hi comp b18c r


N

ntahlerz

New Member
Joined
Apr 10, 2009
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88
hi guys...

im running b18c r in my car.i swap my piston to b16b.everything else in the engine is stock. by using this link Honda B-Series Compression Calculator by ZealAutowerks to calculate my compression ratio,it gave me a 12.32. i think this is very hi comp. the background of the site turns to red by the way. i assumed this is a no no..:))

my questions are, whats the effect of overly hi comp? any advantages or disadvantages? what should i do to take advantages of hi comp if there is any?or if there is disadvantages,what should i do to repair it?

thanks guys..
 
Has there been any additional tuning done since the increase in compression? Upgrades such as that ALWAYS require tuning!!

Benefits of raised compression are many, here are a few:
-increased power
-increased throttle response
-increased engine efficiency
 
i have done a full tuning which include on the road and dyno tuning.one thing i know is hi comp without tuning causes knocking.my tuner says he prefer b18c r with stock piston as the comp is ideal.but normally people will opt for higher comp.why hi comp?that is why im asking.
 
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Everybody has there opinion on how high of compression is "good enough" a race car running race gas could be as high as 15:1, now thats obviously way too high for the street as the octane rating of street fuel is not high enough to resist knock at that high of compression. Furthermore i live in an area where 91octane is the highest available and due to that most people opt for around 11.5:1 compression or less as the ideal for a street car on street fuel.
 
lower the dynamic compression with some big cams as it will enable you to take advantage of the high static compression...careful with the piston to valve contact though...clay everything.

imo, it's a fine balance anytime you're over 12:1 on the street unless you happen to live in an area with 98octane and higher as normal pump gas.
 
Also if you decide to do this build make sure you have a decent breath kit on the engine.
 
im from malaysia.here we have 95 n 97 fuel.im using 95 b'coz of cheaper than 97.since i travel a lot on daily basis, 95 is more profitable for me. :))
 
sorry ime a bit confused, have you done this build ? Or are you just thinking of doing it ?
 
rich, i have done it.sori if i made u confused.im doing it bcoz since normally people would go for higher comp.i assumed it was the way to go without really understanding it until my tuner says its better to have stock b18c r piston.
 
There is nothing wrong with the build you have done. What petrol did your tuner tune it for ? You really want to put the highest octane petrol you can find in it to stop pre ignition (knock).
 
if you need higher octane fuel just go to your local airport and get some 100 octane AVgas........aslong as it is tuned properly higher compression will definately make more power!!!!
 
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96dx-R said:
if you need higher octane fuel just go to your local airport and get some 100 octane AVgas........aslong as it is tuned properly higher compression will definately make more power!!!!
Click to expand...

WOW i never knew that :))
 
Why not use some octane booster? The likes of NF octane booster will give 2 ron increase when mixing 100ml per 50ltrs. One bottle contains 300ml so you get average 3 full tanks per bottle. Using 150ml per 50ltrs gives 3 ron increase.
 
Vtec6000 said:
Why not use some octane booster? The likes of NF octane booster will give 2 ron increase when mixing 100ml per 50ltrs. One bottle contains 300ml so you get average 3 full tanks per bottle. Using 150ml per 50ltrs gives 3 ron increase.
Click to expand...
I saw a test on these a few years back and they actually reduced the octane!
 
96dx-R said:
if you need higher octane fuel just go to your local airport and get some 100 octane AVgas........aslong as it is tuned properly higher compression will definately make more power!!!!
Click to expand...


Not sure if Avgas is the same as british Avtur, But avtur only really works in Diesel engines - A no no for petrol engines though! :nerv: Is avgas american?

James
 
my tuner tuned it for 95. he has done a good job.really feel the difference and here is the dyno graph. what u guys think?is the torque curve good?is the afr good?is the hp good?

afr
myDynoAfr.jpg

torque
myDynoTork.jpg
 
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