Question about the boost for a stock GTS-t

[JasonO]

it start running like hairy goat burr bup blup burr....

That's not a very pretty mental image.....your chasing a hairy goat

it leans out and gets to hot...

Which is, or results in det

unlike a greddy plenum were it has seperate butterflys for each cylinder....

Does it ? Surely you're refering to the RB26 plenum not the GReddy ?

[HoeTrain]

...and the last 3 photos that R33 rb25det had a highflow standard turbo which was able to flow more air which caused piston number 6 to go bang due to running too much boost... (both these have avc-r's)

This is just an excuse to slip some forgies in... My Ex R33 didn't have any problem running the stock IC with .85bar. I just used a bleeder valve. Although on a hot day the boost did tend to spike slightly higher which is something an electronic one should minimise. I never really thought about a FMIC cause the car made adequate power and the torque levels were fine. The aim for me was to have a nice all-round ride instead of a machine that could lay power line in forth gear…

[TTT]

umm... since when does the greddy plenum have 6 throttle butterflies for the RB25?

also, with a front facing plenum say RB26, the air would be rammed right to the back first so that throws out the back cylinder dying from not enough air..

and, why is it that only YOU have lost 2 rb25's on 12psi, when others can run alot more boost through the stock plenum/engine/injectors and not have problems.

it seems more like bad tuning rather than a "fault with the intake manifold" as you put it..

[JasonO]

....at 12psi it was 12:1 -14:1 a/f ratios but at 14psi it was 30:1 leaning out big time..................we just hooked up the avc-r and took it for a strap and it was running 11 - 12psi exact boost..................... when we had the bleede valve hooked up full boost was at 5000rpm..........the avc-r....full boost at 3000 all way to redline....

You were trying to kill it, right ?

[cameron]

umm... since when does the greddy plenum have 6 throttle butterflies for the RB25?

also, with a front facing plenum say RB26, the air would be rammed right to the back first so that throws out the back cylinder dying from not enough air..

and, why is it that only YOU have lost 2 rb25's on 12psi, when others can run alot more boost through the stock plenum/engine/injectors and not have problems.

it seems more like bad tuning rather than a "fault with the intake manifold" as you put it..

what do you mean by bad tuning ? both cars have standard ecu's ? the car with the shot rings had done 160klm on clock but the nismo dash only had 60,000kmls on the clock and the first rb25 had 95,000 so after a really hard thrashed life their were on their way out any way so it just had to happen as we brought it.

i was talking about the RB26 plenum (greddy) not the RB25 ?

"also, with a front facing plenum say RB26, the air would be rammed right to the back first so that throws out the back cylinder dying from not enough air.." ??? im talking about RB25 plenum... thats why i was saying that their a slight fault with the RB25 one... read the previous posts

"HoeTrain" Thats the current process at the moment both engines are getting rebuilds with fogies and rods etc.

[cameron]

You were trying to kill it, right ?

Noo.. thats why it was on the dyno.. to measure a/f ratios. After we left we turned boost down to 10psi for safety...

also that fault that came from a mechanic. the heat up on the northen topics doesnt help.

[Guilty]

I know this is a stupid question, but my knowledge of engines etc. is pretty minimal so don't mind me asking.

What exactly is a bleede valve and what exactly does it do?

I alwayz hear people say it but i never know what it is...

Thanks in advance tho

[rev210]

cameron,

If you had too much timing it still kills the engine. What gets me is that you'd even registered a 30:1 AF ratio on a dyno run! The engine would have pinged its nuts off before you got to that point and damaged said ring lands too more than likely. The tuning killed the engines.

I don't understand what you mean about piston number 6 ".... because its at the back it doesnt really start working intill high up in the Rpm rang which is when its really hot ". Sorry dude it sounds like someone gave you the worng info here or perhaps you got confused.

As others said the g-reddy plenum has only 1 throttle body. The factory RB26dett has the multiple bodies.

