4G91 Gang..

[joe_mirage]

Ok.. I think i'll get the cam.. What if i change to 4g93 ECU and a/f sensor? Does it worth it?

With the money, u can already buy piggyback management which i think more worth it than 93 stock ECU. 93 cam upgrade is a wise decision but don't expect much from it since the gain is hardly noticeable.

since i was a 91 user before, i would like to give some of the recipes to make the engine a screamer.

1) good induction system
- if u plan to use open pod then u need to make it properly. couple it with heat shield and
cold air intake. as for me i prefer stock air-box plus after-market drop in filter and cold air
intake.
2) good exhaust system
- if u r on manual transmission and dun really car ur car will be a little bit noisy than
standard , then go for straight flow design muffler with suitable pipe size. If auto then
better go for s-flow design muffler with suitable pipe size.
- header , PZ or hotbits 4-2-1 is a good choice. 4-1 r3? hmm.. need to think twice.
3) ported and polished cylinder head.
- is all about flow.
4) performance camshaft.
- i really recommend this upgrade. u will get different feeling and more pulling power.
5) management.
- piggyback ecu will be enough. no point go for standalone ecu , if u know what i mean.
safc/emanage blue will be sufficient.

Hope this help. Been there. Done that.

 

[ACQ2305]

agree wif alvin...

but at the same time...
wat will u get wif the RM3.5k???
complete engine (head,block,alternator,compressor) + wiring n ecu + gearbox + anything else???
driveshaft/radiator???

just found out that its d engine alone,n wiring..only no GB..have to use back my 91 GB..abt d ecu,not sure wat it uses..saw d 'ECU',says VDO on it..but doubt tats d ECU..cant seem to locate it just now..if i found a serious buyer 4 my 91 then might consider it..hehe

 

[beztien]

Owh... Since u had d experience... Hehe... Btw.. Wht bout the T/B? Wht bout mivec header? Izzit good? I guess the best pipe size for d engine is 1.8" inside diameter rite??

 

[alvin24]

hi all sifu.....i m using the digital aircond...but when morning..the aircond panel like no bright...is that the aircond panel problem or wiring problem???

Aircond panel problem or wiring problem?
Neither.

Its environment problem! HAHAHAHA...

Turn a torch light on in the daytime and its not bright at all... turn it on at night and it'll light up a path.

Same concept.

 

[ACQ2305]

Aircond panel problem or wiring problem?
Neither.

Its environment problem! HAHAHAHA...

Turn a torch light on in the daytime and its not bright at all... turn it on at night and it'll light up a path.

Same concept.

gosh..hahaha....

 

[calvin9683]

lol...
but i somehow feels dat his "television" for his digital a/c rosak edi....
guess its a common prob faced by most of digital a/c users....
mine last time got stupid red horizontal lines...
then slowly bcome darker n darker.....

time to get it replaced ahshen86.....

bro beztien...
most of us uses 1.8" inner diameter (also known as 2" piping la) for exhaust piping....
as for throttle body....
i uses evo 60mm t/b...some ppl say too big no good...i dunno la....
n for intake manifold....most of the guys here uses GSR ones as it's said to b shorter....
i got no idea as i didnt change mine....oni port it bigger to fit the evo t/b....

 

[CHB]

has any one of the 4G91 gang change the DOHC cylinder head with 4G92 SOHC head successfully? i personally hate the tappets sounds from a 4G91 DOHC. how nice if we can adjust the valve lash clearance manually like what a 4G92 SOHC does...

 

[calvin9683]

i did met a person who rojak 4g91 block wif 4g92 SOHC head...
then using 4g92 SOHC wiring n ecu + highcam n piggyback....
quite powerful man his car....
but to me...this is sort of a "budget" way la....
coz he dun need to spend n buy a whole halfcut....

but in ur case...
u edi bought whole halfcut n put in the 4g91 into ur car...
then wanna change to 4g92 SOHC head + wiring n ecu...
dont u think this is sort of like a downgrade????

 

[CHB]

ECU is no problem for me as i will run programmable ECU on it. so 4G91 SOHC is doable.
as the SOHC is adjustable valve lash, and it is 16V too, so i think it is more realiable than the hydraulic lash adjuster on all DOHC mitsu engine...
did u guys run 4G91 flywheel? i have heard ppl weld and redrill 4G13/4G15 flywheel and mated it with 4G13/4G15 gearbox.

 

[ACQ2305]

lol...
but i somehow feels dat his "television" for his digital a/c rosak edi....
guess its a common prob faced by most of digital a/c users....
mine last time got stupid red horizontal lines...
then slowly bcome darker n darker.....

time to get it replaced ahshen86.....
.

speaking of which,i jst realize that when my AC turns on,d lights do seem to dim up a little..at nite..and d red horizontal lights now is more obvious..and yeah,sumtimes bright, sumtimes dim..
just realize after this discussion came up..hehehe...

