i'm plan on building a 11.5:1 or more GSR. i will be running JDM ITR pistons and omni flat valves, with a 81.25mm bore...i want to know the safe limit of 93/94 octane so i can get the most power out of pump gas

 

i think you'll be ok i'm running 12.8 on 93.

 

tuning, driving style, and cam selection plays a huge role, but to answer simply, 11.5 will be fine on 93, just get a decent tune. I've seen 12.5+ on 93 so you shouldn't have a problem.

 

yep 11.5:1 should run nicely on 93 octane.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 97L-esVeeTeg &raquo;</TD></TR><TR><TD CLASS="quote">tuning, driving style, and cam selection plays a huge role, but to answer simply, 11.5 will be fine on 93, just get a decent tune. I've seen 12.5+ on 93 so you shouldn't have a problem. </TD></TR></TABLE>

so should i go with some p30's instead of the p73's? to give it a little more compression?

this going to be with BC3+ cams, rocket valvetrain, and omni flat valves...im not a spirited driver but it will be used for daily driving

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ericrx_88 &raquo;</TD></TR><TR><TD CLASS="quote">i think you'll be ok i'm running 12.8 on 93. </TD></TR></TABLE>

 

those cams have been proven to work on stock CR, and since you dont plan on going with a more aggressive cam, the itr's should be ok, the increase in ;compression PROBABLY wont yield that much more power or a broader powerband with those cams. I dont have any experiance with these cams personally, but they are not like a toda b or c or jun 3 where you need super high CR to work properly. Plus its daily driven, you may not always be in an area of the country to get 93 so stick with the itr's just my .02 cents

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 97L-esVeeTeg &raquo;</TD></TR><TR><TD CLASS="quote">those cams have been proven to work on stock CR, and since you dont plan on going with a more aggressive cam, the itr's should be ok, the increase in ;compression PROBABLY wont yield that much more power or a broader powerband with those cams. I dont have any experiance with these cams personally, but they are not like a toda b or c or jun 3 where you need super high CR to work properly. Plus its daily driven, you may not always be in an area of the country to get 93 so stick with the itr's just my .02 cents </TD></TR></TABLE>

 

anyone know how to figure out if you mix 6 gallons of 105 with 6 gallons of 91 what your octane would be?

 

98?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spooncivic1 &raquo;</TD></TR><TR><TD CLASS="quote">98?</TD></TR></TABLE>

yea your right my friend just told me (6 * 105 + 6 * 91) / 12

thanks

 

some good high compression reading. note omniman and B20vtec. https://honda-tech.com/zerothread?id=535569

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lohatch &raquo;</TD></TR><TR><TD CLASS="quote">some good high compression reading. note omniman and B20vtec. https://honda-tech.com/zerothread?id=535569</TD></TR></TABLE>

im not going to be stupid and run CTR's, i know better than that, this is a mild build and im only hoping for around 200whp when i get done with everything i want to do...im only aiming for around 11.4/7:1 so there is a safety margin and also the longevity of the motor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spooncivic1 &raquo;</TD></TR><TR><TD CLASS="quote">im not going to be stupid and run CTR's, i know better than that, this is a mild build and im only hoping for around 200whp when i get done with everything i want to do...im only aiming for around 11.4/7:1 so there is a safety margin and also the longevity of the motor </TD></TR></TABLE>
awesome. good to see that some people realize that "the bigger the number the better" isnt always true when it comes to compression