I have Tri-Y Doug Thorley headers on my 95 f350 4x4. I have true duals coming off the headers now, but have been contemplating lately if I should run the y-pipe for the headers? Would the y-pipe scavenge/give me better power? I like how the true dual gives each bank its own breathing ability, but I dont really like the sound of a true dual. My only concern is what the diamter of the collector was on the y-pipe, I don't want to restrict my exhaust flow either you know? What do you guys think? I know the collector diameter on the headers is only 2.5 inches, so I would hope the collector on the y-pipe was at least 3, right?

http://www.dougthorleyheaders.com/pr.../productID/528

 

I think what you want is either an "H" pipe or better yet an "X" pipe. It will improve low and mid-range torque and mellow the exhaust. A "Y" pipe is for taking both banks of the engine and putting them into a single exhaust pipe.

 

yeah, don't use a y pipe. The H or X allows both sides to equalize, a h pipe would be cheaper to do.

 

Yes I have an H-pipe already. Still not a fan of the high frequency of a true dual, but i guess it aint worth taking it off. Thanks guys/

 

ive got duals on my 96 f250 with a 460 and instead of runin flowmasters or any other loud muffler i just went to bumper to bumper and bought 2 quiet stock muffers for whatever and fit them under the truck. now the cops dont even know i go threw town

 

A big 'Y' into a single exhaust like a 3.5" or 4" would be efficient and allow plenty of breathing room.

BUT, you already have true duals with a 'H'! I don't think changing the exhaust setup is going to yield much of an increase in HP/TQ. Changing the "H" to a "X" may change the HP just a little, but may also change the power band just a little too, overall its not going to be a big change.

As far as sound is concerned, you are not running much muffler at all.

--My recommendation. Consider running the Wicked Flow-max mufflers from the sponsor Bear River Converters (or similar straight through style). I have some on a vehicle and they sound great. Smooth deep rumble at idle, no noise at highway speeds, but you can hear it when you lay down on it. Straight through design means that it will likely outflow the Cherry Bomb you have now.

Eric

 

You make a compelling argument sir, but I have tried over 6 different types of mufflers, and none of them have yielded me the type of sound I have wanted. I tried the Super 44 by Flowmaster, Dynomax Bullets, Cherry Bomb Extremes, Dual Inlet/dual outlet Super 40 by Flowmaster, and then a dual inlet/dual outlet Cherry Bomb. So, as you can see, my truck has never given me the sound that I have wanted, and the only time it sounded mean and clean was when I was running a single inlet/dual outlet Flowmaster. But now I plan to run a y-pipe off the collectors, into a 3 inch magnaflow hi-flow cat, then a Super 44, then dual outlet.

 

All of your previous choices are very similar mufflers though and will have similar characteristics.

The muffler I mentioned earlier from Bear River, a Magnaflow, a Dynomax, etc.. Also, all similar design, straight thru, perforated core and flow great.

This is obviously a car that is going to respond to the change more dramatically than your truck, but.... In this example, a turbo'd street mustang gained 25rwhp going from Flows to a straight through Dynomax muffler. Needless to say, I'm not really a chambered muffler fan.

The Turbo Forums.com

 

-Cat. Converter-> Do some reading on Bear River Converter's website. The "high flow" converter in your plans is likely not as high flow as you would think. I have seen cfm testing from S.A.M. (school of automotive machinists) and out of several cats tested, the aftermarket "high flow" cats did not flow as well as expected. Actually there was little if any difference between aftermarket and factory spec. The highest cfm cat tested was a stock 96 tahoe and the highest aftermarket tested was from Random Tech (but it was still not close to the tahoe cat).

-You have spent alot of money changing your exhaust in search of that perfect sound and I can only imagine that you are getting frustrated at this point, but I really think the style muffler I have suggested will help.

-Just a side note- Many other things play into the way your exhaust sounds and while the tube diameter is obviously changable, many of the factors are not easily changed. e.g. motor, exhaust diameter, exhaust length, manifold style/size, muffler and tips.

Best of luck
Eric

 

Yeah, i hear you. I wish exhaust systems were more of a science, but it isnt, so it truly is trial-and-error. But, I think I will take your advice into hand, I will update the forum with the latest sound clip.