What do you guys think... or should I go with lower compression pistons? I kinda traded my 9.0:1 pistons for these 9.8s

Dustin

 

Stay with 9.8. With proper tuning (i.e. Lambda meter and Hondata) your turbo will spool up quicker and the setup will also make more power.

 

I think youre car will have sweet bottom end and throttle response (hp)

 

if anyone can pull off the 9.8:1 pistons successfully i think u can.. Go dustin

 

9.8!!!!!!!!

 

Dustin,

I thought you wanted to go with the 9.8:1 because of the torqueless nature of the b18c1?

 

I did, but I think I needed some reassurance

 

I like the idea of sticking with stock compression myself...

 

High CR + lower boost makes more efficient power than low cr and higher boost

If I went turbo myself, it would be 10:1

 

Me to, I agree. The way I see it Ive been good with my stock motor and I should be fine now.

art

 

are you sure about that ? i'd think it'd be better to be pushing more boost because the turbo is the biggest power adder on the engine...a measly 1 point of compression is not gonna make up for 2 lbs of extra boost you could run .. no ?

 

can this be done on 91 octane ?

 

Hey Dustin
I am running 10:1 with a big *** turbo from XS (T-66) up to 25PSI fully built though. The spool up is absolutely wonderful and the top end is bliss. DFI 7 tuned. large Apex Skyline Intercooler and 720 cc Injectors. Just coming out of the body shop will have pics next week
Colin

 

that 1.0 difference makes a decent difference.
remember all a turbo does is effectively raise the CR.
lower static CR means the turbo has to put more air in to equal
a higher CR.

More air = more boost = more heat = less efficiency = less potential power

 

it also seems that if a properly tuned stock motor can handle 10-12 psi than a built motor at the same compression with proper tuning should be able to handle a good amount more...because it all comes down to cylinder pressure in the end, right? a given amount of cylinder pressure is created by boost and compression. higher compression gives you more power sooner and lower boost gives you a cooler intake charge....yes?

 

Yes, but you get extra fuel with increased boost (hopefully ) and fuel makes power.

Ah yes, All I have is 91 octane too.

Dustin

 

The only real limit is fuel octane... but since oxygen is just a catalyst to burn the fuel it will preignite from heat due to compression and residual heat in the spark plugs at some point. However, it seems you could solve this by: 1) allowing less air in the mixture or 2) allowing more fuel in the mixture. We do not want to do number 1.

What prevents someone from just running the motor super rich at high boost to overcome the limits of their fuel and thus avoid preignition?

Dustin

 

i've read somewhere that ther is a point at which adding more fuel no matter how much won't stop detonation. don't know exactly where i read that or if its true just what i've heard.

 

when in doubt, pull back timing, or get a stronger ignition system.

 

Timing can't stop preignition.

 

true.. but it can lower cyl temps some

 

Hehe, far enough and you'll heat up the exhaust valves enough to /cause/ preignition

Dustin

 

Super rich would make the engine bog right?

What about water injection? You could tune your car to only have the water injection come on at certain boost levels.

A more efficient intercooler would be benificial. What about an air to water IC?

Switch your car to something like methanol.

 

Anyone make those liquid sodium filled valves for hondas?

 

I would go with the lower comp setup. Seems to work well for the DSM guys.