# opinion on rb25det



## santa_clause (Sep 10, 2005)

what do u guys think on my future upgrade plans...yall can add up or comment good or bad is all appreciated...thanx

RB25DET UPGRADE PROJECT

vg30dett pistons
garrett gt30 turbine
HKS racing type 2 Bov
tomei poncam 264"
Modified original intake so the throttle goes to the front
Sard 700cc injectors
HKS iridium plugs
hks 1.6mm metal head gaskets
45mm turbonetics wastegate
blitz sus power pod filter
sard large fuel regulator
blitz large intercooler
Full custom aluminum IC piping
bosch mercedes s500 external fuel pump with r33 gtst internal pump
surge tank
OS Giken twin plate clutch
rb20det gearbox
Apexi Power FC

Project will be done on my nissan cefiro a31

all of this is going to be done in Kuala Lumpur Malaysia....so resources is very limited here....but love for the skylines here is very strong...any Horsepower guesses?


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## Joel (Jun 11, 2003)

whats with the pistons? Personally Id go for some aries forged items instead. I would also go for stainless piping. Its a heavier but should be easier to source mandrels so you dont have to use crappy donuts.

Also thats an interesting fuel system. Maybe research it a bit more. I wouldnt think youd need such large injectors and id throw the R33 pump and go for a bosch 040 or 044 or similar.
Youll need new valve springs too

Ceffys rule


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## ABuSD (Jun 28, 2005)

Ok now, thats a pretty good list. But id give these things a miss:

Modified original intake so the throttle goes to the front
This is a waste and what ive been told only makes it worse as the runners werent designed to have it facing front, if ur gonna do it get a Greddy one, but i think the money u spend on that would be better used on something else.

HKS iridium plugs
Just get average ones and replace them more often. U will fowl a few sets if u tune your car a few times.

sard large fuel regulator
Not needed as the 700cc are more than enough to supply fuel with that setup.

bosch mercedes s500 external fuel pump with r33 gtst internal pump
as Joel said i would look into this. go a Walbro or Bosch.

rb20det gearbox
MASSIVE no no, i dont think this box will last very long at all with that power, stick with a good RB25 box and tll last u forever.

now by saving money not getting this stuff u could put it toward better yeilding mods with ur money like cam gars or proper forgies and rods. Hey maybe u could get a bare 3litre block and turn it into an absolute animal!!!

Just my thoughts on the situation if i were doin it. Please note i couldnt be a mechanics @$$HOLE.
All the best! :cheers:


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## santa_clause (Sep 10, 2005)

[wow thanx a lot guys......maybe we malaysians dont know much about skylines....the vg30dett pistons have the size of 87mm and it only cost about 30aussie each...plus these pistons give lower compression effect on the rb25 block....we have been using these pistons on mitsubishi evo 1,2,3 and they produce 400++horses with a 0-400meter time of 11 seconds...the compression was so low yet the engine was very responsive...there was a case where an evo engine with a vg30 pistons snapped its timing belt while driving but there was no damage done to the engine...a miracle...any way what is the cost of aries pistons?...hmmm need to think more on the intake manifold,...coz i have wasted so much power(lag)on intercooler piping if it goes accross the engine down to the intercooler goes back under the intercooler to the right hole.from the turbo goes to right hole of the intercooler...im using a front mount intercooler.any suggestions?


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## ABuSD (Jun 28, 2005)

Good stuff, uve just helped me out also! A friend of mine just destroyed his GSR engine, he just spent $14000 AUD building it up, hes about to buy pistons im gonna tell him about the VG30 ones!!

The way u have piped your intercooler are u using the same method as the stock one, like is it going back through the factory cut intercooler holes? My car came with a blitz kit, which is what i think your talking about? (pic below)









But i dont like the way it uses the existing return method. So i sold it and bought a HKS front mount, which i had to cut a hole in the chasis, but to me its probably the same length of piping. (pic below of my bay now, messy now but not finished  )










If u have very thick piping maybe u should make it smaller? That may help slightly. If its the same size as mine it shouldnt be laggy, maybe u have something else thats causing the lag. 
Tell us specific things u have done to your car we may be able to help.

[EDIT] had another look at your original post, are those mods u have listed in at the moment and its laggy? whats the specs on the turbo? Maybe you need a smaller exhaust housing? Im pretty sure cam gears help a touch with boost response. Id say ud get around the 300-320 rear wheel kilowatts with those mods u have listed. 
But as ive said before please remember i couldnt be a mechanic to save my life but ive had some experience with playing with my engines over the years to give me a little bit of an idea.


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## ABuSD (Jun 28, 2005)

Oh with the figures your chasing your also gonna want a Z32 AFM for a better tuning scope. U should be able to get them cheap outta a 300zx.
Take it when your getting your pistons :thumbup: hehehehe

Oh and please think about that gearbox!!!


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## santa_clause (Sep 10, 2005)

such an enthusiastic forum....that is exactly the intercooler im using,with the exact setup...the piping goes under the intercooler....im thinking of modifying the intercooler...but since its a blitz...im kinda in a dilemma...tha z32afm is a sure thing,the valve springs not really since the tomei poncam 264 does not need performance valve springs...if its 272 than it will need them....one more thing vg30pistons can only be used in 4g63 vr4,evo1-3....1.8gsr im not too sure on it...better check the block clearance...any way how much does cost for them aries pistons 6 pieces of them?


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## ABuSD (Jun 28, 2005)

Thanks for the info bruv, i forgot that the engines smaller  in the GSr's than the evos so it may be a problem.

To be perfectly honest, id get a compression test and leakdown test. If the engines relatively healthy i wouldnt bother with forgies!!!
Can u set it all up without crackin open the bottom end, see how u go, if tuned right i dont see anything u have listed that could harm your engine. See how u go u may never nee forgies, if it blows then ok go for em.
Know what i mean.
Oh dont forget about that box 
All the best!


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## Joel (Jun 11, 2003)

santa_clause said:


> such an enthusiastic forum....


Not really... you just got answers from the only two aussies in here


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## ABuSD (Jun 28, 2005)

HAHAH yeah true!! These forums are really dead though aint they Joel?


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