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Discussion Starter · #1 · (Edited)
I thought I’d share what I have learned recently about microtuners and tuning software, as these are hot topics whenever SSR owners start talking about performance improvements.

I’ve learned enough to be dangerous, and to know that the process of using these products can be risky, and that has given me pause. Others might benefit from what I have learned so far.

For those who don’t know, our SSRs, like most ther vehicles these days, are controlled by a “VCM” (Vehicle Control Module), formerly called a “PCM” (Powertrain control module). That is, a computer! Manufacturers have resorted to using these, despite the apparent cost, because they actually turn out to save the manufacturers money when you factor in their ability to control and optimize engine power delivery, transmission operation, fuel mileage, emissions, and in the VCM (as opposed to PCM) version, the entire vehicle.

Because the VCM controls so many aspects of the engine and transmission, you can PARTALLY tune a vehicle via computer these days. You cannot tune it TOTALLY via computer, because actual power produced depends on physical parameters. As an example, it is pointless to tell the VCM to squirt more fuel into the engine if (a) you cannot physically pass the required amount of physical AIR to USE that fuel, and (b) your fuel injectors are not large enough to actually squirt more fuel per second.

However, despite this limitation, there are certain parameters that CAN be changed solely via using the VCM, and actually have a tangible (sometimes destructive!) effect.

For example, you CAN instruct the VCM to fire the sparkplugs earlier, and it WILL, and IF you are physically using high octane fuel (92) ONLY, this can successfully extract a bit more power out of the engine. (If you advance the spark withOUT using high octane fuel, you get detonation under certain conditions, and the intelligent VCM greatly RETARDS the spark to protect the engine, and you LOSE power).

Likewise, the transmission parameters controlling shift speed, shift firmness, and shift rpm or shift road speed, can all be adjusted without changing anything physically. The VCM takes care of the physical changes in this case by controlling the hydraulic pressure to the clutches in the transmission, and by sending a signal to shift only after a higher rpm is reached.

As another example, all VCMs for a particular model of vehicle are programmed identically, but the actual physical hardware does not always perform equally identically (some engines just flow more air or have better piston ring sealing than others on the same assembly line). Also, an engine operated in Denver Colorado has a different ambient reality than one operated in Tucson, Arizona, or NYC. In either of these cases (differing engine output or different location), a re-calibration of the VCM MIGHT produce better performance in certain rpm ranges or under certain conditions.

Next, there is plenty of evidence that factory engineers don’t always get their programming right. A skilled and experienced tuner, running your vehicle under controlled simulation conditions on a dynamometer, can often develop a better combination of air-fuel mixture, spark, and other variables than the factory people were able to. Notice that I said “skilled and experienced”. This will loom LARGE later in this posting.

Finally, if you alter any of the physical realities on your vehicle, like gear ratio, headers, exhaust system, air intake, etc., the VCM is no longer likely to be generating the optimal combination of control parameters, and its programming needs to be changed to again optimize things.

So, for a variety of reasons, owners of SSRs MIGHT want to change their VCM’s programming. Turns out, that’s surprisingly easy to do, but very risky too.

Naturally, General Motors frowns on you or anyone else making changes to the vehicle that they designed so perfectly (choke!), so they do NOT sell equipment to do that to end users. They also do not publicize the software content of their VCMs. However, an entire industry has developed that specializes in reverse engineering the programming within the VCMs, and selling you software and hardware that gives you the awesome power to make fairly significant changes in your VCM.

This is good in some ways, but it is also like giving you a fully equipped operating room, and inviting you to do brain surgery without the years of medical training required to do it SUCCESSFULLY. I’m not kidding.

It is incredibly easy with such software and hardware to have the VCM cheerfully command the engine and vehicle to do really stupid things, like advance the spark enough to blow holes into the tops of the pistons, lean out the air/fuel ratio enough to overheat and destroy the engine, try to shift at 7000 rpm when the valves actually begin to float at 6000 rpm, etc.

Consequently, the suppliers of these software and hardware tools tend to segment their products into two different markets: end users, and professional mechanics and tuners.

The products intended for end users are generally called “microtuners”, and the most popular ones for the SSR, in ascending order of allowed capabilities, include the Superchips microtuner, the Diablosport Predator microtuner, and the Crane microtuner. These tools in general limit the number of parameters that can be altered, and also limit the range of alterations allowed, in an effort to ensure that no real damage can be done (inferior performance however is NOT prohibited!).

