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1995 Impala SS
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Discussion Starter · #1 ·
I just put it in. Probably the easiest upgrade so far 馃ぃ

I took her for a quick ride down the street to make sure everything was good. All I can say is wow. Even in my short 10 minute drive, she definitely feels and even sounds a lot more mean.

Had it tuned for 93 octane, CAI, Cooker shorties and firm shifts. I bought a new PCM from them because I didn't want the downtime from sending in mine. I also wanted a backup one in case I get a little froggy and want to mess around with any of the tuning myself.

So far, I am extremely impressed.
 

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I did the same thing recently for my late model truck.
Don't think he tunes customer supplied PCM's anymore.
But ,have gone that route in the past with equally good results.
Was bothered by a check engine light (P0325)....
Until I realized that PCM's typically ship w/o knock modules...
 

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For those wondering

I messaged bryan herter pretty much a 1-2 weeks ago and he told me to message him at [email protected]

He had the tune to me 1-2 days after I messaged him for only 50 bucks.

I thought three pedals would provide a proper tune but the only thing they adjusted was the speedo and they didn't explain to me I had to use the EEB xdf file to get the correct settings... Wasted 200 bucks on it... Don't be me!
 

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鈥 thought three pedals would provide a proper tune, but the only thing they adjusted was the speedo - and they didn't explain to me I had to use the $EEb def file to get the correct settings.
Wasted 200 bucks on it. Don't be me!
There's not that much that can be done with a definition file that's at LEAST 15 years old ... and they avoided doing most of what little they could have done with it, for 2 Benjifranks?
Not laughing at you, toonwarrior, just sayin'.
 

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Guess my expectations were a bit high. Considering that's a company swapping t56s into b bodies left and right. Wonder what tunes their customers are receiving.

Don't get me wrong don't got nothing against them, they are taking on something for our cars and that's always a plus.
 

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While I completely agree an EEB suggests someone is picking away at some cal they got from some renowned tuner ( who got that from someone before him) a long time ago, that in itself is no reason the car shoudn't drive well is it ?
My car worked well 14 years ago when I used tdf's that are now 14 years old

The EEB .tdf has been up dated with time.
Or is there something in your statement I am missing ?
Thanks
 

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The file they provided me did not work with the latest eex definition file from f-body tech as in the scalar speedo values were way out of wack.

So me trying to figure out what was going on ended up learning how to adjust the speedo by accident lol.

All I'm saying is that for 200 dollars I expected a bit more... I guess it taught me how to adjust the speedo myself so there's that.

Only until Bryan Herter mentioned that I'd need the older definition file for his tune it clicked that I needed to do the same thing with the three pedals file. In three pedals defense I didn't really pry them for answers, but to my point 200 usd for a speedo adjustment that I ended up doing is 馃槕.

And I should point out that it is sold as a tune on their site. So I kind of expected a real tune, again in their defense I didn't ask the right questions.
 

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Not to belabor this
The LT1 pcm file used in the first part of 1994 stored infomation in different places than than late 94 and 95.
LT1 Edit would automatically deal with the issue.
Tunercat you had to be conscious of which you were dealing with and use the correct def file when modifying .

I have never used other programs for LT1s
but suspect the same applies.

I do not feel the fact they used the early B in itself was not responsible for how good or complete a job they did.
 

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I'd have to go back and try their file again with the definitions I have now and see what the behaviour is.

Didn't mean to detail the thread LOL. Just wanted to let others know that Herter still provides mail order tunes for 50 bucks. When I did my swap all the threads I read said he no longer did them but after contacting him on FB he still does.
 

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Discussion Starter · #10 ·
I guess this is no exception for infomercials.

"for those wondering", toonwarrior, nobody wondered. 6 people saw my post. Go spam your advertisement somewhere else.
I did something to my car. I wanted to talk about how my car reacted. It reacted well.
I don't need Diet Coke ads popping off in the comments.
 

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Discussion Starter · #11 ·
"Didn't mean to detail the thread LOL."
"
Now, Biff, I want to make sure that we get two coats of wax this time, not just one.
"
 

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Even in my short 10 minute drive, she definitely feels and even sounds a lot more mean.
There are two sets of BLMs: long-term and short-term. These are labeled as LTerm and STerm in DataMaster, and in FreeScan as Integrator (short term) and BLM (long term). As a consistent trend in O2 sensor feedback forms while driving, the PCM will set a "permanent" modifier to accomodate the initial PCM tune being wrong; this is called the long-term modifier. Until those are changed, the PCM uses a short-term modifier which adjusts fueling on the fly depending on O2 sensor feedback. It is best to tune from the long-term BLMs, as the short-term can vary based on inconsistent variables. Both sets of BLMs are reset to 128 when power to the PCM is lost or a new tune is flashed.

