85mm tb, loosting power? to much air??
 

i have a ported out profesional prodcut throttle body and plenum. Is 85mm to big. Will i loose power. Is it to much air for a stock motor? can i casue damagge. its been on for a couple monts but dosnt seem to be bad. I jsut wnat to no if anyhtign long term iwll come

some people say not to go over 70 mm on a stockk motor but i think 75 or 78 is fine. idk about 85 though

It will not be "too much air", because the intake does not push air into the engine, it just makes it available for the engine to suck in. A less restrictive/"bigger" intake makes it easier for the engine to such air in.

The negative effect of too large a TB (and IMHO 85 mm is too large, way too large, for an n/a 4.6L 2V) is that at WOT there will be a reduction in charge velocity in the intake manifold. The lower charge velocity will actually reduce the amount of air entering the engine.

The extent to which this impacts performance depends on a lot of other factors.

You can read more about TB and plenum sizing and performance here...