airbox

[DaNO]

I have a 1998 318. does anyone know if i can use another airbox from a different model my 318. Say a box from a 325 or something?

[bullmand]

I'm sure it would fit in the engine bay, but I'm not sure you would see any benefit. The ti filter is 9x9.25 inches and the 328 filter is 6.875x9.25 inches. My math shows that being 25.73 square inches less area of air filter. Doesn't seem like the way to go.

[DaNO]

i need it to pass smog and i lost my original.

[bullmand]

I think you should stick with the stock airbox for the ti. I don't think there's any benefit to a 328 one. The ti filter has more area so it should allow more air in. You may actually decrease airflow with a 328 airbox. That seems counterintuitive to me, but the filter is smaller. The boxes are very different from each other, so I'm not really sure how much air each one flows. I can't tell from looking at the parts diagrams if the 318 MAF will fit in the opening of the 328 airbox. Check out www.realoem.com and look at the diagrams. Maybe another member in CA could let you borrow his airbox for your smog test.