wire harness/computer options for LS swap?

[CamaroJesse]

I have a 6.0 LS and t56 trans. I have no wire harness or computer so i need to start from scratch. I see there are many options when it comes to harness's. I know i can get a harness from painless or psi and use a stock computer and ive also seen msd, fast, mast, harness and computer kits. The motor will be stock for now but will be upgraded with heads, cam, intake in the future. Im looking for a cost effective route here that will work for my purposes. So the main questions is, when i have nothing to start with whats the best way to go?

[davidomilligan]

So I looked into the stock route. issue I saw was when you do any of those upgrades not being able to tune it yourself unless you are going to invest in the hp tuners. which at that point ill stay conservative. 150 for computer and flashing, 500-600 for a standalone harness. and if remember correctly you have to buy credits each time you flash a ecm with it. I ended up going with the holley route and so far ive only had it installed a week but even my diagnosing why I couldn't start it made my life so much easier. its also a self learning ecu so it doesn't require you to be a tuning expert. I also purchased their digital dash and it hooks right up and runs all my gauges. all and all I think this was the best route to go in the investment for my car. id say going a stock standalone you will be about 1000 into it. I got my holley harness on sale but its worth the exta 600 dollars to be able to tune myself from a laptop

[davidomilligan]

fast makes one as well. I'm sure any aftermarket ecu is going to have similar advantages. don't skimp on this aspect of the build. this is the heard and brain of your engine

[csouth]

The best way to go is going to depend on your budget and how involved you want to get with the tuning. There are plenty of vendors, harness, ecm combos you can use out there. Are you going to tune it yourself? Do you want a self learning setup? Are you willing to use a mail order tune? Not using a 2k efi system does not means that your LS swap will not perform up to par.
If I were on a budget, I would probably use a Current Performance harness and a stock ECM tuned for stand alone. Determine what you're willing to do tuning wise and post here, it may result in a broader range of responses. If money is not an object, the world is your oyster.....

[CamaroJesse]

im not looking for the cheapest route just the route that makes the most sense. I dont have much tuning experience so i might be lost screwing with hp tuners. I have always felt a bit weird about putting a head cam setup on a motor and relying on the computer to self learn or self tune. how do know im getting the most out of the motor? Im willing to spend the money for the right set up but i just dont know where to start since theres so many options out there

[andrewb70]

If you are starting from scratch, the Holley HP is hard to beat. Do you have a Gen III or Gen IV engine?

Andrew

[andrewb70]

If you are starting from scratch, the Holley HP is hard to beat. Do you have a Gen III or Gen IV engine?

Andrew

[csouth]

im not looking for the cheapest route just the route that makes the most sense. I dont have much tuning experience so i might be lost screwing with hp tuners. I have always felt a bit weird about putting a head cam setup on a motor and relying on the computer to self learn or self tune. how do know im getting the most out of the motor? Im willing to spend the money for the right set up but i just dont know where to start since theres so many options out there

If you don't plan on tuning it yourself and do not want a self learning system, this is the path I would take: Your post indicates you will be riding the car stock initially. I would buy the appropriate ECM for the 6.0 that you have.(you didn't say what the motor was from). I would order a harness from a vendor that also does tuning and send the ECM in for stock tune at time of purchase.(I like Current Performance, but PSI seems good too). I would drive the car like that until the heads and cam are installed, then inquire here or LS1tech about reputable tuners in my area and have the car tuned locally.

Nothing wrong with a full on system like Holley. Personally I would save the money on the Holley system since you will be paying someone to tune it either way. Use that money to get a dyno or ride along tune after the heads an cam are installed. Once the tune is done, you won't need to touch it anymore, unless you make changes. In either case you'll be paying someone to do it. If you're paying someone for the head cam install, the tune may be included?

Just my .02

[CamaroJesse]

The motor is a 6.0 lq4 from a 2002 Silverado.

[showdog75]

I'd give Bill at BP Automotive a call. He is a pro and has everything you need.

[andrewb70]

The motor is a 6.0 lq4 from a 2002 Silverado.

So its a Gen III engine. This will work awesome!

https://holley.com/products/ls_power/ls_efi_systems/parts/550-602

Don't be a slave to some "tuner." The Holley system is self learning for fuel and there is a lot of support all over the internet.

Andrew

[CamaroJesse]

The Holley system seems nice. That might be the way to go. So with the Holley system I should never need a tuner? Even if I change heads cam and intake as well as injectors the computer will tune itself?

[andrewb70]

The Holley system seems nice. That might be the way to go. So with the Holley system I should never need a tuner? Even if I change heads cam and intake as well as injectors the computer will tune itself?

The fuel will self tune, but the rest needs to be adjusted. I personally enjoy the learning process of tuning, so for me its fun. The nice thing is that you will have the tools to make any adjustment that you may need in the future.

Andrew

[CamaroJesse]

Is the tuning done using a laptop or should I buy the lcd screen they offer for tuning?

[andrewb70]

Is the tuning done using a laptop or should I buy the lcd screen they offer for tuning?

I do my tuning with an ancient laptop that runs Windows XP...a laptop is definitely easier to tune with than the LCD.

Andrew

[analyte]

I'd give Bill at BP Automotive a call. He is a pro and has everything you need.

^^^^ I agree, Bill at BP was great to work with while building a custom harness to fit my needs.

Be aware that if you're using a DBW throttle body with the LQ4, you'll have to step up to the Holley Dominator ECU as the HP system doesn't support that option.

- - - Updated - - -


I'd give Bill at BP Automotive a call. He is a pro and has everything you need.

^^^^ I agree, Bill at BP was great to work with while building a custom harness to fit my needs.

Be aware that if you're using a DBW throttle body with the LQ4, you'll have to step up to the Holley Dominator ECU as the HP system doesn't support that option.

[andrewb70]

.....



^^^^ I agree, Bill at BP was great to work with while building a custom harness to fit my needs.

Be aware that if you're using a DBW throttle body with the LQ4, you'll have to step up to the Holley Dominator ECU as the HP system doesn't support that option.

Correct, the HP system does not support DBW, but you can simple swap over to a cable TB, which is much less expensive than stepping up to a Dominator.

Andrew

[F-Body International]

CamaroJesse, if on a budget, look around ebay and other sites to find ecu's that are from others unfinished projects. Holley EFI is about 5 years old and it's received much hype due to the name and it being relatively new. FAST, Big Stuff 3, Megasquirt are other systems that can be used.

If starting from scratch, I would invest in a nice computer. Holley Dominator might be overkill if you plan on using a manual transimission and real throttle cable. Holley HP will run your engine but it is rather limited in expandability. Fueltech is another new option gaining ground in this scene. FAST XFI and Big Stuff 3 have been around longer but those systems are just as powerful as most of the new stuff.

A benefit of all these systems is that most can be updated. Big Stuff 3 has been around a long time but users just got a major software update this year. FAST XFI has gotten a few updates over the years and some are expecting a new software update soon. Holley has updated their efi software a few times and it's not even 10 years old. I haven't followed Megasquirt too much but I assume their Tuner Studio software has been updated over the years as well.

[amargari]

If you are starting from scratch, the Holley HP is hard to beat. Do you have a Gen III or Gen IV engine?

Andrew

I agree with this. It may seem like more money but in the long run you are ahead of the game from a tuning standpoint. You can do a stock harness/cpu and HP Tuners for around a grand, but it is work or money to rework the harness. Also, it is easier to tune Holley HP than factory ECU.