Better intake breathing

[TominMO]

On my 91 Subaru Loyale, I noticed that it was struggling over 4500 RPM or so. I drilled a couple dozen holes in the lower airbox half, before the filter, and it revved up nicely to 6500 after that. This car has a very small air intake (before the filter), compared to the hole after the filter, going into the engine. So this is an airflow bottleneck, probably the biggest one.

The same is true for Festys, I saw, so I also drilled about 30 holes in the lower airbox piece, next to the inner fender where the air will be cooler. It revs up really well. But I didn't do a before/after comparison. Guess I could temporarily tape over the holes and see if I notice a difference.

I do this with all my cars now. Costs nothing compared to a cold-air intake system, and probably gives much of the improvement a cold-air system would.

Your thoughts on this please.

[FestYboy]

the loyale, could you post the dimentions of the rear glass (hatch)?

as for the intake hole idea, a friend of mine had an Imprezza and we did the same thing to it. butt dyno said an extra 5 hp, and it was more responsive to the throttle.

[Nihilist]

I drilled a bunch of 1/2" holes in the bottom of my '94 Escort (1.9L SOHC) airbox. Definately pulled better up high, but sounded lean/sluggish when you stomped on it. You could hear a big snort as you stepped on the throttle , then it would catch .

I drove it that way for years. I put a stock airbox back in it , then it was nice and quiet again. It did seem to lose a little oomph , though.


.....................Blake

[TominMO]

Loyale Glass

the loyale, could you post the dimensions of the rear glass (hatch)?

Actually I sold it to my nephew, and don't have access to it right now...try the Subaru board: www.ultimatesubaru.net