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UPDATE: The testing eventually involved a vacuum gauge on the CCV port and the FM (Filter Minder) locations. I have added a pdf file of the results at the bottom of this post so you do not need to read through the entire thread... but please feel free to read through the experiment progression if you would like. Testing results updated to v1.4 as of 12/29/2020. Last test was with an AIS fender sleeve mod. Also see a screen shot of the results at the bottom of this 1st post. I believe this concludes the testing. I hope you find it interesting.
Edit 8/7/2023: @ESwift performed testing on various levels of modifying the box. I want to capture his results here on the first post to prevent losing them in the pages of thread for those reading in the future. He is running 200/30 injectors, T4 364.5/68/.83 sxe turbo, “80hp performance tune”, 4.30 gears. His information is quoted in blue below and can be found on post #259. He is successfully running the modified AIS (fender mod + 2.5” hole below filter) with these performance parts.
“Unmodified AIS- 364.5/68 .83 pulled minder almost fully at heavy throttle mid 30psi of boost run
Did the fender mod- pulled minder half way at heavy throttle mid 30psi of boost run
Added a 2.5" hole in bottom center of housing along with the fender mod- Did heavy throttle run to 40psi of boost at 90mph (boost:ebp stayed 1:1 or better up to 39.3 of boost) Then towed 13k 5th wheel on steep back roads 120 miles in 90 degree weather. Filter minder barely moved 1 notch, egts stayed below 1,200, absolutely zero issues. I will never get rid of this AIS as it helped keep turbo whistle completely silent on the intake side, I also have an S&B which is my favorite behind the unobtanium AIS, but the S&B has more whistle in the cab, which I do not enjoy on long trips.
I have CCV hooked up to factory position, and see zero oil consumption, some people have mentioned concern from the AIS restriction and oil being sucked from CCV.”
Currently I continue to run the AIS with fender mod and really like it (as of 8/7/2023) but may add eswift’s center hole in the future.
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Original post:
AIS with SXE results are in. It most definitely does not flow as much air (which we already knew). But the answer of course can’t be straight forward. I’ll explain in a bit.
So I am using the filter minder, let’s call it FM for the rest of this post, as the way to test the restriction in airflow for the filters. Note all my testing was performed with PHP tunes.
With a used 6637 Donaldson the FM never budged. It was tested using normal driving, spirited driving in 80hp and 140hp tunes, and even a 45 minute test towing run. The tow test was in 80hp Tow tune and included a long full throttle run uphill to 70mph while getting onto the interstate. It sat at 35psi for quite a while during this test. Again, the FM never moved from zero so the filter is not causing enough restriction to even register.
The AIS will be described in a few steps since they varied. All these tests were performed unloaded. Full tank of fuel but no trailer.
1- AIS did not pull the FM under a normal 80hp daily tune run into town(5 minutes). This was with NO full throttle application. It was what I would consider normal driving with a slight heavy foot.
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.
3- 80hp daily drive home with a couple full throttle runs. The FM was at 75%. The video missed the boost gauge and I don’t recall the numbers.
Now for the strange part. Even though boost appeared to be down a bit, it seems like the EGT was a bit lower too. The evening was a bit cooler than my previous testing. Tonight was around 77* while the 6637 testing was probably 90*. I’m not sure how much that would impact the EGT.
It also “felt” a bit peppier or more responsive with the AIS. I figure this has to be my imagination. Or maybe the cooler evening weather. I’m open to suggestions here.
The AIS does pull cooler air, but most folks feel the more airflow of the 6637 overcomes any additional heat.
- Now that I think about it the AC was not on this evening. I’m not sure if it was on during previous 6637 testing (It was intentionally on during the 6637 tow test but I’m not comparing EGTs with that test)
—-Anyone have any thoughts on the possibility of performance increase or EGT decrease with more restriction in airflow?
Noise level.... well the 6637 with SXE isn’t noisy so this isn’t really a fair test. The AIS is a bit quieter but it doesn’t really matter since my 4” magnaflow exhaust is what you hear more than any intake noise or whistle with both the 6637 and AIS.
On Edit: The AIS is significantly quieter. Although the 6637 is not bad with the SXE turbo, the AIS hands down wins this competition. There is enough difference that I may leave it on just for this fact.
Here’s some photo proof.
