DPF Vs. 5'' Delete Pipe On Horsepower, EGT, and More! Massive Knowledge Dive

[@dougpage1309]

I’m glad to see you back doing videos again.

[@Duramaxtuner]

@dougpage Thank you for the support! We're glad to be able to produce them for you all!

[@slimchancejw]

I’d like to see the same results with all stock exhaust and filters, especially on the lm2

[@hadenjohnson2183]

Wonderful video guys!

[@Duramaxtuner]

Thanks! @hardenjohnson2183

[@SilverbulletL5P]

Love the information! 67mm with be on my l5p here in a few weeks. My question is are we just closing off then it’s going back to 5in. What about the numerous filter throughout the exhaust. Are they slowing things down an what about when they heat up after extended driving are we creating more heat thus making less power? I’d love to see a full doc/dpf exhaust an ran again I’m extremely curious on what the results would be. Thank you guys for all the hard work and dedication you guys do on a daily basis to make the most high quality parts.

[@Duramaxtuner]

@SilverBulletL5P The 12psi and 15psi exhaust environments that we created were meant to serve as an example of how an emissions-in-tact LML motor would perform. This is show in contrast to a completely "Open" (deleted) exhaust to give you an idea of the performance restrictions the DOC/DPF put on your engine's performance. Connecting and disconnecting an entire DOC/DPF system was just too much of a hassle to be more worth setting up compared to what we did.

[@joshwaller7237]

Thanks Nick for doing this video. I'd like to see more like this on the L5P. Thank you.

[@nickpriegnitz5895]

Thanks, noted.

[@user-qe3yt8ov8e]

Nick, I'd be curious to see the difference when you put on one of your bigger turbos if there's a correlation between free-flow on those and a stock turbo (especially drive pressure when you push the stock one). You also said in the prior ford/race day video that the doc & system seemed to be at a limit of 630 rwhp or so. Is there any validity to being able to push 7 or 800rwhp in the future or does that whole system become a block?

[@d.williams6891]

Interesting test! 🤔 Not gonna lie, the biggest reason I went with a free flow exhaust 😉 is purely for the sound, not power/mpg gains.

[@HunterSkiff]

The data doesn’t lie

[@Duramaxtuner]

😎

[@stevesauerland223]

Great video. Leads to believe proper AFR is more critical to exhaust temp vs back pressure after the turbine with a VGT turbo.

[@nickpriegnitz5895]

Amen, brother

[@PrivateUsername]

Great data. Thanks.

[@Duramaxtuner]

Our pleasure!

[@bert5003]

kinda bummed that THE GUYS for emissions on tuning didnt actually have emissions running for a proper scientific comparison of straight pipe vs full emissions. did the test engine even have EGR or was this engine completely deleted for your test mule purposes?

[@nickpriegnitz5895]

No fears Bert, we're happy to refund your price of admission. In all seriousness, the test engine is an LBZ (no DPF/SCR/Regen controls) and our test cell is not large enough or capable of cooling everything required perfectly duplicate a full emissions system. The engine is capable of running EGR, but we did not have any recirculation active to minimize variables in the test.

[@justinpinho9916]

The problem I see is you don’t have heat soak bricks ie: DPF SCR and a muffler, all absorb heat, as your restriction. It’s just a reduction in pipe diameter essentially , but still fairly free flowing.

[@nickpriegnitz5895]

Are you suggesting that the pressure sensor in the down pipe is somehow not measuring resistance to gas flow out of the turbine?

[@strokerta1986]

What was the turbo shaft speed 😁 Emissions on will see a noticeable increase in turbo shaft speed. This will result in more wear on the turbocharger.

[@nickpriegnitz5895]

I doubt shaft speed would change much between these tests (although I’d be happy to review data to the contrary). It is worth mentioning that the higher drive pressure-to-boost ratio required to achieve mass airflow rates necessary for power in the emissions on simulation are potentially a little harder on the thrust bearing set of the turbo.

