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Hey guys I will be using an ls3 mass sensor on my ls1 swap , now I know that you have to program the pcm to read the ls3 sensor. But my question is , I know that the ls3 sensor has an incorporated IAT sensor , and I believe my 05 5.3 has a separate sensor for the IAT .. what do I do with this , do I delete the stock IAT sensor and utilize the one from the LS3 Mass Sensor. And what do I tell the harness builder, to wire the the mass sensor and IAT sensor as it was an LS3 ?
If I remember right I think I was told the closer to the TB the better(AIT sensor). That way it's more "accurate" to what the temp of the air is going into the motor. Idk for sure tho I'm sure some one will know more then me lol and have more input. .
For the stock LS1 wiring harness, I just got the conversion adapters from Casper that connect into the two plugs on the harness and then one connector plugs into the LS3 MAF. If you're getting a harness built, just tell the builder to use the 5-pin LS3 type vs the separate MAF/IAT.
As for the tune, you'll need to modify the IAT scale. My stock table was:
Yes. If you do it in a 100mm-ish tube this is the baseline transfer table. You'd need to tune against this. I've started here with my LS3/100mm MAF combo, and added 15% above idle regions and kept close to this for idle regions in cammed cars. For a 5.3L with less cam, I might just leave as is and do some driving to see how far off it is in the light load areas. If it's off 5-6%, just extend it out the rest of the frequency range that much.
But try to maintain this shape of the slope. Don't add 8% somewhere and subtract 5% in the next cell. Try to keep the shape and just move the whole thing up or down as needed.
One thing to note: the MAF frequency is narrower with the LS3 vs the LS1 MAF.
Jake , can the tuner just copy the Mass and IAT peramaters from and LS3 and just put them on an ls1 tune as a starting point when upgrading to an ls3 Mass?
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LS3 Mass sensor on a LS1 (AIT delete) 
