Rb26 Inlet Manifold And Adaptation To Rb25 Heads .

[FineLine]

with the sort of dollars being mentioned here..

can someone confirm what it would actually cost to buy an RB26 head and bolt it to your rb25 bottom end?

then how much could you sell your RB25 head for?

wouldn't that be a better option?

you get a better flowing head (stock for stock), solid lifters, more aggressive cams (?).

the goodness of FFP and 6 throttles.

I guess if you already have a head with work done to it you'd bother with all this, but even still.. from a dollars point of view, wouldn't it be cheaper to go the rb26 head route?

quite possibly mate but dont forget you would still be up for a 26 plenum and t/b combo plus a new exhaust manifold as well.

Given that a new greddy 25 plenum and o/s t/b will set you back around 12/1300 it really doesnt make the 26 adaptor plate look all bad.

[dano4127]

quite possibly mate but dont forget you would still be up for a 26 plenum and t/b combo plus a new exhaust manifold as well.

Given that a new greddy 25 plenum and o/s t/b will set you back around 12/1300 it really doesnt make the 26 adaptor plate look all bad.

When you put it like that, It sounds quite reasonably priced!

[TTT]

I was working off these figures - correct me if they are off

rb26dett head (fully dressed) = $2K

Sell rb25det head fully dressed - $1K

$1k out of pocket.

add $500 for whatever needs to be done to make the 26 head fit on 25 bottom and misc plugs, vacuum bits etc.

$1500

going from what is said here.

$750 for adapter

$350 for rb26 plenum

$350 for individual throttles

about $1500 in total for parts.

are my numbers wrong?

edit - ahh yes.. exhaust manifold.... there goes the comparison..

Edited February 29, 2008 by GTST

[dano4127]

Doubt you would get $1000 for a fully dressed 25 head people were laughing at me when I was asking $600? Seems they usually got for about $500 I let mine go for $480 last week

I think you should be able to pick up a 26Plenum and ITBS for ~$400 seen them go for between $200 and $600

Exhaust mani wouldn't really be a worry for many as your probably not going to be running a stock one at this level of $$$ anyway.

[Rhinorebel]

The only reason I am doing this at all is because I got a great deal on the Plenum and Throttle bodies. If they had been more expensive I would have just got an aftermarket Rb25 plenum and done it that way.

Andy, my turbo is a teeny-tiny GT28/71

[Bunta]

The only reason I am doing this at all is because I got a great deal on the Plenum and Throttle bodies. If they had been more expensive I would have just got an aftermarket Rb25 plenum and done it that way.

Andy, my turbo is a teeny-tiny GT28/71

thought so thanks for making me feel i am not going insane...i dont get to feel it too often ha ha

[The Mafia]

I am after an RB26 intalke setup...where do you see them for that price. The places im looking you can get the plenum for that monye, but the throttle bodies all demand the same money again....and then most of the times the plenum doesnt have all the hoses etc on its underside. If you know of a setup for sale at that price i want it !

Regarding your friends manifold. How is it lasting on the engine and power etc etc. Its interesting. Most multi throttle setups feed a common plenum for all the cylidners to feed from. About the only exception is when there is a throttle per cylinder. So using a single TB per 3 cylinders is interesting. But how does he ensure that the flow out of the intercooler is divided equally into each throttle body and to subsequent cylinders????

He's put dividers inside the manifold to evening distribute the air flow. Not a bad job, but I guess a flow bench will only tell.

Not every body has access to mates that work for cartons of piss Mafia. This project has been undertaken utilising the services of proffessional and trade people from go to whoa. They dont work for peanuts or grog and even if they did they would be raving alcoholics after the first dozen or so of these "carton" payments you allude to.

The project was started because there was enough interest shown by members (including me) to warrant investing the r and d dollars in to making it a viable proposition.

If you have access to sites that sell the plates for around the 3/350 mark then please post them up. Failing that get a ute and head for the bottle o and load up with Mckay currency and start making them.

I would also like access to the 26 plenum and throttle bodys you mentioned. I cant find them anywhere for that price.

You can try and impress us all you like with your knowledge and thats fine but until you have actually undertaken the project and seen it through to the end you truly have no idea of the time and costs involved in presenting the finished product.

Another aspect of this deal that obviously escapes you is the business aspect of this venture. As I said,Not everybody works on the carton of piss contra currency system and i doubt these people are a benovolent society. If they wish to market the product through the regular channels of wholesaler to retailer themselves then the price has to reflect enough room to justify the retailers purchasing said product at a price that leaves them a margin. They arent there for practice either.

At the end of the day the buying public will determine wether it succeeds or fails, I hope it succeeds.

Fwiw I actually have the copy of HPI with the blitz adaptor plae advertised. its reccomended retail was higher than what these guys are offerring it for.

Finally, a decent reply from you. Thank you.

