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HYDRODYNAMIC

HYDRODYNAMIC

Rock Stacker
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Lost in the forest
Doing research on aftermarket ECM for LS. In my application Gen4 6.0
Something I can program or without having to spend years learning.
A new harness would be worthwhile.
Don't need transmission control.
Don't need a fancy screen.
 
Haltech has a reasonable rebel LS that comes with harness, and appears to be more waterproof then Holley terminator. Currently run a terminator, and have problems with no altitude reading and adjustment.
Otherwise, the factory ECU is a robust, good features for $, and most tuners can understand solution
 
I run a terminator X on my 6 liter and love it. Watch some of joe Simpsons videos on YouTube and running for a stock-ish engine is easy as can be.
 
Factory PCM is cheap and easy, I did do a Terminator X on my last build and was happy with it though. Only complaint was it not being as water resistant as the factory PCM.
 
Fwjeep said:
Haltech has a reasonable rebel LS that comes with harness, and appears to be more waterproof then Holley terminator. Currently run a terminator, and have problems with no altitude reading and adjustment.
Otherwise, the factory ECU is a robust, good features for $, and most tuners can understand solution
Click to expand...

TermX has an integrated baro sensor inside the ECU, as well as a wideband 02 sensor.
There is no reason why altitude is a problem if the tune is correct.

Main problem, as everyone mentioned already is the non-waterproof ECU housing, but even that is easily mitigated in my experience.

I would still run a factory ECM if the only thing you're trying to do is run the engine.

edit: spelling
 
Last edited:
Bebop said:
I would still run a factory ECM if the only thing you're trying to do is run the engine.
Click to expand...
What are the gauge options if running factory ECM?

Do you personally thin down the wiring harness or do you have a preferred shop that does that? I assume you do it yourself given your skill set.
 
fl0w3n said:
What are the gauge options if running factory ECM?

Do you personally thin down the wiring harness or do you have a preferred shop that does that? I assume you do it yourself given your skill set.
Click to expand...
It depends what ECM model.

I usually build mine from scratch if I need a specific routing / length, but if I want a standard setup, I have steered customers to LSX specialties with good success.
 
Haltech rebel hands down, if not using a factory ecu. Four programmable solid outputs to wire fans and fuel pumps directly to the pcm without relays, high quality harness and it's waterproof unlike a terminator.
 
I run a BP Automotive harness (completely new) and factory ECM on my Gen 4 5.3. They can make harnesses for just the engine, no trans.

Can't speak on tunability as I paid to have it tuned...

As for gauges, 4 autometers (two for the engine) as seen below and a Scangauge 3 plugged into the new harness's OBD2 port

IMG_2364.JPG
 
I started researching the TermX and was not super excited about the hardware. What version to order with all the different options. Waterproofness. Harness connections looked weird with the blue map wire hanging out. What injectors do I have? Sensors included or not included and which ones. Can I only use the Holley approved pedal?

I started researching the Haltech NEXUS Rebel LS and learned instantly that it comes with all the harnesses that I would need. Learned what injectors I had and what harness was needed. Works with the C6 Corvette pedal which I have. Lots of pictures and diagrams. MAP is built into the controllers and has a hose barb. Weld on fititngs for all the sensors.

Haltech seems like a no brainer because its the same language as my mind thinks. Just need to find out if its worth it over the stock ECM.

Back to researching.
 
I did my first LS swap in 2006/7. Used the OEM ECM and Jim’s performance to modify my harness and do some delete/tuning. I sold it in 2021 and as far as I know it’s still running fine.

Bought my LS buggy in 2020 with a OEM ECM. Had relay issues that I struggled diagnosing due to not having anything other than a $300 scanner from Autozone. Ended up bypassing the ECM with my own stuff so my fans no longer run off my ECM. Over the past year I’ve had a couple other diagnostic issues.

