L83 Throttle Body Swap and Tuning

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Originally Posted by Harlech

Are you getting these numbers from a true Dyno or using calculated torque to see the difference?

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Dyno

Hmm, good info. Stock TB or a ported unit?

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Originally Posted by Harlech

Hmm, good info. Stock TB or a ported unit?

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Stock L86 Intake Manifold and Stock L86 Throttle Body, no porting on either one of them.

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Originally Posted by Mark@TuckerPerformance

Well I ended up finding out what it was causing the timing difference between commanded and actual, just overlooking tables that didn't believe it would have been.
[ECM] 12718 - VCP Humidity Adder Dry: VCP Spark modification based on humidity when humidity zone is dry.
Engine>Spark>Advance>Variable Cam>VCP Humidity Adder Dry table, it had -2* throughout the entire table above .24g airmass.

Set entire table to zero, and fixed the timing issue I was having. It was just normal IAT/ECT advance doing the rest, which is normal
Just crazy that it has tables like that when it obviously does not know the percentage of humidity.
Last night while tuning on the truck, it was approximately 83% Humidity.

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If you look at the multiplier for these tables you will find one of them is-1.6. This system has 2 humidity PIDS. Relative and Specific. Relative has no drive cycle attached to it. The specific requires vehicle speed for it to be able to generate a value. After you flash the ECM the specific pid will read 0 and with the multiplier factored in you will see 3-4* removed from total until this calculation has been performed. This could cause issues if not accounted for. My opinion is zero them out just as you did.

Is there anywhere in particular where you got the l86 intake manifold & the ported LT1 TB ? & also have you ever looked into or heard about anyone messing with they pulleys

I got my parts from Pace performance. I don't suggest a ported throttle body. Stock LT1 is plenty.

You only have to mess with the pulleys if you do an LT1 intake manifold or MSD. Best intake manifold out of the 3 is the L86 proven on a dyno.

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Originally Posted by HeavyChevy305

I got my parts from Pace performance. I don't suggest a ported throttle body. Stock LT1 is plenty.

You only have to mess with the pulleys if you do an LT1 intake manifold or MSD. Best intake manifold out of the 3 is the L86 proven on a dyno.

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Agree I just ordered mine but don't know if it is worth it on a turbo truck. I figure the throttle body being bigger helps but the manifold size make that much of a difference? I wanted to know if the l86 tb would bolt to a l83 intake? just 7mm difference but the bolt holes? Everything I read people said just let the truck recalculate for it, I'm sure that works but tuned is best as we see here.

The L86 intake manifold is completely different internally from the L83. The 5.3 manifold is like the older TBSS in design and the L86 is just like an LS3 manifold.

5.3 throttle body won't fit on the L86 intake manifold and you have to re calibrate for the LT1 throttle body.

Has anyone found a fix for the climbing/hanging throttle issue? I swapped an L83 into a Mazda rx8 and although it idles extremely well if I blip the throttle it'll hang around 2500-3000 for a ridiculously long time like some of the guys in here have claimed. I had to switch to the Camaro manifold and throttle body for clearance reasons so I can't really go back to stock. I have changed the manifold volume and throttle max area settings in HPTuners to match a stock LT Camaro and that made no difference.

All this has been tested in neutral so I'm resistant to even test drive it or drive it to the tuner.

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Originally Posted by rpierce

Has anyone found a fix for the climbing/hanging throttle issue? I swapped an L83 into a Mazda rx8 and although it idles extremely well if I blip the throttle it'll hang around 2500-3000 for a ridiculously long time like some of the guys in here have claimed. I had to switch to the Camaro manifold and throttle body for clearance reasons so I can't really go back to stock. I have changed the manifold volume and throttle max area settings in HPTuners to match a stock LT Camaro and that made no difference.

All this has been tested in neutral so I'm resistant to even test drive it or drive it to the tuner.

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Doesn't sound out if the ordinary, it is annoying but if you blip the throttle with no load it takes for ever for the RPMs to come back down. The joys of fly by wire. I don't know if anyone had figured out a way to get a snappier throttle in decel.

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Originally Posted by Harlech

Update these two parameters.
Attachment 69852Attachment 69853

And double check your TB connection.

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Is that the right area to use? I get conflicting answers using 6.2L truck values vs. 6.2L car values.

What is the difference between the two that would make the truck 4118 vs. the car at 4703.9?

I?d like to know this too. I?ve run both but don?t notice a difference. Can anyone explain their result of the higher vs lower number?

My assumption would be one would idle better right out of the gate. The reason the computer would want to know the maximum area would be to correlate airflow/torque for a given throttle position. At least that is my assumption. Eventually I would expect the throttle position to be learned and it may not make a difference. I would think with the lower value it is possible the throttle could feel a little more aggressive until learned - if it is anything to do with off idle.

Are these numbers from the l86 manifold and throttle body?
Or does this have the lt1 throttle body?

Clarification would be helpful.

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Originally Posted by big_sapper

There are a few threads on performancetrucks.net. Rerouting the belt is just putting a pulley using the alternator mounting bolt and a little longer belt. I did it on my truck, no problem.

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Do you have the part numbers of the pulley and belt? Also a picture will be appreciated.