WTA: Compression Ratio

[jaj_prakaash]

Hi to all sifus, What's the maximum Compression Ratio we can use for 97 RON?

Thanks in advance

 

[pencalat]

Hi to all sifus, What's the maximum Compression Ratio we can use for 97 RON?

Thanks in advance

i think around 12.2~12.5 lar....

 

[AD_EG]

i think so too, cause my friend bumped up him comp to near 13,and was not on high cams,he experienced very bad knocking.had to use thicker gasket to lower it down....so should 12ish should be fine.

 

[jaj_prakaash]

i think so too, cause my friend bumped up him comp to near 13,and was not on high cams,he experienced very bad knocking.had to use thicker gasket to lower it down....so should 12ish should be fine.

If using high cams can go higher, is it?

Sorry, totally baby in this

 

[AD_EG]

If using high cams can go higher, is it?

Sorry, totally baby in this

with high cams you can bump up compression but you also need a piggyback/ecu and good tuner to ensure you dont detonate your baby.

---------- Post added at 09:36 PM ---------- Previous post was at 09:27 PM ----------

with high cams you also need stiffer valve springs (aftermarket) to avoid valve float.
with higher lift cams potentially allows more air to be rushed into the combustion chamber,and this is when you need a piggyback/ecu to be fine tuned by your tuner to ensure everything runs smoothly.

---------- Post added at 09:48 PM ---------- Previous post was at 09:36 PM ----------

you are using a b series right?

 

[jaj_prakaash]

with high cams you can bump up compression but you also need a piggyback/ecu and good tuner to ensure you dont detonate your baby.

---------- Post added at 09:36 PM ---------- Previous post was at 09:27 PM ----------

with high cams you also need stiffer valve springs (aftermarket) to avoid valve float.
with higher lift cams potentially allows more air to be rushed into the combustion chamber,and this is when you need a piggyback/ecu to be fine tuned by your tuner to ensure everything runs smoothly.

Hi, i have jun stage 3 kit with power fc, how high can i go with the CR using 97 RON?

P.S- using 18c with 20b pistons & crankshaft

 

[AD_EG]

i think max 13 bro...to be safe better use vpower...if im not mistaken its still ron97 with additives.

 

[jaj_prakaash]

Thank you AD EG & pencalat

 

[super fei lo]

bro...
better have ron 95 asur base line...
hard to get 97 specially u r not ard kl....

 

[AD_EG]

i think he is from singapore...and JB still got alot of 97 stations..

 

[jaj_prakaash]

Yup, JB still many station got 97, problem will be when i go back Puchong, need to find one around there.

 

[pencalat]

bring along tong kosong la... hehe....
hmmm jun3 n power fc... 2 litre yeah... delicious... lazatsss.......
try to make around that figure la.. at least can give less headache....
last two month i start up with 13++ CR... wahhh really damn damn....
bearing conrod n crankshaft easily hurt meh..... hehe...

 

[caleb_5375]

actually the higher the duration of ur cam u need higher com piston to coupe with it.hard for me to explain here...but puchong got many station with ron97 lah...u no need worry that ...

 

[Yong_5290]

AD EG...wats the highest compression ratio for rotary? FC3S

 

[changchewsoon]

well, you could always reduce your ignition timing if knocking occurs

 

[AD_EG]

AD EG...wats the highest compression ratio for rotary? FC3S

honestly bro i am not very sure...

but what i am sure of,

compression ratio is not determined by what engine you have necessarily,it also depends on how much your fuel octane level can handle...

normally for compression more than 13++ you need a higher level of octane to be safe...when your compression is too high,and the heat and pressure generated in the cylinder can pre-ignite the fuel even before the spark is shot in...which leads to pre-ignition or also known as detonation.

you can up your compression as much as possible but many things need to be taken under consideration if you are going for high compression(my definition of high is 13++)....such as cams,your engine breathing,air flow,fuel octane(ron), good tuning for air+fuel mix...

and normally for cars which are turbocharged,they have lower compression ratio's to be able to boost higher safely...

 

[Yong_5290]

ok ok...but rotary no cam...so many things 2 learn...rotary like so complex yet so little moving parts onli

 

[AD_EG]

ok ok...but rotary no cam...so many things 2 learn...rotary like so complex yet so little moving parts onli

dats i mentioned i really not sure...coz i have insufficient knowledge on rotary engines...and i am in no position to post about it...