I'm ready to get some pistons for my Ls/Vtec setup. I'm looking at either JDM ITR pistons that are 11.0:1 and Civic type R pistons that are 12.4:1 I'm sure JDM ITR are the safe ones to go with I'm also interested in the CTR. can anyone tell me what the power difference between the two are? I'm just trying to figure out if it's worth the risk for ctr with that high of compression.

 

If you can afford tuning, and have access to 93 octane gas, get the CTRs.

 

id go with the ctrs

 

i'm building my ls vtec and i'm going with jdm b16 pistons
p30=11.5
pr3=11.3
assuming with a b15 head
i would not go with ctr's cr is too high for 91 octane here in calisfornia

 

here is some ratios w/ P30 b16 pistons

B18a/b or B20b/z block with stock (pr4) rods w/ B16 or type R head (PR3)

11.5:1 compression
B18a/b or B20b/Z block with stock (pr4) rods w/ GSR head (p72)

11.7:1 compression
B18C block with stock (P72) rods w/ B16 head or type R head (PR3)

11.3:1 compression
B18C block with stock (P72) rods w/ GSR head (P72)

11.5:1 compression
B18a/b or B20b/z block with stock (PR4) rods w/ stock B18a/b or B20b/z head (p75 or PR4 head)

11.0:1 compression
B17A1 block with stock (P61) rods w/ stock PR3 head

10.9:1 compression
B17A1 block with stock (P61) rods w/ stock P72 head

11.1:1 compression
B16A block with stock (PR3) rods w/ stock PR3 head

10.4:1 compression
B16A block with stock (PR3) rods w/ stock GSR head

10.6:1 compression


All compressions are acturate to .05

 

I know what compression I'm going to have but what kind of pony power are we talking?

 

Your compression number are a little more off than .05. GSR head will yield a higher CR than a b16 head.

Powerwise, I think a whole point in compression is somewhere around 10% difference. That's just what I read, but you can't really tell since there are different factors.

Why don't you make a compromise between the two and go with B16 pistons with a 11.6:1 CR?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by specie &raquo;</TD></TR><TR><TD CLASS="quote">Your compression number are a little more off than .05. GSR head will yield a higher CR than a b16 head.

Powerwise, I think a whole point in compression is somewhere around 10% difference. That's just what I read, but you can't really tell since there are different factors.

Why don't you make a compromise between the two and go with B16 pistons with a 11.6:1 CR? </TD></TR></TABLE>

Please show me where I am wrong so I can fix

they look pretty on to me

 

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