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Discussion Starter #1
Hello all,

I just picked up a 92 F250, 460 5-speed, Ext cab/long bed a could months ago. Whoever did the exhaust on it previously had no clue what they were doing. They replaced the cat with a 2.5" outlet to a single 2.5" pipe and bolted it to the fender. This thing is being strangled so badly that it's leaking at both manifolds at the Y.

So here's my quarry... I'm not putting a lot of money into this thing, so budget is important, but I want it to flow properly and breathe easy. I spoke to a local exhaust shop tech who seems very knowledgeable on Ford engines, and he gave me a budget friendly suggestion

He recommended installing a 4" aftermarket 7.3l diesel kit that I can get for pretty cheap and bolt right on (avoiding custom work). Single 4" catback, no muffler, exiting behind the wheel.

My concern is that it will sound too raspy with just the Cat and no muffler. I love loud, deep, aggressive exhaust... But I don't want it to sound like an old farm truck. I expressed my concern and the way he explained it was

"With a side exit 3 inch with no muffler, the exhaust would be exiting the pipe at a much higher pressure which is what would create that "raspyness", so a 4" diameter and having a lot of pipe to travel through on a long bed at a lower pressure will give a deeper, more rumbly note"

I would love some input from fellow 460 owners.




-DK
 

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I have a cat less/muffler less 2001 7.3 that I love the sound of but I’m not sure I’d want to drive around with a straight piped gas engined vehicle. A turbo goes a long way in helping to “muffle” the exhaust noise which in my opinion is why you can get away with it in a diesel.
 

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Discussion Starter #3
Thanks for the input. I would be keeping the cat and just opening it up to properly accept the diameter.

I know those cats do a good bit of "muffling" so I'm just unsure about how it would sound keeping the cat and doing a single 4" behind the wheel
 

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upward swept headers exiting though large holes in the hood?
:grin:

The purpose of the muffler is to randomize/reflect/cancel the sharp pulses of the exhaust valve opening and the associated high pressure pulse. Increasing pipe diameter to reduce velocity isn't going to address this very well. A long pipe with lots of bends does help muffle due to reflections that cause destructive interference (aka partial cancellation).

I would run a single 3" pipe and medium size case straight through muffler of some knock-off brand.
 

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Discussion Starter #5
Thank you for the info and input, I appreciate it.

I think the headers through the hood option sounds like a great idea 😎
 

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I have a 94 F250 and I opted out of the cat and buy a dynaflow exhaust (I went the expensive route though) with banks torque tubes. I personally would rather run no cat with a good open straight through muffler and a k&n air filter. That with a few other small bolt ons really made the world of difference in my truck both in power increase and just all around running.
 

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In an induction limited engine like the pre 93 EFI with their small 1.980" intake valves a 4" exhaust, while it will help power at max rpm a bit it is going to KILL low rpm torque and throttled torque.

A 3" single exhaust with a straight through muffler like the magnaflow large case is more than adequate.

Headers and free flowing exhaust along with a K&N element are the starting points for better performance. Add 2* of initial timing with spout disconnected.

Next is internal.


SJ
used 2b RHP


:D
 

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Discussion Starter #8
Thank you all for the input. I bought this puppy to haul and get things done seeing the house. I've never owned an older model truck but I'm loving this thing. The 5-speed is a feature and the existing exhaust setup is just terrible.

Opening it up to breathe is a must but I don't want it to be too much. I thought about doing the whole system, headers-back but I'm not sure if I really want to dump that money into it.

I definitely have some decisions to make
 
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