Stock SW upgrade on L67

[darkdragon]

Situation: I have a 1998 GTP with a DHP 1.0 PCM. Since the PCM is locked, I would need to reflash it completely or buy a replacement PCM. Even if I could flash it, from the forum FAQ I see that I would need the original bin from the PCM to use as a basis (which I don't have). Therefore let's consider the new PCM option (or one from a junkyard).

Question: Do I have to run a 1998 L67 PCM, or can I 'upgrade' to a newer PCM. In other words, will a 2002 or 2005 GTP PCM work correctly in my car? That would provide me with a newer base SW to start tuning from. Note that I want to retain my Performance Mode button functionality.

[98gtp]

98-02 PCM HARDWARE Is interchangeable.

but would need a proper vin to match the year of the car i believe.

[CSC04]

FWIW
It is possible to take your pcm to a dealer and have it reflashed to a "stock" bin for your car and your VIN. That way it all will match anyway.

Here @ the GM dealership where I work, we reflash vcm / pcm's everyday for various reasons. Including Junkyard pcms.
just a thought.

[darkdragon]

OK, but the question remains: can I use a 2005 SW (either as a 2005 PCM or as a reflash over a 1998 PCM) in a 1998 car?

I suspect I would have to maintain my current VIN (1998) since otherwise it wouldn't match the one in the BCM.

[bilemke]

A 2005, the answer is no.. The software is not interchangeable that far.. The max a 98 PCM can be pushed to is 2002 and maybe a 2003 bin.

[CTX-SLPR]

So if I take a junkyard PCM into a dealer and say I want it flashed with a stock 99 GTP tune on it they will do it? Keep in mind that I don't have a 99 GTP and it will be running a '64 Riviera with an '84 4.1L Buick V6 with a Grand National top end on it that I want to run with an L67 ECM. I don't have a VIN at all for it.

[CSC04]

You can take the pcm to the dealer and tell them to flash it, but you WILL need a vin.

[CTX-SLPR]

Great.... I wonder if Ed would let me have a VIN off of one of his smashed cars he's parting out to use...

[darkdragon]

OK, so if I use a 2002 bin, can I keep my 1998 VIN, or do I have use a 2002 VIN and update the BCM too?

[JerryH]

Are you using a PT or HPT? ... becuase multiple PCMs are easy to do on the PT due to licensing issues.

HPT can do multiple PCMs but it requires more credits.

You do not need to get another VIN from a busted up car... what is wrong with your VIN, is it from a stolen car or something? (lol)

As far as BCMs, that has nothing to do with this. You do not touch this.

[CTX-SLPR]

I don't have anything yet so HPT because I don't want to buy a product no longer in production. For a car its a 1964 Buick Riviera with a basically a Grand National engine in it with an L67 ECM and wiring harness on it. To make the junkyard ECM work I will need to start with an L67 base code though the ECM is likely an L36 ECM out of a late 90's Lumina (picked it up off of a guy abandoning an L67 Fiero project). See the problem?

[CSC04]

Situation: I have a 1998 GTP with a DHP 1.0 PCM. Since the PCM is locked, I would need to reflash it completely or buy a replacement PCM?

What is this PCM? Does it belong to a car you owned or own?

Ok If it is a car you own take the DHP pcm to the dealer tell them to re-flash it to the "original vin 1998 GTP". End of story. (same goes for the Lumina PCM u just bought. Have them Flash it to your 98 GTP's vin.)

Then if u get an HPT, licence it for that 98 GTP vin and be done with it.

If you do not own a GTP, see if ED will give you a vin (car of your choice 98-02 GTP) and do the same as above.

[JerryH]

Yikes, this is not a standard setup, and you have to be careful as hell. I don't think the DHP supports a grand national engine with a L67 setup, so you are doing some majorly different stuff.

As far as physical PCMs, if your PCM from a '98 L67 works, any PCM from 1998 to 2003 will work, but thats not the issue here... its the code *inside* that PCM that is going to give you your challenge. You basically cannot use code just from any year. That is where a custom tune is near mandatory for your case.

DHP v.1.0s are locked, yes, but honestly, there is no real magic in that code that cannot be easily duplicated starting from a 100% stock bin. Indeed, you could likely benefit from some major changes... that engine is likely not running it's best on code designed for a 3.8 litre engine.

