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Discussion Starter #1
Folks,
I was thinking of sneaking some different ones under the bonnet, anyone got any thoughts as to whose and whose and what size. HKS produce a selection obviously and i have read that tomei do one that works with the VVT to do interesting things

Any thoughts?

Paul
 

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Discussion Starter #3
Tiggs,
Maybe, I'm open to peoples suggestions and experiences

Paul
 

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I'm all skylined out o the moment so i feel a trip to the toyshop is in order. This brings me back to thinking about manifolds, valves, springs, cams etc, so my research so far...

Early (non VVT) RB25DE cams are 248 duration. RB25DET cams are 240 duration, GTR cams are 240 inlet, 236 exhaust duration.

All the stock VVT and non VVT cams fit straight into the cylinder head without any problems. Some radical aftermarket cams that have high lift require different valve springs, and sometimes head machining to clear the taller lobes. But standard RB Nissan cams all interchange.

The RB25 and RB26 cylinder heads are the same casting, valves, ports, and combustion chambers are identical. There are many minor diferences though. The GTR has mechanical lifters, and different valve springs.

Because the inlet and exhaust manifolds are totally different, some of the studs have been moved so that the nuts are more easily accessible for manufacture/service. Also RB25 uses 10mm head bolts, RB26 uses 12mm head bolts, so the holes in the head are differnt sizes.

So if you are prepared to remove the head, and tap some new holes to shift some studs, the six throttle body setup will fit onto the RB25 head. (not a mod for the faint hearted id have thought)

Anyone know where i can find out information about aftermarket cams profiles in English?

Paul
 

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Regarding the head what about the waterways and oilways - if the studs etc are in different locations then there's a good chance the water and oil use different routes which would surely make such a conversion pretty much impossible.
 

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Discussion Starter #6
Just going on what I've read, I've not seen the parts in the flesh so to speak
 

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only effective if your going above 500hp apparently.
 

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well here in the states most of the cats swapping the rb25det into their s13 & s14s do it for only a few reasons...to say they have skyline power, still attached to the idea if it fits then install it regardless of the weight balance, and more the merrier. hehe.

just my thoughts. i would just assume leave it in a skyline but the thought is tempting as here in the US we dont have skylines, you bastards suck! j/k :)
 
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