We've got 94octane here in Canada ... but lets just say that I'm using 91 tops ...
whats the highest compression that I can run using this gas?
Trying to decide which pistons to use on my LS/VTEC

 

i used CTR pistons and a milled head. CR was roughly 12.3:1 and i was on 91 oct. my timing was on a nasty 12 degrees, but it works. Tuning is a good thing.

 

i suggest on 91 octane, if you want to run full timing (15/16), dont go over 11.5 to 1.

 

11.5 to one seems to be the universally accepted any and all pump gas CR.

 

I run 11.5:1 compression on 93 octane with timing at 17 degrees all day. Just go with the B16a PR3 pistons and forget about worrying.

 

There is a local guy building a 12.5:1 LS/VTEC that will be his DAILY driver on 91 octane. He said the guys building his motor even asked him if he wanted to go 13:1.
Apparently, its all in the tuning.

 

yes u can run that high you will prolly have to run her a lil rich and less timming but its possible , i know some people running 13:1 on 92 and like no timming just to get there cars to the track and then they just run 101 and call her good , just remember before u even think of runnin hard to throw it on a dyno and get a o2 reading and tune from there (holes in pistons are good conversation but not very functional 0

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by King Tut33 &raquo;</TD></TR><TR><TD CLASS="quote">I run 11.5:1 compression on 93 octane with timing at 17 degrees all day. Just go with the B16a PR3 pistons and forget about worrying.</TD></TR></TABLE>

11.5:1 was what I've always been told the theoretical max was for 93.

However, I run 12:1 on 93 untuned and it's running fine. No knocking or pinging. Still want to have it tuned though.

Like mentioned above you can run 12:1 or higher on 91 it's just a matter of how you tune it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18G &raquo;</TD></TR><TR><TD CLASS="quote">We've got 94octane here in Canada ... but lets just say that I'm using 91 tops ...
whats the highest compression that I can run using this gas?
Trying to decide which pistons to use on my LS/VTEC </TD></TR></TABLE>

Talk to your tuner, he is what you should use to determine how high you can go.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by King Tut33 &raquo;</TD></TR><TR><TD CLASS="quote">I run 11.5:1 compression on 93 octane with timing at 17 degrees all day. Just go with the B16a PR3 pistons and forget about worrying.</TD></TR></TABLE>

I checked ur website ...
What skunk 2 program you running? ... My setup will be very similar to yours, and I also have access to 93 octane gas. Ur dyno chart and A/F ratios look mint btw ... nice work

 

ahhh ... just found out Skunk2 only makes 1 chip for the P28
is this the right chip number?
P30SK489002

 

skunk2 has more than just one program.

 

its all in the tuning.

 

true all tuning
i have 12.5:1 but it doesnt like pump gas too much...im down at 10-12 degrees depending on weather
I thought full timing was 18 degrees?
I can only run that on 100 plus octanes at the road courses

 

14 degrees is stock

 

would 11:5:1 je piston in a b18c1 be just that 11:5:1 even when the weather changes. i'm also deciding to go either 11:3:1 to be on the safe side or 11:5:1 on 93 octane 17, 16 degrees timing and with no piston to valve clearence problems.

sorry to high this thread, but on the same subject.

 

out of curiosity
I run 12.5 with jun 3s and 310 cc injectors
what setup are you guys running
and timing and fuel pressure?
im at 15 degrees with 94 at the moment
with about 47 psi no vacuum
the chipped p28 has a jun prog but i have a mugen and skunk2 proggie also
any thoughts on what worked better for you guys