My PCM tuning with PCMforLess.com - Process and Results - Page 3

quote:

ORIGINAL: Dennis

I am so glad everything turned out great for you Mike..especially the over revs on clutching....!

I'd like to give their tune a shot just like the one you got..and compare it to the tune I got earlier this year,..sounds to me like what Kelly was saying..Alvin's tune make it more driveable in the day to day city driving...Which is where it should be, snappier..Oh well I burnt that bridge..so to speak

Alvin is a very nice guy. I think he might be able to find it in his heart to forgive you , or, maybe he'll just reprogram your PCM to make your engine self-destruct MUAH HA HA HA HA HA HA what.

quote:

ORIGINAL: Alvin@pcmforless.com

Glad you are enjoying it!

As soon as you start driving the truck like you normally do the gas mileage will start to increase. Most of our customers report about 2mpg better (if not more) on thier second or third tank of gas. There is a good bit of learning that has to go on and it does take a few hundred miles or so.

We did do some things to tweak the idle including spark changes and such. Thats probally where your noticing the smoother idle. We really give these tunes a thorough going over and change quite a few parameters

Well, after driving to work under my normal conditions and driving the way I always do, here are the NEW things I have found:

1) I didn't drive no 200 miles yesterday like I thought (I don't know WHAT I was on...) but only about 70 miles.

2) I tell you, I found myself continuously braking the entire time to work, not because it was stop-and-go so much, but because the normal amount of pressure I would use to press on the accelerator made it accelerate much faster then it used to. I kept creeping up on everybody's rear end. I'm surprised my rotors weren't glowing by the time I got to work There really is more pickup. I know there has to be more going on then just a boost in HP. There seems to be quite a bit more torque.

2.5) On the way to work and back, I'm usually in 4th gear most of the time, just because of the way traffic is on my expressway. There is a noticable difference in pickup in 4th gear. I don't even want to shift it into 5th because me likey the power

3) The engine is much smoother accelerating at low RPMs then it used to. When I was anything under 1750 RPMs and floored it to accelerate at higher gears, the engine would virbrate. Now, there is no vibration at all, and even when I am a little under 1500 RPMs and cruising down the expressway, I hit the gas and no vibration. It seems like the engine is not struggling as much as it used to.

4) A HUGE difference in upper RPM vibration. When I would get past 4500 RPMs, the engine would really start to vibrate alot, like I was pushing it too hard. Now, it doesn't vibrate AT ALL. It's SO smooth getting past that 4500 RPM mark. I used to literally feel like my engine was going to just vibrate right out of the engine compartment. Now, it's as smooth at high RPMs as it is at low. I don't know HOW the heck you did that little fix, but it's pretty awsome! I'm not afraid of blowing up my engine anymore! Is there something you did to make it smoother at the higher RPMs?

Since nobody here seems to have a Manual H3, I can't say you guys would feel or see the same effects that I do, but for me, I'm really impressed. It's such a bargain for $149. I don't know what the long term effects will be obviously, but so far, it's really starting to show some hidden power.

I have to say, I'm still VERY impressed by how much power this little I-5 engine can make, especially now. You have to give the GM engineers alot of credit for being able to pull off the H3 with this engine. I just wish they would have come tuned this way. It probably would have given them more selling power. The boost is enough for me to finally be content with the amount of power I'm getting.

Alvin: Thanks! I don't know what else to say You made me a happy driver.

(Yes I sound like a commercial, and NO I didn't get any kickbacks )

One other thing I forgot. I did two 0-60mph runs immediately before and after I swapped the pcm, timed with my watch and the speedo. First two were right at 15 seconds, second two after the swap were right at 12 seconds.

Not very scientific I know and also had my 35" tires on at the time so the actual times were probably a little less but a noticeable difference there.

I hope my buddies from the lotus forum don't see those 0-60 times.....