There is bugger all R&D in this, its just a well thought out adapter plate. We comtemplated doing up a heap and trying to sell them but as I said, I got slack and we never finished the project. ANd in the end, it would have been easier for the boily to just weld the runners to the throttle bodies and bolt them straight onto the head. Much quicker, as it was only really intended for a once off job. These guys are also busy, and only got busier as the mining boom got heavier. And My Boilermaker mate sold his skyline, got married, and bought a house. That slowed things down to almost nothing. Life > Work

About the RB26 intake manifold - I called a workshop and asked if they had any RB26 manifolds and TBs spare and they said no. Then a week later, the called me back and sold me one for $300 delivered. I Had it for 6 months and things slowed down, and I went the cheap route and got a Greddy copy for $250. resold the RB26 one for more than what I paid..

Edited February 29, 2008 by The Mafia

[Mr Jollwah]

That twin throttle RB25 manifold is quite like something that i've been pondering for a while.

How much was throttle response and air flow distribution improved?

Rather than a common plenum I was thinking that seperate plenums with balance pipe with vac box inc. AAC vavle would be better.

I see that he's using twin throttle cables Any info?

[shanef]

Hi shanef , I had wondered if there was more to the adapter plates than just profile cut/machined holes .

Just to press the point - will the injectors in a GTR manifold with these plates still spray down the inlet ports or will they now be aimed at the inlet ports floors ? I guess the only way to really know would be to bolt it all up on a bare head maybe with the inner section of the 26 manifold .

Doughboy sold me an RB26 top end and inlet system a couple of years ago and luckily for me its R33 RB26 so the TPS and possibly the IAC could be electrically compatible , PFC ECU in my case .

Cheers A .

i got half way through bolting it all to a 25 head, but i ran out of time. Hopefully i can get back out to the workshop this arvo after work.

However i did find that you cannot run the rb26 aac as it fouls on the rb25 oil filter/oil cooler block. Adapters will be made to run the rb25 one (hopefully get out to the machinist today)

Also the 2 end studs in the head need to be removed to make way for a recessed bolt.

[The Mafia]

nice work with the pictures.

[FineLine]

He's put dividers inside the manifold to evening distribute the air flow. Not a bad job, but I guess a flow bench will only tell.

Finally, a decent reply from you. Thank you.

There is bugger all R&D in this, its just a well thought out adapter plate. We comtemplated doing up a heap and trying to sell them but as I said, I got slack and we never finished the project. ANd in the end, it would have been easier for the boily to just weld the runners to the throttle bodies and bolt them straight onto the head. Much quicker, as it was only really intended for a once off job. These guys are also busy, and only got busier as the mining boom got heavier. And My Boilermaker mate sold his skyline, got married, and bought a house. That slowed things down to almost nothing. Life > Work

About the RB26 intake manifold - I called a workshop and asked if they had any RB26 manifolds and TBs spare and they said no. Then a week later, the called me back and sold me one for $300 delivered. I Had it for 6 months and things slowed down, and I went the cheap route and got a Greddy copy for $250. resold the RB26 one for more than what I paid..

You continue to dig your hole deeper every time you post. The r and d is not finished yet and will continue until this is a working system on a running car.

Your workforce has evaporated for one reason or another, Its too hard so you took the easy option. You got your 26 t/b on the cheap and then sold it for closer to its true value.

Quit while you're behind mafia. In this instance you are clueless.

[The Mafia]

You continue to dig your hole deeper every time you post. The r and d is not finished yet and will continue until this is a working system on a running car.

Your workforce has evaporated for one reason or another, Its too hard so you took the easy option. You got your 26 t/b on the cheap and then sold it for closer to its true value.

Quit while you're behind mafia. In this instance you are clueless.

And back to your retarded form. I really don't know what the go is with your useless attitude. You actually look more stupid everytime you post.

1. I am not digging a hole. I had the gear.

2. We had the adapter drawn up.

3. We had a chat to the laser cutter guy.

4. There is no f*cking R&D in this. Its just an adapter plate that needs with a bit of careful thinking. The way my boilermaker friend described the bolting together back then is EXACTLY shown in these pictures. We're not developing an new type of bomb, or new type of aeroplane here.

5. Someone that owned a 4 TB setup in a GTiR convinced me that this kind of TB setup was no good for high boost applications. Another reason why I bailed. I got more from selling the RB26 setup and managed to secure a greddy copy. The money saved can go towards a Q45 TB.

6. My workforce hasn't dried up, Its still there, we do quite a few other things.

7. You're clueless, a fool, and have no interesting or intelligent input what so ever, just useless slander, because someone has already thought about it.

I was never behind, or ahead, its just a f*cking adapter plate. If things like this are too trivial for you and require "years of R&D" then enjoy your simple life of never trying something yourself. Anything is easy when you put a few heads together.

Your attitude stinks, and you have a problem.

Edited February 29, 2008 by The Mafia

[Duncan]

jesus mafia, let this go. You were not able to make them on a commerical basis. These guys are and the price is 750. Yes I am sure you can make one for yourself on the cheap.

[FineLine]

And back to your retarded form. I really don't know what the go is with your useless attitude. You actually look more stupid everytime you post.

