Saturday, December 29, 2012

6k to 8k spring

during the previous dato sagor track day i did addressed that my front suspension setting need to be revised... current 6k spring is suitable for street application but when it comes to track day racing, the body roll is just tremendous...
in such situation, the sensible thing to do is to upgrade the anti roll or front sway bar to beefier ones... unfortunately, the only available sway bar upgrade for my car is costly and only improves a tad bit... weighing the performance per cost ratio, i went for aftermarket uprated springs...
these were 220/80... which translates to 220mm in height with 8k static spring rate load... comparison between my 6k HWL spring and the new aftermarket 8k spring...
it is mostly a direct swap as both spring has same diameter... in fact, most aftermarket coilover springs have same diameter unless specified... thus, no harm getting them checked to make sure they are the same diameter... or else they will not sit well on the spring seat...
how it looks like when assembled... i got the spring seat adjusted to the lowest position...
take note that when u increase the spring load rate with same height position, ur car will eventually sit higher than before... this is because the car weight remains constant... when u increase the spring rate, the spring will no longer compress as much as before... so much so in my case after i've swapped to 8k spring with spring seat adjust to the lowest position, the car still sits 2 finger gap in between wheel and fender arch...

shift extender

why would you install a shift extender with a short shifter??... wouldn't it defeats the purpose of installing the short shifter in the first place??... these were a few common questions came when i custom fabricated this 3 inch shift extender...
as those who installed or even used common aftermarket short shifter before, it generally takes a little more effort to change gears due to the shorted pivot point to the gear knob... with the shift extender in place, there are a few added advantage... first foremost, it reduces the effort slotting in and out gears... travel distance from your steering to the gear knob shorted significantly... some might not view this is as important but fast upshift/downshift requires your hand to locate the shift knob accurately without looking at it...
as for shift travel, i would not say back to stock standard... it is some sort in between stock shift travel and normal short shift travel... all in all, this definitely improves the driving feel to the car... makes shifts in between gears much more pleasure...

Sunday, December 02, 2012

Top overhaul (pt III)

continue from part II... with the some help and a special tool, valve seal were snapped into place, valve spring were compressed and retainer was locked in place... apply lubricant generously all over the camshaft before u slit it in...
double check the engine bay... rewire and retuck those messy hoses and wirings...
1mm metal head gasket were used... copper spray were sprayed generously to the front and back of the head gasket to ensure even seal all across the head gasket... this is the most vital part of the head assembly...
a friend of mine who works at proton service center overlook my head assembly process... he even smuggled proton torque wrench so i could get my cylinder head torqued down properly...
there were a few steps (which i could hardly recall) in torquing the head down... starts from a relatively lesser torque, only to move on to the specific required torque... this allows the head to pre-sits evenly on each corner before proceeding to further tightening all of them...
after the cylinder head were torqued down, the intake manifold were next in place... i sandwich 2 normal paper gasket in between the teflon gasket to ensure no vacuum leakage... PTFE (or teflon) intake manifold gasket were made popular because it reduces heat soak on the intake manifold... teflon melting point is way above 200 deg Celsius... it acts as a good heat insulator to prevent heat from the cylinder head transferred to the intake manifold... cooler intake means denser air, which means more horsepower...
thermostat were also replaced with lower temperature rating ones from SARD... normal ones were rated at 82degC while this is at much lower 71degC...
there were not many photos after this as my hands were dirty and oily... its basically bolting on back parts and connecting the wires accordingly... a little wire tuck was done and cam cover studs were replaced with visually pleasing stainless steel allen key bolts... thick mineral engine oil were first poured in for the first 1000km run... thicker oil allows better lubrication on rotating parts because most of the old oil dried up 1 month since the top overhaul project started... initial start up was a little hard as we cranked the engine until battery flat... got the battery charged up at nearby workshop and resume cranking the next day... eventually it fires up... after the 1000km engine seasoning, the oil were drained and new TOTAL 10w40 fully synthetic were poured in... tappet were re-adjusted and everything ran smoothly afterwards...

Top overhaul (pt. II)

continue from part I...
the cylinder head was cleaned thoroughly with chemical to remove away all oil and carbon residue... because this cylinder head was from the old carburetored engine, the intake studs were shorter than those on fuel injection cylinder heads... i removed all of the intake studs and had them replaced with slightly longer stainless steel ones... this allows me to use teflon intake manifold gasket...
the next all important step is valve grinding... bought some grinding paste and took the whole afternoon grinding down each valve to make sure they sit well and no compression loss allowed...
and then finished by using AUTOSOL to ensure perfect seal...
valve spring were also uprated to stiffer ones from JASMA... they were claimed to have the same spec with RPW valve spring... see if you can differentiate between them both...
retainers were also replaced with light weight titanium retainers from JASMA... they are definitely lighter in weight compare to oem ones... unfortunately i forgot to scale them before installing...
viton valve seal were called in to prevent oil seeping into the combustion chamber...
to be continued...