j.kenzie@sbcglobal.net

Hi Fred,
I did consider the filter size. I also could not find flow specs on the Spectre website. I think if I clean fairly often, and since I drive in clean areas, it will probably be OK. The SC inlet is 3", the filter housing is 4", and the inlet aperture is about equivalent of 4". I actually tried the next size larger that you mention, and it interferes with the SC housing and the distributor. I agree that it's possible that I could lose some WOT power, but I don't think I'll notice. I will report on this if I do notice anything.
Thanks for looking,
Dave

Imo000

Nice solution. Let's hope the elbow stays on the intake oval.

j.kenzie@sbcglobal.net

My thought exactly. I will eventually add a fastener or two. The whole assembly is pretty well constrained by surrounding structures.
Thanks,
Dave

Carl Fausett

Once consideration in filter mechanics is the velocity of the particle you are trying to filter out. Larger filter sizes, (larger diameter or more pleats, or both) allow for longer service intervals, so if this was a naturally aspirated car the small filter would just need to be serviced more frequently.

But, when a filter is shrouded like that in a tube, and because the supercharger is pulling so hard from the back-side, the velocity of the dirt particles coming toward the filter will be much greater and many more will actually shoot through the filter media. They are simply moving to fast to be stopped.

It looks nice visually, but you can expect more dirt will make it to your engine. Sorry Dave. Just wanted you and others to know.

j.kenzie@sbcglobal.net

Thanks, Carl. You are the expert.
I'll give it a try for a while though.
Dave

j.kenzie@sbcglobal.net

Because of what Carl said, I decided to modify the inline filter housing. I eliminated the inlet side and replaced it with a 4" long piece of 4" tubing. Then I used another 45 degree silicone elbow, this time 4" at both ends to join to the inlet oval aperture. This eliminates the bottle neck in the original design, and should slow the velocity somewhat. New parts (sorry Petza):

Here's the new look and the old for comparison:


Thanks for the suggestions,
Dave

Petza914

I run an AFM gauge in my car so I'll be able to see if the mixture at the analysis probe changes, like becomes richer since less air might be making in to mix with the K-Jet fuel. My plan for the silicone intake that's at the radiator plate shroud was to leave a little more length so it protrudes through the oval, then, cut a couple slits in the silicone so I could fold it back on the input side and rivet it to the plate to make sure it stays in place. I also run a UOA on all my oil changes so I'll wait to do my seasonal oil change until after the modification is done and then next year at this time, I'll see if the UOA shows any higher silicon (dirt) or any other contaminant levels higher than the last 2 that were done with the current intake. If so, I can always switch back.

j.kenzie@sbcglobal.net

That sounds like a plan, Pete.
I wish you the best of luck,
Dave

FredR

This is precisely why I asked about the rated capacity of the installed element design. If the airflow is within such parameter no harm will be done but exceed the rated capacity and there may well be unpleasant consequences longer term. Unfortunately such numbers are beyond my knowledge envelope but when I purchased the EIS system from Roger I did some checking to satisfy myself the it had plenty of capacity in hand which as I am concerned, it did..If I can find some info I will revert with such.

Edit:

Take a look at this link-
https://www.knfilters.com/filter_facts.htm

If you do the calc suggested and multiply by 1.3 to allow for the s/c you come up with a filter area of about 100 sq inches- how does this number compare to the element you have installed? This is the K&N methodology but theoretically it should be similar for Spectre I suspect.

Rgds

Fred

Carl Fausett

Good job, John!

j.kenzie@sbcglobal.net

Thanks Fred. Interesting reading. I think I am in the ball park on filter area. Hopefully velocity is OK, and I can keep the filter clean. I don't really put many miles on this, and I drive in pretty clean areas.
I appreciate the interest.
Good luck,
Dave (John)

rrickolate

John,
I also have Carl's kit on an '84. I am interested in installing your cold air intake, but have a question:
What did you do with the crankcase vent line that the kit directs back into the intake line after the filter?

Thanks

Petza914

I don't know about John's, but my crankcase vent setup is different and doesn't route back to the intake.

j.kenzie@sbcglobal.net

Mine runs into the front of the intake plenum, I'll see if I can find a picture.
Dave (John)

Carl Fausett

Rickolate: You will find differences between a K-Jet equipped car like Petza's and an L-Jet equipped car like yours. In addition, on some of our earliest kits we plumbed the PCV into the inlet air which is what I think you are describing, and later models vented that to atmosphere.
You could remove that PCV hose and vent it to atmosphere and drive the car a bit and see if there are any consequences. If none (and there would likely be none) then you could eliminate that hose altogether.

The difference is: when the PCV hose is vented to atmosphere, the car may drop a quarter-sized stain on the pavement where it is parked as oil droplets coating the inside of the hose run down and drip out. When the PCV hose is routed into the air intake, this will not happen.