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Rb30 Compression

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guys, ive bought a built rb30, its running forged rods, pistons, race bearings +b/e bearings, but this block was using a RB25NEO head. So comp ratio will be around 8.4:1 with NEO head, 7.9:1 with R33 RB25 head.

and now im going to run an rb26head. ive etimated it to be about 7.8:1 with a 1mm head gasket, should i raise it? or what should i do? how could i make it higher?

or what does this mean? can i run extreme amounts of boost? is it gunna drink fuel faster than i can piss?

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James_03 Mentor

James_03

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Basically for a low static CR you want:

1. Head that can flow (ie porting, valves etc which generally = $$)

2. Turbo/s to support low CR (Lower the CR, more boost to make good power)

If it's a standard head etc, it will just be a pig of a motor at 7:1.

My personal pref would be to raise it, that means new slugs if you want to do it properly. You can't really go anymore off a 1mm HG, and shaving the head is a bit dodge, not too mention it still may not net the required CR.

CP do pistons now to suit the combo with 26 head, that's what I would be doing.

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