have a ton of questions but for starters, can someone explain to me why you need torque management if you tow? I tow my ATV around and sometimes my 19ft boat. Am I to believe that the TB wll just spin its back tires uppon starting with no torque management?

 

[Blckshdw]

Once I get the lifts and such installed, I'm gonna be looking at one of these tunes for sure.

I'm sure I'll have a ton of questions but for starters, can someone explain to me why you need torque management if you tow? I tow my ATV around and sometimes my 19ft boat. Am I to believe that the TB wll just spin its back tires uppon starting with no torque management?

Think of it like how your brain determines how fast you run from point A to B.

If you are empty handed, with no additional weight, you can go for top speed and acceleration in an all out sprint, if you are so inclined and capable.

But say you need to carry some loaded boxes and/or pull a sled/cart, that has something heavy on it, behind you. Your approach will be quite different. Start slower, more carefully, to get the load moving first, and then accelerate gradually.

You can imagine the types of injuries you might get if you just took off as fast as you could, with that kind of additional load on your muscles.

Running stock, our torque management is set high enough that you can't sprint right away. It's more like jog first, THEN sprint

 

[Mooseman]

This video actually shows how torque management works:

https://www.youtube.com/watch?v=VLsY7dYjenY

 

[SmokeyMcBlazer]

Thanks for the reply bro. I'm still a little confused though. Maybe its because this is the first automatic I've ever had, with my other trucks (manuals) wasn't I managing torque with my foot and the gas petal? Without torque management could I not just ease lightly on the gas and pull away slowly?



Edit, can't watch the vid right now. I'll check it out after work though

 

[bobdec]

Smokey your correct, on my Z28 I manage torque management with my foot. However the engineers invented automatic TM to save us from our selves. TM also pulls timing depending on engine load and RPM. It helps save the drivetrain (IMO extended warranties) from the old fashioned nailing the pedal and spinning the tires. The 4.2 PCM will pull (retard) timing up to 15 degrees under load, more like 7-9* coming off a stop light. When the tuners ask for what level of TM you want it's accomplished by decreasing the retard under load. Also the engineers dropped the tranny pressure to soften the shifts. Bottom line ended up with a mushy take off and response. I used Jeremy at lime-swap.com to do my Envoy performance tune for street driving using 87 octane. Reduced TM (timing retard), engage performance mode (WOT)earlier, tweaked timing and shifting. No negative results on mileage, still getting 20 HWY/15-16 city. My Z28 is my performance toy so I kept the Envoy street friendly and did not go radical with the tune, I am extremely happy with the results.

I've been running my 4L60E tranny in the Z28 pretty hard, no TM to contend with, 315 rear tires, 3200RPM stall converter w/o PWM, higher shift pressure, faster shift times and modified shifting points. All behind a cam'ed LT1 engine. If it blows I'll just throw another one in. So far over 3 years w/o any problems I've read people knocking the 4l60E, but many people are running up to 400 HP with them. IMO GM overcompensated on protecting the drivetrain, but I guess the 99+% of the drivers not on forums don't notice it.

 

[Mooseman]

I know the tuners recommend keeping some TM for towing but when do we pin it while towing a 5000lbs. trailer? Really? Like Bobdec said, we used to do our own TM when such things didn't exist.

 

[C-ya]

Jeremy at Lime-Swap (http://www.lime-swap.com/) did my tune, too. I have a V8, so I have little more horse pressure and torque nuts to play with. If I ease off a stop, no biggy to Ziggy. Feels all normal like. If I "get friendly with the skinny pedal" (as Blckshdw said above), it will flat get up and get some. I did TM removal (almost 100% gone), throttle lag eliminated as much as possible (kinda related to TM), disable DOD/AFM, and increase shift pressure / decrease shift times. I didn't do an octane-specific tune, so Jeremy updated both tables so I could run whatever fuel I wanted/needed to and the truck wouldn't care. That's all I can remember right now. I am actually getting better gas mileage with the tune than before. And the truck is more pleasant (read: FUN!) to drive.

 

[rcam81]

I had my tune done with only 3000 miles on the clock. I tow a 4000 lb boat. I went with shift level 2. I am at 82000 miles. i am glad that I got the tune. it made towing a whole lot easier. The dealer hasn't ever said a thing about the tune either. I had a K & N CAI for the first 75000 miles and I have since gone back to stock.

