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Help Me With My Boost Settings, Wastegate, Turbo Settings.


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Ok all so please read the following post to get up to date.

http://www.skylinesaustralia.com/forums/in...p;#entry2732110

So basicaly this is the problem.

I installed a new GIZZMO boost controller, and it apears that the controller is stuffed so getting a new one, but this morning it decided to work for a little bit.

So at a settign of 10% duty, i managed 10.6 psi, but the strange thing is that the boost is only 7psi below 4500rpm, then once the cam has swithed over, it goes up to 10.6psi. I can set the gain then, but i manage to get funny overshoots, and if i back it off, it is very slow to build boost.

The problem i am having, is that it appears there may be some issues with my wastegate. below 4500rpm the boost is steady at 7psi, and above it shoots up to 10psi, eaven with no boost controll, ie. direct coupled wastgate to IC piping. I pulled the cover off and checked the wastgate, and by presurising it with a pump, i could see it move a good 3cm, the wastage arm that is, I presume that is enough. I took the arm off to ensure that it has not moved or something, and it appears to be ok. The wastgate shuts nice and firm, but the boost overshoot has me warried. It makes me think that my wastgate is too small or something.

Now the car is a stock r33, with a FMIC, HPS pod, Flyen 3" belmouth dump, no cat and 3" exhaust. SAFC II tuned pump, etc etc and stock turbo.

I was also wandering if it can be the dump pipe or the cat, causing turbulance or something of that nature? Can it be my turbo dying as well?

ANYONE help. Can you also get a softer spring for the turbo to allow for better boost controll?

For all those with a GIZZMO IBC or simmilar problems, can you shed some light so that i know what to look out for.

PLEASE

I have a gizzmo boost controller on one of mine. We had the problem that sounds similar but was to do with the wastegate. It sounds like the wastegate needs to be bored out because it isn't big enough. sound like it has uncontrollable boost. Other options are to put the bloody cat back in, this can also be a cause, or stick a blow off valve on it, although this will help it isn't really a safe long term fix, eventually your engine will die if you leave it.... Dont risk it because I blew my stock turbo after i put the gizzmo on it.

Edited by r33skizza

yeah i have read a lot of topics and all of the point to the wastgate being too small. So it looks like i am going to have to port my turbo wastgate, yeehhhaaa, something i definatly did not want to do. Does anyone know if i can do it without taking the turbo off. I would like to do it with the turbo in place, with the dump off.

As to the cat, yeah it will restrict the flow, but i can try i suppose, introduce some restriction into the exhaust, will cause the turbo to flow less air and hence the wastgat will flow less. BUGGA.

How much did it cost you to port the wastgate skizza?

I will do mine myself at my mates workshop, got most of it orgornised. will wire the gate open tonight and go for a drive and see if it is that. Go from there. Will also put a cat in to introduce some resistance to exhaust flow.

hmm there seems to be a few things wrong there.

one. dont r33s have an electronic controled actuator so the wastegate actuator cant just be plumbed back to the intercooler pipeing?

two. if it isnt makeing boost then all of a sudden makeing some then it sounds more like the wastegate is open causing exhaust to bypass the compressor wheel and not make boost. then once shut not opening again causing excesive boost.

three. i realy cant see why taking a car out will cause this problem. it may make it worse as the exhaust would be more free floing causing it to generate more excessive boost but it wouldnt cause this problem.

four. id put the boost side of things right back to stock and see what happens then.

i may be wrong but thats how i look at it.

i think i would listen to DJRIFT. he's making lots of sence.

also you can play with the gain on the gizzmo ibc's to make them boost earlyer.. but on high boost this makes it spike up and down ( high boost 18+ psi )

i was using a gizzmo ibc.. there very hard to setup right. boost tee is much better on lower boost.

Ok.

ONE) the electronic selenoid is only set at a set duty, so all it does is on and off, if the boost is higher, it does not adjust the selenoid duty to compensate.

TWO) the GIZZMO is a normaly open selenoid, this means that at all times it is open, untill it reaches max set duty at which point it shuts and regulates the boost. HOWEVER, if your wastgate is not the correct size, you get boost creep, and no boost controll as such. SO putting my cat back in allows for some more restriction in the exhaust, meaning that the turbo will not floww as much gas, and hence the effect of undersized wastgate will be minimised.

