Best EFI harness and ECU for LS transplant. - Lateral-g Forums

7firebird1 · #1 07-17-2013, 04:20 PM

Hello all! I am in the process of dropping a 5.3 LS engine in my 71 Firebird.
I am in search of a good plug and play setup that works good but not overpriced. I have looked at Holley and FAST and not sure which one to go with, or maybe there is another unit I should look at. Any help would be appreciated!

Vince@Meanstreets · #2 07-18-2013, 10:21 AM

Try searching PSI?. They seem to be affordable.

Jr · #3 07-18-2013, 11:12 AM

Factory Ecu with hp tuners has worked pretty good for a lot of people.

XLexusTech · #4 07-18-2013, 12:31 PM

I recommend PSI, veryy happy with mine

PTAddict · #5 07-18-2013, 02:03 PM

We've had very good success with OEM ECU and harnesses from Speartech on a number of swaps.

Jr · #6 07-19-2013, 08:55 PM

Speaking of psi...
http://secure.ultracart.com/catalog/PSI/
Looks like Charley's jackass.

7firebird1 · #7 07-20-2013, 10:50 PM

Awesome!! Thanks for the feedback!! Never heard of PSI but definitely gonna check them out and Speartech as well.

64duece · #8 07-24-2013, 04:04 AM

If the engine is stock or close to stock, a factory ECU is a great option. If you want to play abit or have mods, the HP Tuners/EFILive can do the job but not nearly as easy as Holley. If you factor in the cost of SW,aftermarket harness and a WBO2...your not far off from aftermarket territory.

gnx7 · #9 07-24-2013, 01:31 PM

I run the Holley in my RX-7 and the Chevelle project is getting one also.

The harness is simple to install. I'm no computer genius and the interface is very easy to follow/use/navigate. Upload a file for your combo and then let the self tuning do the work. You will need to clean up the idle/cold start but the rest the Holley does for the most part. I will never ever have to pay a tuner $300-600 each time to tune my car when changes are needed.
I have never been on a dyno or seen a tuner with my LS7 RX-7. It runs like a raped ape. 1.5hrs worth of tuning on it so far.

Comparison:
new LS1 stock harness $700, used computer $100, tuning $500
(then retunes are more $)

or a Holley system with easy to use interface/software
new harness/Holley computer, WB02 sensor $1500 shipped online

7firebird1 · #10 08-07-2013, 02:14 PM

Sounds like Holley may be the way to go. Thanks for the input!!