Taking Suggestions on Intake Ducting

I'm finishing up a 1.8 swap in my '90 Miata. I'm waiting on a header and I have some wiring for the VVT left.

The last piece of the puzzle is connecting the AFM to the throttle. I used the FM throttle adapter; so I have a 1.6 throttle on a 1.8 intake with a bit of a spacer in between.

All of that results in the factory intake ducting being too far forward to clear the fan. I have to either come up with a way to modify that plastic duct or I need to replace it withing something else.

What say ye?

Dryer hose? May look tacky, but PVC painted black?

Also, how significant is the Helmholtz resonator in the stock intake tract?

One of the first thing removed on ZX2's. More noise. Power no.

I've just gone the route of cutting the stock plastic pieces so I can fiberglass them to fit.

You should add NACA duct to hood and route intake to it.

The 1.8 crossover can work. In the past, I've also used flexible ducting like brake duct hose. The chamber does add a little bit of torque (4 ft-lb at 4000 rpm on my most recent dyno test) with no power loss, but it can be difficult to integrate.

This shows the hose. The bit of stock intake is in there because of the chamber.

In reply to Keith:

You make me feel ridiculously cheap for not just buying a stand alone. Unless there's something I don't know. I'm somewhat restricted in my options by the AFM for now.

There's no reason I couldn't have put the AFM up by the filter. You can get a simple adapter to put a round hose on to that square flange - we have them at FM.

Should I be worried about keeping the intake tract as close to the stock length a possible since I'm sticking to the factory ecu for now? I'm probably massively over-thinking this.

93EXCivic wrote: You should add NACA duct to hood and route intake to it.

If it makes any sense, I'm trying to be cheap right now so that I can do something stupid with my money in the near future.

Watching with some interest.

Going to try to figure out a good CAI setup for my STS 1.8 miata. It seems that all the kits cost over $200 and thats absurd.

(FM randall cowel setup is nice and cheaper, but illegal for my class.)

Is the drop in K&N with the stock stuff really the best way to go? I know I am going to keep the stock crossover tube for the resonator.

I am adding a header soon and I am going to wrap it to try to keep the underhood temps down. I just wonder if I can find a good solution to draw a bit cooler of air with better flow.

Depends what you can do legally. A box behind the headlight with the headlight door opened up an inch or two will do a pretty good job. Flow isn't that big a deal with stock-ish Miata power. You need cold.

So a drop in (decent, if I can find better then K&N) and rearranging the tube from the filter housing to get colder air would do well as far as power comparison to anything else (cone filter and ducting)?

Yeah, the box isn't a real problem. Most cone filters simply suck too much hot air.

Keith wrote: The 1.8 crossover can work. In the past, I've also used flexible ducting like brake duct hose. The chamber does add a little bit of torque (4 ft-lb at 4000 rpm on my most recent dyno test) with no power loss, but it can be difficult to integrate. This shows the hose. The bit of stock intake is in there because of the chamber.

What header is that?