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!

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!