New Custom Exhaust Installed - Review

Originally Posted by cssnms

Sorry, I have not posted yet. I promise I will get it done this weekend. I still need to do the follow-up dyno too. Yea I am slaking...

Originally Posted by UncleJ

So after all this, did the OP actually get any measurable gains or not?

He posted that on the other page.

I doubt it is going to be something all that drastic, too much restriction upstream of the rear system.

Thanks. I wondered if there was going to be much gain out of all that work and expense. Oh well, he got a better sound anyway!

I'd do it just for the sound, I really dislike having no exhaust sound at all. If I were to get a little bit more power from it then great but my motivation is for sound.

Originally Posted by UncleJ

Thanks. I wondered if there was going to be much gain out of all that work and expense. Oh well, he got a better sound anyway!

Read what I wrote,,, I have not had a follow up dyno done, YET, anyone commenting on gains or lack thereof is just speculating, nothing more.

Was I expecting some huge HP increase out of this, NO. Do expect that I picked up 8 to 10hp I hope so and I hope my estimate proves to be conservative.

Aside from any potential gains there is also weight savings and a little bit more growl coming from the pipes, plus I think it looks cooler. Now whether or not the previously mentioned benefits make it worth it to "you" is a matter of personal perspective. Am I glad I did it, YES, would I do it again, yes.

I'd expect 8-10, which is not drastic to me. If I wanted more power I'd not spend this type of money unless it was at least 25 or I had long term plans to change things upstream. But like i said, I would do it just for exhaust sound, I'd even go so far as to say I'd give up 8-10 if it meant having a decent sounding exhaust.

Originally Posted by Snipe656

I'd expect 8-10, which is not drastic to me. If I wanted more power I'd not spend this type of money unless it was at least 25 or I had long term plans to change things upstream. But like i said, I would do it just for exhaust sound, I'd even go so far as to say I'd give up 8-10 if it meant having a decent sounding exhaust.

A performance exhaust is a compliment to other performance enhancing mods. If I didn't have a tune already I probably wouldn't do it, but combine it with a tune and I will take the added 10hp all day long. Not to mention with a tune my egt's are likely a bit higher under full throttle, so I think a freer flowing exhaust is a nice compliment. I suspect there is some benefit as far as lowering egt's a bit, but that is just a guess.

Okay here is some video, finally...

I'd be curious to see if the EGTs actually drop and where they are be measured at. With so much other restriction upstream I just have a hard time believing the EGTs will change much at all but I am used to measuring that either in the header and/or downpipe.

Originally Posted by Snipe656

I'd be curious to see if the EGTs actually drop and where they are be measured at. With so much other restriction upstream I just have a hard time believing the EGTs will change much at all but I am used to measuring that either in the header and/or downpipe.

If you believe there is a hp gain, then it is logical to assume that the hp gain is a result of reduced back pressure. Reducing back pressure allows more hot exhaust gases to excape so I do not think it unresonable to assume that there is some benefit to egt temps, esp when running a tune.

Compare to stock exhaust and you decide

Originally Posted by cssnms

If you believe there is a hp gain, then it is logical to assume that the hp gain is a result of reduced back pressure. Reducing back pressure allows more hot exhaust gases to excape so I do not think it unresonable to assume that there is some benefit to egt temps, esp when running a tune.

I probably am wording things wrong. I just will be surprised if any significant drop in EGTs and gain in rwhp happens from a cat back on modern diesels. Now what one person sees as significant will vary from person to person. I'd actually like to do exactly what you have done but until I know if I am moving or not it just has to be on hold for now plus I just bought a "toy" car which also makes it harder to justify messing with the daily beater.

Here are a couple of good articles on the subject.

The cat-back dyno shows a slight hp improvement, but torque jumped up considerably. That said I do not think the chevy had a dpf.


http://www.dieselpowermag.com/tech/g..._back_exhaust/


However here is an interestering test also conducted by diesel power mag comparing a dpf back exhaust w/tune vs a turbo-back exhaust w/tune. Surprisingly the benefits of a dpf-back exhaust were guite good, not only in the hp dept, but lower egt's and improved gas mileage.

http://www.dieselpowermag.com/tech/d...s/viewall.html

Heck I have a dyno graph somewhere showing where we gained 100 rwhp just with a muffler swap on a turbo car. So I definitely understand exhaust is a big player to power generation on them. I can't pull up those links where I am at but a DPF back exhaust implies to me no cat or different cat, was that the case?

Originally Posted by Snipe656

Heck I have a dyno graph somewhere showing where we gained 100 rwhp just with a muffler swap on a turbo car. So I definitely understand exhaust is a big player to power generation on them. I can't pull up those links where I am at but a DPF back exhaust implies to me no cat or different cat, was that the case?

Cats in-place with DPF back. The point being the test appears to demonstrate the dpf isn't as much of a restriction as originally thought at least in this case. One may also draw from this that the mufflers are also a restriction point.

Even the first test (link) w/cat-back exhaust which presumably doesn't have a dpf the results w/just a cat-back exhaust are still favorable IMO.