The products intended for knowledgeable mechanics and tuners include LS1 Edit, HP Tuners, and EFILive Tuning Tool. These tools are dangerously powerful in untrained hands. While they contain some inviolable tuning limits, they in general will cheerfully allow and enable you to set parameters that are very destructive on a stock vehicle, on the assumption that you have altered the physical realities in a way that makes such parameter choices appropriate and reasonable. For a simple example, you CAN set the engine redline at 8000 rpm, but you had better have altered the stock valvetrain AND engine bottom end to make that rpm actually possible without grenading the engine. It will also allow you to richen or lean the air/fuel ratio enough to destroy a stock engine, if you have not changed the physical realities enough to REQUIRE that new ratio at a specific point in the rpm/throttle opening/load graph.

Providing a little more detail, the microtuners mentioned above allows the users a very different range of parameter adjustments, The Superchips is the most conservative. It offers a choice of 3 pre-built programs (performance, lower octane, or trailer haul), allows some limited adjustment of transmission shifting behavior, and does not even allow engine parameter changes outside of its 3 prebuilt programs at all. The Predator greatly increases the number of parameters that can be altered, but still limits the range of adjustment somewhat, and warns the user that destructive adjustments ARE possible. It warns that certain parameters should only be adjusted by skilled professionals. The Crane microtuner is the most aggressive, in that it not only allows parameter adjustments on an otherwise stock vehicle, but also contains pre-built programs to use with specified Crane high performance products, such as Crane cams. In other words, the Crane tuner supports altering the VCM to match certain specified physical vehicle changes.

ALL 3 of these microtuners go to great pains to ensure that you are trying to program ONLY a VCM that has positively not already been altered by another product. This is because the biggest fear that all these suppliers have is that you will think that if ONE tuning package is good, TWO or more must be BETTER! If you applied two or more tunes to the same vehicle in sequence, you would almost certainly generate destructive combinations, just because of the way these microtuners work. This is why they make it so impossible to use their product if your VCM’s current status is detected as “already altered”. They will all only allow tuning a completely 100% stock VCM.

The microtuners also take steps to ensure that a whole clubfull of SSR owners don’t buy ONE microtuner and use it to tune ALL their SSRs, since the microtuner manufacturer can’t make any money in that scenario, and quickly goes out of business leaving you with an unsupported device. What the manufacturers do is write your VIN into their device during the first interaction with the vehicle. From then on, there are two possibilities, depending on which manufacturer’s product you bought (I can’t remember which is which):

1. That specific microtuner is now locked FOREVER to your specific vehicle, or

2. That specific microtuner is now locked to your specific vehicle UNTIL you restore your original factory programming, which your microtuner saved in its memory the first time it had sex with your vehicle, back into your vehicle

So, if you are contemplating buying a USED microtuner, make SURE you KNOW it is not still tied to someone else’s specific vehicle. The manufacturers regard any requests for “rescue” from this situation as a disguised attempt at extracting their product from them “for free”. I can’t blame them.

One other thing they all do is warn you very specifically, prominently, and frequently during the tuning process that you MUST follow their “all electrical devices off and no electromagnetic fields around” warnings. Do NOT underestimate the severity of these warnings. Let me explain.

It turns out that VCMs are rather sensitive. If a “read”, “edit”, or “write” microtuner process with the VCM is interrupted by a loss of vehicle power, or an even minor change in onboard voltage or power drain, or a nearby electromagnetic field, your VCM can be completely “wiped”. That means a 100% lobotomy for your vehicle. I am not exaggerating. This is the manufacturers’ biggest fear because it is based on the reality that such wipes DO occur.

When they do, your vehicle is at a minimum disabled for several days while you scramble to get the VCM reprogrammed at the microtuner facility, or worse, the wipe is UNRECOVERABLE, and you need to buy a new VCM from your GM dealer, whose parts department, with its captive audience and imaginative gross margins, is viewed as the cash cow for the entire dealership AND General Motors both! It’s also hard to explain to the nice Chevrolet service department, and your state’s motor vehicle registration and titling office, how your odometer mileage has DEcreased back to zero. You’ve been warned!.Follow the instructions PRECISELY and FULLY.

That includes getting your cell phone, your pager, your Blackberry, and your portable satellite radio receiver out of the vehicle’s vicinity. If you are in your garage, make certain that no strong electronic or electrical devices are nearby. Even the doors of the vehicle have to be closed for the full duration, as otherwise there is current flow to interior lights.

