Top speed lost...

[aja]

Your air + fuel ("AF") mix was incorrect/ not stable to your MMC ECU AF mapping since u changed to bigger throttle, hence u felt that are underpowered. You will feel more air sucked in but the car was so-call loosing torque. I guess like this case, u are losing mid-range + top end torque a lot. Somemore u will also notice that your FC a bit high and dark smoke labelled at the exhaust tail.

U should get yourself a VAFC or equivalent to retune your AF ratio and match with the MMC ECU apatite. This would turn-back your performance to 99% normal after that. Make sure to get a correct tuner to do it as u are running on after market ECU!

 

[Md Ekal]

Your air + fuel ("AF") mix was incorrect/ not stable to your MMC ECU AF mapping since u changed to bigger throttle, hence u felt that are underpowered. You will feel more air sucked in but the car was so-call loosing torque. I guess like this case, u are losing mid-range + top end torque a lot. Somemore u will also notice that your FC a bit high and dark smoke labelled at the exhaust tail.

U should get yourself a VAFC or equivalent to retune your AF ratio and match with the MMC ECU apatite. This would turn-back your performance to 99% normal after that. Make sure to get a correct tuner to do it as u are running on after market ECU!

Thank to your input.... right now saving money to buy SAFC and to go dyno include tuning.....

 

[vr2turbo]

Your air + fuel ("AF") mix was incorrect/ not stable to your MMC ECU AF mapping since u changed to bigger throttle, hence u felt that are underpowered. You will feel more air sucked in but the car was so-call loosing torque. I guess like this case, u are losing mid-range + top end torque a lot. Somemore u will also notice that your FC a bit high and dark smoke labelled at the exhaust tail.

Just want to ask, if more air suck in and wrong A/F ratio will have black smoke?
I thought too rich an A/F ratio then only plenty of black smoke, right?

 

[^pomen_GTR^]

additional:


if more air=less fuel=no black smoke...but would induce to white smoke since engine running lean with not enough fuel....that would make the engine running at higher temp. and could lead to engine knocking (pre-detonation) thus hurt the piston ring and might as well harden valve seal...

btw thats the worst case if happens la....checking the spark plug tip colour would give your some idea what need to be done.....

 

[vr2turbo]

Running too lean will blow the engine in the long run......

 

[aja]

Just want to ask, if more air suck in and wrong A/F ratio will have black smoke?
I thought too rich an A/F ratio then only plenty of black smoke, right?

Sometimes it happened due to the driver keen to push more pedal to metal in order to gain the respective torque feeling. Therefore FC will be higher or richer than normal.

 

[vr2turbo]

Sometimes it happened due to the driver keen to push more pedal to metal in order to gain the respective torque feeling. Therefore FC will be higher or richer than normal.

Then the ECU is confused already with the mod done......

 

[DanzEterna]

Hmmm... I thought for high end, larger exhaust better. Exhaust faster go out, then must have thought wrong....

u could use slightly bigger exhaust like bordermax or n1....but not too big la..
retain the original diameter piping....

 

[aja]

Then the ECU is confused already with the mod done......

ha ah. Aftermarket MMC ECU was tailored to cater certain AF apatite, for previous owner since u maybe purchased it second-hand. Make sure those AF combination met these apatite or else you have to see Charlie Matspeed to remap the ECUand E-prom for you.. or buy another aftermarket ECU and tailored it base on your current setting.

Best case keep it stock la & work something to gain extra torque..lagi syiok .....and laju2 nak kemana!

 

[^pomen_GTR^]

last time mod my SOHC 4g92 using bigger TB also compensate with bigger injector.....tremendous torque and power but consequences even drive slow got heavy FC.......ekekekekeke....compensate tuning using ralliart chip.....but not fine tuned chip....just plug chipped ecu only...

 

[vr2turbo]

last time mod my SOHC 4g92 using bigger TB also compensate with bigger injector.....tremendous torque and power but consequences even drive slow got heavy FC.......ekekekekeke....compensate tuning using ralliart chip.....but not fine tuned chip....just plug chipped ecu only...

air/fuel = power.
Some mod air, no fuel increase, and some mod fuel no air increase, no point....

Wah! you want power but also want to use little fuel, I also want......hahahahaha

 

[^pomen_GTR^]

air/fuel = power.
Some mod air, no fuel increase, and some mod fuel no air increase, no point....

Wah! you want power but also want to use little fuel, I also want......hahahahaha

talking about mod air...i remember that my daily ride running really lean...white plug tip....no wonder previously i can't advance my ignition timing even a bit from the current setting...


have to sacrifice torque for fuel economy

 

[vr2turbo]

Your white tip turn yellow then gone liao.......
My wife's Sonata runs rich, so now with air mod, run better, but I still think is running rich....

 

[^pomen_GTR^]

Your white tip turn yellow then gone liao.......
My wife's Sonata runs rich, so now with air mod, run better, but I still think is running rich....

then try exhaust mod la...


not the bising2 type..but upsizing overall piping size around 15% and change into bigger flow muffler (from another bigger cc car stock muffler)

 

[vr2turbo]

Now, is 2nd car, don't want to mod too much. Already have Mitsu Sigma rear muffler when original one rusted away. Is an old model Sonata III 1.8i (M).....

 

[^pomen_GTR^]

let the new driver thinking what to mod later.....ekekekeke

 

[vr2turbo]

Now, Son is using, later daughter will too. I think they won't mod this old junk, but get their own when they can.....

 

[Md Ekal]

Thx for the all input...
Right now,a new problem popup when I go to survey/ask mechanic around this area about my problem...
They all said that my block start to "makan minyak itam"...
~Argh~, another problem... but I manage to get the answer,(don't know if correct or wrong).
They said, go saving money and buy a engine management to solve about my top speed lost....

 

[^pomen_GTR^]

yup....so now until u install engine management/piggyback and tune your engine properly it is better not to push your engine too hard....

 

[vr2turbo]

Thx for the all input...
Right now,a new problem popup when I go to survey/ask mechanic around this area about my problem...
They all said that my block start to "makan minyak itam"...
~Argh~, another problem... but I manage to get the answer,(don't know if correct or wrong).
They said, go saving money and buy a engine management to solve about my top speed lost....

Block makan minyak? Cracked? or piston and rings loose??.....

If running lean better go easy on it first......