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reading through this whole thing is rather depressing. im suprised anyone would tune an engine of unknown specs. GTRNUR is right. the only way forward from here is a total strip down and rebuild the correct way. just make sure its built and tuned by the same company so the limits of the engine are known while tuning. i feel sorry for u mate, ive been ripped off before to.

i have the rb30et pistons in my car, so my compression is low but my rb25 head is stock, it still as the pads on it.

makes 400+hp on 1.2 bar and im sure its 3 bar capable. engine is 5 years old now with 160,000km

i have the rb30et pistons in my car, so my compression is low but my rb25 head is stock, it still as the pads on it.

makes 400+hp on 1.2 bar and im sure its 3 bar capable. engine is 5 years old now with 160,000km

What numbers does yours show with a compression test?

This is excelent post. Now These are the things i wish these mechanics i been going to have done but they havent and seem to just brush it off to the to hard corner and just give me blank useless answers.

Well the head assy with cams and valves was around $6000 from spool 2yrs ago

plenum setup from spool was about $2000

6boost manifold was about $2000

turbonetics gtk1000 new was about $5500

the peice of shit turbonetics was gate that was sold to me to match the turbo was about $1200. Never sealed closed from new and was swaped with a tail 38mm

first build used a $400 tomie commetic head gasket witch didnt work cause of the oringed block.

sard injectors were around $1300

sard fuel rail was about $400

Cam gears were around $500

Fuel reg and 2x bosch 044 and surg tank and bosch intank pump plus fittings and braided hoses came to around $3000

eboost2 was around $1000

bosch coils replaced x4 was near $400

superspark coils $450 lasted 2wks

splitfire coils $750

factory coil harness $500

custom exhaust from 3.5 inch to 5inch from turbo into 4.5inch $1750 plus $450 for cannon

new microtech harness and repair and labour was $2500

All braided hoses and speedflow fittings in engine bay came around $6000.

new clutch $2000

Rebuild: all bottom end bearings replaced with acl race and all gaskets and oring and seals $3500

New ballencer $600

alloy radiator $450

this has got to be exaggerated..

i've noticed you've used the terms "stock det" and "det" a lot when i think you actually need to say either e or et. i.e i read somewhere you said you used a stock det head gasket, det forged pistons etc.

i have the mahle 30det pistons 86.5mm 20thou overbore and my compression came to 160 on all 6, i didn't know cp made specific 30det pistons, are you sure you don't mean 30et?

Edited by Char
  • 3 weeks later...

Hi mate it sounds like you have been given the cold shoulder by everyone once they have taken your money unfortunately.. You have got alot of good gear there so try not to get too diss-heartened you just gotta figure out whats working and not working just stick with it mate you have gone this far now.. Just a few questions and I'm not by any means saying this is the problems just trying to help problem solve or maybe take some possibilitys out of the equation for you..

You say that...

Rb30det cp pistons (dish tops) (85psi per cylinder) &

4. big oil breathing issue. Return fitted to the back of head to sump to fix prob..

I would be asking why the compression is so low and what is causing the big oil breathing issue? Could it not be because there is too much blow by past the rings causing too much crankcase compression therefore giving a low 85psi compression and pushing way to much oil up top? But in saying that when the compression test was done was the motor cold or at normal operating temperature because don't forged pistons expand slightly as they get upto temp? which means if it was cold then maybe you would get a better compression figure if it was at normal temperature?

Also if you have too much blow by wouldnt this cause the plugs in affected cylinders to fowl as you wouldn't be getting a good clean burn/combustion of fuel and air in the cylinders? How old is the oil in the motor Is it fresh but turned dark and smelling heavly of fuel already?? What does it look and smell like and if u wipe a bit off the dipstick onto your finger and rub with your thumb and finger does is feel gritty or grainy??

Like I said I'm not saying these are the problems and I'm just trying to throw a few ideas out there to hopefully help you sort it out or atleast narrow down the problem

Edited by jun 2.7

Hi mateouzo hands like you have been given the cold shoulder by everyone once they have taken your money unfortunately.. You have got alot of good gear there do don't get too diss-heartened youth just gotta figure out whats working and not working just stick with it mate you have gone this far now.. Just a few questions and I'm not by any means saying this is the problems just trying to help problem solve or maybe take some possibilitys out of the equation.. You say that

Rb30det cp pistons (dish tops) (85psi per cylinder) &

4. big oil breathing issue. Return fitted to the back of head to sump to fix prob..

I would be asking why the compression is so low and what is causing the big oil breathing issue? Would it not be because there is too much blow by past the rings causing too much crankcase compression therefore giving a low 85psi compression and pushing way to much oil up top? Also when the compression test was done was the motor cold or at normal operating temperature because don't forged pistons expand slightly as they get upto temp? which means if it was cold then maybe you would get a better compression figure if it was at normal temperature?

Also if you have too much blow by wouldnt this cause the plugs in affected cylinders to fowl as you wouldn't be getting a good clean burn/combustion of fuel and air in the cylinders? How old is the oil in the motHoward what does it look and smell like? Is it fresh but turned dark and smelling heavly of fuel already??

Like I said I'm not saying these are the problems and I'm just trying to throw a few ideas out there to hopefully help you sort it out or atleast narrow down the problem

Woh :O , are you half asian?

Jun 2.7 - yeah its been answered, and the 85psi is the problem. i too thought the rings weren't sealing,

but GTRNUR with his personal experience, pointed out the static compression ratio is way too low and is causing the low comp test readings (something i assumed an engine assembler would have measured, which makes me wonder if everything else was measured)

It was an accident I was reading this from my Phone didnt realise it was three pages and I only read the 1st page and thought f*** poor guy! hence my post.. Anyways shit happens atleast I tried to be helpfull ?glad to hear its all been figured out ?

  • 4 weeks later...

Sorry to hear of your problems to date.

I think most people on here have been stung by the multitude of dodgy workshops around.

If you are still trying to find a reputible and honest w/shop Dan at ERD in Stapylton is the king.

He also has Shaun and Rick from EFI Performance sharing his workshop, he can fix it , Shaun can tune it.

He has built my R34 GTR with 30/26 to a standard few could match, I have tried most of the so called big name w/shops in Brisbane

only to be cheated time and time again.

But dont take my word for it, ask around, try the Qld skylines forums and see where they take there cars.

  • 4 months later...

an update. I striped the motor onece again and did some maths. comp is sitting at 6.83:1 I think that may have some of the prob solved new rods and custom pistons going in soon. Block has been honed and decked to remove the orings. new rb30 crank has been machined and ballanced and a spool collar has been fitted as the old crank was never modded for the rb26 pump and was begining to chew out. once all bottem end is bolted ill figure out the comp and post it up and let every one know how the tune turnes out. fingers crossed its gonna be better

  • 2 months later...

you should have a chat to Gavin Woods, I wouldnt take my car anywhere else ever again..

He's honest and knows his stuff, he's tuned some some 1000Hp GTR's in the ignition DVD's and is involved in the international drift scene, he'll sort it out for you without the rip off.. :yes: he allowed me to watch and ask questions and brought me into the dyno room to talk me thru what was going on unlike alot of tuners/workshops that just take the keys and then give you the bill...

Edited by SliverS2
  • 1 month later...

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