Didn’t seem to be any good forum area to post this really.

so a recent you-big-dummy foible I put myself into; just had to go and be different by switching from my tried and true air filter choice that has always served me well without exception; K&N, and order an AEM Dry-Flow filter instead. Which btw they are by all appearances now made by K&N Filter company as best I can tell. The confirmations I received stated K&N Filter despite ordering it on the AEM Filter site.





Except nowhere near the same. This filter has maybe 30 minutes only on it; mostly idling; though with a few short boosts up to 20 psig, and is mounted directly to the turbo compressor inlet fitting. Which we all know can get pretty hot, but apparently the filter inlet flange material type is quite a bit different. On the AEM it must be some kind of cheaper plastic/rubber material rather than silicone based.

Because it became hot enough for the inlet flange to soften/melt, and with the combined heat of the turbo and the pressure of the clamp it had begun to extrude-flow out around the inlet flange. When I went to take it off the hose clamp seemed loose, but I know for sure it had been fully tightened. Then I had some trouble pulling the filter loose from the compressor inlet. Which it was obvious why once it finally separated and popped off:





It had also done some of the same at the other internal end of the compressor inlet, but not nearly as severe. So I sent AEM a note and the picture explaining this and expressing my dissatisfaction. No response yet almost a week later. I can’t find anything in their literature or on the website listing a temperature limit, mounting, etc. So not sure if that’s a $100 bill down the drain (filter and sock) or whether they’ll concede anything on it. Comparing to several K&N filters the material is quite different and the smaller K&N that this replaced never had any issue under the same conditions.

So in summary; an AEM filter should not be mounted directly to a turbo compressor inlet. Yeah, don’t do that. 😑 I would not recommend one at all even based on this. Back to K&N for me.
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...cause the bleed edge is.... well... bleeding. But ultimately, somebody's gotta be on it. Thanks for being there with some of us!

 

off topic...... your oil feed line.................... what is this assembly?

 

lol, not sure that this qualifies as a topic 😂

it’s a modified Freelance Motorsports adjustable pressure regulator assembly. However, the PO setup had the regulator and gauge positioned right up by the CHRA and the gauge fluid was heating up to the point it was building pressure inside the housing and causing the lexan face to bulge like it was about to blow out. So I bought the high pressure stainless “hex” instrument fittings you see there and reconfigured it further out away from the excessive turbo heat.

I’m not sure that Freelance is still around since they didn’t respond to my last email and the website seems abandoned, but concluded that the regulator is just an adjustable pressure gauge snubber and not a true regulator. It works well enough though. It’s nice in that you can precisely dial in and easily confirm oil supply pressure to the CHRA.

If you decide to build one then make sure to get a gauge with stainless steel internals as the brass etc. internal type is not likely going to last against the heat. They’re a bit harder to find now; most places are backordered.

 

i discovered Turbosmart's 40 psi oil pressure regulator this year. no more 110 psi oil pressure going into my turbo. i plumbed the pressure relief port into my front cover.

as to the filter situation, many of us realise that the compressor unavoidably heats the air a bit but until you actually log air temp ot of the turbo with a thermocouple you might not appreciate how much. here's a log from this year at (only) 19.6 psi.

359 F!

at 30 psi it is often over 400.

apparently AEM doesn't have the data.


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exactly, except that the compressor cover temp will most likely exceed the air discharge temperature.

Remembered last night that I have a 6” velocity stack airhorn and silicone coupler to put on the compressor inlet and will buy a 6” inlet filter for it instead. It will be a K&N filter though; never again
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Swagelok makes a nice line of adjustable Stainless pressure relief valves you can plumb into the turbo oil feed with a Tee and dump the relief back into the turbo oil drain or oil fill neck (whatever is closer to where you put the relief valve).

 

Are you guys running these 3 port regulators after a resttictor orifice? Surely a 2 port in line regulator is a more sensible option not to waste oil volume for the rest of the engine? It's not like the turbo is likely to generate unconstrained volume flow back at the regulator or even completely dead head and pressurise with temperature rise like a pressure test rig or closed process vessel might.

 

The -3an fittings/line is typically considered the restriction to avoid wasting oil flow.

 

Back in 1992 my wife bought her MX3 V6, it was a great car. In 1993, I installed a K&N filter. I short while later when doing an inspection, I noticed
that the rubber seal areas of the filter were like soft bubble gum.

Evidently the curing process for the rubber or whatever it was, failed. I returned it to K&N with an explanation.
They sent me a replacement for free and the newer on never failed.

 

I had a genuine K&N fail in the same manner 8 years ago. It was mounted directly to the comp housing on the Holset VGT I had on my FC.
It's been a pen holder on my desk ever sinse.

 

lol

 

Thanks for the heads-up, that's very interesting. AEM split the company and sold the AEM Intakes division to K&N sometime around 2009. I wonder if there's a difference in how the AEM filters vs K&N are manufactured, or if a brand new K&N filter will have similar problems. There's no guarantee that each batch is built the same, especially considering all the supply chain and manufacturing shakeups that have happened since 2020.

 

I notice K&N sells a Dry-Flow filter under their brand name now too. The flange material is definitely different from the K&N filters I have.

I received an email saying they were backed up and to expect a slow response, but no follow up. Live and learn … less flow than a K&N too; not recommended.
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