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Discussion Starter · #1 · (Edited)
Hi everyone, I thought you might be interested in some flowbench data for the LBZ mouthpiece modification for the LLY engine. I was bored yesterday so I ran a few bits across my flowbench.



This modification is the best thing you can do for an LLY! There is no point in buying a CAI with the stock mouthpiece, it is a terrible restriction. I was also suprised that an air filter with less than 17,000 miles was showing restriction.

The chart shows the flow through the mouthpieces only, then the LLY mouthpiece with only the stock duct, then the entire stock LLY system with a used air filter, then a new air filter. The last column is the LLY / LBZ hybrid complete induction system with a clean air filter.

My bench would only pull 21 In-H2O with the LLY / LBZ hybrid induction system, if you look at the orange columns you can see the benefit of this modification. The entire hybrid system with a filter flows more air than the LLY mouthpiece alone by a large amount.

Thanks for a great website, I took your advice and did this modification, it is the best bang for the buck for any LLY owner!
 

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You the man !! Nice, thanks for the effort :)
 

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I think that is the easiest to read explination of this whole mouth piece ordeal yet! Takes the guess work right out of the equasion.:drink


Nice job!
 

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Discussion Starter · #5 ·
I have a JKM flowbench. This modification is a great example of how relatively inexpensive parts can make a big difference.
 

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Mods: Request for sticky in LLY forum. This is excellent data, and we thank you for your efforts. BUMP ^^

BTW, camdoc, welcome to our growing community. :welcome

Jess
x2^^^^ KB's gonna enjoy this one. It's sticky.:D
 

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Wow good work!! Numbers are good, but graphs are great!! We engineers love data :rof
 

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it is deff. easier to see the difference on the chart rather then just reading a paragraph. i just ordered my mouth piece, cant wait itll it gets here.
 

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I ported mine the other day, I am considering buying the LBZ piece though.
 

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Good Work, nice graph. It really puts things in perspective as to why you can't pull the hills at less than 230. :D

…I think that is the easiest to read explanation of this whole mouth piece ordeal yet! Takes the guess work right out of the equation. :drink Nice job!
Unless you’re color blind…:tease

I ported mine the other day, I am considering buying the LBZ piece though.
The added flow bench data with the modded MP would be interesting to see in comparison too.

I was also suprised that an air filter with less than 17,000 miles was showing restriction.
What was the air box indicator showing? Anywhere near being correct?
 

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Great post man. Thanks again for another great contribution to an already strongly supported topic.
 

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Discussion Starter · #14 ·
The air filter only had a couple of inches of water additional restriction. The Donaldson indicator doesn't trip until around 20-25 Inches of water, my filter wasn't that dirty. 25 In-H2O is almost 1 psig, that will certainly kill some power.
 

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Great data. What a huge difference in airflows!

Question - can you get a KB modified 05 mouthpiece comparison with the LBZ one? I hope the modified 05 flow is up close to the LBZ, that's what I have in my truck.

Thanks again for the info.
 

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I agree with this being a great post....After buying my Duramax a couple of months ago I found this site and realized within a few hours the LLY MP was junk. I did upgrade and noticed quite a bit of difference. Since then I've added a TCAI from Killer Bee. Not only does the truck run better, but the fan hardly engages even when towing....
 

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is the orange line "LBZ/LLY modified" system the one killerbee makes or some other setup? and is the blue one (stock LBZ) that goes higher the best or, the orange one that goes second highest but over the higher test pressures better? I bought my truck last week and plan to buy whichever MP setup is better this week so ignore any stupidity, still learning the dmax ins 'n outs.
 

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For the Color-Blond

The highest bar is the LBZ mouthpiece only, the next highest shows how little drop there is when adding the rest of the intake for testing.
 
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