S13 sr20det, ls2 truck coilpacks, jwt tuning --> Question I need answered.

[Bleakley]

I literally just got off the phone with someone over at JWT. I started an order to retune an ECU a couple weeks ago and forgot to add on ls2 truck coilpacks. Called back and said I wanted that in the tune.
I was just informed that they do NOT need to modify anything in order for me to switch from stock to LS2 coilpacks. "Do whatever you want with the ignition as long as it is being controlled by the ECU."
THAT IS FUCKING NEWS TO ME! I'm calling BS, but can someone please shed some light on this?

Every thread I've read that was credible regarding the swap stated that a retune was necessary. I'm about to be REALLY f***ing pissed if I just spent all this money and the ecu isn't worth poop for my setup

[Gingersmurf]

Not sure about your coilpack situation, but i can attest to JWT. They are good people. have dealt with them before with no hassles, or headaches. I can't imagine they would intentionally do something wrong and harm their name?

[codyace]

You do not need a re-tune for LS coil packs. Maybe with super high boost and needing more dwell, but that's about it.

Wire across/rid of the ignitor, run the signal wires right to the signal wires on the LS packs, and rock and roll.

I ended up using Magenecor custom FWD wires in super long lengths and trimmed them to size to make it easier to pull the plugs on/off the engine.

[TheRealSy90]

They are correct that ls coilpacks will work perfectly fine without any adjustments to the tune.


However, higher horsepower applications would benefit from dwell adjustments within the ecu for sure.

[Bleakley]

Awesome! Thanks guys. (what a relief)
Wiring them correctly is a non issue for me for sure.
Plan on running MSD wires.

Still wish I could just have them tuned up from the start, but since they'll work for now I'll just run with it and change it later. Seriously, thanks for the fast responses.

[codyace]

Awesome! Thanks guys. (what a relief)
Wiring them correctly is a non issue for me for sure.
Plan on running MSD wires.

Still wish I could just have them tuned up from the start, but since they'll work for now I'll just run with it and change it later. Seriously, thanks for the fast responses.

As before, find the longer 'post style' (or whatever you want to call them) ends, like the FWD cars, or 4g63 cars have is much eaiser than trying to get the little 'v8 style' ones down in the plug well

[Bleakley]

B18 wires were the ones I selected, Damn near perfect..

[Croustibat]

SR dwell time is around 1.9ms, LS coils need around 5ms .

You don't need a retune as long as you have spark, true, but the spark will just be weak. No matter what JWT says, the tune has to be modified to set the dwell time, if things are done properly ... There is no need for a dyno session, this is a 2 minutes job (that includes the time to plug and unplug the chord)

The reason for the confusion is usually people talk about making modifications to the main fuel and timing map when talking about a retune. There are so many other maps and parameters in an ECU ... and dwell time is one of them.

[Bleakley]

SR dwell time is around 1.9ms, LS coils need around 5ms .

You don't need a retune as long as you have spark, true, but the spark will just be weak. No matter what JWT says, the tune has to be modified to set the dwell time, if things are done properly ... There is no need for a dyno session, this is a 2 minutes job (that includes the time to plug and unplug the chord)

EXACTLY. My findings exactly.
I have seen multiple threads on the ls coils at 5 m/s and their fields collapsing prior to the intended time. While some seem to excel incredibly at ~ 5ms, others seem to throw spark whenever tf they feel like it. If I get the chance I'll find a way to get it around ~4ms or I'll just grab a PFC or other standalone unit like aem or something.