Does anyone make a y pipe for our trucks?It would be nice to cut the stock one out and replace with one with a 3''-3 1/2'' colecter.This looks like a major exaust restiction as the colecter is only 2.5''.

 

there is a worse spot in there


it is about 2" and then spreads back out to 2.5"


but yeah, some companies make generic styles, but what is the point? unless you are running bigger diameter piping the entire way

 

I have read reports of people losing low end torque after replacing the stock Y pipe. Something about it creating backpressure needed for the low rpm range.

 

I was looking at the flowmaster or mbrp single out [3'' 3 1/2'']cat back but sounds like just replacing the muffler will be just as good.

 

Pulse tuning is what you're working with when you think of low end torque or top end pull concerning exhaust pipes...once a puff of exhaust starts down the exhaust pipe it creates a vaccuum at the exhaust valve behind it...its this vacuum that helps pull in the next intake charge and makes the "low end torque" as stated above. To make this work, the size of the tubing has to be matched to both, the size of the exhaust puff moving thru it (cubic inch of engine) and the rpm range the engine is sending the puffs out at. Too small a pipe is restrictive at higher rpm...too big lets the puff spread out and lose heat (heat equals velocity) at slower rpm...a 5.4l is only 330 cubic inches which means its only 165 inches per side...An old school 350 engine made best power with 2.25-2.50 inch exhaust. Anything larger moved the power way up the rpm range and was only used by drag racers leaving the line at 5000rpm. So, using a 3" Y pipe with the short stock manifolds would move the engine's powerband up in the rpm range because the stock manifold only holds the puff for a few inches then it expands into the giant 3" pipe and loses velocity. Long tube headers use 3" Y pipes successfully because they have already kept each cylinder separated (for a longer distance than stock manifolds) via the primary tubes and then dumps into the collector in numerical order right before the point of the puff slowing down. This "pulse tuning" can be visualized by watching zipper teeth fall in line behind each other. Once in line the pulses move out of the tail pipe in an orderly fashion creating that awesome V8 sound we all love and the torque we all feel!

 

I was going buy flowmaster or mbrp single out cat back [3''- 3 1/2'']but maybe should save some money and just replace the muffler.

 

I know of a company.... their name will come to me, that makes a long tube header & Y pipe combo pack. THAT is what I would do.... make the most use of your new mod. Long tube headers on trucks are wicked. If I can think of their name, I will report back.

 

Dynatech

 

You stand to gain what...10-20 hp from a set of long tube headers and properly matched exhaust system.....at a cost of probably close to 1000 dollars....wouldn't a tuner be a better option????

 

I don't understand why people buy these expensive cat back systems from Summit or Jegs or whatever. That is such a waste of money. What you need to do is get a good muffler (Dynomax, Flowmaster, Magnaflow, etc.) and have your stock y-connector cut back a little and have a 3" single ran straight back with aluminumized or stainless pipe with your muffler of choice and either dump it, single tailpipe, or another y-connector with duals. Shouldn't spend more than $200-250 for that system. Better than $400-500+ with cat-backs.

 

the one thing about a cat-back ($300 split dual ss) when i sell my truck i can reinstall my stock exhaust and recoupe some of my cost. i have had muffler shop exhaust and got tired of fixing rusted parts. if he used ss stuff it would cost more than $200

 

I dont want to replace the whole y pipe just the collecter. Cut the right and left pipes back a ft or so and weld a bigger piece in.The 2 pipes are 2.25-2.5 coming off the motor coming together into a 2.5.

 

Ditto...

...also, most muffler shops can't do mandrel bending...if they do, the price is right back up to the 304SS Roush kit...