Was that timed on a track or just you watching the speedometer and your watch

That sounds like something I would do! It doesn't take me no 12 seconds to get to 60! Damn I DO have it good with this 5 speed!!

quote:

ORIGINAL: HummerGuy

OK I'm a bit confused being new at this. People on here say the PCM doesn't learn anything. It only adapts from the time you start the car to the time you stop, and then over again the next time. What exactly does the PCM learn? I'm just curious. I might just be missing something, but from my perspective, everybody seems to have their own theory as to whether or not the PCM actually learns and retains anything. Someone from GM said it doesn't, others say it does. Maybe I'm just stupid :) Please explain. Thank you!!!

The PCM learns three major engine items: fuel, spark, and idle. You can picture that the PCM is pre-programmed with fuel and spark info. As you drive the PCM looks at the oxygen sensor before the cat. converter and adjusts the air/fuel ratio to be 14.7:1. Learning is required because of tolerances in fuel pressure, MAF sensor, etc. The data the PCM learns about the fuel is stored in Trim cells (as in fuel trim not the other kind). So the PCM fine tunes the inital starting points. The data is retained until you reset it (using HPTuners, Tech 2, etc.) or when you disconnect power to the PCM.

Spark timing is similarily learned. The PCM starts with an upper and lower spark table (high octane and low octance). As you drive the knock sensor is monitored and timing is adjusted and ends up somewhere between the upper and lower table. This learning is reset under the same conditions with the fuel but also when you add significantly more gas.

Idle is learned as a function of engine temperature and gets reset the same way the fuel trims do. This learing is fuel, spark, and more importantly throttle position need to for the programmed idle RPMs.

There is other learning that the PCM does besides the big three that I mentioned.

When you say it learns the spark, what exactly does it learn? Does it learn how much voltage the spark plugs should get for the best combustion, or do you mean the timing of the spark? If you put something like Iridium spark plugs, or those Bosch Platinum +4's, how do things like that affect the PCM? Does it adapt to things like that, or does it always just use the first initial xxx miles of data for the rest of it's battery life?

Also, do those goofy 9 Volt battery adapters you buy at the store REALLY help keep your PCM's memory when you disconnect the computer? I can't see how that could work considering it's sending power opposite of what it's supposed to. Someone actually told me to use those things before thinking the computer's memory would be retianed when switching batteries. I'm a sucker though don't forget

quote:

ORIGINAL: HummerGuy

When you say it learns the spark, what exactly does it learn? Does it learn how much voltage the spark plugs should get for the best combustion, or do you mean the timing of the spark? If you put something like Iridium spark plugs, or those Bosch Platinum +4's, how do things like that affect the PCM? Does it adapt to things like that, or does it always just use the first initial xxx miles of data for the rest of it's battery life?

Also, do those goofy 9 Volt battery adapters you buy at the store REALLY help keep your PCM's memory when you disconnect the computer? I can't see how that could work considering it's sending power opposite of what it's supposed to. Someone actually told me to use those things before thinking the computer's memory would be retianed when switching batteries. I'm a sucker though don't forget

It learns the timing. I don't think the PCM would notice the plug change unless the plugs were bad resulting in incomplete combustion or ran hot causing knock/dieseling.

I think the PCM only needs a few milliamps to hold its memory. I thought the these are suppose to provide memory hold power if you disconnect the battery. I don't know what would happen if you would open the door and the interior light drags the voltage down.

quote:

ORIGINAL: lotus4s

I hope my buddies from the lotus forum don't see those 0-60 times.....

lol, its ok the guy from the SVT forum (me) caught you though!

I've stayed out of this thread because I don't really feel like I have much to contribute, but I do want to say that from the sounds of things I'm going to want to get a tune!

quote:

ORIGINAL: CerberusSVT

quote:

ORIGINAL: lotus4s

I hope my buddies from the lotus forum don't see those 0-60 times.....

lol, its ok the guy from the SVT forum (me) caught you though!

