GEARBOX's ANATOMY AND EVO 123 RATIO

Sorry coz some of my pictures were missing...


evo 1



EVO 2

EVO 3

lets see the comparison between evo 123 and gsr gear ratio...since some of street racers like to marry their gear teeth and final drive from other GB...however for me it would be better to have a standard or stock evo 2 or 3 GB with LSD

12GSR

12GSR = 1st and 2nd gear using GSR 3rd and 4th gear using EVO

12 EVO 34 GSR

, final EVO

12EVO34GSR= 1st and 2nd gear using EVO +3rd and 4th gear using GSR, final EVO

JUN 280 racing cam shaft VS oem

JUN valve spring......why do i need this..? answ...OEM may float during high rpm and high power..especially 400whp and above ur engine might be like fuel starving... but when i got this spring and try to see any diffrent..well both are similar in shape, just that jun has more roundness...how ever when i tried to compress to see the spring rate..both of it are bout the same..hmm..

280 duration with 11mm valve lift. at first i would like to have tomei racing cam shaft, but since many seller got no stock than i change to JUN...why tomei...? becouse tomei has 11.1mm lift and proven more power can be produced..try to google on "cam test"...

let see the dimension on pictures above... JUN =36.38mm , OEM = 35.32mm... so diff about 1.06mm

the JUN cam looks so beefy...to open the valve much more longer so than more air can be forced in to combustion

GSR open diff VS EVO LSD

lets take alook at these two different differential. GSR open and Evo LSD viscous
GSR 1.8 final drive is 15/58 while evo2 has 15/64 which abit bigger at pinion gear. so can these two LSD swap or interchangeable to GSR GBox housing? many people say that both can be change easily as they share the same configuration.

the securing bolt are same orientation but different in location. u may see why after this.

above is the lenght between two bolts which is 16mm on GSR but evo is way2 much more bigger u may compare the location around the bolts between these two LSD

above pic is to shows dimension No.1 on LSD's body can't be interchanged between the pinion gears. dimension no. 2 show diff in bolts location. u may sent to mechine shop to cut it but i belief they can't do it couse those are harden gears.

if u swap whole LSD evo 2 in it will fit bcoz of same bearing size but u may tilt the final gear away from its position.

conclusion = They are not interchangeable..... anybody had done it.? please share here for suggestion..

Clutch OEM vs semi race (EXEDY)

pressure plate spring also diff, semi race has 3 spring steel, oem only 2 that would give exedy better clamping force.

i had compared the friction plate between trinity clutch and found that exedy has more thicker and without riveted key.
semi race has 6 double springs while oem only 4 single springs. all these spring used to withstand centrifugal force from flywheel. i belief some of racing after markets do not hv this. the rivet also diff.
after installation it will tighly clamp each other. no free play.

cp pistons finishing fault

ready for fitment


end ring gap also important coz the rate of expansion for aluminum pistons are more higher than cast. and this is to allow relief stress.

take a look very closely to the edge of the valve pocket. its very2 sharp. this may leads to hot spot and detonation. so what i did was failing that area.

CP pistons & I beam rods for 4g93t

All pistons taken out and still in excellent condition.

Before i post my second rebuild thread, lets compare the differences between forged pistons and rods with my current mod

I use CP pistons, made from US 82mm. it's a custom piston with 19mm wrist pin. 9.0:1 compression ratio.


Duratech I beam con rods, i beleif made from China but most of Malaysian using it for more than 500whp and still reliable.


Bolt designed by ARP from US with size of 7/16. it smaller compare to 14mm bolt from CA18 rods but it's stronger and higher tensile strength.