I purchased a set of wise co b18c piston 8.6 i heard it is not good for turbo charged.But my tuner as me to get these

 

low comp is the way to go with forced induction who ever said that it is bad doesnt know what they are talking about so dont worry about it.

 

And where exactly did you hear this?

 

That is perfect for high boost. I'm not sure who told you they were bad.

 

the only time low compression is bad if your build a motor for all motor with no turbo or supercharger, but low compression with turbo + high boost = lots of power

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C1CYA &raquo;</TD></TR><TR><TD CLASS="quote"> but low compression with turbo + high boost = lots of power </TD></TR></TABLE>

Also high compression with turbo + low boost = lots of power

 

But unreliable lots of power. Heat and the quality of the piston become the issue.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93turbo16 &raquo;</TD></TR><TR><TD CLASS="quote">But unreliable lots of power. Heat and the quality of the piston become the issue.</TD></TR></TABLE>

But you pick up alot of low end power.. Im not saying run a 12:1 compression with boost.. Im just saying that 9.3:1-10:1 is great for a powerful boost setup.. People running 8:1 compression is just crazy..

 

as long as u get the motor tuned u can run 10:1 safe

 

If you building a motor to make power run 9:1.. 8.6 is close enough. Running 15psi is going to make good power. Your not going to do that with 10:1 and pump gas.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91EFHatch &raquo;</TD></TR><TR><TD CLASS="quote">as long as u get the motor tuned u can run 10:1 safe</TD></TR></TABLE>

Correct.. Tuning becomes much more important at higher compression levels..

 

I also went with 8.x:1 compression for my poormans type r setup.
I plan on squeezing the most i can out of pump gas, so i went with a conservative
compression ratio. The car is by no means slow on the bottom end either. I do have
a light car (crx), but its not that much different from stock.

 

a buddy of mine ran 11.1 comp ls-vtec turbo. low boost tuned

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 91EFHatch &raquo;</TD></TR><TR><TD CLASS="quote">a buddy of mine ran 11.1 comp ls-vtec turbo. low boost tuned</TD></TR></TABLE>

Sweet.. How much boost was he running and from what size turbo?

 

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

Also high compression with turbo + low boost = lots of power</TD></TR></TABLE>
Yeah...but DETONATION does suck...doesn't it?!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NVturbo &raquo;</TD></TR><TR><TD CLASS="quote">
Yeah...but DETONATION does suck...doesn't it?!!! </TD></TR></TABLE>

I guess it would suck if you have it.. None of my setups have..

 

Lowering compression and upping your boost is a solid method of raising knock limit significantly.

I'd stay high CR if you didn't want a lot of power, 300-ish, since B-series knock limit isn't a problem at that power level. THe car will drive a lot better. The big power high CR setups, however, are very volatile and are lag-city due to turbine selection to accomodate such power. Might as well spray the bottom end, run low CR for safety, it's not an easy to drive streetcar anymore.

 

Thanks guy so basically low cr with high boost is good,but i am runing with 1 bar - 1.2 bar is it alright?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rioninja &raquo;</TD></TR><TR><TD CLASS="quote">I also went with 8.x:1 compression for my poormans type r setup.
I plan on squeezing the most i can out of pump gas, so i went with a conservative
compression ratio. The car is by no means slow on the bottom end either. I do have
a light car (crx), but its not that much different from stock.</TD></TR></TABLE>

when my motor was breaking in, i was NA on 8.3:1 cr pistons...definately no slouch, much faster than my previous motor which put out 185whp and did 13.7@101 on street tires....

 

so it is good even at low end

 

high compression and boost equals nice low end power at low boost levels.

But staying on the topic 8.6 isn't bad real safe you just have to run hella amounts of boost to make good power.

 

Its not that bad to run low CR pistons..Actually on my D series non vtec motor i ran a 17.2 on the 1/4 when i had the stock 9.1:1 pistons..I put low CR(8.5:1) pistons on my car to turbo it and i ran it NA and i did 16.8..Actually the car feels better with the low CR pistons(Strange huh?)

As for the topic i think that its easier to tune with lower compression..Less things to worry about and more peace of mind.

 

From a thermodynamic standpoint, raising compression ratio from 8:1 to 10:1 actually has a minimal effect on thermal efficency and overall power output. Volumetric efficency will always play a bigger role in power production than thermal efficency. Afterall, thermal efficiency is mostly limited by fuel volatility.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Overblown-Teg &raquo;</TD></TR><TR><TD CLASS="quote">If you building a motor to make power run 9:1.. 8.6 is close enough. Running 15psi is going to make good power. Your not going to do that with 10:1 and pump gas. </TD></TR></TABLE>

There have been people who have ran 10:1 and 15psi with pump gas.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18cturbo400 &raquo;</TD></TR><TR><TD CLASS="quote">so it is good even at low end</TD></TR></TABLE>

yea, definately, my daily driving, normal conservative driving, i dont even hit boost, and the car definately has go to it, i think its one of those urban legends that ppl talk about no low end with turbo cars....then again my gf's vw is a slug unless its in boost...but its also a vw...hehe