I have plumed the wastgate straight back from the IC side and the boost creeps up after 4500 rpm, so the wastgate is too small.

Anyway, i'm gona ask Kutsie to have a look and go from there.

uh hu that all makes sence then. so does the gizzmo one operate off injector duty cycle or just off vacume?

all thoe i am no expert this all seems rater strange as ive never heard of any other EBCs on RB25s causing a problem like this with similar mods to yours. i have also seen the gizzmo one on RB20s and seen no problems at all.

was you looking at getting one of the jaycar boost controlers? if so why didnt you get one? just curious.

sounds like you should get some expert advice first before you do any damage.

The gizzmo works by learning the wastgate and turbo characteristics of the car. so you set the minimum duty of the GIZZZMO selenoid, and this pulses the selenoid at a set rate. Once you have done this, you drive the car through 2 and 3rd gears at WOT to see how much max boost is achived. This is the remember by the gizzmo. So now the gizzmo knows that to achive that boost it has to pulse the selenoid at that rate. The beauty with the gizzmo is that it is a closed loop circuit once it has learned the characteristics of the car. This means that if you have a cold morning it will open the wastgat sooner to compensate for the denser air, and vice versa.

THE only problem is, once you have a nice exhaust, no cat, FMIC, and all the mods, the stock turbo wastgate is too small to bleed off enough air, simple. many people don't warry about it and set the boost to 12 psi and it's all fine. However i want to run 7psi, 10 psi 12 psi and 14psi, as it has 4 boost memeories.

Once you have set the boost setings, you can go throught and set the responce of the boost, ie: how hard it comes on. This is a trial and error thing, to much gain, and the boost will be unstable, to little and it will be to slow. So you play arround with this and it's all good. Now i can set mine to 12 or 14 psi, and i can get 14 psi by 3500-4000rpm and it comes on HARD.

Things like an Apexi EBD have manual duty controll, so you can tell it to open the gate compleatly at what rpm, so if you have wastgat problems they are not as easy to pick up. But the gizzmo is the MOST powerfull processor controller on the marcket and it is half the price.

I looked into a Jaycar kit, but you have to build it yourself, or get somone to do it. Form what i heard they are great, but not what i was after. So i went for the gizzmo as it offers acurate controll, providing the wastgat turbo is correct, it's the fastest processor and it is $360.

As for advice, yeah the conclution is all the same, wastgat is too small. I put the stock cat in to restric the exhaust flow, and i droped dow to 9.6psi boost, and fully open the wastgat still comes upt o 9.6psi, so it's definatly the wastgat. I don't feel like pulling it all off, but i have to.

can't really help, I just set the duty cycle on mine and left it there... didn't play around with the responce. Can't even remember how to. Works fine for me until I get the RB25 and a bigger turbo that is!

ok but what is the number you are using, you can just check this, i want to know what number you are ysing to get that boost.

SO PLEASE give me boost reached at what duty, so i can compare it.

I am experiancing boost creep and need to know how to solve it.

hmmm, i dont think its the size of your wastegate as its only a stock turbo. did the boost creep before you installed the gizzmo?. it sounds to me like it isnt set up properly (ie a faulty sensor or something), if i were you id hunt down a rb20 actuator and fit it(holds the boost at 10psi with no possibility of creep, then only run 3 settings (10,12,14) once youve found the problem :( .

yess i had creep after i installed the dump pipe, but it was harder to dignose as the bleeder valve was shit anyway. I am still to recive a new gizzmo controller as i am sure mine is faulty. I have not been able to set the IBC up, as the creep plays havick with the system.

well i was talking to my mate about this problem. he said it was only once installing a dump pipe that he had the same problem. he had a cat back with no cat then as soon as he put the dump pipe on it had boost creep. he said its fairly common on rb25s as the turbo waste gate cant handle the extra flow avalable. this isnt a problem when you put one on a rb20 as they flow less.

he was left with the option of a high flow or a new bigger turbo. he went for a bigger ball bearing turbo.

i know you already know this wogsrus but i thought id shed some light on the story for every one.

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