Intake Brainstorming
 

When we had 1 day to get ready for Solo Nationals and realized that my intake temps were getting upwards of 180 degrees after the car was sitting around, I had to make an emergency change.

https://www.miataturbo.net/attachmen...ine=1349073511

Yep, that's a mushroom sticking out of the hood. On the bright side, our intake temps were only ~15 over ambient, presumably all due to the supercharger and intake manifold heating up.

So, the problem that I'm working with is that, given the setup of the supercharger, the intake points rearward, and there's only ~6 inches of space between the throttle body inlet and the firewall. Doesn't leave me a lot of room to work with... You can kinda see what I'm talking about here:

https://www.miataturbo.net/attachmen...ine=1349073511

So, I'm trying to figure out what to do to make the intake setup better. We're working with a few limitations here:
* There's a giant splitter under the engine bay, preventing almost any air from getting in from beneath the car. So, any air entering the engine bay is currently through the radiator opening.
* Getting a 180 bend in the intake to make it pull from the front of the passenger side of the engine bay would probably require custom-fabricating a 180 degree bend metal piece, since there's so little room to work with. Not the end of the world, but I'm not convinced there's any better air up there to work with.
* There's currently no venting in the hood. I could change this, but in general, there's still a limitation on how much air we can get INTO the engine bay based on the radiator opening, and that air still needs to go through either a radiator or an intercooler (side by side covering the whole opening).

So, I'm at a bit of a loss as to what to do. I'm wondering if it makes sense to cut a hole in the firewall to the rain duct at the base of the windshield, and put a filter in there, covered by something on the top to keep rain from pouring into it. I know that the windshield base gets a fair amount of positive pressure, but the question is if that will reach all the way around under the hood to where I'd place the intake. Any thoughts on that?

Failing that, anyone have any other decent ideas? I'd really like to be able to go back to a totally stock-looking hood so that I could potentially drive the car on the street (sans aero) and parking it somewhere without people fucking with my intake.

I'd just leave the filter poking up over the hood and put a scoop over it. Its a race car, doesnt need to be pretty. Or try to 180* bend it around there and run it in front of the intercooler using the same space for the pipe that you would on a normal turbo intercooler setup. You might also be able to sneak a 90* bend in and run it way down along the subframe to get there but you'll make it harder to change the oil filter.

Just remember that super short intake on a blower car give you the same benefits as it does on an NA car without the draw backs, where as a long intake doesnt give the same benefits but has all the draw backs.

FWIW my suggestioin would be to put your airfilter back on the end of the throttle body in betweem the s/c and the firewall, drill some randhall-style holes in the firewall to allow fresh / cool air in and then make a box or shield around the airfilter to keep the hot air and heat away. It is either that or some sort of hood scoop to a boxed in fiter.

Thomas

cut hole in "firewall", insert tube from SC.

I'm almost certain that firewall cutting is not legal in SM.

I'm pretty sure I can get away with firewall holes under the minor mods clause, but I need to re-read the rules to make sure it's not expressly forbidden. I'm also not sure that section of the wall counts as "firewall" anymore since there's still metal between the engine bay and the driver even if you cut through the little apron there -- that's pretty much just a rain shield for the engine bay there. As such, if I just cut holes in it for venting, I don't think that's legal, but if I cut a hole through it to RUN my intake through, that should be legal.

The scoop idea is obviously the easiest one, but that still massively disrupts aero flow over the car, so I'm trying to do away with that if possible.

I would just be sure the keep the hole you cut out as proof in case someone protests you for removing more than 1 pound under that clause.

Yeah, or I was thinking to just keep a tiny part of it still attached like opening a can lid, and just bend it around next to it like opening a hatch, to really keep the protestability down.

The issue is just if that area actually gets enough airflow.

the best part is you could just put a velocity stack on the end, and then just make your own "filter" by covering the entire cowl area with a mesh grill.

i dont consider it the "firewall." Can you cut a hole in the fender well? that would be the same concept.

+1 for cutting through the cowl wall. Also, don't laugh, but you might be surprised what a full bag of ice sitting on the sc/intake between runs will do. Besides melt the ice...

Ice bagging is common in Mustang circles.

I am in the same boat. I was thinking of a hood vent/box or running a large diameter tube to the fender well. My current setup is a 90* elbow and a flex tube to behind the headlight.

I think the method you tried is best, but drop the filter down and cover with a scoop. Allows you to run a very short tube and larger filter, just box in the filter to prevent creating a conduit for hot air.

I assume you've gutted all the wiper motor stuff on the passenger side. If so, look at post #55 for an idea:

https://www.miataturbo.net/build-thr...d-55737/page3/

Not allowed to, IIRC.

Read the new rules for next year.

You are running w/o a hardtop put a scoop on it and call it good. Remember the KISS principal, don't over think it, w/o a hardtop being concerned about the aero affects of a scoop is silly. Just my thought.

CF Hardtop is on the car now that they've legalized it. Maybe the wing will do something useful now...

Was the HT not legal in SSM before or was the CF HT not legal? We are talking about doing a CF HT for FP when we get there after 2013 most likely. Alas, that isn't the question here in the OP. I would probably put it in the "firewall" like was suggested.

Had to be OEM hardtops before now.

Yeah, I think the firewall seems to be the way to go. Just a matter of how to clean up the area there and make sure I don't ingest a gallon of water...

Oh ok. I didn't realize that but I haven't even glanced at SSM rules except to help build a splitter for a friends turbo NA SSM car. Enough to worry about in *SP.