i run 12.1:1 cr with s2pro2 cams on a b20vtec..so i cant reduce the cr under 12 because of the high duration of these cams as they need high compression ratio .
and i have here only 91 octane so
i read that toluene will fix the problem with some mixing ratio with the 91 octane but its very rare here.
i thought that i should use the water methanol injection kit as it can help a lot and largely eliminating the problem of engine knocking (detonation). This effectively increases the octane rating of the fuel .
or reducing the compression ratio to 11.7:1 and i dont like this solution.
any help will be appreciated.

 

11.7:1 is fine on those cams because you have more displacement than a 1.8L at the same comp ratio. Compression compensates for lack of displacement, so having 12:1 is more important on a 1.8 than a 2L. I still think that you can run your car the way it is as long as you purchase a good basemap from a reputable tuner here and then fine tune your map around it. Toluene is a better option if it was available to you and water/meth is just making your setup more complex IMO. Have you ever checked the combustion chamber size by having them CC'd? If not, you may find that your actual compression ratio may be lower than you thought.

 

Thanks alot as you helping me before in many things,I am appreciate your help so much.
I am already used a basmap from xenocron and I retuned it to my engine before and I will use that basmap again and retune after I finish rebuilding my 85mm with 11.7 cr just for safe.
I read too that I could put a 1 ball of naftaline on a 10 galone of fuel as it enhance the octane .
Or
1 oz of acetone on a 10 galone of fuel .
As the toluene is rare .
Any idea

 

I have considered it because my friend was selling a meth injection kit super cheap. For NA its just complicated, think those are made to only run at WOT and not all the time. For NA your compression ratio is what it is. With boost compression in the cylinders climb so at low RPM or idle its never used. Spraying with alcohol might cool the motor temporarily but it doesnt seem feasable to have to use that system at all RPM's. When or if it runs out then it goes boom. Just tune your motor on 91.

 

No, you can have the meth kit work constantly, no need retard it to run on 91

 

Ok I found toluene,
I read that in the us they calculat the toluene octane as (121 ron+107 mon)/2=114 octane.
In my country we use the Ron so should I calculat the mix from toluene and gas as (121 or 107 or 114

 

i have a 95 RON here that i will use that will be (MON+RON/2)
MON will be lower than RON about 8 to 9 points so MON will be 86
(86+95)/2=90.5 octane
i will use TOLUENE (107+121)/2=114 octane
i will use this method ;

(8 gallon of 90.5)+(1 gallon of 114)/total mix(9)
(724+114)/9=93.11 octane
so is 93 octane is fine with b20vtec ,s2pro2 and 12.0:1 cr without retarding the ignition ?

 

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