Crane goes so far as to specify that specific fuses are to be removed from the vehicle before the tuning process commences, and not re-installed until after the process is complete! This makes restoration of the factory programming for visits to your friendly Chevrolet dealer a bit of a pain in the butt. (Do NOT take your SSR back to the dealership with altered programming unless you want to do some explaining to the nice people there on why you disabled certain “torque management” restrictions, etc. An ugly scene can result if your modification can in any way be deemed to have contributed to a costly failure that you now want THEM to fix under warranty)

One final point on microtuners: Do not try to use a microtuner designed to tune an 03 or 04 SSR on an 05 SSR (or vice versa), unless the manufacturer SPECIFICALLY states that it contains programming for BOTH types of engines. Usually, the manufacturer protects you against accidental stupidity by checking that the VIN of your vehicle is a match for the specific tuner model, but I wouldn’t assume this is always the case.

The professional tuning packages work on a grander scale. They in general include TWO components: software that loads onto YOUR personal computer, and a proprietary cable that links your computer to the VCM’s data port (“telephone sex” via the proprietary cable between your worldly computer and your virgin VCM!). Note that you need a personal computer of sufficient specifications and with the correct cable interface port (serial or USB, depending on manufacturer of the tuning tool).

Here, I found that the choices are much more limited. “LS1Edit”, although a well established “standard” for Chevrolet tuning, does NOT currently support Chevrilet TRUCK tuning in place on the vehicle (It only supports “bench” tuning of the VCM off the vehicle). “HP Tuners” does support in-vehicle tuning of the 03 and 04 SSR, but not yet the 05 SSR. HP Tuners is newer, has good software and a good reputation, but it has a restrictive licensing model, uses a serial cable versus USB, and has less protection built into the process against VCM wipes than EFILIve does. “EFILive” is the newest kid on the block. It has the newest software, best “help” built right into each screen, uses faster USB for the connection, a GREAT licensing model, fast email customer service, and provides a so-called “failsafe” recovery that will apparently protect you better than HP Tuners or LS1Edit against VCM wipes. EFILIve works with 03 and 04 SSRs (even though the website does not say so – I specifically asked), but will not work with 05 SSRs yet.

The big new wrinkle with any of the professional tuning products is that on top of all the other precautions, you must ensure that the LAPTOP does not lose power during a read or write to the VCM, because if you get coitus interruptus, you can again wipe your VCM. AC power, backed up by a fully charged battery is a really good idea.

I concluded that if you want to just get a bit more performance out of your otherwise FULLY stock SSR, the microtuners are a less expensive, easier, and safer, benefits-right-out-of-the-box way to go.

But, if you plan to make a number of mods, you are going to need the professional grade product in order to enable matching the VCM tune to the physical reality. However, you are also realistically going to need a professional to USE it for you, as the raw product as it arrives does absolutely ZERO until someone uses it intelligently. You could probably do yourself minor changes to parameters like shift rpm and shift speed, but the critical changes to air/fuel ratio and spark control, required to capitalize on, or simply make workable, changes in exhaust or intake, require solid engine tuning expertise. So, the REAL cost of the professional grade tool is that of the tool itself PLUS the cost of a professional dyno tune. That means $500 to $850 for the tool plus $200 to $500 worth of professional services (the cost of the professional services varies with the product used, as the professional’s incremental cost of licensing for HP Tuners to do YOUR specific car is much costlier than it is for EFILive).

Even if you use a pro to dyno tune your SSR, these professional level products enable you to do important stuff that the microtuners do not, like:

 Back up that costly dyno tune on YOUR computer, not just the tuner’s computer

 Store MULTIPLE tunes on your computer, installing the one you want at a specific time (“performance” for street, “good mileage” for tours, “strip” for dragracing, “factory” for warranty visits to the Chevrolet dealer, Tune “A” versus Tune “B” for comparison, etc))

 Buy and install a commercial tuner’s custom program written for your model of car or YOUR specific car (Pro’s use one of the 3 pro grade products for their development work)

 Be easily able to change from one tuning shop to another (YOU have your VCM software on YOUR computer, not at the shop you are planning to stop using)

 The “commercial” versions of professional grade products also enable you to electronically “lock” your VCM against reads or writes, so you could perhaps theoretically ensure that your Chevrlolet dealer doesn’t reflash right over your costly custom dyno-developed program. (The EFILive commerical license that offers this locking feature is only $150 more than the personal version)

It’s all a matter of how far you intend to ultimately go. The microtuner products offer “canned” performance right out of the box, The pro level products are a tool that skilled hands and mind are required to build on to get ANYTHING different than “stock”.

