Differences in exhaust systems?

AIS becomes exponentially more restrictive compared to "6637",when elevation goes higher.

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See bold....As in doesn't breathe at all? Breathes a LOT less? Again, I think you are overthinking this. Until one can actually measure the CFMs that move through each of these intakes, this is just a hypothesis. I can't imagine the AIS is so much more restrictive as to stunt the performance of a truck. I have had both and currently run the 6637. I could not tell any difference as in, say, the difference between a dirty filter and a clean one. But, as I said we need, I could SEE the boost numbers on my gauge. I had 15 max with a dirty filter and then back to 22 with a clean one....and I could FEEL the difference as well. Until we have a CFM test in similar conditions with the filters to change out after each measurement, this is just a WAG.

I do know this....tunes or not, turbo or not, injectors or not, Betsy PULLS like a scalded mule. And even though I do NOT recommend towing my weight at 75 mph, when I did do it a few times to pass or make a little time, she was happier there that an at 65-70. I also blew a hole in my hot side boot on a hard run. I carry a few spares, so easy fix, but that was fun LOL

 

Stock turbo with 360*!thrust washer and RDP 4+4 wheel at 2000-2500ft elevation in video. 175/30’s and PHP tunes.


Over about 5000ft really changes things. I frequently traveled from sea level to over 12k ft elevation and can easily confirm that lower density air makes a HUGE difference. I went from ****ty dp toons to much better tunes and my challenges with controlling EGT completely disappeared.

 

I repeat myself,do you and Colorado350 have any differences in exhaust systems?

 

I do not see the ais flowing less at elevation then it does at sea level.
Each filter flows "x" amountObviously each brand of 6637 flows different as well.
There should be no change of gap in flow between the 2 filters during elevation change.

 

Rpms making the performance difference?
What are your rpms at 65 vs 75?

 

No differences. 4" turbo back exhaust....as stated in our signatures.

 

Ok,since we're started picking..

Both of your sig does not say muffler or not?
​​​​​​What kind of muffler?
Straight flow or baffled?
Resonators maybe?

 

The problem with this "comparison" (term used very loosely) is that the very basic amount of information was provided for the comparison, which in itself leads erroneous observations and conclusions...

There is so much more to it than that...

But, without getting too detailed with charts, documented history, measurements, specifications, images and long explanations/comparisons that bore people, there will be no conclusion and the basic level discussion will remain opened ended and opinionated. Long explanations/comparisons is the nature of the beast when comparing highly technical parts like a turbo and someone cannot simply say "blah, blah, blah happens because at blah, blah, blah I saw blah, blah, blah".

Think about how Charlie (KC Turbos) has told us about his findings in the past and the painstakingly difficult task of arriving to those findings. That is just here on the FTE, not even considering the PSA where he is much, much more active. He only shared a very small percentage of his findings with us and has without a doubt spent years and years doing his thing. Think about how Mark K has told us about the amount of time he spent developing, testing and refining transmissions in his previous life.

Simplicity and leaving out variables is not how it works in a research, development and testing world. Well, not in the real world where measurements, specifications and data logs matter...

All that said, the results from BBSlider001's rebuilt turbo are truly amazing! A MST towing heavy that cannot reach 1000* in an EXTREME tune no matter what he did... He should not change a thing and he should keep the hammer away from that turbo!

This is why the FTE always insists on people knowing their truck/van, knowing their goals for the truck/van, knowing their budget, knowing their mechanical ability, knowing what to expect, knowing what to look out for and knowing how to get there!

 

Another FTE'r just sent me a text regarding this thread and its content, or lack thereof. I asked if I could share it with the FTE. He agreed that it was not under copyright law and I could share it with the FTE...

That is exactly how I received the text, no grammar changes or edits.

 

4" Turbo back, straight.

 

dirty filter vs a new one makes a remarkable difference. I was towing a heavy 5th wheel one time in the summer with a dusted filter and it was getting a little brutal trying to make it west across North Dakota’s rolling hills without having to babysit the EGT gauge and downshift a lot. in a perfect world there would be zero restriction in front of the turbo.

I drive mine like it’s about to break most of the time. I get anxious just reading these tales of 3000 rpms and 30 pounds of boost lol. I rarely hang the shift put much past 2200-2300 and try to keep the truck moving fast enough with as little help from the turbo as possible. If I see 10-12 pounds I’m thinking “whoa getting a little crazy in here!”

 

Y’all are missing the major points of the thread:
1) The E99 turbo provided excellent performance on one truck but didn’t perform as well on an almost identical truck. WHY?

2)Our trucks are almost identical, that doesn’t mean exactly identical. Someone with more time on their hands, can go back six months and count up the number of times we have all stated; every truck runs different in someway with the same setup. Sous mentioned his MST didn’t work great for him on his truck but Byron states a MST is working great...

The E99 turbo is often shunned because it’s “smaller” than the L99...maybe the size isn’t an issue after all, BUT maybe it’s more of an issue of AIR DENSITY...not just air FLOW!

3)EXHAUST was brought up. IIRC @SkySkiJason has mentioned numerous times that in his opinion a larger exhaust doesn’t provide enough performance gain to justify the expense. Besides who puts ON a more restrictive exhaust on their trucks????

4)The issue of TUNING was of course brought up. As mentioned earlier tuning is about fueling and shift points.
What’s the FIRST thing we recommend to a member that brings up...Help, I’m suddenly rolling coal and don’t know why?? We tell them to check their turbo for play and their air filter....AIR FLOW.
Great air flow is completely different at 600’ of elevation than at 10,000’ because of AIR DENSITY aka ambient air pressure.

5) AIR FLOW is completely different than AIR DENSITY. PER GARRETT’s TURBOCHARGING at ELEVATION:
Contrary to belief, the higher you are in elevation the less atmospheric pressure you experience. That said, oxygen levels at any set volume (a breath of air, or an engine cycle) at sea level contain more oxygen then the same (breath of air, or an engine cycle) at a higher elevation. The chart below shows how pressure changes with elevation. The higher the ambient pressure (psia), the more oxygen it contains.
[img]blob:https://www.ford-trucks.com/b9cfbdba-83e7-4f4c-9671-97ec36981fd1[/img]

IIRC... RacingJason has a whole thread reporting on the AIS flow compared to other filters...What elevation are these tests being done at? How would those results change if repeated at 7000-9000’ of elevation?? Air density makes a huge difference...

6) If you have a tune that you consider (subjective) HOT aka lots of fuel that works great at sea level it may not work great at elevation because the ambient pressure is significantly lower at elevation. You may see higher EGT’s going through the Rockies than you did at home.

7) You’re going on vacation across the Country and you start to notice significant performance changes as you head West and the elevation starts to climb. Did any equipment on your truck change from the time you left home and got to higher elevations? No, but the performance of those parts change significantly at elevation...the absolute constant variable here is air density aka ambient pressure.


READ THIS: https://www.garrettmotion.com/news/n...r-air-density/

 

High elevation and high ambient temps will have a noticable effect on power and EGTs. Not enough oxygen to burn the fuel as efficiently as a cool day at sea level. (Lots of black smoke and EGT trouble). Throw in a dusty air filter and a crappy tank of low cetane fuel and it will really struggle to get down the road with a trailer on.

 

Difference in Wastegate actuators?