Stock Power Numbers
The 5.9L-powered truck put down 269 hp at 2,550 rpm and 594 lb-ft of torque at 2,300 rpm; and the 6.7L-equipped Dodge put down 259 hp at 2,850 rpm and 487 lb-ft at 2,750 rpm. Runs were made in direct drive for both trucks-however it should be noted that the 5.9L Cummins was backed by the 48RE four-speed automatic transmission and the 6.7L used the new 68RE six-speed automatic. Unfortunately, the 5.9L Dodge used in our test had 35-inch Toyo tires on 20-inch Eagle Alloy rims. In order to limit the variables between the two trucks, the stock tires and wheels from the 6.7L truck were swapped onto the 5.9L truck, resulting in 10 additional peak hp and 10 lb-ft of torque. Advantage: 5.9L Cummins



Exhaust System Install
While the S&B intakes and Edge modules were very similar for both trucks, the Silverline exhausts were dramatically different. Both exhaust systems are constructed from mandrel-bent T304 stainless steel and come with a limited lifetime warranty (5.9L P/N DS105 and 6.7L P/N DS109). Some other exhaust manufacturers can make these same claims, but it was the details that really set Silverline apart from the pack. Welded hangers, easy fitment, polished exhaust tips, bolt-on construction, and excellent packaging were included with both Silverline exhaust kits. While the construction was the same between the 5.9L and 6.7L systems, there were a few differences. The 5.9L system was 4 inches in diameter from the turbo back and used a polished 6-inch muffler with internal louvers. By contrast, the Silverline 6.7L exhaust started behind the DPF (by law all aftermarket exhaust systems must be this way) and used 5-inch diameter tubing with no muffler. We were nervous about running the daily-driven Mega Cab without a muffler, but the exhaust catalyst and DPF provided plenty of muffling-both trucks are scarcely louder than stock. While the noise did not change significantly, the fuel economy increased on each truck and the EGTs decreased. We were very surprised by the improvements offered by the DPF-back exhaust on the 6.7L.Advantage: Tie

The 6.7L Cummins engine comes equipped with a mass air flow (MAF) meter (arrow A), something not used on the 5.9L engine. However, both trucks do utilize air inlet temperature (IAT) sensors (arrow B).

The 6.7L Cummins engine comes equipped with a mass air flow (MAF) meter (arrow A), somethiIntake and ExhaustDyno Numbers
We went back to Flash Auto to quantify the changes on the chassis dyno, particularly to see if the horsepower gains on the 6.7L would be as great as the 5.9L since it did not benefit from a full exhaust upgrade. With the Edge Juice in the Stock setting, the 5.9L gained 38 hp and 117 lb-ft of torque, and the horsepower peak rose 300 rpm. The 6.7L was even more impressive, gaining 64 hp and 158 lb-ft of torque with just the intake and exhaust. Clearly there are restrictions on the 6.7L besides the DPF and exhaust catalyst, since they were retained.Advantage: 6.7L Cummins




Conclusion
The 6.7L Cummins didn't show the same power potential as the 5.9L, but that's no surprise considering that it's saddled with so many emissions controls. What is surprising was that even with an increased stroke length (4.88 inches versus 4.72 inches), the 6.7L made peak horsepower at a significantly higher rpm than the 5.9L Cummins. The fact that we were able to get so much out of the 6.7L without affecting the DPF or throwing any codes spoke volumes about the quality of parts that S&B, Edge, and Silverline are producing.

As more 6.7L Cummins-equipped trucks hit the roads, we expect even more products to become available for them in the future, closing the gap between the new 6.7L and the trusty 5.9L. While the displacement may have changed, the Cummins B-series engine is still alive and well.

I posted some measured data on back pressures today that may be pertinent to this discussion.

http://www.bimmerfest.com/forums/sho...=1#post6695813

Originally Posted by TDIwyse

I posted some measured data on back pressures today that may be pertinent to this discussion.

http://www.bimmerfest.com/forums/sho...=1#post6695813

Thanks

Originally Posted by TDIwyse

Interestingly the pressure across the DPF during full fuel isn't as bad as I would've expected. 140 hPa is ~2 psi.

This seems to support the findings from the recent Diesel Power Mag test.

The more I think about it, I am not sure why I have it so stuck in my head the DPF is a huge restriction. I remember someone on this forum posting up a link to another OR perhaps I read it via a google search to a thread about a guy in Europe who removed his DPF and had the car reflashed for that. I do not recall him picking up significant amounts of power, but did get some sound out of it and I think he was saying he was going to go back to the DPF since the drawback(soot) was not worth what little gain in power he got.

Originally Posted by Snipe656

The more I think about it, I am not sure why I have it so stuck in my head the DPF is a huge restriction. I remember someone on this forum posting up a link to another OR perhaps I read it via a google search to a thread about a guy in Europe who removed his DPF and had the car reflashed for that. I do not recall him picking up significant amounts of power, but did get some sound out of it and I think he was saying he was going to go back to the DPF since the drawback(soot) was not worth what little gain in power he got.

I recall reading that too. If memory seerve me right, I think he lost some power and in a follow-up post he ended up reinstalling his DPF because he did not like the increase in soot?

But you're right, the prevailing thought seems to be that the DPF is a significant restriction and anything short of removing is just a waste.

I can't remember on the power, I thought he gained just a tiny amount. But I do recall he was planning to put it back on and I think because of the soot. Regardless of the reasons though it did show the DPF is not a big restriction on these cars.

I just read a couple threads on it. Sounds like just removing it and adjusting software to not throw a code will result in next to no HP gain. Sounds removing it and adjusting software to take advantage of it gone can result in some power gain. Removing it and adjusting for no codes appears to increase throttle response and mpg which kind of makes sense due to no burn off. Wonder of perhaps it is a decently sized restriction and just ECU's are tuned for that so the removal of them does not change power output significantly, I'd think EGT readings maybe could show this though.

I saw this link as well:

http://www.ecotune-scotland.co.uk/pr...moval_Solution

That is some incredible work. It looks as good as some of the GP expansion chambers! Wow, hope they prosper!

Just wrote to ECOTUNE for some info, Ill keep you all posted

bump

All is silent as of today!!