2nd Gen Non-Engine/Transmission 2nd Gen Straight Pipe - Yea or Nay

[KATOOM]

You got me curious too. I may just go pick up one and see how loud random things are in my life.....

 

[KATOOM]

OK…..just for sake of curiosity, I acquired a decent dB reader and performed some noise level tests of my own. Remember, the truck is a 2001 with a 4” straight pipe exhaust which has been heat shield blanketed from the down pipe angle to the end of the transfer case. All stock exhaust pipe hangers were used and the exhaust tip exits in the stock fashion. Weather was approximately 75* outside and there was no surrounding structures to bounce noise waves off of.

This is the data I came up with:
In the cab, windows up, engine idling = 61 dB
In the cab, windows down, engine idling = 63 db
In the cab, windows down, in neutral, engine at 2000 rpm = 75 dB
About 3’ from the front of the truck, hood closed, engine idling = 61 dB
About 3’ from the engine, hood open, engine idling = 87dB
About 3’ from the tip of the exhaust, engine idling = 89 dB
In the cab, windows up, 5th gear, 55 mph (approx 1600 rpm) = 74 dB
In the cab, windows up, 4th gear, 60 mph (approx 2300-2400 rpm) = 78 dB

So in reference to these numbers, all I can say is that…..even though my exhaust is straight piped, I don’t know why but under normal driving conditions my truck is NOT loud by what most consider to be loud. I can easily have quiet conversations in my truck while cruising down the road. But all that said, it’s certainly not quiet on the outside either. The Cummins engine is just plain loud as the 2nd gen 24 valve trucks are noise makers by design. Drive through bank tellers and drive though fast food orders must be done with the engine off otherwise the engine rattle alone simply dominates.

Now to bring some relative data in this situation for comparison….. I also took some dB readings of my wife’s minivan and this is what I came up with:

In the car, windows up, engine idling = 45 dB (cant really hear the engine)
In the car, windows up, 55-60 mph = 73 dB. (more noise being heard from tires and aerodynamics)

So it would seem that my numbers are not unrealistic but are pretty much on par.

 

[Chief USA]

I went with a straight pipe primarily due to egt issues. The only way I was able to get egt's in check and control was changing over to a BHAF and a 5 inch turbo back straight pipe exhaust. It is tolerable but can be a bit of a pain in the arse for cabin discussions when the engine is under boost conditions. 10 psi boost and above, you can REALLY hear it, otherwise it is not too bad.

 

[senorlechero]

I've had the same experience as KATOOM, even the same db readings.

I just removed the factory cat and muffler and replaced with exhaust pipe.

Are you guys with the really loud trucks running 5" exhaust?