4G93T Club

[sleepwalker]

There's no boost cut in our 4G93T. Boost control is done mechanically and the ECU does not cut the fuel if excess boost is detected. Excess boost is actually controlled by the original bypass valve with can only withstand boost pressure up to 1.0bar before it starts to open automatically. Are you still using the original bypass valve?

There are many reasons for your engine to have that 'boost cut' feeling. One of them is a leaking intercooler pipe. This will cause excessive spooling of your turbo to generate the appropriate boost (and to compensate for the leaky pipes too), causing too much intake thru the MAS. MAS will then send the wrong air flow signal to the ECU, which automatically compensate by pumping more fuel, causing the fuel injectors to overheat and jam. That symptom is very typical to leaky intercooler pipes and those using the original bypass valve to increase max boost.

Do you hear your engine knocking/detonating just before the cut? Usually excess pinging will cause the knock sensor to retard ignition, giving the sensation of a 'boost cut' again.

 

[alvinpck]

sleepwalker,

I'm still very new in 93T world, there's still a lot for me to learn. The info you provided is quite technical in some ways.

Is the bypass valve the 'original' bov?
I have yet to check for intercooler leaks.

By looking at the 2nd paragraph, what I can conclude is, 'cheating' the ECU?

MAS is sensor of?

Don't think I here any engine knocking. But I will check again.

 

[Cheong Mou Kei 4G9XT]

rorytate : here is my number 016-3968079 (MOU KEI)

 

[Cheong Mou Kei 4G9XT]

ECU 8XXX dat i i saw twice....one from a GSR owner.....n another from a halfcut shop...

both oso cam from LIBERO GT halfcut 1

performance wise....all is da same ler....
n got no turbo light on da meter





BYPASS VALVE is da original BOV ler....oem 1 spring veli weak....tat y when full boost dat time da valve will leak out a little bit air out...

 

[alvinpck]

oh~~
now i get it, cmk...

i change mine dy....da ori one is on my monitor now.... :D

 

[rorytate]

I think the simpliest solution to the problem is to have a proper engine management.

with engine management system..your car will perform alot better than standard or phase 2 modding.


renegade,
you can do ither was by using safc or if your ECU allow you to remap...make it towards lean...BTW my car is running on 2 additional injectors to reach the mileage.which in short 4 pistons and 6 injectors.. :)

CMK, call me if you bypass my area. go for a drink~

 

[dolly]

can you explain how adding extra injectors help?

 

[sleepwalker]

Originally posted by alvinpck@Feb 15 2004, 07:09 AM
sleepwalker,

I'm still very new in 93T world, there's still a lot for me to learn. The info you provided is quite technical in some ways.

Is the bypass valve the 'original' bov?
I have yet to check for intercooler leaks.

By looking at the 2nd paragraph, what I can conclude is, 'cheating' the ECU?

MAS is sensor of?

Don't think I here any engine knocking. But I will check again.

The MAS is the airflow sensor, reads the amount of air being sucked into the engine and sends this signal to the ECU. If the intercooler pipes are leaking, then more air is being sucked in but not all are entering the engine. The excess air will also translates to excess fuel being pumped into the engine.

 

[sleepwalker]

Originally posted by Cheong Mou Kei 4G9XT@Feb 15 2004, 08:20 PM
BYPASS VALVE is da original BOV ler....oem 1 spring veli weak....tat y when full boost dat time da valve will leak out a little bit air out...

The OEM spring is not weak. It is by design and Mitsubishi controls overboost with it. It is made to open at around 1 bar in the event of an actuator valve failure. This way you will not blow your engine that quickly.

 

[rorytate]

Originally posted by dolly@Feb 16 2004, 11:52 AM
can you explain how adding extra injectors help?

Dolly,

when you go for high boost for instance of 1.3bar....where as the stock injector of GSR is only 390cc..and it's not enuff to fuel in after 5krpm...

so you add additional injectors to compensate the necessary fuel.

on doing this you need one external fuel pump to have the pressure on the fuel.

regards

 

[BLaCkHoWLiNG]

i just heard someone bought big big turbo....

 

[Charles]

BLaCkHoWLiNG Posted on Feb 16 2004, 03:44 PM
i just heard someone bought big big turbo....

izzit a T88 for someone's 2jz? :P

 

[dolly]

kk good, no need to spend extr money then :D thx

 

[alvinpck]

Thanks for the info, sleepwalker.

guys, hv u guys encounter a relatively loud 'tak tak tak' when u start da engine when its cold? happened few times dy lo....but after da engine is warmed up, the sound gone....or when i tap da accel.

y ah? <_<

 

[JUN]

Originally posted by alvinpck@Feb 16 2004, 04:41 PM
Thanks for the info, sleepwalker.

guys, hv u guys encounter a relatively loud 'tak tak tak' when u start da engine when its cold? happened few times dy lo....but after da engine is warmed up, the sound gone....or when i tap da accel.

y ah? b]

That's the hydraulic lifter's sound :) Common problem in GSR. :) If u wanna eliminate that sound then have to change the lifters (not so sure abt this...ask the sifoos...) Or if not just use thicker engine oil which is a temporary solution :)

When the engine oil warms up edi then the sound will go away. :)

Regards;

 

[alvinpck]

hey jun...
thanks man~~~ :D

im using 15-50 series oil now...izit appropriate ah?
da 1st round i used 20-50, but feels da engine abit heavy la.... :P

but dat 'tak tak tak' sound got no side effect wan right? <_<

 

[JUN]

Originally posted by alvinpck@Feb 16 2004, 05:19 PM
hey jun...
thanks man~~~ :D

im using 15-50 series oil now...izit appropriate ah?
da 1st round i used 20-50, but feels da engine abit heavy la.... :P

but dat 'tak tak tak' sound got no side effect wan right? b]

err..dunno got side effect or not but i think most if not all GSR owners have experienced that kinda sound b4 :) I also experience it a few times.

I forgot how much is my engine oil SAE rating liaoz.. :lol: I'm using Shell Fully Synthetic. :)

Regards;

 

[alvinpck]

mmm....

valve slightly loud is common in 93 n 93t, but dat relatively loud 'tak tak tak' really get on my nerves leh....
im ony using semi-syc 15-50.. :P

 

[waikitfire]

Originally posted by Charles@Feb 16 2004, 04:07 PM

BLaCkHoWLiNG Posted on Feb 16 2004, 03:44 PM
i just heard someone bought big big turbo....

izzit a T88 for someone's 2jz? :P

:lol: :lol: :lol: :lol: :lol:
:P

 

[dolly]

i hear it on my new gti too! didn't think much of it