Turbo Problem?

[niran]

Hey every one

I have a slight problem with my car as i feel it does not pull even under full boost.. but before i go into that let me give you all the information..

Mods:

Nissan skyline r32 gtst (rb20det)

Greddy intercooler

Pod filter

R32 gtr Fuel pump

Vg30 single version ball bearing turbo

Stock rb20det ecu

Apexi SAFC 2

Apexi AVCR

Initially i had all this installed in my car and had not done any dyno tuning and had the avcr on basic settings running 0.83 bar on my turbo and it was pretty quick and the car pulled hard and lost traction in first gear and second..

About 2 months ago i had my car tuned (using the safc and avcr) at a tuning place in Perth , WA.. after i got the car back now it is just hesitant to pull sometimes.. however when i look on my avcr and change it to the graph mode i hit full boost and keep a smooth straight line ( on full boost ), however i get a whine/high pitch noise and the car does not pull. First of all i thought it maybe be just a good tune and its smooth so i don't feel the pull but nope i cant even break traction in first gear any more ( to give a comparison ).

I thought it was my intercooler core that was leaking as it was a second hand china spec one so i ended up buying a new Greddy intercooler kit and i still am faced with the same problem.. it gets worse as the higher gear i select. for example 1st gear i have pull no whine noise, second gear before full boost i get a whine/high pitch noise and it pulls but not as hard, third, fourth and fifth gear before full boost i get a whine/ high pitch noise and even after it has reached full boost the car still wont pull.. then about 3-5 seconds delay all off a sudden the car pulls..

So in other words it seems as if the turbo is at full boost but there is a lag off about 3-5 seconds and then the car desides to pull..

Does any one have any ideas what could be the problem.. could it be the way the AVCR and SAFC has been set so that it has a delay?

Any help appreciated

Thank you, Niran

[paulr33]

at a guess your hitting some sort of fuel cut

keep turning the boost down by 0.10kgcm2 at a time (or bar) and repeat until you get your power back

its probably tripping out a fuel cut somewhere in the rb20 ecu, i cant remember what its mapping is like

with a different turbo, its probably beneficial to get a complete remap or stand alone

it should work with an SAFC, but its a juggle exercise

and whilst it might be spot on, on the dyno and run flat out

once you plonk it on the road, the load axis could be slighly different

which means it could use a different mapping axis and correction etc

[niran]

Hey man

Oh awesome .. yer i was going to go for a full ecu but im saving up for a rb25 so just wanted a small tune to get a bit more power out off the car at the moment.

so it should be fine to turn the boost down in 0.10 kgcm2 increments without having to change any settings on the safc?

Thanks, Niran

[hypergear]

Most people who brought in their dead skyline turbos for high flow said similar thing before their turbo totally died. Its good idea to check for shaft play and see it spins freely.

[niran]

Most people who brought in their dead skyline turbos for high flow said similar thing before their turbo totally died. Its good idea to check for shaft play and see it spins freely.

dam, thats what i was afraid of.. definatly will check that out today and see what it feels like.

Thanks

[niran]

Hey mate i removed the turbo and checked for shaft play it doesn’t move side to side, however it moves forward and back 1-2mm give or take.. However when i spin it by hand it makes a slight hum noise?

Could the bearing be gone? if so would it stuff up my power like this and cause it not to pull?

[hypergear]

Hey mate i removed the turbo and checked for shaft play it doesn’t move side to side, however it moves forward and back 1-2mm give or take.. However when i spin it by hand it makes a slight hum noise?

Could the bearing be gone? if so would it stuff up my power like this and cause it not to pull?

Its dead needs to be highflowed or replaced. BB turbos are not suppose to have any play. There are only 20thou between wheel so its probably touching its housing.

[niran]

Its dead needs to be highflowed or replaced. BB turbos are not suppose to have any play. There are only 20thou between wheel so its probably touching its housing.

Dam that sucks . hmm just wondering mate how much would it cost to highflow/rebuild the vg30? and also is it worth rebuilding a turbo like this?

Thanks man for your help

[pipster11]

been chasing a similiar problem in mine

its prob the stock ecu pulling timing as it gets close to too much air flow for the stock ecu

there should be settings in the safc that will cap the voltage being sent to the ecu from the safc

i just finished putting an old school 5 button safc on my 32 today and its pulls onto boost much harded (even though i only roughly tuned it by feel)

but as hypergear said, play is not good although i may have to argue with him a little and say that a vg30et turbo (off the top of my head) it a bush bearing turbo, but i'm probably wrong

[hypergear]

Just $800 to high flow. with the VG30's rear housing it can be high flow it to produce around 280rwkws with supporting mods.

I haven't had VG30 turbos been BB yet. the topic says its VG30 ball bearing turbo. so maybe a unusual version.

[niran]

Maybe you both are right.. i don’t think this turbo is a ball bearing turbo as it doesn’t spin for a long period of time when you flick it with your fingers..

pipster- i will keep playing around with the safc and see if anything gets better

hypergear- i will keep in contact with you.

Thanks , Niran

[R33_NICK]

damn !!! i just got the same problem with mine today. i can only hear it at 70-80kmh, cant hear it when accelerating out of 1st gear and car feels weird as well and it constantly whines when i got up to freeway speeds. my car only has an intercooler, exhaust and air filter done and the boost is untouched, still with the stock ecu. previously it made signs like it whistles when im on 2400rpm and when i accelerate, it dissapears. looks like its finally decide to give up. can a highflow turbo or any similar turbos be safely run with the factory ecu and boost controller still in place?

[hypergear]

Well if you run around 10~12psi of boost with factory ECU is fine. The VG30's got .63 rear end which is very good for high flowing. But to get that 280rwkws you need injectors, fuel mods, ecu, afm and etc.

[R33_NICK]

Well if you run around 10~12psi of boost with factory ECU is fine. The VG30's got .63 rear end which is very good for high flowing. But to get that 280rwkws you need injectors, fuel mods, ecu, afm and etc.

ok cheers. ill keep in contact with you as well.

[paulr33]

get a 2nd opinion or try what i said please

the guy who is telling you what is wrong is a business

selling an exact product that would you need if yours failed

[buckets]

checked your clutch?

[niran]

get a 2nd opinion or try what i said please

the guy who is telling you what is wrong is a business

selling an exact product that would you need if yours failed

Hey buddy

I tried what you advised and turned my boost down in small increments, and in the end as you would know the avcr can have 2 settings A and B so i didn’t touch the tune setting, and changed to B and put all the basic settings again.. it doesn’t screw up as bad however it still comes and goes..

Ill try removing my safc or again if it has a setting a and b i will return it to standard also and see how it goes.. if that doesn’t work my plan was to get it on a dyno to make sure exactly what’s going on..

Thanks, Niran

[niran]

checked your clutch?

Hey mate, yer man thought it was clutch so i ended up putting a new exeddy brass button one..

Thanks , niran

[buckets]

Hey mate, yer man thought it was clutch so i ended up putting a new exeddy brass button one..

Thanks , niran

thats cool, has it done it since the brass one has been in?

you got after cam gears? they are known to make a whine

[niran]

Buckets - hey man, yer still doing it after i got the clutch put it, and nah have stock cam gears it sounds like a turbo noise as it just does not pull unless if my fuel pump isn't getting enough voltage to pump fuel through is my only other idea left..

thanks