4" Exhaust Restriction

[GregSmith]

I'm researching 4" exhaust systems for my new truck. Most setups seem to neck down to about 3-1/2" at the turbo. Is anyone aware of systems that are 4" from the turbo back? Thanks for your help.

 

[Kimber]

Try www.dieseldynamics.com They seem to have a high-end system.

 

[rbattelle]

In order to get larger than 3. 5 inches at the turbo you'll need a new turbo exhaust elbow. The exit of that elbow is around 3. 5 inch.

 

[Car_nut57]

The neck down to 3-1/2" at the connection to the turbo should not make any appreciable difference in performance of the system compared to a 4" connection. If the entire system were 3-1/2" that would be a different story.

 

[RDietze]

carnut is right

the 3. 5" "restriction" actually compliments the torque of the truck - you lose torque as you increase diameter - unless you have modified your fuel and are throwing more at it than stock



the banks is 4" turbo to tailpipe and eliminates the cast iron turbo exhaust elbow - i don't think the turbo exhaust elbow is 3. 5... . i think it is more like 4" (look at it)



mark from dppi should be chiming in here soon, i know he knows

 

[Snow man]

Greg,until you upgrade the turbo,the 3 1/2" restriction doesnt restrict anything at all. The exhaust side of your turbo necks down to about 1. 5",so the 3. 5 " pipe about 5" long is fine .

 

[RAMINSPEED]

Banks replaces the elbow with 4 inch pipe from the turbo back.

 

[RDietze]

raminspeed,



what do you think of your banks?

i have a banks on my psd - love the exhaust, strongly-dislike the banks mafia (now THAT was PC)

 

[RAMINSPEED]

Originally posted by RDietze

raminspeed,



what do you think of your banks?

i have a banks on my psd - love the exhaust, strongly-dislike the banks mafia (now THAT was PC)

If I had to put it on again, I wouldn't! It HOWLS in cab way tooooo loud.

 

[RDietze]

HOWLS?

HOWLS as in turbo whistle?



where is the "HOWLING" coming from? all over, exhaust tip, underbody, kick board?



thank you

 

[RAMINSPEED]

Sounds like under body, possibly the muffler. Not the exhaust tip where it should be. It hows with the windows down or up, it doesn't matter. It's so loud in cab you cant hear your wife yelling at you for buying the darn thing! LOL :-{}

 

[Vaughn MacKenzie]

Carnut_57 helped me hook up an exhaust using a Ford PSD intermediate pipe, Aeroturbine and 4" straight-thru muffler. Turned out nice and sounds great and the only 3. 5" part of the system is the downpipe. The PSD intermediate pipe clamps right to the downpipe and flares to 4". I reused my tailpipe for a budget sysem (although the Aeroturbine costs a couple bucks).



Vaughn

 

[rbattelle]

Oh, I agree completely that expanding the turbo exit pipe would have a negative impact without increasing airflow significantly. I was just pointing out that if you want a "complete" 4-inch from the turbo back you'd have to replace that elbow.

 

[DPKetchum]

That howl is the drone thats be complained about with the stock exhaust etc. I like the howl a whole lot better then the drone. wife agrees