July 20, 2019, 12:33:19 PM

Author Topic: Holley Terminator X EFI Kit - My Experience  (Read 185 times)

Offline bimbleuk

Holley Terminator X EFI Kit - My Experience
« on: April 15, 2019, 10:03:28 AM »
Been a while since I last posted but I thought I would give some feedback on installing a Holley Terminator X LS1 24X/1X MPFI kit.

I imported one at release to the UK for my RX7 FD, 5.7L LS1 T56 manual conversion. Up till now I'd relied on the GM LS1A PCM, OEM modified wiring loom and EFI Live tuning software. I spent months learning to tune with it and it was mostly perfectly adequate for running the majority of conversions. I'm not particular fond of wiring so I wasn't completely happy with the wiring install however it's always been reliable and thankfully I did label everything which has been a real boon when installing the Holley kit.

I did the original install in 2010 so you can imagine how much time I saved re-learning what all the wires were doing under the dash. The Holley kit comes with a minimal engine loom. Separate ECU power loom. Importantly a single Bosch LSU 4.9 wideband sensor that goes in one exhaust bank. The whole kit is pared to the minimum to run an engine conversion and the price reflects this though the Terminator ECU can be tuned in real time with the optional CAN cable. Otherwise you just download the tune to an SD card in the 3.5" hand unit and make changes offline and upload them again. Compared to the LS1A PCM upload times it's near instant!

You can log data real time too and it has the most common sensor channels recorded. Probably the big feature for those with next to no tuning experience is the self learning function that takes the hassle out of getting a conversion with mods up and running. Just drive and the ECU logs the difference between targets and actual sensor data then stores this in a difference table that can be blended back into the base fuel table at the end of each drive. No spreadsheets hoorah! There are 3 base tunes supplied that cover standard to wild cam installs so your experience will vary until the maps have been relearned a few times. The setup Wizard will generate a start tune based on some simple questions about your setup. This should at least allow you to start and idle with minimal adjustments.

I spent 1 day removing the old PCM and wiring loom and spent some time tidying up the remaining RX7 harness. I spent the next day installing the Holly engine harness and connecting the 4 or 5 loose wires that need to be run. The worse connector is the crank sensor which is just behind the top of the starter motor on a 24X LS1 and required the exhaust manifold to be dropped to reach. Not sure how I got the connector back on with out dropping the starter itself but I did. The wire is well heat shielded and stiff so that helped. The third day was spent making up a trans harness from the old wiring loom see below.

Again to save cost the one thing that is missing with the basic Terminator X kit is the gearbox connectors. There is no provision for them. I pulled the Reverse lockout,  VSS sensor & reverse light sensor from the old loom (CAGS deleted). I wired them separate from the Holley loom and connected the VSS output directly to a Digital Dakota conversion box to drive the speedo. The signal came from the GM PCM previously.

If you want auto trans and electronic throttle control you can buy the terminator X MAX kit which will talk to the most common setups. One thing to note is the Holley EFI has a dedicated tach/RPM output but it is not directly compatible with the RX7 tach as it's a V8 signal. In theory you have 4 programmable outputs with the Terminator X and should be able to reduce that signal by half however Holley have restricted the options a bit too tightly and I couldn't select a PWM 12V+ signal so in the meantime I've ordered a Dakota Digital tach conversion box. I'm impatient as that'll take 2 weeks to arrive here. Maybe they'll fix this in a future firmware update.

So once all the wiring was complete I was able to create a base tune via the Wizard. Complete a TPS setup and start and idle the engine first time! I spent a bit of time getting the TPS and IAC setup to the recommended values and let the car warm up and turn on the rad fans. Mine are separately controlled but you can use 2 of the Holley ECU outputs for a twin fan setup.

The best thing to do is read the kit description, manuals and wiring loom diagrams. Download the free software and see what sensors, injectors etc. are selectable by default. That way you can pick the nearest kit to your setup and see which sensors can be re-used. For example as the MAF is deleted you will need a separate GM IAT (MAT in holley speak) and the common GM oil pressure sensor will not work or at least the one I have doesn't even though the plug is correct. I think Holey might want to sell their own pressure sensors (oil & fuel) at $100+ a piece!

The knock sensors can also be enabled for resonant or non-resonant so I'm currently adjusting the sensitivity of my two single wire GM sensors.

This is the sort of conversion kit I would have killed for 10 years a go to get my setup installed and running with mods. Though in the long run I've learnt a lot about tuning engines from the slightly clunky EFI Live tuning method. I highly recommend it for those loath to mess with wiring or at least minimise the job and maybe could save themselves hundreds of dollars in dyno time alone.

Plus it's got me interested in driving my RX7 again which has barely done 3000 miles in the 4 or 5 years!
« Last Edit: April 15, 2019, 10:09:40 AM by bimbleuk »

Offline digitalsolo

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Re: Holley Terminator X EFI Kit - My Experience
« Reply #1 on: April 15, 2019, 11:02:15 AM »
Glad to hear it's a good setup.   I'm helping with a Holley Dominator setup shortly, so I'm interested in hearing how their stuff works.

Thanks for taking the time to be so detailed about it.  :)
Blake MF'ing McBride
1988 Mazda RX7 - Turbo LS1/T56/ProEFI/8.8/Not Slow...   sold.
1965 Mustang Coupe - TT Coyote, TR6060, modern brakes/suspension...  project car
2016 BMW 428i xDrive Gran Coupe - Completely stock...ish

Offline bimbleuk

Re: Holley Terminator X EFI Kit - My Experience
« Reply #2 on: April 15, 2019, 01:06:48 PM »
Thanks for taking the time to be so detailed about it.  :)

Actually quite terse for me as I used to do detailed builds with pics but several years of build blog went puff with a forum delete over here one time.

Worth adding that the Terminator X software is both capable and limited. The tools for changing the base fuel map for example are limited to single cells, drag selections or a global adjustment. Not what I'm used to compared with the EFI Live software with many more mathematical functions. However the learn function is doing a great job and only after 3 or 4 runs I'm already down to single digit adjustments. The generated maps are very conservative and I sneakily adjusted 3 broad areas based on my experience and EFI Live maps. That got my start map much closer than most may experience but they are obviously playing safe.

Coincidentally love em or hate em I was watching Cleetus McFarland prep Ruby 2 or 3 weeks a go and they opened a box with a Terminator X kit and I was just undecided at that point whether to import one. So if they trust it on their "junkyard" LS with turbo then I thought it must be good enough for my NA setup.