new 86 engine 12.5:1 - can we do same?

Acoustic

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Acoustic

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Hi, just curious since new 86 come standard engine compression ratio 12.5:1 with standard fuel ron 95 and above, hence was wondering our good old 4AGE from 1st-gen till last, can we just shave off head, block, thinner gasket to do the same?
 

xMika

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xMika

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huh ? New 86 use boxer engine wor .. you want to reduce displacement for higher compression by shaving off the block ? Why don't just use high compression piston ?
 

bera

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bera

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wow...targeting 12.5 compression ratio...interesting idea...

but with our beloved 4ag ancient fueling system...i have some doubt...err...actually not "some"...its more like will it work at all...
 

me2kimi

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me2kimi

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Hi, just curious since new 86 come standard engine compression ratio 12.5:1 with standard fuel ron 95 and above, hence was wondering our good old 4AGE from 1st-gen till last, can we just shave off head, block, thinner gasket to do the same?
Fuhhh..otai in da house. glad can read your post here.
 

Acoustic

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Acoustic

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Hi bera, EXACLTY!!!

It was this doubt that NO_ONE ever did this "stupid_&_straight_forward" quote from Initial_D_stage_1 episode early where Ryosuke discover Takumi use the drainage to gain traction.

OK, may be NO_ONE is my wrong wording. May be these people just didn't report the outcome. May be they received the gain but do not expect any, hence no report???

May be I should trigger the question of "Has anyone skimmed HEAD by ??? 1mm, block by ??? 1mm, metal gasket 0.8mm from 1.2mm of normal and kept standard all others like ECU, fuel and ignition mapping, CAMs, etc etc" and faced NO_PROBLEM, but more power.

In short, ARM_KONG, win win win, no problem but more power.

And as of the ancient fueling system, this is also my question, we all know the ron 100 and 105 thingy, and thought need to have, but newer and newer engines are going higher and higher.

svt 10.5 : 1 ???
bt 11:1 ???
we don't feel it's a big step, don't care, malaysia ron can handle.
then what engine 11.5 : 1 ?? I don't know, didn't follow progress.
then what engine 12.0 : 1 ?? I don't know, didn't follow progress.
now 12.5 : 1 on a standard car, standard fuel system (still EFI only mah, not new science) using malaysia ron 95 +/- ??

Actually then it trigger to me now, only I wake up and realize, if use ron 95 fuel below 8k rpm, 12.5:1 is OK lah !!!

Welcome enlightening from fellow members :) correct me please if I'm wrong???

wow...targeting 12.5 compression ratio...interesting idea...

but with our beloved 4ag ancient fueling system...i have some doubt...err...actually not "some"...its more like will it work at all...


---------- Post added at 01:01 PM ---------- 6 hour anti-bump limit - Previous post was at 12:51 PM ----------

Hi me2kimi, thanks for welcome back :)

haih,,, the s_upid new Toyota 86 lor, in HK only 350k = RM 145k, at least not like KL 244k lah.

then saw many goodies like Subaru GC8 1997 HKD 30k only - my god.
also got Daihatsu Cappucino throw in backward no body wants, may be I get for 1k only :) hahaha but how to bring back leh.

Buy and keep as toy car, track car :)

Fuhhh..otai in da house. glad can read your post here.
 

bera

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bera

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yeah... i get the idea... but i think the modding trend particularly when it comes to 4ag is to increase the cc...either stroking or boring or both...less hassle perhaps...people rarely look into the CR thingy...

with the stock 11:1 CR...without correct tuning will ping like no tomorrow...let alone 12.5...i cant imagine my engine will sound like...tickticktickbooooom....hehehehe

and by ancient i mean is that the 86 have one of those direct injection thingy...i dont know whether it is directly related to prevent/suppress knocking or not...

anyway this will be an interesting thread...subscribed...
 

D7zul

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D7zul

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i've read sumwhere b4, direct injection reduces knocking..

but if u use racing fuel ron 100 n above, should be ok
 

meg_omen

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meg_omen

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BT + TRD 0.8mm metalgasket + re-surface head + 81.5piston + 272cams = 11:1+ kot...
already hard to use Ron95...

now moving to 2ZZ = 11.5:1...:hmmmm:
hopefully Malaysian Ron95 can support...
at the moment, i only plan for Ron97 since its weekend car...

but 12.5:1... might be worse kot...:smokin:
is Malaysian Ron95 actually Ron95...:confused:
 

^pomen_GTR^

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^pomen_GTR^

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with direct injection sure la no knocking/pinging since fuel only injected directly into the combustion chamber when piston reaching TDC....

cannot compare with multipoint/normal injection method....

normal EFI system only inject fuel inside intake manifold and piston coming down sucking air+fuel mixture=easy to to ignite when piston coming up for compression stroke....

for direct injection engine piston coming down just sucking air..then piston coming up compress only air....then only reaching top position injector give fuel...thus no fuel during compressionstroke=no pinging/knocking happen because no fuel to burn...


did u know that diesel engine minimum CR was around 18:1 and higher?

because of what?? heard common rail injection??? it's just a fancy name for direct injection...but why diesel so noisy?? because of the mechanical pump to give high pressure for the injector (mechanically firing each injector inside combustion chamber) <very old method of direct injection...
 

Acoustic

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Acoustic

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Thanks ^pomen_GTR^, good teaching,

borrow statement from meg_omen, ron 95, really? actually what was in my mind in my first post was also same, but forgot to write or shall I say didn't express my question in a better, hence now add = toyota officially dare to sell a 12.5:1 engine in Malaysia wor, they very well know the conditions of our fuel, means what?

I think (my own opinion only) = means OK lah, we also can do 12.5:1

OK OK I know I sounded like a kid, but hey, give me break, this is chit chat mah. Can or not I think till kingdom kong also no one will give a definitive answer, hence everyone share brain-storm lah.

One fine day in the future I will do and let you guys know. Better not end up engine blow, hahahahahhaa.
 

^pomen_GTR^

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^pomen_GTR^

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another engine qith high compression if not mistaken miaubishi 4g93 gdi engine if i remember...wih 12:1cr compared to normal 4g93 with just 9.5:1cr
 

meg_omen

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meg_omen

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probably Toyota already prepare a lot of tuning tables for this new 86...
to cater various fuel type and emission regulation...
yeah! that's why they take time to launch it...:hmmmm:

anybody with it willing to dyno test, to compare against stats Toyota stated...
we can at least compare the power output between our Ron95 against Japs Ron100...:burnout:
 
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meg_omen

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meg_omen

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well thinking that there's better and smaller chips nowadays...
some more with 128bit or more programming + Java embedded etc...
surely they can fit more in a faster PCB, in a the small ecu casing...

some more they're releasing an 'Icon'... worldwide...
with different brands...
surely they must cover all grounds...

well! probably anyway...:hmmmm:
my tech getting rusty along with age...:rolleyes:
 

pcmoddingmy

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pcmoddingmy

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Well actually someone posted saying that the 86 requires RON 98 as per the fuel lid sticker... don't know how true is this but UMW didnt put any notice on RON requirements for the 86