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Mod advice... ported TB and tuning

Old 05-25-2019, 07:57 PM
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Default Mod advice... ported TB and tuning

I bought a 15 6.2 A8 Sierra. Iíve mainly dealt with the older stuff without the driver demand crap and always used Hptuners. On the older stuff a ported TB helped throttle response. This truck seems to do decent with it but itís hard to ignore that giant step. My question is with the ported TB, CAI, and Flowmaster catback will I have to mess with the driver demand stuff in the tune? I donít want to make the truck undriveable while I figure out how those tables work. Plan was to touch up MAF curve lean PE add some timing and TM and go with it. Also anybody that did the ported TB without a tune how was the throttle response.
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Old 05-25-2019, 08:06 PM
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Everything is torque based. You will have to go over the entire airflow model and torque model if you port the throttle body. How much you have to change is different from vehicle to vehicle.

There are two side to the airflow model. The MAF and VVE tables.

Because it's torque based, not touch anything torque mngt related is the best idea. Altering that stuff can and will throw everything off if something is done wrong. Aiming for mid 12's afr and trying to optimize the timing is a good place to start. A wideband is required to really make sure you are working in the right direction.
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Old 05-25-2019, 08:23 PM
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Does changing the MAF curve whatís throwing the torque model out of whack? I have several wide bands Iíve tuned dozens of LS1s and 5th gen Camaroís. The 5th gen cars I always tuned in MAF only mode. Basically if the MAF frequency table doesnít change from stock with the throttle body still effect the driver demand?
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Old 05-27-2019, 01:52 PM
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I ported my throttle body but the lip was so small already it really didn't make a difference. Does your L86 have a huge lip, have you looked at it to make sure? The old ones did for sure but my L83 throttle body is far different than the ones that came on the 07-13 trucks. I haven't seen a L86 throttle body in person but online the lip looks very small like on my L83 but who knows if I saw an accurate picture. All I did was smooth the sharp edge on the lip of mine and cut down the bolts that hung out of the throttle blade shaft. I didn't notice any difference, but I haven't had the tune looked at since I did that either. I wouldn't think there's really anything there though since the lip was so small.

From what I can tell about what sam did when he tuned my truck is he more so left stuff alone due to adaptive shift etc. My truck is A LOT faster now after the tune but I'm pretty sure all he really did was increase the shift point to 6k, tightened up the tq management just a tiny bit, and made sure my A/F was correct for the mods which are in my sig. He said on the newer transmissions is best to let it mostly do it's thing and not mess with it much.
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