u MUST install the thermostat. cos if no your fuel comsumption will high
no nid to diy. go to standard a bit workshop can liao.
termostat buy better one cos nid to use long time. ur car nid to know the water temperature if not it will keeping boiling it made ur fuel takes more

mao2@
r3 piping is more than enough. stock ecu will need more time to adapt to the engine head changes, so, you may not be able to experience the benefit for a couple of days.  4g18 to dohc require at least a proper diagnostic after run in to ensure smooth running.

killer8550@
any modification on the intake manifold? which engine oil were used?

sphiroth@
am using yokohama c.drive with 85% thread, same wheel spin happened.
swap to s.drive, same thing, tested with semi slick r888 and no problem 

roxx@
the easiest was resetting the ecu and let it adapt to your driving style by itself. it will only takes a couple of days.

WhitE LighteR@
it was definitely legal because the engine capacity remained. but to be on the safe side,  you need a letter of approval from puspakom(cost about 50 bucks with fast inspection through runner); just in case jpj / traffic police stopped you at the roadblock. they will try to frightened you by telling you it was an illegal modding due to the different head and you end up paying! been in that situation a couple of times