Maybe something like this

12" x 2" Aluminum Washable Chrome Top Lid Air Cleaner Oval Red Filter Lid | eBay

Give it a try, back in the old days race cars ran open velocity stacks all the time.

Cut a hole in the parcel tray and feed the motor fresh, dust free interior air. [emoji23]

Sent from my Nexus 6P using Tapatalk

Remove a speaker and use that hole

What speaker and hole? No holes in my 79 but I have thought about making one big air filter over there.

^^^ Ditto. No speaker holes here either. If you have them someone cut them in.

To be honest, I don't listen to the radio in either of my turbos. The 79 is at a shop 200 miles away and I'm in the hospital right now so I can't look. I was guessing cause that is where I'm use to seeing them in American cars.

Since I am good friend and my car wont be done for awhile still you can borrow the air filter setup off my motor to see if it makes a difference.

And I have one of those big air raid plenums and filters sitting in my garage you could also try, the plenum pieced needs a little work but its functional.

Thanks!

On this topic, I am curious what the max power anyone has pulled through a stock airbox. I am sure it is limited on an unmodified box (that hole is tiny). Modified with a larger hole (or holes), might be adequate.

Sent from my Nexus 6P using Tapatalk

Don't know about your harbor freight or whatever filter, but I doubt there's any restriction on any reasonable airfilter or stock airbox. There's plenty of documentation that aftermarket filters don't flow much more if anything better than stock. Otherwise why wouldn't they simply make "stock" better.

If there's any restriction in the CIS system is probably in the airflow metering setup or the intake plenum itself.

I'm not sure it is reasonable. It is a pretty tiny paper element. The surface area is somewhat comical. Will see if running open has an effect.

Sent from my Nexus 6P using Tapatalk

I think you will see a difference

Doesn’t hurt to test it


Sent from my iPhone using Tapatalk

Ah, well, reasonableness makes the difference :D See the other alternate thread on this topic.

Old filter was definitely choking it off. Finally seeing AFR above 10 approaching 7000 RPM. It's still pig rich from 4500 to 6000, but 11.5:1 @ 7K redline is much better! A little more tuning and it should be perfect. I think this turbo is right at the limit in terms of what unmodified CIS can handle with a Leask WUR.

This KN filter is cheap and fits GREAT!!!https://uploads.tapatalk-cdn.com/201...efc24f59c4.jpg

Sent from my Nexus 6P using Tapatalk

That KN looks similar to the one I run. It should be washable?
What WUR WP are you running now? You could probably lean it out a bit (harden the pressure) to help deal with the 4500-6000. Presumably your Leask switch is set at 4500. At what AFR (12.5?).
You won't be running at 7k that often, but I run mine to 12.5 AFR on the track at 1 bar with no issues - so you can tweek the AFR a bit leaner yet.
Regards
Alan