PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Which ECM/PCM for boost and why

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Old Jul 17, 2015 | 07:51 AM
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Default Which ECM/PCM for boost and why

Im planning a ground up build in the near future and the control system is up in the air. From a tuning perspective, which would be preferred for a forced induction build: GEN III PCM vs E67? What benefits would one have over the other?

So far the best I can come up with is DBC vs DBW

Planning a 408 with a TVS1900 at +18psi through a manual trans of some sort. Expecting 8-850. I will be custom building the harness so wiring it in isnt an issue
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Old Jul 21, 2015 | 08:38 PM
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Default Which ECM/PCM for boost and why

E38/E67 have boost tables already, you have to correctly populate them, and have IFR table with sufficient range for boost.
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Old Jul 22, 2015 | 06:39 AM
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Are they worth the extra steps required for a GEN IV control system? Prev boosted GEN III PCMs didnt seem to have a problem with the boost, but I dont have any experience with the newer stuff to compare to
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Old Jul 22, 2015 | 05:59 PM
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GenIII has some boost limitations: IFR does not cover boost range (ok so you can run a boost-referenced FPR), VE and OLFA tables do not cover boost range (ok so you can scale).

HPTuners and EFILive provided custom operating systems (COS) for some GenIII PCM's/OS's that provided boost tables (so you didn't have to scale anything).

GenIV OS's already have boost tables (even if they are not used; you have to populate them).
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Old Jul 22, 2015 | 06:00 PM
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Also note that if you are contemplating running a GenIII engine from a GenIV ECM you will need to either replace the CKP/CMP reluctors or use the LPE converter.

If you are running a GenIII engine then I suggest running a GenIII PCM with an OS that HPTuners or EFILive supports with a COS.
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Old Jul 22, 2015 | 10:44 PM
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Why not a Holley HP?

Andrew
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Old Jul 23, 2015 | 02:08 AM
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Originally Posted by joecar
Also note that if you are contemplating running a GenIII engine from a GenIV ECM you will need to either replace the CKP/CMP reluctors or use the LPE converter.

If you are running a GenIII engine then I suggest running a GenIII PCM with an OS that HPTuners or EFILive supports with a COS.
Its a clean sheet build, can order either a 24x or 58x crank and the timing sprocket is a simple swap. Ive been itching to do a GEN IV conversion to nail down all the details, just wasnt sure if the benefits of the ECM would make it worth the extra steps for a conversion. Guess its time to grab an E67 ECM and get busy

Why not a Holley HP?

Andrew
Cost

Im building the harness, so add the materials, plus blank ECM plus a couple dyno tunes still wont touch the cost of a holley ECM. Ive read quite a bit on how Holley ECMs blow OEM computers out of the water, but the cost is still quite steep. That and Id have to custom build that harness too, so even more expense
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Old Jul 23, 2015 | 02:50 AM
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Default Which ECM/PCM for boost and why

Correction to my post above (sorry my mistake): the LPE converter is for running a GenIV engine from a GenIII PCM, and not vice-versa as I had said above.
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Old Jul 23, 2015 | 10:03 AM
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From: Little Austin
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Originally Posted by Pocket
Its a clean sheet build, can order either a 24x or 58x crank and the timing sprocket is a simple swap. Ive been itching to do a GEN IV conversion to nail down all the details, just wasnt sure if the benefits of the ECM would make it worth the extra steps for a conversion. Guess its time to grab an E67 ECM and get busy



Cost

Im building the harness, so add the materials, plus blank ECM plus a couple dyno tunes still wont touch the cost of a holley ECM. Ive read quite a bit on how Holley ECMs blow OEM computers out of the water, but the cost is still quite steep. That and Id have to custom build that harness too, so even more expense
Why would you have to build a harness for the HP? Do you plan to buy a wideband and tuning software?

Andrew
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Old Jul 24, 2015 | 01:03 AM
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Default Which ECM/PCM for boost and why

The Holley system uses a wideband to continously trim fueling thru out the operating range, this is a nig advantage over the GM PCM/ECM...

however, the GM PCM/ECM does have far better engine protection mechanisms/failsafes that the Holley does not.

And it also provides for the various emissions systems/functions (which obviously you do not need).
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Old Jul 24, 2015 | 08:31 AM
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From: Little Austin
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Originally Posted by joecar

however, the GM PCM/ECM does have far better engine protection mechanisms/failsafes that the Holley does not.

.
Can you give me a couple of examples of this?

Andrew
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Old Jul 24, 2015 | 10:49 AM
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Originally Posted by Project GatTagO
Can you give me a couple of examples of this?

Andrew
The GM PCM has tables for engine protection (overheating), piston protection (high load for extended time), catalyst overtemp protection, HO/LO adaptive ignition timing (knock detected), safe fueling selection (LTFT applied on top of richest of active tables)... I am not aware of the Holley system having these.
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Old Aug 1, 2015 | 03:54 PM
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Fair enough, E67 wins

Why would you have to build a harness for the HP?
Does Holley make a LSA harness? Do they make one for 3rd gen Fbodys? I do, so Id be making that aspect. Choosing which ECM/PCM to control it is required before building the harness and assembling the engine
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Old Aug 1, 2015 | 10:11 PM
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From: Little Austin
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Originally Posted by Pocket
Fair enough, E67 wins



Does Holley make a LSA harness? Do they make one for 3rd gen Fbodys? I do, so Id be making that aspect. Choosing which ECM/PCM to control it is required before building the harness and assembling the engine
Holley sells an unterminated harness that you can build to your desires no matter what engine you are using. As for the chassis, the engine harness doesn't care what car it goes into. Since this is a swap into an older vehicle, there would be minimal integration required between the engine and chassis harness.

As far as tuning a boosted engine, you can't beat the options that the HP will give you compared to a E67.

Andrew
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Old Aug 2, 2015 | 07:07 AM
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Default Which ECM/PCM for boost and why

The Holley system uses a wideband to trim fueling across the whole operating range... this is a big advantage.
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