Jump to content
HybridZ

exhaust manifold adapter for Rb25/20det


Recommended Posts

Well my HKS cast manifold and To4e do not clear the steering arm and time has come to look for something differnt. I remember seeing an adapter that would allow for the bolt on application of rb26dett manifolds. An offset bolt pattern kind of deal. Heavy plate that would bolt into the stock Rb20/25 exaust side of the head and had a series of studs installed so that the Rb26dett manifolds could be bolted on. I do not remember if they were sold on ebay or Yahoo.jp. Either way I search both and came up empty. Does anybody have one that could be copied? Or know of where I can find one. Much thanks

Link to comment
Share on other sites

I thought about modifing the steering arm similar to FJ280z's application to allow for his FJ to work out. But I would like to keep everything as "bolt on" easy as possible. The car will eventually be my brother-in-law's once I get back to Japan.

 

well if you run two head flange adapters, you would probably have to use two gaskets, as they woud ultimately warp due to heat buildup, and wouldn't seat well.

 

to make it easier just modify the steering arm. it can still be a bolt on affair, and if he intends to keep the car in as good shape as you do, then if it ever breaks or happens to deteriorate, he should then take it to someone who can modify another one or fix the current one that should be modified.

 

my 2.1 canadian pennies.

Link to comment
Share on other sites

  • 1 month later...

Found it. Do not remember it being this expensive. Anyways here is the link. I have found a couple different twin turbo RB25 manifolds. May be easier to just grab one of them. Looks simple enough to duplicate. Not that I am advocating copying someone else's design and research.....But if I had access to the proper tools....It would be done...http://page16.auctions.yahoo.co.jp/jp/auction/u13327494

Link to comment
Share on other sites

The adapter in that link seems to be for the intake, not the exhaust. If you want to run RB26 twin exhaust manifolds, I think all you need to do is change the angle of one of the port flanges. If I remember correctly, the RB20/25 looks like this;

//

 

Where the RB26 looks like this;

///

Or thereabouts. Cut the flange, turn it and reweld it.

 

Brian

Link to comment
Share on other sites

Brian, Sure enough I caught the adapter part in the title and totally overlooked the surge tank portion in front of it. Boy do I feel like an ass for not looking at the pic. Good catch...Still pricey for an adapter but not a bad option for those without access to an aluminium welder. Rb26 surge tanks are cheap on yahoo..

Link to comment
Share on other sites

After taking Brian's thought on rewelding the bolt pattern on the exhaust manifold I am even more motivated to do this. The twin tubular manifolds are fairly inexpensive and easier to weld on than the cast, so first I will have to grab a set of them. I am thinking of adding new ears on them similar to how MMS adds to the rear hubs for the 5 lug pattern. Grab a set of BNR34N1 turbines and then start bolting on things such as downpipes, cold piping and BNR3X front mount. With a forward facing plenum it should be a real unique Rb20. Have to make sure my brother-in-law keeps mailing me the parts. Time to re-pull the RB20 and put it back on the stand. More mods time...Will definitely have to start saving pennies for the injectors and cams now...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...