From your 1st post with the AIS and 140hp tune:

"2- 140hp short drive (5-10 minutes) with a full throttle run up to speed. The FM was fully pulled. It did not seem to make quite as much boost as the 6637. Boost did hit 35psi but it seemed to stall a little at 33psi where the 6637 settles more at 35."

I'm going to guess you hit 35psi again, and hope for inHg at 3". Feel like a contestant on "the price is right".

 

No difference.

(I doubt it, but Someone has to be ‘that guy’).

The suspense is KILLING ME!!

 

Sorry guys. We had a family day and that’s why it’s so late getting back to you. (I meant to say that in the previous post but forgot because I was hurrying. ). That’s all I had time for before we left. But glad I left a teaser

I’ll tell you up front that the data is still iffy. I’ll leave it hooked up until I get a chance to tow again.

More boost? Lol. No where close on the vacuum.

You get half credit.

Ahhh good research. I guess the boost side has already been stated. Basically repeated the 33 sustained. It fell short of your hopes for the vacuum. See below.

You’re cracking me up here. And I hear ya on the $1 price is right bid. Lol




The correct answer is 33psi (sustained) and 2inHg max. Yes only 2. So it was only double the vacuum under full throttle hot tune.

Here’s some caveats though.
1) Is it possible the shape of the CCV tube does something weird with the vacuum on the port? It is shaped with a weird deflector and air will be moving VERY fast past this deflector.
2) How much vacuum will the turbo/engine pull? My guess is PLENTY. Have you ever stuck your hand in front of the snorkel with it just idling? I did in front of my loose IC port after some work. Man that thing pulls some air!
3) I’m pretty certain vacuum or restriction in the intake system will not be a linear function. Meaning just because it is double doesn't mean it’s only 2x as restrictive. This 2inHg may be 4x as difficult for the engine to work with. I have no idea.
4) boost is definitely down. So that means it’s not getting as much air. But then again this is at extreme conditions. I prefer to not boost 33psi as a normal habit.

So I’ll try to gather my thoughts some more and post up the photos in a bit. But figured I’d kept you all waiting long enough.

 

Today’s testing was late morning (9:30am) 72*. 6637 testing was evening (8:20pm) at 84*.

I previously stated the 6637 was 35psi boost. This was mostly true. This stuff is hard to say for sure even when reviewing video. It may flatten out at about 34 but you can see 35 at times. It spikes to 40 during a shift.

The AIS can maybe hit the 34 but it tends to settle at the 32-33 range. It also appears to fall back further during shifts. I would also guess the overall boost building is a bit slower as it climbs to peak range.

The vacuum gauge was a little surprising. I was expecting maybe around 4-5 with the AIS. Since I never saw the FM move at all with the 6637 and the AIS can pull it full during a hard run I expected to see a bigger difference between them. The real test is probably going to be during work while it’s towing. I just popped back up the thread and the 6637 only pulled 0.25inHg max while normal cruise towing. I expect the AIS will be closer to 0.75inHg based on a 65hp 20psi snapshot, but this is a different condition since it was WOT with no load.

The EGT between the runs was pretty close. You can look at the snapshots below but it appears only about 20* hotter with the AIS. If that’s even measurable. But it did seem consistent from various snapshot points of the video. The max EGT with 6637 =1202*, AIS 1214* (same physical location, same speed, peak at same mph), AIS 1234* (another run, different location, same speed, peak at same mph)
The lower temp during this morning's test may have kept the EGTs a touch lower for the AIS in regards to a direct comparison.

The smoke output is still up in the air. (Ha, accidental pun!). It still seems to not smoke quite as much during throttle tip in at low rpm cruise speed 50-55mph. But this is another item that’s hard to quantify and it makes no sense that this could be true. It still smokes under these conditions that’s for sure. But I don’t think it’s quite as much. Hopefully we can get a better judgement after my next tow. My Uncle usually follows and he stated during our recent tow that it was definitely, without a doubt smokier than the MST. My guess is he will say it’s the same with AIS as 6637.

Overall the AIS is super quiet and seems to flow better than expected. It is not what you want for all out performance obviously but may end up being plausible as a daily driver or tow machine. This of course depends on each persons goals and desires. Personally I am willing to leave a few HP on the table for a nice quiet rig. But let’s not get too excited until we have some towing results. We can review EGT, boost, and vacuum at that point.

Summary for AIS:
1) boost is down 1-2psi, drops further at shifts, and likely builds a bit slower
2) vacuum is up by 1inHg max, or double
3) EGT is up by maybe 20* at peak

The following snapshots are the closest I could get of same conditions on each filter. This is a pretty good representation of where the boost and vacuum would settle down as a flat peak as well. Speed, physical location, rpm are all pretty similar here.


AIS, 140hp PHP tune, 55mph, 32.5psi, 2inHg, 1186*

6637, 140hp PHP tune, 55mph, 33.7psi, 1inHg, 1168*



Close up of AIS vacuum from 55mph photo above. 2inHg



FM after testing runs with AIS. No surprise here.

 

Something else interesting to share.

I also tested in the 65 daily tune. This is more in line with how the truck will normally be driven. There was no noticeable movement of the needle under normal driving. So I wouldn’t really expect to see a difference in mpg for daily driving. (K&N advertisements debunked. lol)

EGTs were no issue in the 65hp tune. 1056* max during WOT run.

