i was playing with the compression ratio calculator on c-speed racing, and when i put in the stock specs for a b18a it yielded 9.2:1.
the stock statistics for the b18a are 9.1, right? so how close is this compression ratio calculator?
i’m looking at a setup using some p30 pistons (jdm b16a), and c-speed says it will yield 11.4, is it more likely that this will be 11.3?
please tell me what’s goign on
the calculator is correct. i’ve even done some calculations by hand and they are the same (their calculations are probably a tad bit more accurate).
stock compression for the b18a is 9.2:1 I have no idea where you heard it was 9.1:1
I think you put in some wrong values. p30 pistons in a b18a will give you 11.015:1 its the ctr’s that’ll give you 11.4:1
oh, and so you know. p30’s only came in 92+ jdm b16’s. All usdm and pre 92 jdm b16’s have pr3 pistons.
neither the p30’s or the pr3’s will require any mods to fit your rods. However any of the gsr/itr/ctr pistons will require that your shave your rods a little.
colin, have you started or finished your b17 buildup yet???
yeah, i don’t know where i got 9.1 from, i just like embedded that number into my head as my stock CR.
but as to p30s in my b18a, i was referring to my ls/vtec with a b16a. so yielding 11.4 should be fine on 92, correct – i’m upgrading my oil pump, water pump as precautionary measures, anything else?
Originally posted by x4evawizex
[B]yeah, i don’t know where i got 9.1 from, i just like embedded that number into my head as my stock CR.
but as to p30s in my b18a, i was referring to my ls/vtec with a b16a. so yielding 11.4 should be fine on 92, correct – i’m upgrading my oil pump, water pump as precautionary measures, anything else? [/B]
11.4 is a bit high on 92 octane… a few members have done so, but it may require retarding your timing a bit…
cspeed: I never made the conection… do you run that site? if so 
Originally posted by 92GS-R
cspeed: I never made the conection… do you run that site? if so
hehe, nope. actually, i wish i did–they’ve got some fast all motor cars. i was “cspeed” before they were “c-speed.” 
Originally posted by cspeed
[B]
hehe, nope. actually, i wish i did–they’ve got some fast all motor cars. i was “cspeed” before they were “c-speed.” [/B]
hehe… wannabees…
so what does cspeed stand for?
Originally posted by cspeed
[B]
colin, have you started or finished your b17 buildup yet??? [/B]
hehe. started… yes. finished… i wish!
Project All Motor B17a Status:
-engine pulled from donor car
-block and p30 pistons sent to Bensons (courtesty John (amerikan))
-exedy organic clutch in the mail
as you can see, i’ve barely gotten started. and this whole thing has to be done before i go back to school in mid/late september!!! damn i gotta get to work.
Originally posted by 92GS-R
[B]hehe… wannabees…
so what does cspeed stand for?[/B]
my last name starts with “c” and, a long long time ago, when i used to have an 89 civic si hatch, the mods i did to it i’d tell my friends that it was tuned by “cspeed” as if i was some kind of independent tuner/car racing crew (it was just me… :shy: ). just one of those stupid things that stuck with me. :crazy: (whispering i still think i’m tuned by ‘cspeed’) :crazy: X100 
colin, keep us updated. because you know i’ll be hitting you up with questions sooner or later… good luck with the build-up. when you finish, you gotta take me for a ride…
Originally posted by 92GS-R
[B]
11.4 is a bit high on 92 octane… a few members have done so, but it may require retarding your timing a bit…
cspeed: I never made the conection… do you run that site? if so [/B]
actually, my compression would be 11.54 according to cspeed, say i were to run retarded timing on 92, are there any downsides besides having the timing retarded?
or would it be more beneficial for me to run pr3s at 11.3 and could i keep stock timing?
tell me what i should do, i feel motivated to drop in pistons since it’s not as hard as i had imagined
Originally posted by x4evawizex
[B]
actually, my compression would be 11.54 according to cspeed, say i were to run retarded timing on 92, are there any downsides besides having the timing retarded?
or would it be more beneficial for me to run pr3s at 11.3 and could i keep stock timing?
tell me what i should do, i feel motivated to drop in pistons since it’s not as hard as i had imagined [/B]
well, i’m not sure how much you would have to retard timing. If its pretty minimal then i’d do it that way. The plus to having your timing retarded all the time is that you have extra power there for whenever you may need it. Going to the track? Just advance the timing a bit and get some race fuel. if you get a compression that runs fine on stock timing or even 18deg you won’t have the option to turn up the power on special occasions.
but like i said, i’m not sure how much you’d have to retard it. hopefully someone knows.
well, i’m not sure how much you would have to retard timing. If its pretty minimal then i’d do it that way. The plus to having your timing retarded all the time is that you have extra power there for whenever you may need it. Going to the track? Just advance the timing a bit and get some race fuel. if you get a compression that runs fine on stock timing or even 18deg you won’t have the option to turn up the power on special occasions.
but like i said, i’m not sure how much you’d have to retard it. hopefully someone knows.
so the only downside would be an upside, that’s pretty sweet.
does anyone know how much i should retard with this setup…
b18a block
PR3/P30 pistons (give me diff numbers depending on the pistons)
b16a head
i would be yielding 11.54 or 11.3 CRs with the respective pistons
ttt