I've stayed out of this thread because I don't really feel like I have much to contribute, but I do want to say that from the sounds of things I'm going to want to get a tune!

quote:

ORIGINAL: CerberusSVT

I've stayed out of this thread because I don't really feel like I have much to contribute, but I do want to say that from the sounds of things I'm going to want to get a tune!

Let me know if you have any questions or anything like that. I really feel like we have a great product for these Hummers. Our tune has got to be the absoulute best bang for the buck performance wise or mileage wise. They have been slow to take off but I sorta knew that was going to be the case as hummers are kinda on the rare side. I'm really eager to get a bunch of people to try the tuning.

quote:

ORIGINAL: Alvin@pcmforless.com

quote:

ORIGINAL: CerberusSVT

I've stayed out of this thread because I don't really feel like I have much to contribute, but I do want to say that from the sounds of things I'm going to want to get a tune!

Let me know if you have any questions or anything like that. I really feel like we have a great product for these Hummers. Our tune has got to be the absoulute best bang for the buck performance wise or mileage wise. They have been slow to take off but I sorta knew that was going to be the case as hummers are kinda on the rare side. I'm really eager to get a bunch of people to try the tuning.

Well, it's been 3 full days, and every day I drive it, things get faster and more responsive. Last night I took a trip out to the new house, and I really opened it up on those country roads. As I said before, it is definitely struggling less then it was before, especially at the low end, but when you hit 2000 RPMs, man that thing really goes, especially when you are already rolling in 2nd or 3rd gear.

I'm still amazed that after you hit 4500 to 5000 RPMs it runs so smooth.

Here is how I KNOW it's not in my head:

My wife, who knows absolutely nothing about cars other then what I have taught her, can tell the differences the same as I can. She even made a comment to me last night about how smooth and quiet it is. I have drivin 250 miles so far with the new tune, on 93 octane, and the highway driving is just better. Now, everybody is different, so I don't know if you would call the difference Dramatic, BUT, when you consider the Before and After results, I really think there is a big difference now that I have been driving it more, and for someone (my wife) that knows nothing about the stuff to tell me how smooth and quiet the engine is now, there is obviously a difference. Lane changing is sure easier. I don't even want to take it out of 4th anymore because I actually get some good lane-changing acceleration staying in 4th. If I get past 3k rpms, I shift to 5th, but I keep it there in case I need some torque. Before, It really didn't matter too much It honestly has become more apparent now that I have driven more, but I would say the performance has increased about 25% overall then it was on Saturday when I first installed the PCM. I'm very impressed to be honest, but then again I don't know as much technical info as ChevyHighPerformance, Linus and Ghostrider do (OK and MAYBE Dennis )

I was able to get to 60 yesterday in approx 11 seconds. THAT is pretty damn good for a H3. Before, once I got to 5000 RPMs the thing would just feel like it would fall apart, as I said before, but now, I hit the 5K rpm mark, and it's really smooth, and honestly dangerously tempting. I think I hit redline once yesterday, and that was because I didn't even realize it the thing was so smooth, but I don't remember what gear I was in. I think it was 2nd.

Now, I have another one of my infamous questions for all you gearheads. I had a 95 Camaro that I would redline often, and never had problems. I don't drive hard, but have been just to test out the new setup obviously. I'm not going to blow anything or break anything if I hit 6000 or 6500 rpms every now and then will I? I'm assuming the engine can handle it, but I don't want to push it.

And as Alvin told me "It's not a sports car" and I know that but man when you have a H3 stick that gets faster and faster every day, you really start having flashbacks to your sports car days

Thank you Alvin, trust me when I say that it is on my 'to do' list.

quote:

ORIGINAL: HummerGuy


Now, I have another one of my infamous questions for all you gearheads. I had a 95 Camaro that I would redline often, and never had problems. I don't drive hard, but have been just to test out the new setup obviously. I'm not going to blow anything or break anything if I hit 6000 or 6500 rpms every now and then will I? I'm assuming the engine can handle it, but I don't want to push it.