Look at the photos below for the 65hp WOT test conditions. Again though, I don’t normally drive the truck WOT.... But the 20psi one may be somewhat representative of towing.

20psi = 0.75inHg
25psi = 1.0inHg (same as max seen with 6637)
30psi = 1.7inHg



20psi, about 0.75inHg


25psi, 1.0inHg


30psi, about 1.7inHg

 

Are you running the stock filter minder or the AIS? I know the Stock has historically been less sensitive.

 

Stock FM. The AIS version seems to be more sensitive. I can check with the vacuum gauge once all this other stuff is finished.

 

Short drive this morning, my wife had to run to town for something. Running the PHP 65 daily tune. No noticeable movement of the needle under normal conditions. Slightly heavier acceleration moved to about 0.25inHg.

Rolled into about half throttle at one point. It hit around 25psi and 1.0inHg. It appears the WOT run compared to a part throttle condition has the same vacuum at the same boost level.

I doubt there would have been any needle movement in this situation with the 6637.

Back to the original question though. What is “acceptable” vacuum or restriction to be seeing here? Again I think towing will maybe be more telling for us.

 

My experience was the extra vacuum sucked extra oil out of CCV. I can’t quantify if performance was different, but I ran probably 2500 miles like that - mostly towing. Seems like I remember a couple psi more max boost? But not like OMG THATS BETTER...

I think we are quantifying that the only time vacuum is ‘high’ is during higher boost levels - so only a fraction of time during normal driving. Since I love my cruise control, I will frequently see high boost while towing, especially here in the mountains. Even with CCV to atmosphere, I would not compromise ANY performance for noise and that's why I went to 6637 from AIS - even with the MISERABLE 38R.

Still interested in an answer to your question!!

 

Yes thankfully I still have the CCV to atmosphere right now. This test may have a completely different spin otherwise. No desire to make it suck all the oil out of my crankcase.

I can’t run the cruise control while towing. It just doesn’t handle it correctly. Any type of hill will make it go too heavy on the throttle and kickdown on the interstate at 70mph when it’s not needed. It also doesn’t preemptively “see” the hill and start applying a touch of throttle before the need.

I guess if I were to run OD-off at a bit lower speed then I could use the cruise. But normally in those cases cruise isn’t the best option on a 2 lane.

IIRC the towing boost levels I was seeing was around 25 max except for the time it kicked down at 70mph and went to 35psi. Normally it would find its home around the 20psi range while going up hill.

And you’re right, any compromise isn’t the best situation so I’ll probably end up back in the 6637 or some other higher flowing box type filter which would be a bit quieter.

Another test I need to perform would be the AIS box without the filter. That would tell us if the snorkel is the main restriction (doubtful). And even possibly cut a fender hole. But I hate to do that just for poops and giggles if it’s ultimately getting sold.

 

Yeah, ZF6 and 4.10 in my dually means I can run cruise control. I used it less towing with the Excursion and BTS with 3.73, but I’d let it downshift and wind out - because my fuel (WVO) is free and I was not afraid of hurting my transmission. I would lock OD out until cresting the grade to avoid repeated shifts. Boost would max out while CC regained its desired speed, then level off.

on edit: I would envision myself cracking the whip on a rented mule while ‘racing’ up long grades. Smiling as EGT’s level off below the red and I zipped past those ‘stock’ d-max’s and Cummins trucks. Lol.

 

I knew I was going to be way off on my numbers, but there has to be one jackass that just goes off the deep end, and I don't mind being that jackass...

I forget what your intake looks like... Do you still have the green hose port or do you not? I don't know how much of a factor the CCV port venting/vacuum flow is affecting the vacuum gauge, but perhaps if you can get a more streamline reading, that would make a difference.

Another thought I had isn't the FM inside the box, but before the AIS filter? So, the FM on the AIS is before the filter and the FM on the 6637 is after the filter. Is that right? I used a 1/2" bolt to plug the FM hole in the AIS when the FM shattered and I didn't want to replace it. You could possibly hook the vacuum gauge up to the FM port in the AIS and take some more readings.

Maybe what I have said will have no noticeable difference on the gauge, but maybe it will. I believe that when a groundbreaking theory or idea is discovered by a scientist or doctor, they publish the theory. Then, the entire community picks apart looking for flaws or ways to disprove the theory. I think that is where you are at now and we are throwing ideas out there for you to contemplate and possibly put into action.

Great job so far Jason!

You are gathering some good data here and I have added this thread to the 7.3L PSD Tech Folder.

 

Sous thanks for the reply. Comments above in red.

 

Interesting theory about the physics physics of CCV port affecting vacuum measurements.... That is over my head for sure, but my gut reaction is the port faces the direction it does to mitigate the Bernoulli effect that might increase scavenging of CCV.

My standard 6637 FM is effectively ‘in the same place’ as the OEM location.

 

Yes that was my thought for the shape of the CCV port as well. Otherwise it could potentially pull a very large vacuum on the CCV. My guess is the shape is to cancel out the Bernoulli effect as you said.

I’ve never ran the FM with the 6637 other than the 1 test I did recently. Mine was located in the end of the filter. Is there really a reason to add the FM port for the 6637? Have you seen the filter get so dirty that it will pull the FM? That would take a lot of dirt!