Just do a cowl intake on the pax side, and skip the water ingestion/multiple bends/ size transition(?) ... cold air from a high(er) pressure source -> win!

Its 3” the entire length, and is ducted from the radiator bumper inlet so probably similar or higher pressure than the cowl. I live in southern California so water ingestion isn’t really a concern. The cowl area is pretty small in terms of fitting a decent sized filter in there.

Thanks for both replies. Problem with the PS cowl is that the header is tucked right below, so a fair amount of heat. I do have plenty of room to sweep some tubing across the engine front, so will take a look at that. Thanks for alerting me!

For the record, I had in mind the filter stays in the engine bay (you can do it the other way, but more trouble than it is worth IMHO) fed by pipe from cowl. Exhaust heat (radiant) easily fixed, after that the heating from hot engine bay air would also be fixable if it were troublesome.

Cowl intakes are pretty common on RHD cars, because they are easily doable (generally), not so much LHD. Swapping the hot and cold sides with an engine swap opens that possibility for LHD.

One downside, or upside for some, is induction noise ...

I don’t understand what you’re saying; it’s a LHD car, but it has had an engine swap that does flip intake and exhaust from the stock configuration. Are you saying it’s easier now that it has been swapped? Or it would be easier if it was RHD…?

You need the bulkhead to be clear of immoveable obstructions on the side opposite the intake (to avoid convoluted/constricted inlet tract), and LHD NA and NB put the brake stuff there. So RHD NA and NB8A (NB8B getting messy with ABS unit) avoid that. Then, LHD with intake/exhaust swapped opens up the bulkhead area in question (ie the Honda swap).

I ran one in my NB8A for about 15 years, pretty simple mod, still available out here.

Mounting your radiator at an angle may allow space between your core support and the top of the radiator for a filer setup like I have...

You can view my post about it here:
https://www.miataturbo.net/build-thr...0/#post1621184

With his bigly modded firewall and the motor pushed back I think he has plenty of room as is. But the V mount setup you did is rad. Def taking notes

The front sway bar is really the piece that gets most in the way (regardless of how far back your engine sits)

Some progress; exhaust system finished up, so she's a runner. The driveshaft finally got finished as well. New intake air tube swapped in, after it being brought to my attention here (thanks!). Had to face up to the new top install before I could make the roll bar. The car came topless, so I didn't have the old one to look at, and the junkyard one I found was missing parts, but finally figured it out. Only problem now is it is so F#$!ing tight I can't latch it. Even with me straining away, and my Wife helping, it will only do one side. Reading up on this, it sounds like hot sun might help, but that is four months away, so who knows. Have the roll bar 90% finished, then the car's pretty much done till I can get her out on the road.

https://cimg3.ibsrv.net/gimg/www.mia...0f3a69716d.jpg
https://cimg5.ibsrv.net/gimg/www.mia...12f217ff26.jpg
https://cimg1.ibsrv.net/gimg/www.mia...e39d61f942.jpg
https://cimg2.ibsrv.net/gimg/www.mia...65d70619c7.jpg

Glad to see it almost done!

Sorry to say, but that filter location still isn't great. If you have the ability to log IATs you'll see that the engine is sucking hot air right off the back of the rad.

On my E30 I could see the IATs come up and when idling in traffic things got hot enough that I had to start playing with the IAT correction tables to keep it running correctly.
Off the top of my head I recall 160F+ intake temperatures. Even when moving the intake temps were noticeably above ambient.

I agree with you on the hot rad air, probably something to keep working on. We get enough Summer rain I don't want a low to the ground source of air, and the engine bay doesn't offer too many good spots to make a cold air box, but once it's on the road I can keep thinking about the options.

Yeah, seconding that. Anywhere in the engine bay will be hot air.

Short option - cold air box taking outside air from headlight duct. Or take it from the front of the bonnet into said cold air box (front of bonnet is a low pressure area, so anything in that area is problematic pressure-wise)

Long option - either cowl intake on pax side, or taking cold air from in front of radiator. If you prefer, a rear-facing scoop inlet at the back of the bonnet would also work, but it is the windscreen driving the high pressure so you don't want to move the inlet any further away from it than you can avoid.

(cold=ambient)

All good ideas, but require the stock body be cut, or altered more than I care to do. I have a vintage formula car to race, so this baby is mostly a street project sleeper; I like an unobtrusive car that can surprise. If the cowl wasn't so non-existent due to the engine set back, that would be my path. For now I will leave alone, get some miles on her and keep thinking. Appreciate the ideas 'tho!