dohc upgrade is having a minimal impact on 4g18 due to the engine nature itself; limited powerband to play around. NA mod usually cheaper to maintain and more reliable in the long run.
btw, with proper piggyback programming, dohc is quite viable option by being cheaper. then again, haltech and e-manage blue is quite costly.
with BOT at 0.5 bar, i doubt a port and polished with turbo manifold 4g18 can take higher than 0.7 bar, anyway, the engine lifespan itself gonna be shorter

14sec is definitely slow... but not too slow
if am not mistaken, manufacturer claim also below that figure.
perhaps, slow due to the heavier wheels

mao2@
puspakom should have no problem with sohc to dohc conversion; provided that it was properly done. in some case, they will check if the brake system can cope with the slight changes too
engine oil definitely need to be changed, any semi-synth will do, timing belt is different, but without intake and exhaust mods + better quality gasket and improves ecu, no point going for the conversion.
hot cam / port and polished top is more effective for low end torque in sohc engine.

sphiroth@
if am not mistaken, it was below 13 seconds for auto and about 1 second faster in manual(11.x sec?)
btw, my waja auto easily wheel spin on tarmac during a start-up in D. even if my foot was very light on the gas
already checked bearing and others... no problem.

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

some ppl need the torque at early rpm, some other prefer top speed. some others prefer a leisure ride and good fc.
this may explain the different
in other words, it's individual preference.
a fact; sohc engine in waja is more beneficial at low rpm while dohc is mainly for higher rpm run with more room for improvements; depending on how 'fertile' the source(engine) was.

exactly! thats why am trying to explain in my post.
hot cam is more fertile' on 4g18 sohc.
btw, reprogramming ecu doesn't help coz it will eventually adapt to your driving style again....

This post has been edited by yngwie: Mar 15 2010, 11:37 PM

agree with you.
it's not as simple as just swapping to open pod.
since waja engine bay is damn hot, you need some sort of vacuum box for the open pod itself, coupled with a good cai filtration.
not to mention wrapping the exhaust with heat resistant material to lessened the heat generated.

even the stock drop in already very well design.
silent killer rox!

i installed the atf cooler in my waja sometimes in 2008. seldom drive the car btw. during occasional town drive, i find out the gear sometimes refuse to engage / change. i suspect maybe the cooler caused the atf to become too cold thus it doesn't operate at optimum level due to colder atf.
got it removed and no problem ever since.
conclusion; for waja, if you don't drive on hilly road like karak everyday, atf cooler is not necessary. better spend the 300 bucks on other upgrade.

i think he mean berjaya times square

jolipoli81@
you mod is still ahead of me. my cat-con still intact.
i'd better stay away then

btw, am about to go for spark plug change. any recommendation, guys?

you can slowly mod until it reach the desired performance / comfort. but bear in mind, 4g18p is very limited in term of engine upgrade option.
thats why i am planning a big makeover on my waja soon. engine and gearbox already in. just waiting for the right time to swap.
can't bring myself to sell the car due to sentimental value
btw, am currently using iridium spark plug bought from garage sales about a year ago. it's time to change...

our waja has a top speed too. and surprisingly, it takes quite a breeze to reach 190km/h. all you need it guts
but don't without a twin pots front and a good set of suspension
btw, my waja 4g18p rpm at 190km/h read at a surprisingly low 5.2k ! anything wrong?

all adjustable are bumpy. btw, do you noticed the sound from suspension side is quite loud when going through uneven surface / potholes? perhaps, need a better bush / noise insulation in that area.

there is no way am going to attempt a top speed on this weak but reliable waja engine
the car is in for a big change, btw.

suddenly this tread has become so poisonous. lucky i already made up my mind on certain modification

either sachs or apm performax

jolipoli81@
depending on the disc indicator. max should be 2x only but it's not advisable to skim twice due to safety reason.
btw, brembo max works better with better quality pad. so does those slotted / cross drilled rotor. ie; ferodo zero or metal king ti
for waja, if the stock disc and pad is fine, bleeding the brake fluid after every year will be just fine. and upgrading to dual layer brake servo
should be sufficient enough.

bex9432@
which part of selangor were you staying? i know a good leather shop somewhere in taman maju jaya btw. shop can be seen from the roadside on the way from shamelin to pandan indah.

WhitE LighteR@
rerouting the air intake is akin to CAI mod. could be from anywhere else except the bumper cuz the hole looks ugly.
a friend of mine modded his waja air intake. assembled another air intake that connect direct to the properly holed existing air intake(underneath).
problem was air filter need to require frequent clean up coz' it was still a drop in type.
btw, the existing air intake placing is already good enough for sohc 4g18p

if am not mistaken, over 80% of the braking are done by the front unit. so, it's very important but never neglect the rear brake for better braking stability.
btw, make sure to have a good suspension setup. else, car feels somehow shaky during emergency braking.
anyone of you guys already upgrade to dual layer brake servo?


TUV-hyperstar@
from my observation, waja power steering is stiff but it's more 'telling' during hard cornering

bex9432@
must be something wrong. steering should be straight when the car going to straight direction.
when you're driving fast, slight turn on steering will have a big effect to the car; it was due to fast movement and not because of the steering. this apply to all car. not just on waja.
understanding the car's (engine, steering degree, brake behavior and so on) is fundamental.


TUV-hyperstar@
change to PU bush. changed mine and it does wonder

TUV-hyperstar@
if am not mistaken, it stand for polyurethine which is a tougher material than plastic. changed mine.
all round including lower arm all side / rear all side and heck! the car feels very tight
no more steering free play too. cost almost 1.5k with workmanship.

WhitE LighteR & jolipoli81@
changing to dual layer brake servo with good bleeding 'will increase the respond rate and solid' feel
braking depend very much on the amount of 'vacuum' produced by the engine.
waja stock brake sux' bit time. especially the auto variant which is of very heavy usage.
the moment i changed to dual layer servo with bleeding'. i can instantly feel the braking is more responsive and solid.
as for more bite, disc size and amount of caliper play the biggest role.
slotted / cross drilled disc will have less fade' effect compare to the stock disc, thus,
will be usable during frequent braking.