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Discussion Starter · #1 ·
Hi all,

So, I am looking to make my first power mod and am looking to decide between a CAI or a power tuner. For the CAI I am leaning towards an AFE and the Trinity for the tuner. I also plan to port and polish the TB to improve both the effects of either of these mods.

What do you think will give me a bigger bang for the buck?..and why? ...all advice is appreciated! Thanks
 

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Discussion Starter · #2 ·
...anyone?
 

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I talked to A speedshop in Richmond,va.They tuned A C6 that had been tuned by Diablo.They put the tuner down big time.They changed the tune of the C6. They said the Diablo didn't do the job.Just passing this on.
 

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A canned tune wont be any more than a "one size fits all" guess. IMHO I would go to a trusted tuners with experience with the C7. That way all is optimized for your car.
 

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Discussion Starter · #6 ·
Thansk for the info thrilled.
 

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OTOH, you could get the Diablo, see if it gets you where you want to be, then find a tuner who can create a Diablo specific tune that you can then use the Diablo to load. One huge advantage of the Diablo is the ability to flash back to your stock tune and since they don't mess with the check file it's very difficult for GM to detect you have used it once you go back to the stock tune. They also have a canned tune for a CAI that you get with the unit as well as the ability to pull updates from their site as they improve the product.

I will disagree somewhat with the idea you always need a custom tune and in fact, unless the tuner is using a brake dyno and walks through the partial throttle cells you are only getting a WOT power tune which may or may not be noticeable in normal driving. If all they are doing are 4th gear power pulls to tune you are wasting your money.
 

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I just installed the Diablo AFE-93 tune this weekend and I have been running an AFE-CAI since May and mid-length headers from ARH w cats. I noticed better throttle response and it pulls good and smooth after tune on some short driving. Easy tune, worth the $400 (to me) I'm going to get it dyno'd in early Nov (busy weekends coming up) so I'll post the pulls for comparison. I have not seen an Diablo / AFE-CAI / ARH combo but I may have missed the thread. I only have 2 K miles so being able to swap back to factory was a key decision factor for me. From my experience AFE, ARH and Diablo have been worth the $. But it's early for the C7s and anything can happen so it's up to the individual and you only live once.
 

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Admittedly my tuning knowledge is a bit out of date but Tuner Boost is spot on. Out of the box generic tunes are usually crap. Back in the LS1edit days I had a number of "base" tunes I would drop into a car as a starting point but they were exactly that..a starting point. Next came dyno, street, and track tuning with wideband o2 sensors and a lot of data logging.
 

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Totally untrue and a disservice to Corvette owners into thinking that ANY tuning tool can hide from GM that their federal certified tune was not mucked with

Fact : the tuning tool can only touch the calibration space but GM is smarter then what your repeating by that vendor
as the memory flash chip where the calibration (tune) resides has a internal flash counter that ups the counter each time data has
been uploaded rewriting the flash contents

No one can prevent that and even if stock calibration is reinstalled that counter alone tips off GM that if there is no records of that car having PCM GM updates then it only points that someone is trying to scam GM out of warranty costs.
Thus if the car's GM records shows the controller was updated 2 times then the time memory was flashed counter better not be higher then that.

There is also a major issue owners should know is the tune was certified by federal testing and worse case GM could notify them that federal smog laws have been violated at a fine of $100,000 to the person who changed the tune and $10,000 fine to the car owner for instructing vender to do so

Check file, is wrong, it would be checksum of tuning space content but also GM has code segment IDs
In the end GM can tell within 10 seconds what the flash counter is and that someone is trying to cheat them from bad tuning causing the failures

It is not an advantage of Diablo as any tuning tool that uploads to PCM can put the stock calibration back in but cannot undo the flash memory's upload counter values

One huge advantage of the Diablo is the ability to flash back to your stock tune and since they don't mess with the check file it's very difficult for GM to detect you have used it once you go back to the stock tune
 

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Obviously J.R. Has issues with Diablosport and I did misstate the term "check file", I meant to say CVN and Check Sum. CVN is the method used by GM to determine if the ECM has been reprogrammed and I can confirm the CVN check with a dealer's Tech2 system on a Diablo flashed vehicle, whether it has the Diablo tune or the rewritten factory tune passes the CVN test.

CVN is actually the sum of the checksums of the various sub systems within the ECM, Diablosport has developed a method of applying their table updates without disturbing the CVN. More than likely they are adding bits within each table to make that sub systems checksum match stock so when the ECM reboots and compiles the CVN it matches what's in memory and nothing is changed. The CVN is only updated when the system detects a change and it stores the last 10 (could be more with the latest ECM). That's how they detect that an ECM has been flashed at some point, they look at the CVN history and if it doesn't match what's stored in Tis2Web they can deny a warranty claim.

There is no proof a raw flash counter exists that I could find, a dealer could re flash your ECM 100 times but as long as the new program checksums match the previous one the CVN counter would never be updated.

You can thank all the Diesel Pickup owners for all this. GM got tired of replacing Allison transmissions these numb nuts were blowing up with the power packs.

With all this said, no one outside of GM knows what forensic capabilities a lab back in Warren has so it's possible an ECM sent back to them could be diagnosed as modified at some point but warranty claims for major failures require the dealer perform the CVN check using Tech2 and Tis2Web and it they match the claim moves to the next step.

I personally believe the risks associated with the Diablosport are low having talked to many tuners as well as Diablosport at length.
 