[@bradleydavidsankey]

Awesome data! I would be curious to see what shaft speed does as vane position climbs to maintain desired output.

[@bert5003]

shaft speed should increase relative to vane position as long as pressure differential across the turbine stays constant until you hit the choke point of the housing with rpm climbing and the vanes wide open

[@nickpriegnitz5895]

Typically if MAF and engine speed are equal then so is shaft speed. While vane position did increase in the restricted exhausts, I would be surprised if shaft speed changed. (Our turbo speed sensor failed a day before this test was run).

[@trbokmro]

I am curious after all the other exhaust diameter tests I have seen done. Maybe a good test would be to measure the opening in the restricted filter sim box and translate that into pipe diameter and see how that translates to the length of the filter assembly. If the filter is 2’ long and you have a back pressure opening that transfers to a say 2” opening maybe install a piece of 2” pipe 2’ long? Data doesn’t lie but I can’t help to think if you installed a filter assembly to this test the data would be different. Interesting testing and straight forward data reporting as always keep up the good work!

[@zimmyflip]

It’s simply less stuff to go wrong if you get rid of it. Once’s it’s past warranty that gets expensive

[@dandable]

I fully expected the straight pipe to be much less in EGT’s and drive pressure. Interesting

[@Duramaxtuner]

@dandable Supprising right!

[@DDescalchuk57]

I’m curious if you’d lower EGT with a 4” vs 5” . If you had lower temps with the exhaust closed off I’m curious if it’s making more exit speed by building that pressure coming out the pipe pulling the heat out with it faster

[@nickpriegnitz5895]

I think the takeaway from the video is that the EGT was not statistically different from the 5'' to the simulated DPF. Going to a 4'' exhaust would likely not change EGT in a statistically significant way.

[@specializ20]

Would this data be the same on a stock turbo?

[@nickpriegnitz5895]

Good question. Although I've not run the tests, I would expect very similar percentage differences in vane position, pressures, and EGT. Keep in mind the stock turbo peaks about a 100HP short of this STR prototype so the experiment would have to be run closer to 550 Crank HP.

[@specializ20]

@@nickpriegnitz5895 thanks for the reply Nick. I am running a new emissions pick up now. I hated the idea of running emission. But you continue to prove that it is possible. Nice work

[@joeb.8625]

Still waiting on why can’t we do tcm tuning in the same manner?

[@devanleeds]

So you’re saying back pressure doesn’t hurt horse power ?

[@nickpriegnitz5895]

I’m saying that within the constraints of this test the exhaust restrictions costs the engine about 10hp, or slightly less than 2% of its output potential.

[@Suomyice]

So is the conclusion from this then that backpressure doesn't really matter on a turbocharge engines when it comes to create torque and horsepower?🤔

[@nickpriegnitz5895]

It matters only slightly within the experimental limits of this test. IF the restriction in the exhaust had caused the engine to run up against its maximum vane position limit while chasing desired boost then HP would have been much more dramatically limited.

[@matthewsteadman5740]

Ya see what they're doing here boys don't yas

[@HSKFabrications]

Ah, the joys of torque demand based common rail diesels. Will hit the number requested, no matter what's in it's way lol. I try to explain this to all the people who fall for gimmick bolt-ons from Banks. All for nothing without tuning.

[@ThanksHero]

Even with tuning it’s questionable haha

[@HSKFabrications]

@ThanksHero lmao yes. Be careful, the Banks zealots may be lurking. Wouldn't want to conjure their anger lol

[@Eric_V410]

​@@HSKFabricationsyour correct that at full power without tuning the newer engines won't let it go past their "fence" however power under the curve and response are arguably more important for most driving conditions.

[@ThanksHero]

@@HSKFabrications they would sell 6” boost tubes if they could fit under the hood 😂 muh flow bench

[@HSKFabrications]

@@ThanksHero "air densityyyyy!!!!"