Air Box Modifications

[galaxie428]

Hello all. I have an M998 that I'm doing a 6.2 to 6.5l TD swap on and was looking at all the air box to see what could be done to help with air flow to the turbo. The filter looks like about 1/2 of it is covered with that baffle. Has anyone trimmed that baffle and or the stack to help with air flow? Any negative effects on what modifications you've done?

I do some light offroading with it so there is some dust and dirt where I go. Obviously, I don't want to do anything that will damage the engine but I do want to let it breath more.

 

[Mogman]

That air box will flow many times what that turbo can pull, no need for modification.
EDIT, I am running a stock intake with a Duramax, it of course is monitored by the ECM and it has no issues with the stock intake, the numbers all look good (at up to 475HP) and the Duramax of course flows much more that the 6.5T.
the filter itself is grossly oversized to compensate for harsh battleground conditions.
I am convinced they only put the different hat on the Alpha just so it would be instantly identifiable, seeing it only has a 300HP tune in it.

 

[Vapor Trail]

I was thinking about just leaving the round lid off the end of the air box.

 

[Mogman]

I was thinking about just leaving the round lid off the end of the air box.

WHY?

 

[galaxie428]

That air box will flow many times what that turbo can pull, no need for modification.
EDIT, I am running a stock intake with a Duramax, it of course is monitored by the ECM and it has no issues with the stock intake, the numbers all look good (at up to 475HP) and the Duramax of course flows much more that the 6.5T.
the filter itself is grossly oversized to compensate for harsh battleground conditions.
I am convinced they only put the different hat on the Alpha just so it would be instantly identifiable, seeing it only has a 300HP tune in it.

You are probably correct, just seems like a lot of unnecessary baffles blocking airflow path to the turbo.

 

[Mogman]

The 6.5L was the end of a miserably failed attempt by the gasoline engineers at GM to design a diesel engine.
I am not sure who at GM decided to go to folks at Isuzu that REALLY knew diesels to design the 6.6L but that guy deserves a medal, GM went from LESS than 4% of the light duty truck market to well over 30% now

 

[Vapor Trail]

WHY?

Because my intake has to be a large K&N. I don't want to look at it all the time (most people leave them out exposed) so I was going to route it into the existing airbox and leave the lid off so it can get more air. That little round cap looks restrictive.

 

[87cr250r]

You do not want to use K&N filters in dusty off-road environments. They really aren't good for on-road either.

If you want the best of the best, replace the entire filter housing with a Donaldson PowerCore housing.

 

[Vapor Trail]

The guy that did the computer tuning said this works best so I’ll probably stick with that but I’ll look into the housing. I know Donaldson makes good stuff

 

[Mogman]

The guy that did the computer tuning said this works best so I’ll probably stick with that but I’ll look into the housing. I know Donaldson makes good stuff

That is a Donaldson type housing that is stock on the HMMWV, I would certainly not expose my filter to the wheel well where more dirt, dust and rocks can get into the filter.
If you want to stick with the K&N (which I also have a low opinion of because of the maintenance required to keep it effective) just leave it under the hood, sucking hot air is probably better than sucking up dirty air.

 

[Mogman]

In fact Donaldson makes that filter #P521242
EDIT, looks like it has been discontinued......

 

[Vapor Trail]

I’ve used the K&Ns in SxSs and ATVs for years with no trouble. You just have to keep it cleaned and oiled

 

[87cr250r]

Never had valve recession?

 

[lpcoating]

This reminds me of the 80's when everyone drilled holes in the airbox of their motocross bikes so they'd go faster...

 

[87cr250r]

Speaking of dirt bikes. This is what happens when you run aftermarket air filters on a XR650R.

 

[Mullaney]

Speaking of dirt bikes. This is what happens when you run aftermarket air filters on a XR650R.


View attachment 896139

.
Oh yeah...

And don't forget turning the air cleaner "over" to expose the filter so the "engine could breathe better" trick too. Suck up the dirt and pile it up on the airbox...