My PCM tuning with PCMforLess.com - Process and Results

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.

10/16 - Sent loaner PCM back

10/18 - Deposit for Loaner PCM Refuned

10/20 - Things still improving little by little. Everything is positive so far

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!

Sweet!

Please let us know how you like it and please let us know if you have any troubles.

Thanks!

Good luck Mike...I'm sure you will see and feel very positive results compared to the stock tuning....Also note, if that revs continues as you push in on the clutch like it use to...If that goes away..it will be a God send of Alvin's and Kelly's for all the manual tranny owners too..

quote:

ORIGINAL: Dennis

Good luck Mike...I'm sure you will see and feel very positive results compared to the stock tuning....Also note, if that revs continues as you push in on the clutch like it use to...If that goes away..it will be a God send of Alvin's and Kelly's for all the manual tranny owners too..

That's what I'm hoping also. I thought about that yesterday when it started happening again. It's happening more often then it did before. I didn't mind it before, but now it's getting really annoying.

Alvin and Kelly: Do you know about the problem some of us have with manual trannies and the engine idling at high speed when letting off the clutch?

The loaner PCM has been shipped out this morning. I should have it by Saturday at the latest.

I just installed the loaner PCM. It was a pain in the butt, but not complicated. I'll post more info later (the wife is mocking me!) and pics of the little piece I broke! Talk later

So, it took me about 30 minutes to get the plugs off the PCM. Even after releasing the levers it was really hard to pull the plugs off. I took the PCM off the mounting thinking it would be easier, but it's actually harder because you don't have any leverage like you do when it's attached to the bracket, so it's easier to leave it in the bracket while trying to remove the three wiring harness's. Once I finally jiggled them loose and removed them, obviously the PCM was easy to remove from the bracket.

I installed the loaner PCM and had a hard time with one of the three harnesses, where I found I cracked a little tiny orance piece inside one of the harnesses (I'll post the pics later), and after trying to put that harness on for 20 minutes, I examined the other one that was identical and found out about the cracked piece, which I removed and then the harness when in with no problem. All together it took me about an hour to swap them. It would have been about half that time if I would have realized there was a little piece of clip stuck in the harness getting in the way of me locking it back down. It wouldn't go in all the way because of it.

I had to do the security relearn procedure to get the car started with the loaner PCM, which took about 35 minutes, and worked successfully. When the truck first started, the engine vibrated alot and it seemed like it couldn't figure out what the appropriate idle speed should be, but after running for about ten minutes, everything smoothed out and it ran just like my original one did. The Check Engine light is on all the time, but that is normal for the loaner PCM since they disable the crank angle sensor. It didn't seem to affect anything in a negative way.

SO, despite all of my trouble getting the wiring harness's off and on, everything was pretty smooth. So far, no problems. I drove about 80 miles with the loaner PCM installed and everything is fine. I'll ship them mine on Monday and hopefully I'll get it back before Saturday, but that probably won't happen.

So far, so good!

Maybe too late now to mention..But I got PCM out and in, in 10 minutes...I removed the Coolant reservoir first..

Did they tell you the check engine light was ok?

I had a loaner in for a week and never had a check engine light.

I remember Kelly mentioning that they would program the loaner PCM so you wouldn't see the check engine light..Guess that one Mike got didn't get the program to ignor the error like yours..But the problem is simple..The PCM has to be told to re-calibrate to the engine it's attached to..Dealers can do it in 10 minutes..otherwise it's nothing to worry about..your returned re-programmed PCM is already calibrated for your engine, provided they didn't reflash completely...

OK good. I emailed her this morning to tell her. I forgot to mention it this weekend. It does run a little rough at times, but after it runs for a few minutes it's ok. The Change Oil light was on also but that's easy to fix. Big deal. The automatic headlights don't work anymore though. They are on 24/7 even in bright sunlight. That's also not a big deal. Unfortunately this is a holidy so I probably won't get mine back until next week because of the shipping process. Oh well. As long as I have a drivable vehicle I'm fine.

Does anyone here have a recal box yet or is this the first..

Yes, but I don't know who. Kelly said one person from the forum already got his back and said he was happy with the performance boost, but she doesn't know his name on here, just that he is from the forum. I would like to hear from him/her about the results. I will probably have mine back early next week, and you can be assured I will post the results that day. Just keep in mind mine is getting tuned for 93 octane so it may be a little different then the standard tune, but probalby not by much.

Well, I shipped my PCM to them early this morning via Priority Mail, insured and delivery confirmed. The woman that took care of me barely put all the stickers on there, and covered up the end of the zip code somewhat with another sticker, that will probably fall off because of her kinda tapping it on there with a as much force as a feather falling to the ground from an airplane! I hope it gets there OK.

quote:

ORIGINAL: HummerGuy

OK good. I emailed her this morning to tell her. I forgot to mention it this weekend. It does run a little rough at times, but after it runs for a few minutes it's ok. The Change Oil light was on also but that's easy to fix. Big deal. The automatic headlights don't work anymore though. They are on 24/7 even in bright sunlight. That's also not a big deal. Unfortunately this is a holidy so I probably won't get mine back until next week because of the shipping process. Oh well. As long as I have a drivable vehicle I'm fine.