And as Alvin told me "It's not a sports car" and I know that but man when you have a H3 stick that gets faster and faster every day, you really start having flashbacks to your sports car days

I used to drive my TT fairly hard, and that car was modified just a weeeee bit. The car ran extremely hard for what it had (APR 93 octane chip & exhaust and a couple other tricks of the 1.8T trade. should have had ~240hp, but it ran with and sometimes out ran my friends 286hp 6 speed G35 coupe). Also I used to drive a good bit faster than I do today (for obvious reasons I suppose). The car got into its rhythem at around 84-90 mph (meters per hour, of course) and really seemed to be the most comfortable at that speed, but that was also about 3750-3800rpm. I also had it reprogrammed to ignition out at 7000rpm instead of 6500, an engine speed that the car frequented rather often and everything held together great for me. I know two different engines and all, but I figured that it would ease your worries a bit

That's cool. I used to love the TT's, but they haven't really changed them at all over the years, so they kinda got boring after the 350Z came out. Do they even sell the TT anymore?

Thanks for giving me reason to push my little I5 harder

yeah, they still sell the TT, they just released the new model a couple months back, I'm not sure when they are hitting the showrooms

link: http://seriouswheels.com/top-2007-Audi-TT.htm

quote:

ORIGINAL: CerberusSVT

yeah, they still sell the TT, they just released the new model a couple months back, I'm not sure when they are hitting the showrooms

link: http://seriouswheels.com/top-2007-Audi-TT.htm

That is sweet. I love the redesign. Do they have a convertible version of the new one?

So, now that I have driven it hard and tested all the speed improvements out, I filled up this morning and started driving normal again. Now that I have more power, I don't have to give it as much gas as I used to. I noticed that right away. I can keep it in higher gears and not worry about not having the power to accelerate.

That being said, here are my results so far with my drive to work:



That needle has barely moved. We'll see how the rest goes. I've seen this sneaky needle before. It can be devious

1st - We've already had a H2 come in that we had to replace the mass airflow sensor ($250) because the K&N filter collapsed and the oil was sucked out of it, shorting out the MAS.
2nd - Pesonally, and according to a few of the techs I'vs spoken with, performance plugs are just a waste of money. You'll get just as good detonation from a regular spark plug.

quote:

ORIGINAL: Hummer Parts Man

1st - We've already had a H2 come in that we had to replace the mass airflow sensor ($250) because the K&N filter collapsed and the oil was sucked out of it, shorting out the MAS.
2nd - Pesonally, and according to a few of the techs I'vs spoken with, performance plugs are just a waste of money. You'll get just as good detonation from a regular spark plug.

umm? what are you talking about? We are talking about custom tuning here not filters or spark plugs.

quote:

ORIGINAL: HummerGuy

Progress timeline (for all you geeks like me that want to keep up with it):

09/28 - Submitted Payment

10/04 - Loaner PCM Shipped (they had to order more loaners - demand is high)

10/6 - Loaner PCM Received

10/7 - Loaner PCM Installed

10/10 - MY PCM shipped to PCMforless via Priority (hope it gets there. Damn P.O. woman barely put the stickers on the box)

10/12 - PCM Programmed and shipped out today.

10/14 - MY PCM Received and installed. Testing in progress.

I started this thread because I'm going to start the process today or tomorrow. So far Kelly has been very helpful at answering my questions quickly and accurately. I'll keep everybody posted as to what I'm having it tuned for in case anybody is thinking about doing this. As you all know, my magnets weren't cutting it (inside joke)

The only modification I have in my H3 is a K&N Filter in a stock air box. I was looking to purchase the cold air induction (with Dennis's help and advice) and a high-performance exhaust, but after re-thinking it, I realized with as much driving as I do, I probably am not going to want to listen to that rumble in my ears driving 100 miles a day.