Here’s where it got foggy. Local support shop with HP Tuners was not able to pull a ticket because the VIN had been wiped on it. :eek:
Was able to track down the guy who tuned it and he was “less than helpful”. He was very sarcastic like I’m an idiot. Well, yes I am and that’s why I offered right up front to pay for your services. We were able to pull the tune which I emailed to him - again with a note asking his fees.
“I’ll get back to you”. Numerous emails and calls and he ignored me. :flipoff:


So I was able to track down a friend of a friend who knew his shit & we got it resolved.

Bottom line, I’ve been running OEM LS ECM’s for going on 20 years. They have been great for me. You just gotta make sure you have a way to diagnose & do tunes.

I have a couple friends running Holly Terminators. I don’t know much but think they like them. (Even the one that went through a fire) :lmao:
 
I have a Holley Dominator and like it. It is fully waterproof, has dual wideband inputs, and a ton of inputs and outputs. With that said compared to the EMU Black on my 2JZ it feels like a tuner for dummies setup, for good or bad.
 
I have gone through 3 dominators in 6 years? They are not dust or waterproof, the first one I had was a brick out of the box and would not power up. Holley was not very helpful.

There is so much to be desired from the Holley ECU's, they operate on a closed CAN system so not very upgradeable or user friendly.

The GM ecu is far superior for diagnostics and HPtuners is super common. For the price of the Holley stuff now I would spend the extra money for ECU master or Haltech stuff.
 
$350 for stock ECM w/ vats delete and rear 02 delete... Vrs $3500...

I've had some issues with my ECM. #2 knock sensor and bank 1 O2 sensor heater.

Don't really seem to affect it and I haven't bothered having them tuned out as it takes 2 seconds to clear the codes.
 
HYDRODYNAMIC said:
Haltech seems like a no brainer because its the same language as my mind thinks. Just need to find out if its worth it over the stock ECM.
Click to expand...
It is not. There is no reason for you to change your ECM other than blowing money and feeling good about it.

cdemart2 said:
Haltech rebel hands down, if not using a factory ecu. Four programmable solid outputs to wire fans and fuel pumps directly to the pcm without relays, high quality harness and it's waterproof unlike a terminator.
Click to expand...
What if you want to use the outputs for something else? You can't...
The Rebel isn't the worst product out there, at all, but it's not the miracle answer.
Holley is not the best either (at all) but you have widespread support, tuning info absolutely everywhere and the company will stand behind their products.

PS : I still think a OEM ECU is the way to go for OP.
 
And what's funny is that I have almost all of the EFI systems in play out there... default for me is always OEM with a converted harness.
 
I don't understand the desire for an aftermarket solution? The OEM will work to meet the goal , cost less and is easily replaceable if the controller or sensors fail?
Internal map sensor in the controller vs a spare sensor in the tool bag that fits a bunch of rigs in the group?
New harness yes 100%
Quality wiring for external outputs triggered by the controller. Wire in a permanent wideband if you do your own tuning.

Get a good tune and copy it into a spare controller and leave it in the truck or even the rig considering the desert can get big.
 
apimpdad said:
I run a BP Automotive harness (completely new) and factory ECM on my Gen 4 5.3. They can make harnesses for just the engine, no trans.

Can't speak on tunability as I paid to have it tuned...

As for gauges, 4 autometers (two for the engine) as seen below and a Scangauge 3 plugged into the new harness's OBD2 port

IMG_2364.JPG
Click to expand...
like one of these?
 
I haven't really looked into them, I'm running a E38, but HPTuners has a complete ECU they've released about a year ago.


www.hptuners.com

CORE ECU – HP Tuners

Introducing HP Tuners' debut standalone ECU, CORE ECU and VCM Live. Initially supporting Gen 3 and Gen 4 LS engines.
www.hptuners.com www.hptuners.com
 
mobil1syn said:
find tuner, use what they are familiar with and do what they say.

this will make your experience significantly better
Click to expand...
I agree, that is my goal next year is to find a tuner with HP tuners willing to ride shotgun and watch laptop or dyno tune. (stock LM7). More than enough for a trail rig.
 
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