R33 Gts-t S2

[mr33gts-t]

hey i got a R33 S2 had it for a year and a half got intercooler exhaust and had a vg30 turbo put on it as i blew the old 1 up, i dunno if they are a better turbo, i finally got a profect B II controler and had it on the dyno and it would not go more thank 10 psi before it spike to 20psi plus then cut out i have splitfire coilpacks new spark plugs even a HKS fuel cut defender, now i cant run any boost other than standard so i have to turn controller off or it just shhots up past 20psi.

sensers are all clean, the mechanic said it can it could be something to do with the turbo the gate staying open or something not to sure exactly wat he said i just want to make my car quicker but dont have alot of money to spend, so if i do need a new turbo is there any good upgrades or ballbearing turbos or something that i dont need a computer for as i can not afford to buy a computer and tune it as well as a new turbo.

is there any other option rather than a stock 1 as later on i can get a power fc or something!!!

hope someone can suggest something cheers Aaron

[R31Nismoid]

ALL turbo upgrades require a ECU... even the one you have now...

Hell the stock turbo benefits from aftermarket ECU/Tuneable setups...

To not have one is nothing short of silly and more than anything you are putting your motor at risk.

If the boost is spiking its one of two things.

1. The boost controller.

2. The turbo wastegate staying shut.

A dying turbo does not make more boost, its just the control behind it not working correctly

[mr33gts-t]

ALL turbo upgrades require a ECU... even the one you have now...

Hell the stock turbo benefits from aftermarket ECU/Tuneable setups...

To not have one is nothing short of silly and more than anything you are putting your motor at risk.

If the boost is spiking its one of two things.

1. The boost controller.

2. The turbo wastegate staying shut.

A dying turbo does not make more boost, its just the control behind it not working correctly

thanks for the reply mate

are u seriouse even that turbo need a computer. its definatly not the boost controler as i bought another1 just to see if it is.

how come other ppl have the vg30 turbo running sweet on there car, for a long time with no probs and no aftermarket computer....

all it is, is a bigger exhaust housing isnt it 3 diff mechanics said that its fine does not need computer!!

[paulr33]

do you need to change the computer to fit and run a bigger turbo (start the key, plod around etc)? of course not

do you need to change the computer to make more power and run heaps more boost? absolutely

it flows too much air (over the stock turbo), the stock computer panics and thinks there is something wrong (ie failed wastegate etc) so it takes all the timing out to protect the engine. a remap is required of the stock ecu or change of ecu or a piggyback to trick the ECU into thinking there is less airflow

[mr33gts-t]

do you need to change the computer to fit and run a bigger turbo (start the key, plod around etc)? of course not

do you need to change the computer to make more power and run heaps more boost? absolutely

it flows too much air (over the stock turbo), the stock computer panics and thinks there is something wrong (ie failed wastegate etc) so it takes all the timing out to protect the engine. a remap is required of the stock ecu or change of ecu or a piggyback to trick the ECU into thinking there is less airflow

so if i put the standard turbo on it will be fine to boost up to 14psi

[Mattw_83]

do you need to change the computer to fit and run a bigger turbo (start the key, plod around etc)? of course not

do you need to change the computer to make more power and run heaps more boost? absolutely

it flows too much air (over the stock turbo), the stock computer panics and thinks there is something wrong (ie failed wastegate etc) so it takes all the timing out to protect the engine. a remap is required of the stock ecu or change of ecu or a piggyback to trick the ECU into thinking there is less airflow

So in saying that, if i was to hiflow my standard (same car) turbo but continue to run the same boost 12psi, id realistically need another remap again? ive had it remapped already to run 12psi on stock turbo. Goes really well.

Ill be getting this done very shortly out of fear the stocker will blow out and course me grief... i figure for a grand or so its better than the possibility of a rooted motor entirely...

[mad082]

more than likely....no. anything over about 12 or 13 on the stock turbo and the stock ecu packs up its bat and ball and goes crying home to mummy.

that said, with the vg30 turbo on there you should be able to make the same power as you would on the stock turbo, you will just do it at lower boost pressure (vg 30 turbo is a touch bigger than the stock one).

if you are getting boost spiking then it has something to do with the boost controller. maybe it is how it is hooked up rather than a faulty unit.

