Hello, I have been building my 460 and was wondering what size of exhaust should I run. I was thinking L&L fenderwell exit headers, flowmaster delta force mufflers and dumping the exhaust in front of my back tires. This is going on a 79 f-150 4x4. It will be true dual but should I run 3inch exhaust? and should I run an H pipe or X pipe? or is it not worth it, might be hard to do.

 

On my 1992 f250 i went from the 3" flange to a 3" inlet thrush glasspack that split to dual 2.5" with a 27" pipe on each outlet that kinda points towards the ground. All my friends know who it is a half to a full mile from there house from putting it down. It sounds deep and it sounds nice i think and so do the people i know. I checked out a youtube vid of a monte carlo or something similar with a 396 or 454 with a thrush glasspack and it sounded pretty much the same. The part number is 24224 at thrushexhaust.com.

To answer your question dual 2.5" or a single 3" to the muffler will be fine. After that you could up it a size for a deeper tone and to make it look pretty cool. Which i may redo the end pipes and make them 3" and point them out in front of the tire for a nice deeper tone and cool looks.

 

Years ago I made a crossover pipe for a set of outboard headers on my truck. I had a 400 in it at that time. I couldn't get it very close to the collectors though. It would have been a real pain to take it that far. It did quiet it down a little but that was all, it didn't run any better. Even if I would have gotten it closer to the collectors it was obvious that it wouldn't have been worth the effort. I run a set of L&L outboards with a small set of stainless straight through Borla header mufflers & 3" stainless pipe on my 460 now & it's loud, real loud.

 

I did mine when the exhaust was shot. there were holes everywhere and it practically fell apart when i took it off. So i noticed a bit of a gain in power and an increase in mileage. So it will help but it will take longer for you to pay it off

 

I like the deep rumble of a big inch single exhaust. Just thought I would throw that option out there.

-e.g. highflowing Flowmaster "Y" with 4" outlet (not always listed in the catalogs, but they do make one) and then a mandrel bent 4" CB typically marketed to the diesel crowd with your choice of muffler. I like the straight thru style mufflers like magnaflow,dynomax, etc..

The single with a good "Y" should be just as efficient as an "X" and duals, if not more. Also I would expect the single would be lighter.

Eric

 

I'll be dad gum,, son you just gave me an idea for my exhaust, diesel muffler or mufflers.

Ok, need to think about something here & this could help rye or some others but might have already been covered.
Starting at the exhaust port exit, like if your bolting on headers & say maybe an inch or two from the port opening you increase the header tube ID a good bit, wouldnt that create a suction like effect & pull the exhaust out or would it just be messing the exhaust up.
If it would create a suction, what would be the effects on performance or would it harm the engine.

I have allway heard you need some back presure in the exhaust system, but how much do you need.
Neil

 

Little to none.


The only feasible reason to have back pressure over and beyond what your headers or manifolds are creating, is to ensure a good reading on the O2 sensor.


As far as the exhaust tube size, I think the tuned long tube header design is about as good as it gets.

Glad you like the BIG single idea.


Happy Trails

Eric

 

X2 It is not the back pressure you want it is the exhaust scavanging you want from th tuned length of the header and collector. But comprimises always have to be made in the real world to get it to fit in the truck.

I like the big single also

 

How about a 3" opening stock muffler off of a F350 7.3.
Neil

 

The diesel muffler will flow alot better than your stock garden variety gas muffler, but still not as well as an aftermarket.

The tailpipe that I currently have is a factory take-off from a Ford diesel (3.5"). I considered using the muffler, but after looking inside the muffler I was able to see that it necked down considerably, despite the fact it had a generously sized inlet/outlet. I dont know the year of the donor truck.

hope that helps
Eric

 

 

16-year-old Zombie thread!

That said, on my current 'slightly tweaked' '95 I'm running a no-longer-offered stainless mid-length header/y-pipe combination that looks very similar to the Hedman 89510, stock 3" in/out catalyst, 3" pipe to the 3" in/out stainless Magnaflow straight through muffler, then a single 3" stainless tailpipe.

I had the same cat-back system on my previous bone-stock '97 7.5L and loved the sound (deep rumble). This one with the headers has a slightly different rumble, but still not excessively obnoxious with the catalyst acting as a 'smoothing' muffler..

 

Have any pics to share?

 

I don't have any current pics. Truck is at my other property out of state right now - see my engine build thread here: https://www.ford-trucks.com/forums/1...onversion.html

 

Thank you that was awesome