11:1 11.3:1 11.5:1 ?? assuming its not tuned right in the begining. obviously this isn't for me, seeing i'm turbo. its for a friend building all motor.

 

11.5:1 untuned
13:1 tuned maybe higher if your good

 

well in my car i have ctr pistons in a gsr block with a decked gsr head and i run on 93 octane wit a stock p72 ecu and untuned and my car runs fine with no problems...im guessing my c/r is about 12.8:1

 

so i could run 11.5:1 untuned.....thanks for the quick response guys. basically, i'm lookin for 200whp out of a b16. what am i gonna need to do? was thinkin of getting it sleeved and bored to 84mm..CP 11.5:1 pistons..crower rods...head fully built with skunk2 stage 2 cams..high comp valves, springs retainers, valve job, p&P..skunk2 manifold..bigger TB..etc. what do u guys think?


Modified by SpoolnG2 at 6:34 PM 9/12/2003


Modified by SpoolnG2 at 6:35 PM 9/12/2003

 

i am running 12:1:1 , but my head is milled and i have flat faced valves. so i am guessing it is around 12:5:1, and i drive around on 91 octane just fine

 

Depends on your cams.

 

200 whp out of a b16 is going to take either a bore with some medium compression and some pretty meaty cams, or un sleeved stock bore b16 will need some awesome head work, high compression and meaty cams, thinking like 12:5 comp with some jun 3 cams, and a full head job, that might get the job done

 

Here we go again......tough to say, depends on cams and how "untuned" the car is.

 

I wish i had 93 here in CA. I am running 11.5 pistons with 91 gas. If i had 93..i would go 12.5.

 

if u look to the top, i put the setup i would be using. what cams..pistons..etc.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AllMoToRB18c &raquo;</TD></TR><TR><TD CLASS="quote">well in my car i have ctr pistons in a gsr block with a decked gsr head and i run on 93 octane wit a stock p72 ecu and untuned and my car runs fine with no problems...im guessing my c/r is about 12.8:1</TD></TR></TABLE>

You must have done alot of milling to get the compression from 12.0:1 to 12.8:1 by just decking...

 

Its all in the tuning. My car has 12:1 CR and running 91 just fine as long as it isn't 105+ degrees out

 

[QUOTE=SpoolnG2]so i could run 11.5:1 untuned.....thanks for the quick response guys. basically, i'm lookin for 200whp out of a b16. what am i gonna need to do? was thinkin of getting it sleeved and bored to 84mm..CP 11.5:1 pistons..crower rods...head fully built with skunk2 stage 2 cams..high comp valves, springs retainers, valve job, p&P..skunk2 manifold..bigger TB..etc. what do u guys think?


Modified by SpoolnG2 at 6:34 PM 9/12/2003


that would be a start to reaching 200 whp but if he's untuned then there's no telling where he'll be.... i would probbaly go with a higher comp just to make sure you don't fall short of the goal...

if i were your friend i would go with a higher compression than 11.5:1 and tune it...

cause if your not tuned you won't get the 200 mark

 

it is gonna be tuned, don't get me wrong. i just wanted to know a safe c/r for him, so that until he doesn get it tuned, there won't be any detonation. thats all. i totally know tuning is they key.

 

im at 13:1 and able to run 93

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SpoolnG2 &raquo;</TD></TR><TR><TD CLASS="quote">it is gonna be tuned, don't get me wrong. i just wanted to know a safe c/r for him, so that until he doesn get it tuned, there won't be any detonation. thats all. i totally know tuning is they key.</TD></TR></TABLE>

oh ok then well how long after it gets built till he tunes it? cause if it's not that long just run to that gas city and fill up on 100 octane.... it'll be expensive but that way you can raise the compression and leave it untuned for a bit

or i know there is a place in joliet with 108 octane...

good luck though...

 

i heard , that high octane can hurt more that harm you. i didnt understand why tho.. wont the higher the better!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wm5holla &raquo;</TD></TR><TR><TD CLASS="quote">i heard , that high octane can hurt more that harm you. i didnt understand why tho.. wont the higher the better!</TD></TR></TABLE>

Higher octane burns slower, so if you don't have enough compression or whatever (Nitrous, F/I) you won't be able to burn it all off completely.

 

Wow some of you all's cr's seem way high for pump gas. Anyone here running higher than 11.5:1 have to retard your ignition timing to run pump gas?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MackSpeed-616 &raquo;</TD></TR><TR><TD CLASS="quote">im at 13:1 and able to run 93</TD></TR></TABLE>

what's your setup?

 

I don't see a point of going less than 12.5:1 if you're going to spend a lot of money building the motor. I'm sure you can still run it with a few degrees retard and upped fuel pressure. Currently running 11.7:1 on 93 octane with advanced timming, but will be up in the 12.5:1 soon.

 

How high do you think you can run without retarding your timing on 93 octane + octane booster fuel additives?

 

all i can say is TOULENE at the paint store and he shouldnt have any problems with pinging

 

Have you used toulene yourself?

 

actually, i've just started hearing about toulene. what you do, is use 91 or 93 octane, which ever you have around you. go to the hardware store and buy some toulene (paint dept). The mixture is ...1 gallon of gas....25% toulene...and a tablespoon of 2 cycle oil so that the toulene doesnt dry out the gaskets in the motor. supposed to make your octane about 101 octane. couple of my buddies have used it. one of em had a JDM GSR w/ 11psi. had no problems. also heard a lot of grand national guys use it. i'm gonna try it out as soon as i get my car back together.