 

[KNBlazer]

I had my tune done with only 3000 miles on the clock. I tow a 4000 lb boat. I went with shift level 2. I am at 82000 miles. i am glad that I got the tune. it made towing a whole lot easier. The dealer hasn't ever said a thing about the tune either. I had a K & N CAI for the first 75000 miles and I have since gone back to stock.

Lime vs PCM4Less vs PCMofNC

why go with one over the other...RRRRRREADY DISCUSS!!!!

 

[littleblazer]

Lime vs PCM4Less vs PCMofNC

Though PCMofNC used to be PCM4less?

 

[Mounce]

That's what I've heard. But someone adopted that name.

 

[KNBlazer]

How many of you bought the core package and kept your original tuned PCM? Also, any of you have emission testing problems with the tune?

 

[Blckshdw]

I opted for the HPTuners file, since JimmyJam has the program/adapter and is local.

In the long run, it's the more expensive route, but there is zero downtime, don't have to mess around under the hood at all, and we can make as many changes to the tune as desired. Not to mention reflash back to the stock or professionally done tune if needed.

It's also kinda cool to be able to load up both tune files and compare the differences. Of course, not knowing WTH I'm doing, most of the values carry little meaning. But I like having data in front of me to compare all the same.

 

[Mooseman]

How many of you bought the core package and kept your original tuned PCM? Also, any of you have emission testing problems with the tune?

Whatever you do, I recommend keeping your original PCM as this will eliminate the requirement to get a CASE relearn, which is required for most PCM swaps. If you have a u-pull type yard, you could pick up a spare PCM cheap to avoid the loaner and shipping charges. You can run a loaner or temporary PCM without the relearn, you'll just have the CEL in your face until you put your tuned PCM back. You will have to do a security relearn with any temporary PCM. Yours will go back in, no relearn at all.

And absolutely no emissions testing issues at all. Nobody has a clue.

 

[rcam81]

How many of you bought the core package and kept your original tuned PCM? Also, any of you have emission testing problems with the tune?

I went with the standard tune. Level 2 shift. Still have some torque mgmnt due to trailer pulling. I got a loaner pcm and sent my original in. The dealership hasn't said a word about finding the tune. The tune hasn't caused any issues either. I ended up keeping the loaner for a spare.

 

[littleblazer]

Sounds like I'm getting a tune. So do you guys reccomend swaping in the corvette servo with the tune and any other things with the transmission? its felt a little sloppy when you baby it lately. But when you get on it the belt cant help itself but chirp and well, lets just say it grabs the next gear pretty hard still.

 

[Pittdawg]

Whatever you do, I recommend keeping your original PCM as this will eliminate the requirement to get a CASE relearn, which is required for most PCM swaps. If you have a u-pull type yard, you could pick up a spare PCM cheap to avoid the loaner and shipping charges. You can run a loaner or temporary PCM without the relearn, you'll just have the CEL in your face until you put your tuned PCM back. You will have to do a security relearn with any temporary PCM. Yours will go back in, no relearn at all.

And absolutely no emissions testing issues at all. Nobody has a clue.

True. I just passed my Cali emissions testing last week with flying colors!

 

[IllogicTC]

I only heard of one offroad buddy of mine who hated his tune and had driveability suffer because of it. He's the only one I know of who reverted to stock. PCMofNC is the place. It would require you to have some $500 software to look at the existing PCM tables and see if they've been touched. I think the speed limiter is 104MPH. I can't do that even downhill, so it's a bit irrelevant. But I *do* love my tune.

Speed limiter I believe is set to 90 or 94. I remember some dude on the OS going "My speedo goes to 120, but it doesn't go over 90. My truck is broke! Help me fix it?" And you were the one who replied on the limiter, and he's like "but dude it goes to 120 on the speedometer!!!"

Good times.

 

[Mounce]

I've been over 100 with no tune.

 

[Capote]

I've been over 100 with no tune.

Was going 112 two weeks ago in Augusta

 

[littleblazer]

I can confirm that the roadie is right on the limiter, well.... i guess i can't really say that can I.