1. I am not digging a hole. I had the gear.

2. We had the adapter drawn up.

3. We had a chat to the laser cutter guy.

4. There is no f*cking R&D in this. Its just an adapter plate that needs with a bit of careful thinking. The way my boilermaker friend described the bolting together back then is EXACTLY shown in these pictures. We're not developing an new type of bomb, or new type of aeroplane here.

5. Someone that owned a 4 TB setup in a GTiR convinced me that this kind of TB setup was no good for high boost applications. Another reason why I bailed. I got more from selling the RB26 setup and managed to secure a greddy copy. The money saved can go towards a Q45 TB.

6. My workforce hasn't dried up, Its still there, we do quite a few other things.

7. You're clueless, a fool, and have no interesting or intelligent input what so ever, just useless slander, because someone has already thought about it.

I was never behind, or ahead, its just a f*cking adapter plate. If things like this are too trivial for you and require "years of R&D" then enjoy your simple life of never trying something yourself. Anything is easy when you put a few heads together.

Your attitude stinks, and you have a problem.

ROFL

[GTRgeoff]

Shane

for the benefit of everyone, my immediate step would be to remove the filter/cooler block and make Dave get a relocator and cooler.

The relocator will screw straight onto the block just as onto the cooler setup IIRC.

When I conducted the fairly simple process of designing the lightest and most foolproof HICAS bar I went through several iterations of design, a batch of 10 that had 2 fail (not catastrophically due to the underlying design principle that compensated for that specifically) through a fabrication error so all 10 were recalled and immediately replaced and finally, after a ludicrous number of hours of hand fabrication and modification I had the right design. NC machined components, the perfect materials for the job, only 700grams in weight and idiot proof to fabricate. For all that, it just isn't worth it to produce any more due to cheaper products using much cheaper materials (that are fine from what I have inspected from a functional perspective). The first prototype is still in my racecar so surely that was good enough? Not for me. Giants 32GTR still has an early robust design without a problem but still I moved on looking for a better product. The end product had to look good for the consumer and be safe enough for someone close to me to be at zero risk if using it as well as be uber light for a commercial enterprise that was interested. I even had Autobarns' national supply manager ask for a regular supply of product.

Yes, you can do things by the seat of the pants, but that will almost never be a commercially viable solution and customers will demand more. I, probably more than anyone here can understand what Shane is facing but I think for limited return on investment.

[shanef]

Shane

for the benefit of everyone, my immediate step would be to remove the filter/cooler block and make Dave get a relocator and cooler.

The relocator will screw straight onto the block just as onto the cooler setup IIRC.

like everything, yes and no lol.

the way ur saying would work perfectly, but then we would have to supply the different hoses to block up the water pipes that are now obsolete, and then supply an oil cooler/adapter setup - both of which are added cost

the other way is to get these adapters made which bolt the 25 aac onto the 26 plenum and its done.

re daves car, speaking with mick yesterday, he is going to just remove the aac control all together, as the haltec has that function built into the ecu to control the cold running.

i'm off to the machnist, see ya in 3 hrs

[discopotato03]

Hi all , I was talking to someone about this topic yesterday and there may be a few gremlins that I didn't know about anyway .

Its a little O/T for a thread I started but not unrelated to the RB26's six throttle inlet manifold .

As I mentioned in the beginning - the burning question is to compare the conversion with just fitting the complete RB26 head and its inlet manifold assembly .

Cost is generally greater with RB26 engine components but what are you actually paying for head wise ?

Mentioned to me was better porting/exhaust valves/non hydraulic buckets/cams/valve springs/water cooling jackets .

The downside compared to the 33 25DET head is the lack of VCT and slightly different exhaust manifold stud pattern .

The more I think about it the more issues the 26 lid solves but it comes at a price .

I suppose in the end the ultimate 33 25DET would run the complete RB26 top end with some sort of adaptation to a single turbo exhaust manifold - if you didn't want the added complication of twin turbos factory style .

BTW I'm not knocking those who are going ahead with the 25/26 adapter plates its just that once you achieve it will the lack of the 26's cooling jackets valve train etc paint you into an avoidable corner and at considerable cost ?

What's everyone think ? Cheers A .

[Cjmartz2k]

You can keep the RB26 aac valve, but you have to change to the RB26 oil cooler set up. Also, the RB26 plenum will not clear the VVT solenoid on the side of the motor. It hits a coolant passage, so you either have to do non-vvt cams, or do some grinding/aluminium welding.

Throttle response is pretty cool though

[The Mafia]

I took a R32 GTR for a tune last night, the throttle response is fantastic. Absolutely nothing like the Single TB designs.

[Kaido_RR]

I just through i would let everyone know that i have found a source in japan who can supply the kit

the kit includes

Changing Flange

Hexagon Bolts

AAC Valve (for RB25) fitting Flange

It will use normal gaskets. (guess this means i can use nissan gaskets)

there is a 1week production time from placing order. price looks to be under $1000 delivered.

So shanef kit is very well price at around $700