I was in the market for a good exhaust as well but after reading these post im not sure i want to go ahead with it. How much wear and tear can this cause to the turbo. Whats some of the break downs thats people know of happening. (what can actuly happen)

 

IN short you want bank pressure so its best to not cut out the cat and straight pipe although some guys love the noise.
AN aftermarket exhaust can be a good thing by achieving better flow at the cost of a slight reduction of the back pressure .
This is desirable to lower your EGT's = greater effiency= better power and MPG's.
Oh , and it sounds good too.
Most guys go with a cat-back system and others like myself(i tow alot) go with an aftermarket downpipe before the cat.
And that sounds good too.

If you just want looks then slap a shiny tip on the end.
If you want more power and sound and looks then you know what to do.

*edit* i just notice dyou are in the area. IF you wanna hear a full system and check out a "tuned" ride before you buy then PM me a message.
I'm in Miami for the next month or so.

 

"If thats the case why do you think the EBP IS THERE."

I'll just assume you meant "why is the exhaust pressure sensor there?" Probably because pressure can be used to directly control the variable vanes for best efficiency and can also measure EGT indirectly.

The reason that turbo spins is that there is more pressure on one side than the other. The bigger the difference in pressure, the faster it spins. You can pump more fuel, create more heat and produce more pressure on the inlet side of the turbo to get a bigger difference. Or, you can reduce the pressure on the outlet side of the turbo and get a bigger pressure differential that way. Lots of folks here are doing both.

 

You have the basics right, but there is more to it. The Exhaust Pressure (EP) sensor is a variable capacitor sensor that is supplied a 5-volt reference signal by the PCM and returns a linear analog voltage signal that indicates pressure. The PCM uses the input from the EP and other sensors to control the VGT control valve. The Electronic Variable Geometry Turbocharger (VGT) Control Valve is a four-way proportional hydraulic flow control valve with closed center position. The valve controls linear actuator position of a closed loop hydraulic servo by charging and venting flow on both sides of a piston. Linear displacement feedback from the actuator varies a feedback spring force to move the valve spool to the center closed position when the actuator reaches the desired position. Therefore, actuator position is dependent only on control valve current — it is independent of hydraulic fluid temperature and viscosity. The PCM closes the vanes when little or no exhaust pressure is indicated to focus the exhaust flow onto the turbo turbine blades. As exhaust pressure increases, the PCM opens the vanes. If the downside of the turbo exhaust is too free, not enough pressure will build up. The PCM software is calibrated for the stock system and will not allow the turbo vanes to fully open. This can be a problem where air density is less.

Do a search on this site and you will find some posts where Ford or the dealership has told the owner to return the exhuast to stock or has denied warranty claims on turbo system repairs. I read one post where the person modifying exhaust was a tech at a dealership. They claimed that some customers with exhausts modified were returning to complain of issues with the turbo surging.

If it was me, I would stick with the stock downpipe or one close to it. I had this whole discussion with the service manager and diesel tech at the dealer I use. They confirmed the above. In addition, they stated they had not seen evidence of downpipes being restricted or deformed if removed properly.

 

Very interesting discussion. I really appreciate the knowledge one can gain here. It looks like Ford's choices in control strategies work well but the calibrations don't accomodate getting that last bit of thermodynamic efficiency.
I expect to get my new truck in two weeks or so and have been doing research for possible post break-in mods. Between this thread, warranty denials for exhaust mods only and the recent report of a Banks equipped truck melting pistons, I'm very wary of doing anything.

BTW, sorry for hijacking the thread...

 

Good point.
IMO i would drive it for 10k miles to fully break it in and see if any issues come up.
Then i would go mild with a tuner in the lower settings and cat-back exhaust and definitely unplug the EGR from day one.

Like most folks i thought Banks was the stuff before i came here and learned the real scoop.
I do have Banks exhaust but that 's it for Banks.
Their tuners really aren't that great.

Banks is a big name.
You can do more for less $$ with other products especially from motorhaven.

 

Are you saying that if I replace my turbo back with let's say an MBRP turbo back with cat delete, that I have less performance and could ruin my turbo? Should I replace the cat?

 

I find it interesting that they didn't put in an EGT thermocouple to incorporate into the software. It might prevent some of the melting problems.

On the other hand, a Predator on the 65HP program added to your stock machine will put a big grin on your face. However, the fun factor might offset the mileage improvement.

 

I am not saying you will have less performance. You would have lower exhaust temps and perhaps better mileage. But, could invoke turbo performance and longevity issues. It's not worth it in my opinion.

 

So then we are saying that exhaust is ok and safe for the turbo on a stock engine tuners aside (i dont have one , stock engine) as long as you leave in the cat?

 

My conclusion (that and $2.50 will get you a beer in some cheaper places) is that a cat back would be ok with the cat still in place.

 

What really bothers me about the reported melting of pistons on the Banks equipped truck is that Banks claims to monitor EGT and defuel as required. I've read the installation guides for installing the temp sensor. Maybe the installation on that truck was improper or, the Banks system failed. I don't know but I'm probably going to follow LOOnatic's advice and put lots of miles on before I install any perf mods.
Pity that Ford decided to control EGT indirectly. It's cheaper and it works for a stock truck but a thermocouple would be a more fail-safe approach.

 

Something doesn't add up on the posts of the piston melting with that six gun app. There had to more than a little knock if you melted two pistons. I would suspect a pretty dramatic change in performance. I wonder what the driver was doing when that happened.

 

I agree. It all sounds wrong and there has to be more to the story. Right now I'm expecting an info package from Banks and have had one call from a rep. Next time we speak I'm going to ask about this event.

 

If I were to install a turbo back exhaust, is there any benefit to replacing the catalytic converter with a bypass, or should it just be left in place??? Would this help alleviate the "longevity" issue? Thanks!!