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RB25DET Cylinder Head

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1.5 - 1.8bar

HKS Fcon Pro-V

Stage 3 HKS Cams 275 deg duration.... bigger than standard lift i dont have the figures with me im working til midnight :huh:

not sure on followers i know valves retainers etc have all been replaced with aftermarket parts.

Internals are trust built, forged pistons rods, aftermarket bearings, prepped and balanced crank etc

No dyno graph unfortunately :laugh: had one from when it was still in japan but its been lost.

Rev Limiter is set at 7200rpm as it sits, it wasnt during the tune (im conservative :blush:)

Hope that helps.

OK, you have a lot of money invested in the RB25 cylinder head, to much to throw it away (and use an RB26 cylinder head). My understanding is that you are going to make an adaptor so that you can run the RB26 throttle bodies, as you need the response. The standard RB26 plenum has proven to be very effective up to ~600 bhp. Over that, the common choice is the Nismo plenum, a number of people (Mines, HKS etc) utilise it to good effect for circuit use.

For drag use there are a number of single throttle body plenums that will do the job, but the huge volume of the plenum and the distances (from the inlet valves to the single throttle body) are not good for throttle response.

:laugh: cheers :laugh:

OK, you have a lot of money invested in the RB25 cylinder head, to much to throw it away (and use an RB26 cylinder head). My understanding is that you are going to make an adaptor so that you can run the RB26 throttle bodies, as you need the response. The standard RB26 plenum has proven to be very effective up to ~600 bhp. Over that, the common choice is the Nismo plenum, a number of people (Mines, HKS etc) utilise it to good effect for circuit use.

For drag use there are a number of single throttle body plenums that will do the job, but the huge volume of the plenum and the distances (from the inlet valves to the single throttle body) are not good for throttle response.

:3some: cheers :)

Exactly hence why I went for the ITB setup... the only thing that concerns me if I opt for a Nismo Plenum is that I will still be utilizing standard runners. Should I invest the extra money in getting aftermarket runners to suit the plenum or will standard suffice???

Currently talking to ISL33P about runners/plenum anyway might see if he can get them separately.

Exactly hence why I went for the ITB setup... the only thing that concerns me if I opt for a Nismo Plenum is that I will still be utilizing standard runners. Should I invest the extra money in getting aftermarket runners to suit the plenum or will standard suffice???

Currently talking to ISL33P about runners/plenum anyway might see if he can get them separately.

Standard throttle bodies, with the inlet manifold match ported to the cylinder head = 750 bhp no problems. Way more than you should be using for your purposes.

:3some: cheers :)

Here's a question for ya.

Has anybody ever used an RB26 throttle body setup with 6 throttles and all the shiznet on an RB25.

What are the results? Worth the effort?

Just out of curiosity

Here's a question for ya.

Has anybody ever used an RB26 throttle body setup with 6 throttles and all the shiznet on an RB25.

What are the results? Worth the effort?

Just out of curiosity

This is what I am in the process of doing right now, you require an adaptor and apparently it is very worthwhile.

I have a friend (Rick from Adrenalin Motorsports) that runs a 700hp+ RB25 R33 with a T78 and has a similar setup to what I will be running. He swears by it. (pretty sure most of his stuff is aftermarket though)

Will definitely keep you posted on results, I'll also be looking into selling the adaptors in Australia as the only place you can get them is Japan unless you wanna have them custom made which = $$$$ :( If your interested let me know, the first run will be limited numbers only just to guage interest.

  • 3 weeks later...
500hp at the wheels and full boost by 3500rpm are you sure? Is that possible with such a big turbo?

My stock turbo doesnt make full boost until 3000rpm.

It's possible when you buy quality parts and don't skimp on the important things. The car in question is my old R32 and has ATLEAST $25k spent on the motor. The head alone is a joke, and realistically is really is an overkill for a T67.

The results speak from them self however, huge power, huge turbo and full boost at only 3500 - 3800rpm.

Have fun James, with the power you want to achieve you’ll get there, while all the “race kiddies” are still waiting for full boost at 6000rpm.

Edited by Nismo_Boy
Here's a question for ya.

Has anybody ever used an RB26 throttle body setup with 6 throttles and all the shiznet on an RB25.

What are the results? Worth the effort?

Just out of curiosity

I can't remember where I saw it but I have seen adaptor plates for the RB26 ITBs to bolt onto the RB25 head... from memory they were made by HKS or Nismo or one of the big jap companies...

...tempting hey Bass :huh:

We have been heavily promoting the PLAZMAMAN range of plenums, not purely because they aesthetically look good, but they are backed by years of knowledge, Research and development, and continuous testing.

We're off to DUBAI in the coming weeks and will be taking several of these plenums with us to show their quality, design to the rest of the world.

Its not just about having a HUGE japanese brand name, its about being able to deliver the goods and in this case the performance and effectiveness of upgrading to an aftermarket plenum

We will have our own adaptors in the coming weeks

Thanks

Tarek

RACESPEC

Will do

I speak to quite a few of the workshops and individuals on MSN, and the amount of money invested into cars over there is crazy.

They are Turbonetics crazy over there aswell, and everything HAS to be BRAND NAME, otherwise, they wont use it simply

Tarek

RACESPEC

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