300rwkw club please read I need you're help!!!!

[cameron]

pic 3

what series rb26 is it because it looks like an rb25 to me ?

[Gradenko]

what series rb26 is it because it looks like an rb25 to me ?

RB26 breather hoses are towards the rear of the cam covers and the covers have different curves on them. So I think you're right. Or its an RB26 with its cam covers swapped.

help, fwiw, I prefer pnuematic boost control too.

[Guest INASNT]

RB26 breather hoses are towards the rear of the cam covers and the covers have different curves on them. So I think you're right. Or its an RB26 with its cam covers swapped.

help, fwiw, I prefer pnuematic boost control too.

hmm true, didnt spot that.

Y would u swap cam covers???

[RNS11Z]

Look at them carefully it does seem to be a rb25, unless my eye vision is abit hows it going. It looks exactly like my engine covers when it was polished

[VIPERGTSR01]

they are 100% RB25 cam covers

[DoughBoy]

They could be RB20 cam covers?

[RNS11Z]

yeah but his engine is meant to be an rb26 he paid for a conversion

[VIPERGTSR01]

ok ok 100% not RB26 cam covers

[cameron]

also the oil lines were you plum the oil catch can into are at the back of the motor on the rb26. and i think the rb26 is a bit wider than the rb25 so i dont think you can swap the cam covers ?

[cameron]

You should be able to tell by the different sound of the motor. if the engine sounds the same as the original motor then its a rb25 not rb26.

[RNS11Z]

after comparing both photo's, its definately an rb25 head. Either its a complete rb25 engine or rb26 bottom end and rb25 head, no idea why they would do that though

[cameron]

Could this be part of power problem ? and that T-piece boost controller, they can only handle a certin amount of boost before they do what they want.

eg: it can only hold upto 14psi intill it canrt hold it any more and the boost will go all over the place ? that why i said turn the boost right down and see if it works any differnt.

[DoughBoy]

Simple way to check - does it have 05U stamped above the first exhaust port?

[Fitzpatrick Speed Works]

at a guess its a 1.0 rear housing...

get a few places to look at it as a basic engine checkup and see if they all concur similar idead about your car... i know this is money but it will iron out most of the probs...

forget the t piece to although its not ideal the car still runs 22psi, agains boost controllers affect response and delevery. if the gauge is running from the plenum and it reads 22 psi then the bleeder is working in creating this boost... in responding we need to remember its not that he cant make boost its that the power figure for that boost reading isnt right which means its a ignition issue ie. the fuel isnt being lite, or a fueling issue theres not enough or theres to much fuel... look at this would be my advise to you get a better tuner someone who knows haltech, go to haltech.com.au or something and look up there distributers for your area im sure most of them are workshops with dynos use one of them to tune the vehicle. theres also a forum on the site you can ask whos the best in your area!!

[help]

Trust me it is an RB26 I will take a picture of the engine number if you like I did that for the exact same reason you guys were argueing. Open the bonnet it just looks like a 25 but it is really a 26. Before I blew my 25 however I did have a gtr plemun and throttle bodies fitted to the car so for those who have asked it can be done just need and adaptor plate made up. It made the throttle heaps more responsive on the 25, I think it was worth it you can get the right people to do the work. RNS11Z thanks for you're help mate I will give him a call today. Thanks for the help guys i will keep you posted on what is happening. Are most of you guys running power fc's and has anyone ripped out and old computer to put in a new had any problems.

[Guest INASNT]

Trust me it is an RB26 I will take a picture of the engine number if you like I did that for the exact same reason you guys were argueing. Open the bonnet it just looks like a 25 but it is really a 26. Before I blew my 25 however I did have a gtr plemun and throttle bodies fitted to the car so for those who have asked it can be done just need and adaptor plate made up. It made the throttle heaps more responsive on the 25, I think it was worth it you can get the right people to do the work. RNS11Z thanks for you're help mate I will give him a call today. Thanks for the help guys i will keep you posted on what is happening. Are most of you guys running power fc's and has anyone ripped out and old computer to put in a new had any problems.

sure u havent been jibbed by the guy that did the convertion??? You cant fit rb25 covers to the rb26, they dont sit on there properly.

I got a PFC and have had no problems with it.

[cameron]

sure u havent been jibbed by the guy that did the convertion??? You cant fit rb25 covers to the rb26' date=' they dont sit on there properly.QUOTE']

thats what i thought.

help. does the engine sound different to the original ?

[nv033]

Is anyone here making over 300KW with a halteck on board, if so did you have any tuning problems/sensor problems. What are you guys using computer wise to make good power.

i fink u r using the wrong computer for an rb26 motor...u need something that tunes through throttle position the e6k does not have this feature.... it will thus be running super rich on cruising and possisbly making it feel like a nugget to drive... the mictotech mtx12 or something like that tunes through throttle position or y not go for the e11 which i would recomend for a rb26 ..... hope this info can help.... call adam from JEM in sydney he can tell you what u need to know about haltechs (02) 96006567 correct me if im mistaken :wavey:

i know of a few skylines making over 300rwkw with a haltech

[Fitzpatrick Speed Works]

good point amu but this doesnt matter as it is not making power as opposed to not cruising nicely.... WOT is WOT if the computer knows that, which it does, then its tuning and so forth... help, go for your real problem as i have stated before your car isnt making numbers at 22psi... it makes 22psi so theres no turbo related problem the problem lies between where your boost gauge is plumed and the exhaust ports!!!!

[Sydneykid]

Hi Help, I'd like to start with the wastegate, I have pretty good success using this formula to determine external wastegate sizes;

Airflow in lbs per minute = diameter of wastegate in mm X boost correction factor

So let's apply it to your car;

300 rwkw = 480 bhp

480 bhp = 44 lbs of airflow = 44 mm wastegate

Now if you want to run 19 psi, then that's the right size wastegate.

But we need to apply the boost correction....

My experience indicates that to get 300 rwkw out of a GT3040 you would need to run around 1.5 bar (22psi). So using the formula...

44 / 22 X 19 = 38 mm.

For those who haven't read the thread..............

http://www.skylinesaustralia.com/forums/sh...light=wastegate

So I would say that your wastegate is too big, what this means is it has to open and close more often, as it has too little exhaust flow when closed and too much exhaust flow when open. All this opening and closing of the wastegate affects the amount of exhaust flow though the turbine, this leads to fluctuations in the boost control. eg; I have seen a relatively low powered engine, with a very large wastegate, move up and down 0.3 bar in its boost as the boost control circuit struggles to keep up with this open, closed, open, closed requirement.

Moving on to one of my favourite subjects, the wastegate actuator spring rate. If you want to run 22 psi then you should have an 18'ish psi spring in the wastegate actuator. That way the boost controller only has to control the 4'ish psi. If you have say a 12 psi spring, then your boost controller (doesn't matter what type) is struggling to keep up with bypassing (or pulsing) the required amount of pressure (10 psi) to control the boost.

Summing up, I think you have 2 problems, the wastegate is too big and (most likely) you have too light a spring in the wastegate actuator. Consequently I am not at all surprised that you have boost control issues. The bypass style boost controller is probably not helping, but it isn't the cause of the problem.

So the very first thing I would do is make sure you have at least an 18 psi wastegate actuator spring. If not then get one, I reckon it will fix most your boost fluctuation problem.

Lastly, too big a wastegate, since it seems to run OK at low boost and makes good power there, that would confirm the calcs that the wastegate is too big. I would try the spring mod first and if it is still a problem then look at trying a smaller wastegate.

Hope that makes sense.