[HoeTrain]

I know this is a stupid question, but my knowledge of engines etc. is pretty minimal so don't mind me asking.

What exactly is a bleede valve and what exactly does it do?

I alwayz hear people say it but i never know what it is...

Thanks in advance tho

It bleeds off air from the actuator line which controls the waste gate. This in terns reduces the amount of gas going through the gate which in tern increases the amount going though the turbine thus increasing boost.

[cameron]

Its a manual boost controller. by turning the silver dial you can control the boost pressure, its called a bleed valve because it bleeds off boost.

[HoeTrain]

I know, I need a spel cheker.

[JasonO]

i was talking about the RB26 plenum (greddy) not the RB25 ?

Cameron, Either you're just toying with us for a laugh, or you're very confused about this subject.

FFS You can't mix RB25 / RB26 plenum design pros and cons willy nilly, they are completely differing concepts of design.

[cameron]

cameron,

If you had too much timing it still kills the engine. What gets me is that you'd even registered a 30:1 AF ratio on a dyno run! The engine would have pinged its nuts off before you got to that point and damaged said ring lands too more than likely. The tuning killed the engines.

I don't understand what you mean about piston number 6  ".... because its at the back it doesnt really start working intill high up in the Rpm rang which is when its really hot ". Sorry dude it sounds like someone gave you the worng info here or perhaps you got confused.

As others said the g-reddy plenum has only 1 throttle body. The factory RB26dett has the multiple bodies.

i was surposto say RB26 factory... yeh i dont get it either... it was running 30:1 and it was running sweet didnt detinate or ping from what we could hear any way... because usally you can hear it and i was right next to the engine when it was getting run.

(it was dyno dynamics)

[JasonO]

my knowledge of engines etc. is pretty minimal so don't mind me asking.

Can I advise you to pay little attention to what Cameron is posting in this thread and follow the advice of others.

Cameron,

Please don't be insulted by my comment above, my only intention is to ensure that Guilty gets relevant advice to his initial question.

[cameron]

Cameron, Either you're just toying with us for a laugh, or you're very confused about this subject.

FFS You can't mix RB25 / RB26 plenum design pros and cons willy nilly, they are completely differing concepts of design.

??? i didnt say anything about mixing RB25/26 intake manifold ? i know their a different design thats what nissan built the new design because the RB25 intake manifold had a fault ? im just going off what i've seen and heard. i havent seen to many Rb26's blow piston number 6 but i've seen a fair few rb25's go its usally piston number 6....

[cameron]

im just trying to help him aswell as he's new to the skyline thing (i think?) and its the wrost feeling when your driving a Sht!b0x camary and you see holdens, silvias etc going past you !!!! and its not a cheap exercise to get it fixed either...

[cameron]

let me tell you this, the first sympton of your pistons on its way out is white smoke coming from the exhaust.

[JasonO]

??? i didnt say anything about mixing RB25/26 intake manifold ? i know their a different design thats what nissan built the new design because the RB25 intake manifold had a fault ? im just going off what i've seen and heard. i havent seen to many Rb26's blow piston number 6 but i've seen a fair few rb25's go its usally piston number 6....

Cameron,

If there was a huge fault in the RB25 inlet manifold design, then surely they would have changed the design of the inlet manifold on the RB25DET NEO used in the R34GTT. More importantly, the RB26DETT was not developed from the RB25DET.

Please stop comparing RB25 / RB26 designs as this is a sure fire way of confusing everyone. Even yourself it seems

[JasonO]

let me tell you this, the first sympton of your pistons on its way out is white smoke coming from the exhaust.

Errr, you are having a joke :Oops:

White smoke form your exhaust, suggest moisture, nothing else. Where that moisture is coming from is the source of the problem, and not necesarily the pistons.

[cameron]

yeh its not a HUGE fault but it is.. i was told this by a mechanic. the reason why i'm comparing them is because of the 2 different intake manifolds