hey im having trouble choosing a compression ratio for a turbo build, its going to be a b16, sleeved 82mm.. still doing all my homework, but im also trying to figure out a good compression ratio.. ive seen ppl run like 12 psi on stock b16 sleeves, pistons and rods.. since my block is going to be sleeved with forged pistons and rods i of course want to run more boost, and gain more hp.. would 10:1 be too much compression for a turbo build? .. i dont know if it makes sense to some ppl, but i also want the car to have some kind of all motor power, or some decent pickup while spooling .. i dont know its kind of hard to explain.. but i know i dont want no lower then 9:1.. anyone have any info to clear up some of my confusion?

 

Is this a daily driver or a strictly weekend/race car? I'm assuming its a daily driver so I would say go with a 9:1 c/r so you can make good power on pump gas. If your so worried about spool, then go with a little bit smaller sized turbo. But then again if its just for racing then the turbo is always spooled with a 2-step

 

its not adaily driver, i have a95 civic i use todaily drive.. however iwant to be able to drive it whenever i please without problems.. i plan to keep it on 93 pump gas.. do you think im good for 10:1 compression? .. what kind ofprecautions should i take from using 9:1 to 10:1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXherbie91 &raquo;</TD></TR><TR><TD CLASS="quote">its not adaily driver, i have a95 civic i use todaily drive.. however iwant to be able to drive it whenever i please without problems.. i plan to keep it on 93 pump gas.. do you think im good for 10:1 compression? .. what kind ofprecautions should i take from using 9:1 to 10:1</TD></TR></TABLE>

it sounds like you have your heart set on 10:1, its your call, SpoolnG2 gave you good advice, i suggest you take it, im rockin 8:3:1 compression right now, before that i had 10.8:1 compression and honestly the spool up is not that bad like everybody things, my low compression setup is way faster since i can run more power on pump gas and off boost driving can be improved with proper tunning.

 

Another factor for spooling will be your choice of manifold being it log, ram horn, twisted or equal lengths ..... Usually the onses provide the faster spooling has less top power. Example log will spool much faster but ram horn might not but will produce more power than the log manifold.

 

well i guess i kind of asked the question long, or left out a few questions.. if i were to do 10:1 how much more psi would i be able to run if i were to go 9:1.. i want to run a decent amount of boost, but i was figuring if a stock b16 can run about 10-15 with stock block, then i should be able to run more then that with sleeved an forged pistons..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRXherbie91 &raquo;</TD></TR><TR><TD CLASS="quote">well i guess i kind of asked the question long, or left out a few questions.. if i were to do 10:1 how much more psi would i be able to run if i were to go 9:1.. i want to run a decent amount of boost, but i was figuring if a stock b16 can run about 10-15 with stock block, then i should be able to run more then that with sleeved an forged pistons.. </TD></TR></TABLE>

um 10-15psi on a stock b16? with pump gas? maybe 10 but not 15psi unless your pulling loads of timing which is gonna hurt power, forget about psi, there is not really a psi limit on pump gas, its more like a horsepower limit. there is only so much you can make safely with X compression.

 

There are a few ways to tackle this problem. If you're set on having a higher hp car on pump gas, then a lower compression setup is the best bet. This coupled with a slightly oversized turbo will allow you to make a good amount of power on pump; however, you will be sacrificing off-boost response and power.

On the other hand, a higher compression (9.5-10:1) will give you good off-boost response but will limit the amount of power you can make on pump gas. There's a tradeoff to each route.

Decide what you want, what you want to do with the car and what your power goals are...then let us know. Compression will change your off-boost and limit you on a certain octane fuel, but there are small ways to get around it.