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PCM has eight operating software segments as I show below,

Each has a CVN, this changes as a newest GM update comes out with new part # for that segment ( as shown below) ,
the CVN is how a dealer's tech tool can tell if segments in the PCM need to be updated.

The marketing that some tuner is preventing the CVN changes really has zero to do with the calibration space as it is not itself
running software but pointers the other programs point to for data values so you can tune that space all you want and the CVNs
are not being changed
A CVN has zero to do with the calibration (tune) space's CRC (checksum) and even if the stock GM calibration that was downloaded from the flash was then copied back into the PCM to attempt to fool GM does not wash as many of GM's values ( as shown below) are several digits right of the decimal point.

Depending on the tools CPU or software it can tend to round the numbers out a bit so the copy sent to the PCM's memory flash is no longer EXACTLY the same as when GM flashed it in and hence the CRC will NOT match

Marketing the CVN pitch is just that way to make Corvette owners FEEL they are safe from GM catching on the PCM, TCM, etc was tuned but it is smoke and mirrors.

Would be the same as you using an excel spreadsheet, making changes to a XLS but of course it is not going to change the CRC (checksum)
of any of the MSwindows programs, DLLs, drivers etc.

Stating flash chips do not have counters means someone has little I/C experience, those counters are required if for the I/C vendor to be able to know
if their designs are failing before the (TTL) Time To Live or(MTBF) Mean Time Between Failures) they spec'd and nameplates want them for this exact reason as that counter cannot be touched and these internal counters have been around as long as I have been in the electronics field of 30 years

I teach a SAE degree course all about this at a college and this subject comes up each quarter and is shot down as nameplates are much smarter then mid 1980s when using 32K byte E-proms to passing electronic finger prints over the car's GMLAN and stored on other controllers.

Any major failure that will cost GM big money or questions a new design such as the LT1 and GM will suspect tampering
Example check the thread here on the C7 that has blown 2 engines and they snapshot the dealers papers and notice GM states in writing for the dealer to send information for GM to determine if the calibration has been replaced or tampered with but in the end the flash chips do have internal counters no tuning tool can undo
 

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I don't disagree that there are flash counter built into the flash chips at the base level but what seems to be in question is whether, at the dealership level, the tools they are given have the ability to interrogate that counter. There is also a question as to whether simply incrementing that flash counter, which a number of people including someone I talked to at a dealer said they cannot access with the Tech2 system, is proof of tampering. As I said, a dealer can refresh the system any number of times and each flash attempt is not recorded on any master database at GM that anyone I have talked to can confirm. All that is done is an update to the system Tis2Web access to record what's been loaded on the many modules within the car by part and CVN number. I have confirmed that at the dealership level the systems in place will not throw a red flag when using a Diablo tuner. I also said it's was quite possible that someone from GM could apply a different tool and get different information so I never said it was undetectable, just not the red flag HPTuners and other systems throw.

What I find interesting are the comments by many that Diablosport is out right lying to the general population and has been for many years. I would think that if that were true someone would have had a claim denied and that would be all over the Internet. I just don't see it.

BTW, my use of the system is primarily to disable AFM and CAGS and to improve the throttle response. I'm a firm believer that the factory knows a hell of a lot more about tuning the thousands of variables in the tuning tables that the aftermarket. I also know that all these tuners are doing are changing the values the core program uses and not the program itself.

How about we put this to bed with the agreement that ANY tuner runs the risk of being detected and voiding your engine warranty, OK?
 

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Mark the point really is and we're talking about the same but different

I fully agree with you that NO tuning process can make it look like the PCM ( or TCM) was virgin and not touched by a 3rd party
GM has a defective design process and the more they suspect a tune caused the damage ( if power or drivetrain) then the deeper their process is
in finding if the controllers are still GM virgin

I know I have been tuning since the mid 1980s and I worked in GM tech labs and there is always "other" non public known ways of tracing

Good example is a 2009 C6 owner buys a EVI supercharger kit that comes with a blackbox "canned tune" for both the TCM and PCM
All the install is done including flashing in the canned tunes and owner goes for a drive
Soon as the car starts moving the A6 is in sixth gear by 30 MPH !

Owner drives car for about 5 miles, nothing gets better.
He puts the GM TCM tune back in as instructed by the tuner vendor,
A6 is still screwed, the tuner vendor tells him to not to tell dealer a tune had been in TCM
Owner goes to dealer for A6 warranty repair and within 10 minutes GM voids the warranty finds flash counter up to 3 and knows
a tune was in it
How come ?,
simply as the ONLY ones that would be flashing would be dealers for GM updates,
GM sees they had no A6 updates yet the flash counter shows 2 flashes more then there should be so they know it was touched

End of story it cost the C7 owner over $3,000 for the A6 repair and warranty shot, what was broke ?
the TCM as the bad tune corrupted it.
Cause the tuner knew crap and in their blackbox the tune for the A6 was really for a A4 which I found by debugging code

Point of all this is to protect the Corvette owner to understand ANY changes to the controllers can be cross checked and anyone saying
it can be hidden from GM is not caring of the end results to the C7 owner and a ripped up GM warranty
 

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for what it's worth I put an AFE cold air intake on my 2015 Z51 Stingray and got 415RWHP on a dyno, then applied the "stock tune" from DiabloSports hand-held tuner and got 422RWHP. Oddly enough I would say get the CAI first, then retune if needed or doing more mods.
 
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