How to turbo your N/A

[linedup33]

hey would it b possible to put a rb30 bottom end on? n how do u reckon that would go? like would it b safe? n would u b able to run higher boost?

cheers.

[andylaurel]

there's an entire thread related to RB30 conversions.

[linedup33]

ahh ok sorry man, ill have search

[linedup33]

hey man just had search but i couldnt reli find what exactly i was looking for...i just need a quick answer...is it a big job to put a rb30de bottom end onto a rb25de? n will help me run higher boost more safely?

plz plz plz

[SilverECR33]

hey man just had search but i couldnt reli find what exactly i was looking for...i just need a quick answer...is it a big job to put a rb30de bottom end onto a rb25de? n will help me run higher boost more safely?

plz plz plz

The correct CR will help you run higher boost safely. so while u got the RB30 block apart, replace the pistons for lower CR, just grab a set of VLT pistons, they will be fine. if you read thru the rb30 conversions in the "forced induction performance" section, you will notice it isnt sucha big job.

[linedup33]

ok soo cant i use the pistons already from the rb30?

how much would those vlt pistons set me back?

n much would i b looking roughly to put the rb30 bottom end onto my rb25?

thanks soo much n sorry for the 21 questions

[666DAN]

if anyone is planning to do this, i have the stock R33 intercooler and piping for sale atm, for $80 ono. just pm me, its all in very good condition btw.

Don't be fooled gents. its not only the compression factor, but the piston itself, the N/a pistons are not Hyperputectic. therefore, even with low boost pressures, after a while you will melt a piston.

By all means, do this upgrade! turbo is 100% better effecient power, than most other mods. But do plan to change your pistons over in the near future.

Not really, my car ran fine for a over 50,000kms and as far as I know is still running fine without ever being cracked open to change pistons.

Melting pistons is from a poor tune, you can do it with any engine

[andylaurel]

the cast pistons will not tolerate the higher combustion temperatures associated with boost.

of course a good tune will help keep detonation to a minimum and the correct supporting modifications will ensure oil temps and water temps are kept low, but eventually the pistons will give up the ghost.

an example is my good friend who has a famous AE86 drift car here on the gold coast.

He had a stock 4AGE bluetop (bigport) bottom end which has the smallest rods, crank and gudgeon pins of all the 4AGE's and it took 6 months of punishment from a HKS GT2510 at 13 PSI pushing 150 kw at the wheels out of 1600cc.

It had a great tune from Adam from JEM and had all the supporting mods like a alloy radiator, great intercooler, big fuel system and oil cooler. The water temps never got above 82 and the oil never about 90 - 95. Eventually, the pistons gave up. But it goes to show that a motor can be pushed to nearly triple its factory power and still last for a while given that the correct supporting mods and great tune are applied.

Side note: I have read that the turbo RB30 pistons with the twin cam head will result in a 7:1 CR. too low

[linedup33]

i think its beta to use the rb30de na bottom end n not the turbo as the compression ratio is too high on the rb30de turbo bottom end.

[unarmed_skyline]

hey i just though i would go back a little bit and add something in, in relation to drilling the oil return line into the block a way of getting around this would be to buy an oil cooler and run the oil lines from the oil filter to the oil cooler to the turbo out the turbo then into the engine and around agian, this way you would have the best oil going to the turbo and you wouldnt have to worry about drilling holes in the block, and as a bonus it would be even easier to return to stock if needed

[666DAN]

Yeah it's easier to put a 'T' piece at the oil pressure sensor, works well enough and that's what GReddy do with all their bolt-on kits.

[666DAN]

the cast pistons will not tolerate the higher combustion temperatures associated with boost.

of course a good tune will help keep detonation to a minimum and the correct supporting modifications will ensure oil temps and water temps are kept low, but eventually the pistons will give up the ghost.

an example is my good friend who has a famous AE86 drift car here on the gold coast.

He had a stock 4AGE bluetop (bigport) bottom end which has the smallest rods, crank and gudgeon pins of all the 4AGE's and it took 6 months of punishment from a HKS GT2510 at 13 PSI pushing 150 kw at the wheels out of 1600cc.

It had a great tune from Adam from JEM and had all the supporting mods like a alloy radiator, great intercooler, big fuel system and oil cooler. The water temps never got above 82 and the oil never about 90 - 95. Eventually, the pistons gave up. But it goes to show that a motor can be pushed to nearly triple its factory power and still last for a while given that the correct supporting mods and great tune are applied.

Side note: I have read that the turbo RB30 pistons with the twin cam head will result in a 7:1 CR. too low

13psi in a 10:1 is asking for trouble that would have contributed to the death of that engine...I owned a blue-top as well and managed to melt the piston without a turbo.

under 8psi with stock pistons will see a reliable engine that won't need forgies and will live a long prosperous life.

[andylaurel]

i wish i could get this Rb20 turbo to boost at 8 psi but it simply wont!

aforementioned 4AGTE was using 440cc injectors with a NA + Turbo friendly tune but it still fooked a slug.

[Chi100188]

mmm so as un armed skyline has said this means i don't have to drill a hole in my engine just get an oil cooler and its allsolved ?

Cheers

Chi

[666DAN]

yeah that's a perfectly doable way of getting the oil feed.

Andy why won't it boost to 8psi?

[andylaurel]

ive got vacuum hose running straight from the compressor nipple to the wastegate actuator and its natural boost is .8 bar.

i do have a bleed valve in the line but its completely shut. i might delete this as it may still be causing a boost increase.

[666DAN]

If you've got an RB20 turbo that's normal though, the actuator I put on my highflow from an RB20 was 13psi straight on the actuator, no bleed valve.

Grab one from a series 1 R33, it should be nice and tired and give about 6psi

[juddieR31]

Absolute bullshit, my series 1 25de had the oil return just above the sump blanked off which simply unscrewed to fit my return line fitting. The same as the water return and oil feed, the only thing I had to source was a water feed which I t-pieced from a heater hose. Piss the rb20 crap off, accept a 25det stock turbo as a minimum.

[andylaurel]

mine was cast over. simple as that.

Sliding RB25 hi flow turbo is on the cards.

[666DAN]

Slide highflow will be great! Will spool nicely on the high-comp