[mr33gts-t]

more than likely....no. anything over about 12 or 13 on the stock turbo and the stock ecu packs up its bat and ball and goes crying home to mummy.

that said, with the vg30 turbo on there you should be able to make the same power as you would on the stock turbo, you will just do it at lower boost pressure (vg 30 turbo is a touch bigger than the stock one).

if you are getting boost spiking then it has something to do with the boost controller. maybe it is how it is hooked up rather than a faulty unit.

i have tried two differnt boost controlers tho, they are definatly set up properly we have put it down to having a faulty watsegate i think, thats just wat im told..... im no pro obviously lol. but surely i should be able to run more than the stock 7psi i did whan it was first all put together had it on the dyno to get tuned and all i could get was 10psi it made 213rwkw lasted about 2days then i gave it a hit and just went crazy got it set again lasted half a day went crazy but the contrller settings didnt change i put a different boost controller on a cheaper 1 just to see if it would spike.

sure enough it shot up strait away 22psi

but as soon as i turn the controller off its great runs like a dream

could definaltly be a waste gate problem?????

[mad082]

are both controllers you are using electronic? or is 1 manual?

[paulr33]

once again for all those who refuse to search or cant be bothered

can you run 14psi on the stock turbo and ecu? probably not

why cant it? 1) its inefficient, 2) it risks the turbocharger, 3) it will trip the "excess airflow" protection

does the stock ecu have the ability to run larger turbochargers (start the car, idle, plod around)? yes

does the stock ecu have the ability to run larger turbochargers (full load, high boost, unleash fury on the throttle pedal)? no

does the stock ecu have boost cut? no

does the stock ecu have excess airflow cut? yes

does the stock ecu have its own built in protection over more airflow? yes

does the stock ecu typically panic and run like ass with heaps of boost? yes

does changing your turbo typically mean you need to remap or piggyback or replace the ecu? yes

why?

when you change the turbocharger, up the boost, change the compressor wheel, hiflow it, fit a larger turbo, run tons of boost the following occurs

more air is injected into the intake as a result of running either more pressure or running a larger compressor wheel

this in turn drives more air into the intake. the ECU has mapping against the standard AFM and knows when "too much" air is coming in

it uses the AFM signal to watch for this, and when its see's f**kloads of air coming in (ie from your assloads of boost, or larger compressor wheel)

it goes "hmmm way too much air is coming in, i reckon something has failed, lets f**k off all the timing to protect my beloved engine"

so the timing is dumped and it runs mega rich

is this boost cut? no

its excess airflow protection

people usually call it "boost cut" cos they dont understand it any other way and its usually "hit" when people up the boost pressure

usually when a stock ecu is remapped, the edit the "excess airflow" ramp and basically disable it, which in turn gets rid of it

other devices like the apexi SAFC bend the AFM signal, which in turn work around the issue, and the stock ecu never see's the high level of "airflow"

standalones dont have any such code in the maps so you can run whatever you like

[Adriano]

Paul you are a very patient man

[zebra]

ive had both things mad082 is talking about, 2 different stock ECUs though, the first one I tried was just make make sure it worked before i sold it (had a PFC) it just cut out,

the one I have now (waiting for my EMU to arrive) misses and sounds like its on a limiter.

Maybe there are different setups depending on the year model of the factory ECU, I couldnt tell you what its from as I bought it off a member on here.

Quick edit : the first one I had (the one that completly cut out) was the factory ecu in my 93 model r33

[mad082]

i think of it as boost cut (although i refer to it as rich and retard, and i know how it works) because of the way it activated in my 33. it wasn't just a bit of popping and a bit less power. when i upped the boost then took it for a spin, when it started to spool up and boost went too high it just cut out dead. no popping or missfire. 100% cut in power, then came back to life. on various occasions when i was upping the boost i encountered this. never did i encounter a missfire or anything like that. i would slowly up the boost until i encountered this cut, then backed it off a bit. and it wasn't anything such as the afm playing up because when i put in the remapped ecu and boosted it up to 15psi it didn't miss a beat and ran good afr's.