TRD exhaust - Page 3

spjonm3 · #31 (**permalink**) 09-20-2005, 07:47 PM

The is only one problem with having a muffler shop custom make your exhaust. They can't mandrel bend the pipe, or at least none that i've ever been to. So every bend, especially the one over the axle, will be a smaller diameter than the straight pipe. So you wold in fact be decreasing the diameter of the exhaust if you were to start with the same size tubing. You also don't want to go too large for pipe because you don't want to loose some back-pressure, you do want keep some of that back-pressure. From my limited understanding you will actually loose some power (torque I think) if you take away all of the back-pressure.

Phi Kai · #32 (**permalink**) 09-20-2005, 07:58 PM

I've decided to go with just replacing the muffler so I don't that I'll have any problems with pipe size loss.

We shall see...

spjonm3 · #33 (**permalink**) 09-20-2005, 08:46 PM

Quote:

Originally Posted by Phi Kai

I've decided to go with just replacing the muffler so I don't that I'll have any problems with pipe size loss.

That is probably the best way to go besides a full system like the TRD that way you don't have the restriction of the bent pipe.

MERCULA · #34 (**permalink**) 09-20-2005, 09:13 PM

I like bolt on **** , The way I figure it the less people that touch my truck the better. Just a muffler would be cheaper for sure,The trd is also stainless, Not sure If anybody really cares ? or if thats readily available at your local muff shop ? But its an upgrade in my eyes atleast .

And I could honestly care less about having duel pipes .And there will always be a cheaper way of doing things , thats no dispute ,but sometimes they are just that ...cheaper things .

After driving around a little more today I really like the sound it gives the truck .

Snakeii · #35 (**permalink**) 09-20-2005, 09:52 PM

The shops that I have gone to have machines to make mandrel bends. I know what you are saying, yes a good number of them will create pinches or whatever you care to call them but not all shops are a like. Get out there beyond your cheap Midas and "we only install bolt on systems" shops.

And for me its important to have a smooth flow for exhaust. Why? Because the smoother is it the easier it is for the exhaust gases to exit. So why not increase the flow even more by going with dual exhaust? Especially when its cheaper (not quality except if you dont do your shopping around). Have your pick of SS, ceramic coated or whatever you want to setup. 2 1/2" pipe would be good.

So go pay $600 or whatever for your single piped cat back system if youd like. As far as back-pressure, perhaps if we go back in time 30 years where technology sucked compared to today. You want close to zero back pressure. What you are mainly concerned is having the best velocity of the gases to get them out as fast as possible. So if you have back pressure that aint gonna happen, you lose power. If you have too big of a pipe the velocity is going to suck, the gases arent going anywhere fast, so you loose power. Since there lacks any companies that Ive seen yet that has dynoed the 4.0L with different systems going by what Ive seen from owning various Mustangs, etc I figure a dual 2 1/2" system would work great, possibly with a h-pipe. I havent looked that much underneath to know if a h-pipe is possible but its nice to have to equalize the pressure on each bank.

For example take a water hose with a couple different sized ends, like from one of those radiator hose adapters or whatever. Its important to crank open that facet the same amount with each sized ends. A small one will create quite a bit of pressure in the hose with very little water, although a long stream, coming out the end. A big one will just have water pouring out the end with little to no velocity. One in between will create a little pressure on the hose but will be streaming out the end fairly good. You can try this with a water/gatorade bottle or whatever. One of my points is you dont want to create pressure in the exhaust, otherwise it will flow back through to the exhaust valves and back into the cylinder.

If you dont believe me than do some googling (find some competent sources) or just go ask someone that builds performance exhausts. Email the various manufacturers, just dont listen to the BS myths and legions...