Use the PCM you have now, reflash it to 100% stock code and start tuning away. I also now understand why you need a GP vin... lol. Yes, just ask Ed to send you a VIN from any 98 GTP for your use and flash that to your PCM if your current PCM doesn't have a VIN in there already that you could use. You will be "stuck" tuning a 1998 GTP as far as the HPTuner is concerned, but at least you will be able to tune.

[CTX-SLPR]

Sensors are a hybrid of the 2 engines. I'm starting out NA with just a blockoff plate on an empty turbo housing so I can see how the engine likes timing and fueling compared to an L67. The crank sensor bolted right on, the cam sensor is a distributor type stub that I will have to set but functions the same way. The MAF is an LQ4 85mm, has one knock sensor disabled with a jumper resistor, and the injectors are L67 pieces. I need L67 code for the 2-bar MAP function mostly.

[JerryH]

Definately... and strongly consider dropping those L67 33# stock injectors *before* going forced induction. You will run out of injector at around the 7-9 PSI of a higher flowing engine. On my GTP, I ran out of injectors with the 3.2" pulley, headers and LQ4 and P&Ped M90... around 9-10 PSI on that setup. A turbo flows A LOT more. Nothing under 65#s for a turboed engine that will see over 12 PSI is my suggestion.

Until you are boosted, though, its ok and the code to compensate for either 42.5 or 65 pound injectors is a walk in the park to change.

[CTX-SLPR]

the L67 injectors are only there till I get beyond stock turbo and if I'm running out of injector before then I'll just upgrade to the 60pph Motrons. The real interesting thing is going to be if I run out of injector in the 60's and have to go for the new and from what I've seen untested 75pph units.

[darkdragon]

What is this PCM? Does it belong to a car you owned or own?

Ok If it is a car you own take the DHP pcm to the dealer tell them to re-flash it to the "original vin 1998 GTP". End of story. (same goes for the Lumina PCM u just bought. Have them Flash it to your 98 GTP's vin.)

Then if u get an HPT, licence it for that 98 GTP vin and be done with it.

If you do not own a GTP, see if ED will give you a vin (car of your choice 98-02 GTP) and do the same as above.

Yes, it's for a 98 GTP I own, but why stay with 98 HW/SW if I can get something better? It seems that on the HW side I can use PCM's to 02 since they are the same, so no benefits from newer hardware. The question is then SW: moving up to newer base SW which includes bug fixes, updates?

So, then I would install either a 'new' 02 PCM or my old 98 PCM with 02 base SW and my 98 VIN. The concern is if the 02 SW in the PCM will accept my 98 VIN.

[JerryH]

Careful... there are potential issues with just randomly flashing complete code from one year to another year car. This is DEFINATELY not something a person with little experience should do, nor play around with. Been there, and done that.

What we are doing is tuning for performance, mileage or both. If your car is a 98, you can accomplish your goals using a 98 BIN that is properly tuned from your car and mods.

Now... taking HINTS from other years is not a bad idea. Example... the spark tables from a 2005 GTP are far superior to that of a 98-02 table and make a GREAT starting point for a timing tune... but again, its ONLY a starting point and you have to BE CAREFUL. The 2005 GTP bins maximum timing is a lot higher than a 98 car and can increase KR if you are not paying attention, so whether you choose to start from a 2005 bin or make your own tables from scratch (which I love to do since it is then a lot closer to perfect for my car than anything any year bin can offer), this is your choice... I prefer to spend more time when I tune on making baby steps and not looking for shortcuts all that often. Timing tables (and PERHAPS the TPS vs AFR tables) aside, there is little else that I would suggest taking from other year bins... do the work and change the things that you KNOW work on your car becuase you worked up to it slowly and diligently.

Thats one the best secrets to getting your car dialed in right.

[darkdragon]

Agreed, and the car would be completely retuned anyways. What I'm looking for are the benefits of bug-fixes or added features of a newer base software, regardless of tuning parameters.

[JerryH]

Agreed, and the car would be completely retuned anyways. What I'm looking for are the benefits of bug-fixes or added features of a newer base software, regardless of tuning parameters.

There aren't any real ones. Also, since the 98s are around the longest (from the tuner perspective), they are the best mapped out bins in GP tuning history. Fixes would also be year specific and unreated to other year cars.

What would be good is to make sure that your car has the latest iteration of your year specific bin.