Engine/Transmission (1998.5 - 2002) Stock airbox and 400HP?

[tractorface]

I upgraded my transmission in December with plans to run about 400rwhp. Have been struggling to find a problem before upgrading injectors and recently removed my Raptor because it seems to be the source of my Gremlins. When I did this I put the OEM airbox back on and reset the wastegate for 20psi max. I hate the lower power but love the new found peace and quiet in the cab. Now I want 400 QUIET Hp. How do I do that??

I know the stock airbox can't flow enough air can it? I was running an AFE filter and a homemade heat shield. Is the AFE stage 2 unit as quiet as the stock box. Trying to eliminate the turbo whine as well as the Rush of Air sound. Also thinking of installing a second muffler on my 4". If 400 Quiet HP is out of reach than I'll shoot lower. Guess I just want some feedback from other Old Foggies :-laf When I say Quiet I am not getting carried away I mean close to stock levels. For what its worth I am against installing a bunch of overweight sound deading material. Maybe I'll do the back wall but that is it.

Thanks, Loving the peace and quiet

 

[KLockliear]

AFE Stage 1.

 

[tractorface]

C'mon

Are you trying to tell me an AFE stage 1 is as quiet as Stock. I don't believe you :-laf :-{} . My setup is very close to a stage 1. Anyone run the stage 2?

 

[HookMeUp]

I have an AFE stage 1 and I'm running stock HP. It makes noise! You can hear the rush of air, the high pitch turbo whine(I still have the ring in it), and the drone(the "wuff-wuff") at around 2000 RPM. I myself would like to knoe if the Stage 2 is any quieter.

 

[KLockliear]

Are you trying to tell me an AFE stage 1 is as quiet as Stock.

No, but that's the kind of airflow you will need to support that kind of HP. The Stage 1 is definitely quieter than the Stage 2 though.

 

[RColston]

The AFE Stage 2 is nowhere near as quiet as stock.

 

[Regcabguy]

How is a drilled out stock box for noise compared to a non-drilled one? Anyone using this compromise?

 

[Clmsnow]

A minor increase in whistle with the drilled box. Much louder with AFE and bigger turbo.

 

[tractorface]

Anyone want to speculate on why the Stage 2 is louder. I work for a company that keeps large gensets quiet and the most challanging part is airflow. Flowing lots of air quietly is not easy. I really hink this can work. I want to build an airbox that draws air from somewhere near the front of the truck and uses the AFE I already own. Thinking of relocating the passenger battery and going from there. Anyone have a source for intake plumbing? Any idea of how much air 400Hp needs

 

[Gary - K7GLD]

How is a drilled out stock box for noise compared to a non-drilled one? Anyone using this compromise?

I used that with a K&N filter up at 311 HP with no problems - had the Comp listed in my sig, but no other engine mods at that time. But my injector and exhaust upgrade motivated my switch to a BHAF, and I'm totally satisfied with it so far.

 

[jandtjil]

I want to try something like "Whitmore" has fabricated, pretty awesome.

https://www.turbodieselregister.com/user_gallery/displayalbum.php?&albumid=474

http://www.oilburners.net/forums/vbgarage.php?do=view&id=117

Maybe add a cover and sound insulation to one or both sides.

 

[EBung]

My stage 1 is loud and got almost unbearable with my hx-40 I know a silencer ring would definitely help but the 40 has no provision for one so I'd be interested in what you guys come up with.

 

[reddge]

Stock air Box

OK This is what is. I have twin turbo’s and running 450 hp and 850+ torque.

We dynode with stage one and compared it to the stock air box. There was an increase of 12hp. and a loss of 25ft. lb. of torque. This is not enough to make a difference one way or the other. The stock box works just fine and is a lot quieter.

 

[tractorface]

Red

Any trouble with ripping the filter or anything like that? I wish I could find Cummins data on allowable restriction and how many CFM the motor wants say at 300 hp or something close. How were your EGT's? I still think a custome steel box with say a 6 inch inlet would flow more air and be quieter in the cab. Just a lot of work when your not sure. Thanks for your input it was encouraging. I need to get the recorder out and see what frequency range the objectionable noise is in so I cn see best how to block it. I never seem to find the time for this stuff

 

[jandtjil]

Good thread on CFM

https://www.turbodieselregister.com/forums/showthread.php?t=129468&highlight=engine+cfm+stock

 

[reddge]

Tractorface

This is the beauty of BD’s Twin Turbo I have to work will hard to go over 1,200 EGTs

Pulling 8,000 lb. trailer up some good grades with AFE filter it gets pretty loud.

I get a little tired of the noise on a long trip.

No problem with the stock filter. 5,000 miles looks good.

That is my truck in issue 47 page 138 and issue 48 page 136.

 

[Lsfarm]

You have an instrument

Tractorface, you have a built in instrument to answer your questions on a stock airbox: the restriction guage. If it gets pulled down regularly then you need a less restrictive filter. If not, then enjoy the quieter intake.



If you really want to quiet it down make a new battery tray and move the passenger side battery up where the airbox is. you will have to use an Optima battery. Then make a new intake hose and put your filter down low behind the right side headlamp. Build a box around the back side of the filter and you will eliminate most of the intake noise getting into the interior



I ran single battery with a repositioned air filter for a summer and it was much quieter. I run two batteries and a BHAF during the winter.



The other option is to buy some 1" thick dense foam and make an additional hood to cowl seal or gasket and double up the seal at the rear of the fender near the door hinges. Also add some foam to the air intake trough where the HVAC intake pulls in air. This is the main source of your interior noise.



Hope this helps, Greg L The Noise Nazi

 

[tractorface]

Thanks. I was wondering if relocating the AFE would help. Sounds like it may be worth while. Why can't I run my normal batteries if I swap places with the OEM airbox? You lost me there. Thanks for the other noise control tips as well. That is the type of information I was looking for. Controlling noise without adding extra weight.

Thanks again

 

[Lsfarm]

Moving Battery

The measurements I took make me believe that the stock battery would be too large to put up on the inner fender. I was thinking of using an Optima on it's side to keep the height down. Maybe the stock battery can be moved and not have any clearance problems??? I haven't gone beyond just thinking about it and making a few measurements.



Greg L