Soooo I know there are a ton of posts comparing which is better, Crawford plenum or the MD spacer. But my question is, if I combine both will I see gains? This is not a question of "is it cost effective or are the gains worth the price". But I already have a 5/16 spacer ad want to know if,after a tune, will I see gains if I add a Crawford plenum on top of it? Has this been tested?

 

I don't think it will.

 

So If I have a md spacer and add a Crawford plenum it will do nothing? Can anyone support this claim? I'm sure it shifts the curve, but after a tune can I expect to see any gain at all? Even 3-4 hp...? Or will it lose power? Anyone have data on this?

 

It won't really add anything to the curve (diminishing returns), but stacking them could introduce fitment problems.

I wouldn't do it. Just use one or the other.

 

Your overall gains are gonna be minimal at best (1-2 HP) with possible fitment issues and maybe even some losses in the rpm band.

 

It's the same as stacking 2 spacers or something like that.

Would be better to add a MREV to either of those units

 

Yeah I would do mrev, but I'm non-revup auto

 

^^^ me too... dont let that stop you