I have already had my SSR dyno tuned, and already have other mods on it, so I am pretty much committed to a professional grade tool, and am leaning pretty strongly towards the EFILive tool, because of several advantages that I perceive are important to me. I’ve asked Reese Cox at MTI, a current LS1Edit user, for HIS opinion.

Your needs might be quite different than mine.

One final comment: Many of these products offer an owner’s manual or even fully featured demo software on their websites. Do yourself a favor: Download them and READ them. You might be surprised at what you learn! This is how I found out about Crane’s “pull the fuses” instructions!

(Sorry for the length of this post, but there is no way to make something this complex “short”!)

Jim G
 
G

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I took my '03 to have the dealer reprogram the computer for the 4.56 ratio, and Mr. Badwrench told me that they couldn't figure out how to do that. So now I have to remember to manually switch off the traction control and try to make a mental adjustment of the speedometer until I either 1) find a speed shop to do it or 2) make up my mind on a tuner (haven't had time to research, I'm moving) Having your vehicle die when it shifts into 2nd gear because you forgot about this is not fun....:mad
 

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Discussion Starter · #4 ·
Psychoslpahead: I can't believe that the delaership couldn't figure out how to change the gear ratio field in the VCM!

Gosh, I think I'd go pay a tuning shop to do it. I doubt they'd charge you much for it! It's literally a one field entry (at least with HP Tuners software), as the software then auto-scales the shift points and automatically adjusts the speedometer caluclation and readout.

Also, Chuck Wolf, who owns that 98 Corvette hardtop with the 427 smallblock, drove me to the track and back on Saturday in his Chevrolet Silverado 2500, towing the Vette on an atatched trailer. I noticed his speedometer was not working, except when it occasionally leaped up past ALL the digits and pegged itself! I asked how long it had been doing that. He replied "it started right after I changed the tire size upward quite a bit to lower the highway rpm".

Hmmm. The Silverado has the same pulse counting system as our SSRs do - it's in the driveshaft pinion assembly. So, when he changed the tire size, the VCM could no longer reconcile the pulse generator's signals with other signals that were spposed to agree with it, so the speedometer ceased to function. He says it took just a short time for the speedometer to stop working on his truck. I'd get that ratio number changed in the software pronto!

Jim G
 

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psychoslaphead said:
I took my '03 to have the dealer reprogram the computer for the 4.56 ratio, and Mr. Badwrench told me that they couldn't figure out how to do that. So now I have to remember to manually switch off the traction control and try to make a mental adjustment of the speedometer until I either 1) find a speed shop to do it or 2) make up my mind on a tuner (haven't had time to research, I'm moving) Having your vehicle die when it shifts into 2nd gear because you forgot about this is not fun....:mad
Or you could buy the DiabloSport I have listed in the for sale section and do it yourself. Also the Diablsport tuners have the ability to download cutom tunes from your Computer also. A diablosprt dealer can assit in cutom tunes. As you know youcan store as many as you want on your computer and pick the one you want and load it up.

the hand held also gives you the ability to return it back to stock in less than 2 minutes... nad then back to your tune in about 4...

My tuner I have listed is gaurenteed to work on arrival.
 

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Jim,

I find a wealth of knowledge from your posts, even though I'm not ready to take on some of the upgrades you've done, I do find I have become more comfortable believing I may want to take some of them on. You have broken down and laid out the steps of the tasks, in down to earth communications, that are quite easy to understand. Same way you eat an elephant....cut it up in small pieces.

Keep up the good work, no one will complain about the length of your posts. If they do, let them by pass by your threads.

P/P

Peace :flag
 

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I guess I will be slow

With all the changes you people are doing to your car, I think mine will be the only stock unit out there and it will be worth all the money in the year 2075. My great great grand kids will have a ball. I think I will just hide and watch and see how this all washes out in the end. I hope there isn't a lot of damage done, either to hte car or the brain.
steve
 

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Ditto!!!!!!!!!!

Purple Penelope said:
Jim,

I find a wealth of knowledge from your posts, even though I'm not ready to take on some of the upgrades you've done, I do find I have become more comfortable believing I may want to take some of them on. You have broken down and laid out the steps of the tasks, in down to earth communications, that are quite easy to understand. Same way you eat an elephant....cut it up in small pieces.

