Randall Style Intake?
 

I've been thinking for a long time about trying this, but somehow only just learned about the "Randall Intake". That's on the driver's side, but the principle is simple -- pop through the cowl area and get air from the area at the base of the windshield.

Right now, I have to run a super long pipe with a bunch of bends all the way up to the driver's headlight from the passenger side of the motor where the supercharger is. Wondering if it makes any sense to instead run it through the cowl wall there, and put a filter either half way across, or even just run it all the way to the corner where the randall style intake usually goes. Still way less bends than the current setup, and gets the intake out of the engine bay.

Is there enough air that really feeds that spot? Reading random threads, there seems to be pretty proven benefit even on a stock motor to pulling air from there. Thoughts of any sort?

Pictures tend to help the imagination. Just saying!

Fair enough. :)

This is my current setup:
https://www.miataturbo.net/attachmen...ine=1386907131

I'm contemplating basically running that pipe straight through the firewall cowl there over to by the driver's side windshield wiper base area, and putting a big filter there, much like the Randall style intake. Just with a different source than the usual method. :)

Would be really nice if I could just run it at the passenger side right there, but all the wiper crap is in the way.

Wonder if I could do the reverse and put the wipers on the driver's side with RHD parts? :)

Check out hornetball's Greddy build thread for cowl intake win. We also have another guy on here (and m.net) with a M45 supercharger that also did a cowl intake duct thing. Weird PRM cone filter in a tubular airbox assembly iirc. It looks strange but it was very well executed. Search "miata cowl intake" and its like the first image result on thegooglemachine

Just make sure you cut less than an inch and remove less than a pound. Would hate to have to protest you in lincoln. :p

I see you used to have a mushroom filter going through the hood, just prior to the firewall. What was your experience with that vs. the long pipe you have now (throttle response or power)?

I think the only issue would be that you have a 75mm throttle body, that's roughly 7 square inches. Do you have enough space to open up around the cowl? Naturally aspirated and low boost setups would be fine, but wondering if it becomes a restriction at your level. If you removed the rubber seal above the firewall, you may end up where you started, pullling in heated air from the engine bay.

I didn't log any real apples to apples comparisons. At nationals, when I switched from the mushroom filter in the back of the engine bay (against the firewall) to the mushroom out of the hood, my IATs dropped by like 80 degrees or something absurd like that. I didn't log a comparison when I did the long intake, as it took me several days of futzing around to come up with something I was happy with, and in the process I had the hood repaired. :)

Yeah, that's my concern as well. I need to do some measuring to see if I can actually make that work somehow.

Did you ever try this? I just got back to looking at it, I love these sort of things.

Not yet. The car's been down in Portland at a tuner for a while, so I'll look into it in a few weeks when I get it back.

how about just put a velocity stack straight through the firewall and put mesh over the entire opening...

this is why admin.

:party:

That's the other form of what I was thinking. The question is if you can get enough airflow through a mesh filter over the stack without making it 3d in some way.

Depends on how fine of a mesh you run.

not over the stack. make the entire cowl area a "filter".

Run a 180 degree piece of the back of the charger and relocate the filter behind the passenger headlight. Looks like the current setup is nicely heating the portion of pipe over the header.

No room, the abs brick is in the way. Unless I went with a stupidly flat piece of restrictive pipe that'd make the turn, it won't go.

Oh you added abs since the picture you posted of the current setup?

No, there's ABS in that picture. But the current 45 degree up and right pipe is right against the abs brick. I can't turn it any more back that way. And there's no room between there and the hood to run a full 180 straight up and over the setup. So, without relocating the ABS, it has to go that way.

Oh, your abs brick is just in a weird spot. It looks like you have room to do a 180 and run the pipe over the top of the passenger side shock.