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Maggie and good heads

2K views 13 replies 6 participants last post by  2007V 
#1 ·
Is anyone running a Maggie with cnc or aftermarket heads? I'm trying to get a feel for how much the boost will drop with some better heads.

I know most will say it isn't worth it, but reduced boost is lower iat and frees up hp to spin the blower.
 
#5 ·
I personally doubt you will have a drop in pressure for you are keepin the volume of the cylinders the same...You are just making it easier for the cylinders to be filled in...

Oddly enough i found your SC are causing the pressure build up prior to enterin the heads...The cooler inside the SC is low and the cooled air has to be squeezed out, then the runners are not of the same size as your heads thus causing even more pressure.

I was going to raise the Cooler of my SC by a 1/4" and port the runners the same size as my head gasket.

Ppl online have reported better performance with almost zero drop in psi.

I sold the SC before i could play around with it...So i dont have actual proof
 
#14 ·
Naf,

You are right on the boost level. I was assuming the heads were the source of the restriction but if you calculate what the boost would be for an 6L engine with 100% VE (NA) and the amount of airflow the Maggie is putting out, there is only a ~2psi difference. I have to go back and look at my power estimates but that was 20 or 30 hp. And probably a cam would do a better job getting to 100% ve than the heads.

Stroking it to 4"bore 4"stroke drops the boost a little but it is still on the order of a couple psi. Hard to justify any of it.

Thanks for your post!
 
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