i just put an ls in my eg hatchback. the rings were bad on the stock pistons -so i am trying to decide whether to use itr pistons or ctr pistons. will the ctr pistons be ok to run on without octane boost? -also , i know when attaching itr pistons to ls rods- you have to mill 1mm off each side of the rod. --do you have to do this when attaching ctr pistons also.-------oh and what do you think about b16 pistons?-they would raise my compression to 11;1.
10.8;1 for itr and 11.4;1 for ctr.
i want ctr's for highest compression , but i'm worried about running only on 91 octane because thats all california has to offer.

 

11.4 should be safe on 91.

 

that is what i thought , but i am hoping to find out from someone that has done this mod. thanks for your input. --how sure are you?

 

You can go up to around 12:1 on pump gas

 

even with stock fuel injectors, regulator,etc..?

 

CTR pistons on an ole friend of mine's LS, came out to be right over 12:1 compression.

 

According to all the CR calculators, with stock bore, stock head gasket, stock deck height, and no head milling, compression should be 11.40:1. With a b16 head it would be closer to 12:1, actually 11.97:1.

 

yes, those were the calculations i got. And this hatch is for street use so i am not putting a vtec head on it. ---but what about the milling on the rods for clearance ?
i know the rods need to be milled for itr pistons , but what about ctr's?