Keep up the good work, no one will complain about the length of your posts. If they do, let them by pass by your threads.

P/P

Peace :flag
:thumbs :thumbs :agree :agree :agree :thumbs :flag
 

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Diablo

Wellllll...I am going to have to back up my statment in another post here.

I did not think much of my Diablo Sport tuner when I first installed the "Performance Tune" yesturday and went for a spin around the block. I even called my dealer and hinted for a refund.

Now, this morning at 5:00 AM getting on to I10 I was really amazed at the difference. A very noticeable difference in shift point and power. Guess I had to get it over 2000 rpm. Another nice side effect...I reset Avg Fuel Econ and I picked up 2 MPG and over 3 MPG difference on the instant read out over factory program with cruise set at same point on interstate. I guess the computer might make real time adjustments as it seems better and better.

Just the feeling could be me but the Readouts should be correct. I know that cooler or hotter temps and humidity plays a roll in it but I am pleased at this point.

Scott
 
G

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It gets worse. After finding that Mr. Badwrench has no brain, I called a so called "speed shop" to see if they could reprogram the computer. After putting me on hold for a long time, a guy comes on and says "the tuner will be $350". I say, I can buy the tuners all day long, I just want you to use tuning software to edit the field value from 3.73 to 4.56. He says, we don't have that - groan. For crying out loud - I just went down to the warehouse and grabbed a cheap a55 Superchips tuner and will do it myself.
 

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Discussion Starter · #12 ·
Psychoslaphead: I read the EFILive tuning manual (comes as the "help" capability within the demo version of their software) cover to cover last night (gripping reading!!).

FANTASTIC capabilities.

Turns out, to change the ratio, you literally type the new ratio into the "new ratio" box, and it's done. Then, to reset the shift points in proportion to the change AUTOMATICALLY, you just hit another botton! If you then want to customize the shift points, part throttle or WOT, you can literally EITHER change values in a table manually, OR , multiply all values by a factor you set enmasse, OR drag a graphic representation of the shift points with your mouse. I love this stuff!

Turns out that Reese at MTI has the EFILive software, and did not realize it would work with the SSR, because the SSR is not listed as one of its supported vehicles. However, I emailed EFILive customer service and within 20 minutes (!) had a confirmation that my VIN proves that it WILL work with the SSR.

The possibilities are immense . . .

Jim G
 

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I have AutoTap, EFIlive & LS1edit that I use for tuning the Vette. All 3 are fantastic BUT a word to the wise. Be very careful as you can destroy your enging quickly if you make a mistake. Only make one change at a time and test it out to insure ALL is ok. When tuning L-Trims, AFR (Air Fuel Ratio) or IFR (Injector Flow Rate) for WOT (Wide Open Throttle) you need to do it on a DYNO and have a O2 wideband sensor. If you get it to lean you will have major problem quickly.

Attached is a OLD document that I started with and here is a link to another source that describe the basic's. ==> Click here ** NOTE ** both of these were written in the early days of the LS1 (circa 1997-9) so use them as a guideline only ***

George
 

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When I was researching tuning the PCM I captured data via AutoTap and wrote some programs to extract data a feed into and EXCEL spreadsheet to analyze. Here is a sample of the data I was using to test the programs, not all data from from an actual HARD RUN.

Sorry for the size but I need to reduce file size.

 
G

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Well, whatever you guys do, DO NOT TRY TO USE A SUPERCHIPS TUNER WITH THE SSR - THERE IS A VERY HIGH PROBABILITY YOU WILL WIPE THE VCM. I found out the hard way. You will have to get a rep on the phone to walk you through the process of getting your vehicle running again. They don't know why this happens on some vehicles and not others.

My first instinct was to go Crane, which is what I ended up with...
 

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Discussion Starter · #18 ·
I'm just moving this back "up", as I heard SO many questions about microtuners today at our Atlanta gathering.

If you are considering a microtuner, avail yourself of what I and others have learned. It will save you considerable grief.

Jim G
 

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Discussion Starter · #20 ·
Jim,

Any recommended tuners in Atlanta?
Reese Cox at MTI Racing. He did the initial tuning on my own SSR while I was working in Atlanta, before I came back to Austin, Texas.

Reese specialized in Corvettes at the time, but did my SSR as a special project, and did really well with it. Before tuning it, he did a custom exhaust for me and tuned for that mod, then a 2002 Z06 cam install and tuned for that mod. He got really good results each time.

Jim G
 
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