i have a gsr rite now, was planning on going turbo but changed my mind being it will most likely be my daily driver for the next couple of years. so im planning on going all motor, i want to go w/cp 12.1 pistons, skunk2 valvetrain, w/sk2 stg2's, with an anr header. i would be using 93 octane and getting it tuned as soon as the motor is broken in and most likely by jeff (boosted hybrid) or by ralphy at drt being those are the best tuners i heard about on the east coast. i want the highest compression that i can get with out sacrificing reliability, is 12.1 too high or would i be able to run higher lilke 12.5, i know 13+ would be out the question but just wondering before i order my pistons, i have everything else. and are stg2's good for that compression or should i get somthing more agressive?

 

with 91 octane 11.8 is the maximum i would run w/o having to retard the timing. i think 93 octane should do fine on low 12's cr. sk2 stage 2 cams are great at the cr.

 

it seems like every state in the US has 93 octane except for california, we are stuck with the 91, i have my ratio around 11.8:1 with P30 pistons and a gsr head, so you could do low 12.somethin:1

 

I'll be using low 12CR, since i also have access to 100RON its not too bad

 

high 11's low 12's should be fine. I'm in cali and can only get 91 i'm running 11.7:1 compression

 

oh ok, that sux, i see som many sick rides from cali how do u guys do it w/91....here sunoco carrys 93 and 100 octane, u gotta cross the bridge to jersey but its only like a 10min drive past the bridge

 

I'm running about 12.2-12.3:1, tuned on 93 octane with stock ignition timing (16deg)..

I drove this car from AZ to NC, and I currently have about 20k on the motor. Very streetable.

 

Stay around 12:1

 

is 13.0 on 95 octane possible?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg4matze &raquo;</TD></TR><TR><TD CLASS="quote">is 13.0 on 95 octane possible?</TD></TR></TABLE>

Depends, The minimum octane we have here is 95RON which is equivalent to prem 93 in the US, but we have a range of 95-100. So your 95 Octane is 93octane equiv maybe? If so then a CR of 13 on 95 is possible but slightly on the high side.

 

no I mean our 98 octan, that should be 95 octan in the us

 

I'm running 12.5 on 93 octane gas.....but I wouldn't really reccomend it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mohsin &raquo;</TD></TR><TR><TD CLASS="quote">

Depends, The minimum octane we have here is 95RON which is equivalent to prem 93 in the US, but we have a range of 95-100. So your 95 Octane is 93octane equiv maybe? If so then a CR of 13 on 95 is possible but slightly on the high side.</TD></TR></TABLE>

Not exactly. 95 RON is 90 to 91 in the US ((R+M)/2)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg4matze &raquo;</TD></TR><TR><TD CLASS="quote">no I mean our 98 octan, that should be 95 octan in the us</TD></TR></TABLE>

Your 98 RON is equivalent to 92 to 93 in the US

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thedread &raquo;</TD></TR><TR><TD CLASS="quote">Your 98 RON is equivalent to 92 to 93 in the US</TD></TR></TABLE>

ok thx, but I think I buy an cometic gasket and drive with 12;0 compression

 

north cakalacki citgo=93 and 110 race gas at the pumps

 

afaik our 95RON is your prem 93 RON.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMdc2lsVtec &raquo;</TD></TR><TR><TD CLASS="quote">it seems like every state in the US has 93 octane except for california, we are stuck with the 91, i have my ratio around 11.8:1 with P30 pistons and a gsr head, so you could do low 12.somethin:1 </TD></TR></TABLE>

we only get 92octane at the BP stations in kansas city

 

what are you guys doing for fuel management to compensate for the high compression but with our low octaine here in cali?

 

According to the compression calculator I am running 12.26:1 I live in Oregon, running 93 octane tuned on Hondata s100 (Too Rich I Think). 15k on motor.

 

IMO 12.5 should be the max.

 

Anything over 11.0 will give you very little detonation head room and you could get small amounts of inaudible detonation that will shorten the life of your motor. If getting the maximun life from your motor is not important to you run more. Dan

 

and what is with oem turbo engines? They have an effective compression till 15:1

 

why not???