Thanks izzy for the info . Never thought of that about getting the wheels all black. I was going with the exit in front of rear wheel because I only have a rear fuel tank. It looked a little tight to run duals over the axles and between the tank. I will try to look up Dans clips. THANKS.....

 

I haven't read all teh details of Ernest's posts yet, but in the first couple, he is syaing virtually the exact same thing I'm hearing from Pinnacle Performance systems in terms of their own exhaust system's design parameters.

For instance, to get a little more specific, their downpipe design includes running out of the turbo with a 3.5" section for about 17" before expanding into a 4" diameter. They do this because to rapidly expand into a 4" pipe straight from the turbo would allow the gases to cool too fast and thereby increase in density and actually create additional backpressure on the system due to the density gain. At the same time, once the gases have gone downstream a bit and land at the muffler entrance point in the pipe, going with a straight pipe (muffler delete) will also result in a little torque loss.

In other words, what I gain from this thus far is this... to gain ideal horsepower and torque, the changes in exhaust pipe diameter need to be limited in scope and gradually implemented so that the velocities and thermodynamics do not end up working against you.

 

Wow This is the most techincal I've seen these posts get.

So an exhaust brake will rob hp?

On my old 89 I had a 4" straight pip cut off behind the cab because the pyro was getting too hot, instead of choosing a location directly behind the cab for noise purposes, I should have found an optimal length which would best maintain exhaust temps. Too short may have cooled off too fast? and increased bp?

oz

 

Does anyone have sound analysis software that can analyze sound clips from various types of exhaust systems to see how distinct the individual exhaust pulses are after going through the turbo?

 

Just wait until I've read my new book, then I'll start regurgitating all the technical stuff from it! It will rob more HP if you mount it right next to the turbo outlet, where most are located. There's a vortex in the exhaust flow there due to the turbine, and locating a butterfly valve there causes a lot of turbulence which increases EBP, even when the brake is off and the butterfly valve is open!

That's why I went with the US Gear E-brake that I have located well downstream of where the DP connects to the tailpipe. This is also a desired approach, because the volume of the piping from the brake to the engine acts as an accumulator so that the backpressure builds up gradually when you apply the E-brake. I've been talking about "optimum diameters" not lengths. We don't have much choice as to the length anyway. In TX the tailpipe has to exit at least 22" to the rear of the passenger cab, at least that's what I was told when I did my side exit exhaust in 1999. Everything I've seen so far suggests that for a PSD, the shortest straightest length is the best, but the largest diameter isn't necessarily the best.

 

I have 2000 F250 7.3 SWD and I want to install a 4 inch turbo-back sytem myself but getting the downpipe off and a new one on, appears to be a major challenge. Anyone done that? What do I need to do?

 

I just fooled with it for a couple minutes and it went right back on. I took it loose and put it back on myself with the assistance of my floor jack when I did my Wicked Wheel install. No problems at all.

 

I've had to use a floor jack for assistance as well.

 

I have a wife that held my pipe for me

 

Please confirm for me, if I run a stock exhaust except that I remove the pipe from the muffler back this should improve my horse power and egt. over stock exhaust system w. muffler. Would I see better performance gains with stock 3.5" w. no muffler dumped before the rear tire or 4" exhaust w/o muffler exiting behind the rear tires in stock exit location. hope I'm clear in my question

 

In a word, yes.
Turbocharged engines need to breath to be most efficient. The best exhaust system for the turbo outlet is a very short pipe about 18 inches long, but that would be unbearable for daily driving.
So the best exhaust for the PSD is the big one.
I personally run a 4" downpipe which flares to a 5" exhaust. It's louder than the stock, but I love the sound.
4" all the way back is just fine, but the 5 sounds better. MUCH better. You can set off car alarms.

 

I have a the 4" exhaust on my 99' from the turbo back (see signature) and all I can say is that it made a big difference over the stock exhaust! The turbo spools up quicker and so the low end is more responsive. Also the gas mileage did increase about 15% with this mod and it sounds sooo much better so, overall I'm very satisfied. Good luck!

 

The 3.5" stock system is MUCH more restrictive than the 4". The 4" (or 5") after market systems are mandrel bent, and the stocker is not. Between the larger pipe and the mandrel bends, you get a way better performing exhaust than just cutting out the muffler. But the latter is certainly better than nothing if you don't want to spend ~$300-$500 on after market.

 

huh, saw this post and thought that Gene paid us a recent visit...

 

lol... actually he did!!

https://www.ford-trucks.com/forums/7...-to-fte-5.html