 

[calvin9683]

bro ACQ...
time to scout around for a replacement...lol

 

[inky]

to all sifu2 i'm back. i lost my 4g91auto after i transplant manual gearbox. 1of the piston gone case makes 2valve bengkok. checked: no prob wit the radiator and timing belt. i change the head to 93 but not the injector. the injector still remand 210cc.
now i have extra parts wit me:
1. 93 cam, checked no prob.
2. head cover.
3. lifter
4. block can be fix and everything from the top till the bottom. sifu2, wat shell i do wit it? i'd already replace another 91 engine. i really lost a lot non of the foreman can give me a right answer. anyone have 1or 2cent? my pocket already dry.

 

[alvin24]

SOHC vs DOHC.

Overlapping is fixed with SOHC, there's where you lose power and efficiency of the engine. So on top of losing power, you also end up getting poorer mileage.

Worth it or not? Spending money to convert from SOHC to DOHC, and then later endup paying MORE for petrol for the rest of the time... all just for what? Got tappet sounds? LoLz...

Just jaga the engine properly sure no the tappet sounds won't come out wan ler. =) I've been using my 4G91 for like 5 years or so, summore turbo-ed. No issues with tappets. =)

 

[CHB]

ok i have a mate driving 4G91 Carb on Saga gearbox and he experience serious tappet sound EVERYtime he start his car. some times after 15mins of driving the tappet sounds still there haha!!
mind to share what should be carry out in maintaining the famous 4G mitsu tappet sounds?

 

[beztien]

Haha.. Some people say by using castrol magnetec can reduce the sounds....
Btw, to all sifus.. im planning to install a 4g93 NA cam on my 4g91.. Nt confident yet la.. Haha.. Anyone ever done ths?? Sifus??

 

[calvin9683]

agree wif bro alvin.....

tappet sound some ppl say use thicker engine oil will do the trick....
as for mine....when i was using castrol magnetec around 1.5-2yrs back...no prob...
then switch to castrol edge....after some time cold start got tappet sound...
didnt wanna switch back to magnetec as wif edge the engine r more rev-friendly...heehee

bestien...
quite a number of member here using 93cams....
well...dun expect much....

 

[ACQ2305]

cal,yeah,,think better safe up 4 another ACdigital unit..darn..but it is still working though..oh well..
abt the tappet sound,having noise also during cold morning start up..but only 4 20- 30 seconds..after that,smooth..m using semi syn Mobil..thinking of using Motul for my next service..
bez,did change my cams 2 use 93 cams..lose abit on d low end rpm,but mid to top end increase slightly...dont expect much thought..but at least can feel that it does run out of breath fast...top end can still 'play'

 

[joe_mirage]

hydraulic lifter sound ... it is so annoying. i also face the same prob like u guys. 4g9X common problem.

 

[Gobbi_21]

to all sifu .... my wira 4g91 carb is having some prob ...
1) currently FC is very bad ---- RM10 -50KM
2) No top ...maximum can hit 160

im totally not so sure wat am i suppose to do .....
thanks

 

[alvin24]

If your tappets are noisy beyond saving... invest and get a new set of tappets. Its not going to be cheap... its like 80 bux a tappet or so after factoring in the workmanship for installation... 4G91 DOHC got 16 valves... you do the math.

What is actually happening is, that our tappets were designed with a very small passage for oil to flow through. It was a flaw in the design, but they are not doing any corrections to it because our engines are already in the Mitsubishi Museum ages ago. =p

When the oil passage is clogged up, the oil doesn't pass through fast enough. That's when you hear the infamous tappet sounds. Metal hitting metal. Which will damage the valve lifters over time, which is why your tappet sounds get worse and worse.

There are aftermarket tappets that are designed with bigger oil passage to eliminate this problem... but I don't know if malaysia got lar. Overseas market memang got. Malaysia I've never seen before yet.

The logic behind using thicker oil is that the oil sticks to your tappets longer, so during cold start, the lifters would've already had lubricated due to the oil still sticking onto the tappets. Using thinner oils would've made it all flow down to the bottom (due to gravity) and have to wait for the engine to start to start pumping oils back up to the lifters.

This is why it is important that you jaga your engine, must always service ON TIME before the oil gets too dirty so you don't clog up the lifters. If you jaga your engine's well being... you will not face any tappet problems at all.

I used to use Castrol Magnatec also... which I later changed to using Endless semi synthetic... and then HKS semi synthetic... =p No problems with any of them.