Trying to decide between the two compressions for an allmotor car. The two pistons I am looking at are Arias 11:9 and the JE at 12:5. Please any suggestions would be very appreciated. Does anyone have personal experience with the 12:5 as a daily driven car?? I am leaning towards the 12:5 but am worried seeing as though it will be a daily driven car.

I'm running a b18c5 motor with the JUN valve train w/JUN stage 3 cams. Previously had the JUN 12:3:1 and the worked great. but would really like to do something different and can't seem to get a handle on what to do.

Any personal experience wanted with either piston.


Modified by blackbeautyITR at 10:46 PM 3/10/2004


Modified by blackbeautyITR at 11:21 AM 3/11/2004

 

personally i'd go with which ever one is lighter, those JE pistons are pigs compared to other pistons like CP or weisco, but I am not sure about the weight of arias stuff, so I would look into that.

 

i didnt think the JE's were that much heavier,
but i would like to know, i just bought some JE 12.5:1pistons for the hype R

 

i'd go with the 11.9's..just me tho

 

I would not worry about running the high CR on a street motor. The higher the CR the more "steetable" the car is, in other words you do not loose "streetibility" by upping the compression. You need to ensure you can build the motor and tune it to run on pump gas though.

 

i'm running 11 to 1 and as far as i know thats about the highgest you can run on pump gas around here. 93 octane is the hishest i can get.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 88civichbz6 &raquo;</TD></TR><TR><TD CLASS="quote">i'm running 11 to 1 and as far as i know thats about the highgest you can run on pump gas around here. 93 octane is the hishest i can get.</TD></TR></TABLE>

you can easily run much higher than 11:1, especially on 93. I've personally run 11.6:1 and my new build will be 11.8:1 or so, maybe a little higher. And I'll be using 93. People run 11:1 on 91 octane. You just gotta make sure it's tuned right.

s

 

u can get away with like 12:1 or 12.5:1 on pump gas, wiht good tuning, 13+ might be pushing it though

 

can 91 octane handle mid to high 11 compression, i did a serach and it seems to be mid 11 is the most 91 can take, wats a good mid 11 compression piston to get?

 

what motor are you using.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Eddiebx &raquo;</TD></TR><TR><TD CLASS="quote">u can get away with like 12:1 or 12.5:1 on pump gas, wiht good tuning, 13+ might be pushing it though</TD></TR></TABLE>ive seen 12.5 on 91 ...13.+ can be run with good tuning ...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ba4 &raquo;</TD></TR><TR><TD CLASS="quote">can 91 octane handle mid to high 11 compression, i did a serach and it seems to be mid 11 is the most 91 can take, wats a good mid 11 compression piston to get? </TD></TR></TABLE>


I want to hear more opinions on this too.

 

id go with the JE 12:5:1 or it may be the fact that those are the ones i am running

 

i'm pushing over 13.7 on 91 oct. it all depends on the tuning, combustion chamber, cams*, and how you drive.

i'm not saying anyone could or should push this kind of compresion, i'm just expressing my personal experiances. so don't say " evilxkid said you could " i'm just saying " i do ".

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM2ndGen &raquo;</TD></TR><TR><TD CLASS="quote">ive seen 12.5 on 91 ...13.+ can be run with good tuning ...</TD></TR></TABLE>

haha my bad, premium for me is 93-4 octane,

but....i think that guy 2.6 runs 12:1 on 91

but still tuning is key at compressions that high

 

I didn't see it asked, and in order for me to answer the question...

what cams are you running?

 

yeah with an 11.9 or 12.5 compression i would match it with a nice wild set of cams. and you would definatly be fine with 93 octane on either setup.

 

High compression all motor rocks! Isn't it every 1 you raise compression the engine is 4-5% more efficent?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by evilxkid &raquo;</TD></TR><TR><TD CLASS="quote">i'm pushing over 13.7 on 91 oct. it all depends on the tuning, combustion chamber, cams*, and how you drive.

i'm not saying anyone could or should push this kind of compresion, i'm just expressing my personal experiances. so don't say " evilxkid said you could " i'm just saying " i do ".</TD></TR></TABLE>nice 13.7 on 91 ...that good tuning right there ...whats ur setup? ...and ive heard people say they ran 14:1 on pump gas ...it was on this board somewhere in one of the compression threads i forget ...but tuning is the key

 

i'm actualy pushing over 13.7:1(i rounded some of the numbers down while doing the math so it's problobly more towards 14). 50 mm itbs with some of rockets cam's(custom grind, basicly the m25's with larger primarys), bizmoto race header and a reprogramed ecu(i also have an aem ems i'm trying to get dialed in, but my reprogramed one works better for now).

it only has probloms when it's under a heavy load. like going up hill's in 5th at 3k. before i put the cams in i couldn't even go over 1/4 throttle with out detination, but now it's fine. by the way, high compresion motors seem to get really good gas milage. i thought the cam's and itb's would kill it but the comp more than make's up for it.

good luck boys

 

Sorry, only 91 octane here.

 

Go with the JE with tuning.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by evilxkid &raquo;</TD></TR><TR><TD CLASS="quote">i'm actualy pushing over 13.7:1(i rounded some of the numbers down while doing the math so it's problobly more towards 14). 50 mm itbs with some of rockets cam's(custom grind, basicly the m25's with larger primarys), bizmoto race header and a reprogramed ecu(i also have an aem ems i'm trying to get dialed in, but my reprogramed one works better for now).

it only has probloms when it's under a heavy load. like going up hill's in 5th at 3k. before i put the cams in i couldn't even go over 1/4 throttle with out detination, but now it's fine. by the way, high compresion motors seem to get really good gas milage. i thought the cam's and itb's would kill it but the comp more than make's up for it.

good luck boys</TD></TR></TABLE>sounds like a nice setup ...what numberare you using ? and what pistons are your running? i mite look into having rocket make me some custom cams if his M24E's dont work out for me or maybe ill look into some Toda D's ...