Using these BLMs, one can sense whether there is a problem with something mechanical; things like exhaust leaks (the BLMs will rise, as the O2 sensors sense unmetered air thinking the combustion is running lean), or fouled spark plugs or O2 sensors (the BLMs will decrease, as the O2 sensors see less air and think the combustion is too rich). The BLM can also show a need for a change in the PCM tune; if the VE tables are set too high (low BLMs) or too low (high BLMs), or if the MAF sensor is miscalibrated. Even timing can affect combustion efficiency and thus BLMs.


Short version: 10 minutes with a new tune does not give you a good indication. After more and varied driving your different long term blocks of fuel trim will be populated and you will then get "a real feel for the tune"

As stated above: "Both sets of BLMs are reset to 128 when power to the PCM is lost or a new tune is flashed." This is why used car lots let the batteries go dead on cars. The PCM has preprogrammed "defaults for the engine and transmission that are "spirited". The real test of a tune is when the PCM has learned and adjusted the long term tables.
 

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Z09B4U's pretty much on the nose here. Brings back memories ...
Some of us still remember when the F- / Y- car MAF sensor WAS a popular performance mod.
That was before enough drivers had tested them THOROUGHLY.
The admittedly real INITIAL benefits were only temporary and wore off as the pcm learned to understand the 'trickery'.
The 2door MAF sensor was still using the 4door MAF sensor tables.
After a few hours of driving at most, any performance improvement disappeared.

Still, as accurate as dreeeeew's first impression is, it's a first impression.
I bet he'll return with a more thorough evaluation of just how much GM held back in a month or so.
 

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As stated above: "Both sets of BLMs are reset to 128 when power to the PCM is lost or a new tune is flashed." This is why used car lots let the batteries go dead on cars. The PCM has preprogrammed "defaults for the engine and transmission that are "spirited". The real test of a tune is when the PCM has learned and adjusted the long term tables.
Not quite sure I buy into that exactly.
If the car learns and runs markedly different over time, I see it as
Bone stock car, parts have degraded to the point original calibration doesn't cut it.
Modifed car, calibration or "tune" is not spot on.
If the car is good, and the "tune" is good, it shouldn't be significantly jacking around the short,then long terms.
Cars, that run completly different after a battery disconnect, they have something going on.

Lots of adaptive stuff going on in new cars learning the drivers habits sure,
I submit, not so much in a 94-96 lt1

We may be agreeing, just misinterpreting
 

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Such a learning experience for me here with various PCM threads. It's a world I am just learning the basics about. I have the port cable and know I will need software for the PC. I haven't touched my PCM ever, but I have a set of Sherlock's injectors waiting to go in, which will require PCM modification, as will changing to a 3.42 rear end when I can find the time to tackle that. Until then I just leave the PCM stock and leave the AC on, which keeps the passenger fan on so no overheat.
Feeling my age--I can rebuild and tune a late 60's big-block Quadrajet to run better than new, and I know dealing with the PCM will eventually become comfortable, but right now I feel like a caveman looking at the HVAC screen on my girlfriend's Lexus. Instinct says just set something on fire to get warm. :confused:
 

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May I suggest, the most important thing to own with this generation,a spare PCM.
Save it or your original with a working calibration in your trunk.
The dreaded com failure, disconnect, glitch , whatever, can and will happen at the most inopertune moment.
Having the spare is like warding off evil spirits.
With the knowledge you will not be stranded, you will be more apt to make frequent minor changes getting it to your liking

If you know your qjet, think of this a rods, jets, pv springs without picking up a screwdriver :)
 

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Rectangle Font Circle Number Document


Here is a example:
"My TA with pick up 1-2 MPH and a couple of 10th's just by reinstalling the HPP tune or simply disconnecting the batter for a moment. On the dyno it picked up 8 HP and 3 FPT just from the battery disconnect and reconnect. Does anyone have any experience with this and will a real tune do away with that? "


Could we agree that it would be a good idea to do a drive cycle (like for emission ready) before evaluating if a tune has improved a engine/drive train? It may not be a good assumption that a 25 year old car is perfect. Any part of the software that learns (BLMs, spark tables, ect )will have a effect on the final product.

My personal experience with older PCMs is they are "perky" until they learn and fill in all the tables with real data.
 

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Yes we can agree,
Can we also agree that if it is quicker, more perky after the reset, then gets slower and lazier one needs to address things so it wants to be " Perky" as long as it is not a result of borderline or dangerous settings
Yeah, instant pull on the dyno after reset or flash, not real world.
E38 and E67 have a rich part throttle after flash that needs to be waited for. ( had to reach out to remember what that one was)
 
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