Chevy and GMC Duramax Diesel Forum banner

21 - 29 of 29 Posts

·
Registered
Joined
·
543 Posts
Do you recommend that just because the LBZ is known to be good, or are the K&N aftermarket kits known to be bad for LLY? This K&N looks to have been professionally installed... it's the entire intake system including mouthpiece, not just a replacement filter. The kits are in the $350 range when new so I hate to scrap it, unless we know it's not as good as the LBZ option. Several have mentioned to ditch the oiled filter and put a paper cone filter on, since they run just as clean and won't send oil into the MAF sensor... so I do plan to do that (if I keep it).
Well the complete LBZ setup is best as GM even had a TSB to install them on LLY back then. The K&N is not good all around as there is better options available. I do not think K&N ever made a turbo mouthpiece where the problem is with the factory setup. Look at the turbo mouthpiece closely and maybe even take a pic.
 
  • Like
Reactions: scottydl

·
Premium Member
Joined
·
1,310 Posts
Discussion Starter #22
Does anybody know how to remap the MAF with efi live? I have a v2. I do not know if the tune is locked form Idaho Rob.
 

·
Former GM Tech and parts
Joined
·
2,644 Posts
Does anybody know how to remap the MAF with efi live? I have a v2. I do not know if the tune is locked form Idaho Rob.
I would bet the tune is locked. And unfortunately you cant get him to adjust the tune now either.
 

·
Premium Member
Joined
·
1,310 Posts
Discussion Starter #24
I installed the tune 8 years ago and have never touched my EFI live as far as doing any changes. I am pretty sure it is locked to but how would I tell?
 

·
Registered
Joined
·
28 Posts
Well the complete LBZ setup is best as GM even had a TSB to install them on LLY back then. The K&N is not good all around as there is better options available. I do not think K&N ever made a turbo mouthpiece where the problem is with the factory setup. Look at the turbo mouthpiece closely and maybe even take a pic.
Not that you needed my validation ;) but you're right... I mistook the K&N system to include a mouthpiece because I misunderstood where/what the mouthpiece was located until I watched a few videos. Mine appears to still have the stock LLY mouthpiece with resonator on top. My K&N system is the "77 series" all metal inlet pipe that seems as smooth as anything could be, as far as air movement goes. See pics:

20200917_111225.jpg 20200917_111201.jpg 20200917_111241.jpg

I assume if I installed a stock LBZ mouthpiece, I'd need to cut the metal intake pipe in order to mate them up. Correct? Or would the S&B mouthpiece or another brand (already shortened) be a better match?
 

·
Administrator
Joined
·
1,037 Posts
I’ll also add that while your K&N kit is using the stock LLY mouthpiece, I can almost guarantee you that you’re pulling more hot air that you’d want to be with that cheap “airbox” that the filter is sitting in. Intake air temperature is CRITICAL to any engine. Especially turbocharged engines that are going to add even more heat to the intake air charge via normal turbocharger operation. Get that thing breathing as much cold air as you can. It needs it.

My personal belief is that EGR cooling and poor intake air design had more to do with failed LLY head gaskets than any other causes. The only saving grace that I think the LBZ, LMM and LML have over the LLY is better intake air design. Other than that most all of the engine hardware, as far as cylinder heads and cooling goes, is very similar. LBZs, LMMs and LMLs suffer less head gasket issues than LLYs in return. There is more than one reason why L5P K2 trucks got the hood scoop/ram air function added.
 

·
Registered
Joined
·
28 Posts
My LLY had the head gaskets replaced about 30k miles ago by the previous owner, so I've got that going for me. I thought the same thing about heat potentially getting sucked in through the wide opening that the K&N pipe passes through from the box to the engine bay. If I fashion some kind of foam or rubber something to fill in that gap, that should help, right? There's the top also, but I need to see if the hood (when closed) gets anywhere close to capping that K&N box.
 

·
Registered
Joined
·
543 Posts
I’ll also add that while your K&N kit is using the stock LLY mouthpiece, I can almost guarantee you that you’re pulling more hot air that you’d want to be with that cheap “airbox” that the filter is sitting in. Intake air temperature is CRITICAL to any engine. Especially turbocharged engines that are going to add even more heat to the intake air charge via normal turbocharger operation. Get that thing breathing as much cold air as you can. It needs it.

My personal belief is that EGR cooling and poor intake air design had more to do with failed LLY head gaskets than any other causes. The only saving grace that I think the LBZ, LMM and LML have over the LLY is better intake air design. Other than that most all of the engine hardware, as far as cylinder heads and cooling goes, is very similar. LBZs, LMMs and LMLs suffer less head gasket issues than LLYs in return. There is more than one reason why L5P K2 trucks got the hood scoop/ram air function added.
GM changed to MLS head gaskets in December 2005 so early LBZ had the same problem.
 

·
Registered
Joined
·
543 Posts
My LLY had the head gaskets replaced about 30k miles ago by the previous owner, so I've got that going for me. I thought the same thing about heat potentially getting sucked in through the wide opening that the K&N pipe passes through from the box to the engine bay. If I fashion some kind of foam or rubber something to fill in that gap, that should help, right? There's the top also, but I need to see if the hood (when closed) gets anywhere close to capping that K&N box.
The S&B mouthpiece alone will run you about $200. I would look locally in your area to see if someone has a complete LBZ setup for the same or less $$$. Sell the K&N to help pay for it.
 
21 - 29 of 29 Posts
Top