I don't think your auto headlights are on 24/7 like you think. I think the loaner pcm you have is using your headlights as your drls, like newer model 06's have. I know my headlights are my DRLS, sounds like what you have now as well.

Ah ok. That makes more sense. I kinda figured that but wasn't sure. I should have remembered that whole discussion we had on here about that.

Alvin called me this morning to ask me a couple of things about my preferences. He is a very nice and friendly guy. It's nice to have that personalized attention to detail. I was impressed

He's also shipping it back to me today. It's already been picked up. MAYBE it will be here by the weekend, but I doubt it. If I get it Saturday, I probably wont be around to post the results until Sunday, because I have my #@$#@ sister in law B-day thing to go to (no I don't like her very much)

Umm..your sister-in-law just emailed me and wants me to ban you, cuz she just read your post....Decisions, decisions

She's not smart enough to to figure out how to email you, so right there I know you are lieing

And she has her own tax office. I'll just end it at that

Here are pictures of the piece of the clip that broke off inside one of the three PCM wire harness plugs:

quote:

ORIGINAL: HummerGuy

Alvin called me this morning to ask me a couple of things about my preferences. He is a very nice and friendly guy. It's nice to have that personalized attention to detail. I was impressed

He's also shipping it back to me today. It's already been picked up. MAYBE it will be here by the weekend, but I doubt it. If I get it Saturday, I probably wont be around to post the results until Sunday, because I have my #@$#@ sister in law B-day thing to go to (no I don't like her very much)

I think you are going to like the tune. I just loaded Alvin's tune on mine. Idle is super smooth. Low end torque has a nice boost.

That's great news. He is also anxious to hear how I like it and wanted some feedback. I told him I'd give him a call and let him know how things feel. The Idle is definitely a good thing.

I had mine did and love it.

quote:

ORIGINAL: jn1300r

I had mine did and love it.

So, YOU are the mystery man/woman! What kind of a increase did you notice? Are you getting metter gas mileage? Please share with us

Here is some new fuel economy test data.

First, the goal was to test my modified tranny shift table versus the one supplied from Alvin in his tune.

There are two elements to fuel economy: acceleration efficiency and cruise efficiency.

CRUISE EFFICIENCY

For highway traveling, the goal is to maximize the cruise efficiency. For example, for a typical vehicle the amount of gas it takes to accelerate from 0 to 60 MPH is about the same amount required to keep the vehicle traveling 60 MPH for about a mile. So you can see that when you are traveling many miles the amount of gas used to accelerate you is very small compared the amount of gas you’ll use to keep you at speed for many miles. This sets up my first test for which everyone probably already knows the results. I ran the H3 at two fixed speeds (40 MPH and 44 MPH) in both 3rd and 4th gear and measured the rate at which the gas is consumed. (The gas volume was measured and since the temperature was constant for all tests the volume is reflective of the mass of gas used.)

3rd gear:

40 MPH - fuel utilization rate = 3.38u/s

44 MPH - fuel utilization rate = 3.92u/s

4th gear:

40 MPH - fuel utilization rate = 2.90u/s

44 MPH - fuel utilization rate = 3.05u/s

u/s is a scaled volume of gas used per second

The conclusion here is that if you are cruising you want to be in the highest gear with the torque converter locked. My guess is that even though the drivetrain efficiency is higher in 3rd than 4th gear, the higher engine parasitic losses associated with the higher RPMs in 3rd than 4th gear dominated the fuel rate utilization.

ACCELERATION EFFICIENCY

For city traveling, the goal is to maximize the acceleration efficiency. If you are starting and stopping every block then the amount of gas used to accelerate the vehicle will dominate the fuel consumption and MPG. The trick the hybrids do is absorb energy and store it during braking; then use this stored energy to accelerate the hybrid. This is why the hybrids do proportionally better in the city than the highway.

I ran the H3 at three different constant throttle positions (35%, 45%, and 55%) and measured the total fuel volume used when going from 20 to 50 MPH. (The gas volume was measured and since the temperature was constant for all tests the volume is reflective of the mass of gas used.) I ran this test for both my tranny shift tables and Alvin’s tranny shift tables.

My tranny table

35% throttle: time=28.8 sec, total gas used = 3583u total

45% throttle: time=15.8 sec, total gas used = 2945u total

55%+ throttle: time=13.1 sec, total gas used = 2567u total

Alvin’s tranny table

35% throttle: time=29.3 sec, total gas used = 3803u total

45% throttle: time=12.0 sec, total gas used = 2473u total

55% throttle: time=11.1 sec, total gas used = 2508u total

u total is a scaled amount that represents the total gas volume used

Because it was difficult to precisely hold the throttle in a fixed position there is some variance (maybe +/- 5%) about each time and total fuel used data point. There are two conclusions from this test: 1) Alvin’s table resulted in less fuel consumption than mine and 2) the more throttle you use to accelerate (within reason) the less fuel you use. This goes against the EPA’s advice to not accelerate fast when pulling out because you’ll waste gas. I think the reason why the higher throttle resulted in less total fuel being used is due to the lower pumping losses associated with larger throttle positions thereby increasing the engine’s overall efficiency. Basically, your engine doesn’t have to work as hard to suck air into the engine when the throttle body is open more.

I think the key is learning how to drive based on how the tranny tables are set up. I think my tables are better for cruise (highway) and Alvin's are better for acceleration (city).