AIS/SXE combo. Isn’t it pretty? I do love the clean look of the AIS.
6637/SXE test including towing
Same condition for AIS/SXE with normal driving
AIS/SXE with 140hp tune and full throttle run
AIS/SXE with 80hp tune and full throttle run
Looks like I’ll be putting the RDP Donaldson Blue with cover on tomorrow.
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UPDATE: Result file is attached. Below is a screenshot of the file.
Last edited by RacinJasonWV; Sep 19, 2020 at 07:40 PM.
Reason: Updating with results
I installed AIS in front of my 38R in an attempt to quiet it down. Took s test drive around the block and was STOKED! Much quieter.
SoI hooked up the 5ver and drove 1100 miles to TX. I noticed FM was pulled at my first stop, but truck was running fine and I didn’t have the parts to put 6637 back on - so I rolled on.
Well, at a later check under the hood I observed I was a gallon low on oil. Strange. No leaks and I had never used oil before??? Ok, I’ll just pay attention.
Used 2 gals of oil on my 1100 mile trip out and similar amount on the way back a few weeks later.
The CCV was hooked up. I decided it was SUCKING oil out of the engine!!
Whoa! Good point about the CCV. Mine is currently still run to atmosphere. So if someone was to run the AIS with a “high flow turbo” then maybe the CCV mod would be a good idea....
Tell me more about your performance experience. How were the EGTs with the 38R/AIS? It seemed to run fine yesterday with the only possibility of maybe top end power loss. I’m not real concerned about that.
I’m a huge fan of the AIS. Just wish it flowed a touch more.
To be fair I have not done the fender mod to the AIS. Really don’t want to hack it up if it looks like I’ll have to sell it.
which filter minder did you use ? The one that cane with the ais?
Good point I forgot to mention. The same FM was used for both tests to minimize variables.
I unscientifically compared the 2 just for kicks just by pulling a vacuum with my mouth (no jokes guys!). There was a noticeable difference as the AIS version pulled easier. I’d always heard this was the case and ran the original when using the AIS previously.
Good point I forgot to mention. The same FM was used for both tests to minimize variables.
I unscientifically compared the 2 just for kicks just by pulling a vacuum with my mouth (no jokes guys!). There was a noticeable difference as the AIS version pulled easier. I’d always heard this was the case and ran the original when using the AIS previously.
oh cool
so the ais minder would have probably been pegged?
oh cool
so the ais minder would have probably been pegged?
Well I felt like the one I used was pegged with the 140 test. It may have had 1 more click.
I seem to recall testing the AIS version back with the MST and felt like it pulled too easy. Basically my thought is the FM is setup for factory conditions. If this is correct it would indicate the AIS actually flows easier and more freely than the stock filter system, hence the softer set “filter replacement” indicator.
I justified the use of the stock box FM by telling myself that it was still not seeing any more resistance than stock.
The MST could easily pull the stock box FM halfway if on a hot tune.
I think we have at least proven that the “different airflow” characteristics of the SXE still require as much or more intake air than the MST. Not a surprise, but nice to confirm.
Still hoping someone can jump in and tell me what I’m missing about the “feel” and EGT condition I saw last night. The truck felt very good if not better under normal driving conditions other than wide open.
The butt-dyno could not tell a difference. That’s why I decided to roll on after noticing FM was pegged.
That WAS the AIS minder which we learned back then was ‘more sensitive’.
I hated the 38R/6637 for a loooong Time. - like 70k miles or so. It was punishing on long trips.
Hmmm. Now I’m considering leaving the CCV mod and the AIS for just a bit to see how it does more long term.
I will say it sounded more restrictive when doing the wide open run test. That’s hard to explain but maybe like it was trying to suck through a straw....
There is no doubt the 6637 flows all the air any turbo will need.
I know the topic of hot vs cool air has been beat to death but man I can’t even hold my hand on some of the parts (like the steel mesh on the 6637) after shutting down. Still wonder if a partial heat shield would help the 6637. I know everyone says the engine bay temp is almost the same once up to speed but I haven’t tested this for myself or seen the real data to support. I run the bottom of the stock box so it does get some fresh air funneled in to the bottom of the filter.
The evening was a bit cooler than my previous testing. Tonight was around 77* while the 6637 testing was probably 90*. I’m not sure how much that would impact the EGT.
