Thread: How big of a cam is allowed with stock heads?

IMO if you run fully ported heads and you are going to stay m90 the XPZ is your best bet if you dont want to go full XPZ a S1X or XP will also make good power. Stage 3 and 4 cams tend to like a larger power adder to be worth it. However if you do plan on running nitrous you may be able to get away with a bit bigger cam. The problem you run into here is that a M90 loves a intake bias cam and a nitrous setup will love a exhaust bias cam. So you will have to make that choice.

Originally Posted by Dawings33

IMO if you run fully ported heads and you are going to stay m90 the XPZ is your best bet if you dont want to go full XPZ a S1X or XP will also make good power. Stage 3 and 4 cams tend to like a larger power adder to be worth it. However if you do plan on running nitrous you may be able to get away with a bit bigger cam. The problem you run into here is that a M90 loves a intake bias cam and a nitrous setup will love a exhaust bias cam. So you will have to make that choice.

Well you mentioned the m90 loves a intake biased cam and nitrouse loves an exhaused biased cam.


The Thing i don't get (and that may be because I don't understand it) is why let's say if i'm running nitrous is it better to ONLY have a cam that flows more on the exhaust side. Why not both? The way I think about it is what comes in must go out. And the same with what goes OUT will have to come IN.


I understand it may be a little different for nitrous. But lets talk about the m90. Why would I want a cam that has a higher valve lift then the exhaust does? Why not both?

Even if it is POSSIBLE to flow that amount it seems like i wouldnt be ABLE to or it seems like it would be easier to do so with a cam that has equal int/exh lifts.


From what you're saying about the M90 and the nitrous Dawings it seems like a high lift cam would be the way to go so the m90 and the nitrouse will be happy.


Would you agree?

Or would anyone agree?