I'm going to have the PCM tuned for 93 octane since it's attainable at every gas station in the midwest, and will keep the K&N filter installed, but keep everything else stock. I have a 5-speed manual transmission. The whole proces should not take more then a couple of weeks depending on them having a loaner PCM available for me to use, and how long the shipping back and forth takes.

I'm looking forward to this considering this is the last engine modification (besides perhaps installing some high performance spark plugs when somebody makes them) I intend on doing to my H3. I told myself I'm going to stop after this because I want to concentrate on my house.

Anyway, just some background info if anybody is thinking about doing this. I'll post the results as I get them, from swapping the loaner PCM to the changes I see when it's all said and done. They do alot of business, so it may take a few days to get the loaner PCM shipped out to me while mine is being upgraded, so be patient!

quote:

ORIGINAL: Hummer Parts Man

1st - We've already had a H2 come in that we had to replace the mass airflow sensor ($250) because the K&N filter collapsed and the oil was sucked out of it, shorting out the MAS.

Some one obviously had over oiled the filter or put it back on wet after cleaning it...The filter was not at fault.

BOY THOSE LETTER CAME OUT A LITTLE TO BIG

quote:

ORIGINAL: dilo2001gt

BOY THOSE LETTER CAME OUT A LITTLE TO BIG

LOL I thought you were just trying to rub it in my face!!

Well, so far, the power is still getting better little by little. The engine is just smooth as glass. It's so much quieter in idle and on the expressway, and also accelerating. I'm not too sure about the mileage yet though. So far, it seems to be about the same, but I have been stuck in bad traffic lately so it's hard to tell. I'll wait a little longer and see how it goes when I start hitting the highway more. So far, everything is great. This is the best money I have ever spent on an upgrade for a car (even my home-made ones). When I figure out if my mileage is improving, I will post a follow-up. Right now it's too early to tell. I'll give it another week or so and see how it's going.

So, I finally have some gas mileage info for you guys.

I burned almost through my first tank of gas driving normally. I would say 80% city stop-and-go driving and 20% highway driving at about 70 MPH. I filled up at the same pump at the same station on level ground and tipped it off (OH NO I VIOLATED THE WARNING SAYING NOT TO TIP IT OFF!!!!!!) with the engine stopped. I don't know if ANY of that matters, but it's the only thing "I got".

I went 286 miles and I filled up to 18.12 gallons. That comes to roughly 15.8 MPG. I don't know what you guys think about those results, but to me, I think that's not too bad considering most of it was stop and go. Keep in mind also that I did have the car idling for about 20 or 30 minutes also when I was working on it on the weekend, so the MPG may actually be a little higher then that. I would say that is promising. For the most part, I drove the same way I always do. I noticed the needle is not as low as it used to be and doesn't move as quick. The last time I checked I was getting something like 14 MPG in the same driving situations.

I don't know what my highway MPG is yet because I haven't done much straight highway driving. I can tell you that after I get past 65 MPH I notice the mileage drops, so I try not to go over 70 most of the time, which is VERY hard for me since I'm a fast driver

What I'm going to try to do is fill up tomorrow morning early and try to beat the morning rush hour and leave late and also try to beat rush hour, so I'll see what my mileage is driving between 65 and 70 non-stop for about 25 miles to and from work. I'll see what kind of mileage I get. So far, I think i'm doing well. Alvin said it will get better and probably take a few weeks to reach optimal performance as far as the MPGs go. I'll post my results by Friday and let you guys know when I successfully drive all highway speeds on a day.

Well so far, my mileage hasn't increased too much. It's moderate though, enough to say that they were right about the 2 to 3 MPG increase. I'm slowly but surely seeing it. So it's definitely worth it. I really think if anybody has the means financially and technically to do it that they should get it done. It's definitely worth the long-term investment.

Now, onto my next magent experiment.............