RB26 intake manifold on RB20

[jmknights93]

Sad thing about this, Otaku know about this issue yet they continue to sell the product.

 

[Ben C34]

8 hours ago, jmknights93 said:

Sad thing about this, Otaku know about this issue yet they continue to sell the product.

 

True. Their r34 to R33 iac adaptor also relies on needing a huge amount of sealant to work due to where one of the bolt lands.

[Jordie Lewis]

On 9/15/2020 at 10:12 AM, jmknights93 said:

Sad thing about this, Otaku know about this issue yet they continue to sell the product.

 

Yea thats the thing that gets me.

I design stuff for production at my day job. There would be no way I would release a part or product that would require that much dicking about to get to work properly. AND sell it as a bolt on solution.

[Jordie Lewis]

Not the update I wanted to make but I feel its important to keep people updated.

As everyone else echoed the Otaku adapter kit is TRASH and will leak no matter what. I've taken every precaution with getting this to work and it leaks no matter what I did. It Achilles heal of this kit is the added points of failure. Stock you have a single leak point where there manifold meets the head. 

With this kit, you create 3 potential leak points.  

I've gone back to my single throttle setup for the time so I can enjoy the car. 

Not to give up on having ITBs, I have also ordered a stock lower plenum to cut and weld on adapters I have designed and had machined at work.  

Ill keep everyone updated as we move forward.

-Jordie

 

[iruvyouskyrine]

Where was it leaking for you in the end mate? I have actually just got the engine running again for the first time in 2 years but yet to have the cooling system under pressure so will see how we go. I do have a coolant pressure sensor on the ECU that i can use to monitor. 

[Jordie Lewis]

It was leaking from where the forward most coolant passage met the block. On the small ear. (shown in the screen cap from your video)

 

 

Edited April 22, 2021 by Jordie Lewis

[iruvyouskyrine]

yeah nice. fk otaku. its such a piece of shit but i have invested so much time and effort into like you that i just really want it to work and run. Hope mine works at least for a while 😅

[Ad's]

I have the exact kit and haven't had issues like this, only issue I had was leaking between the plates as I hadn't sealed the two plates together haha. Though my plates were ordered back in 2017 I believe so not sure if they are a different batch?

Mine are in, running and tuned with almost 1000km so far with zero issues. Strange how others are having trouble. 

[Jordie Lewis]

That's the thing. I don't want to give up on this. I think just need to take a different approach. 

 

Adam, I wish it were that easy

[iruvyouskyrine]

I also purchased mine in 2017 so not sure about that. I believe you are running an RB25 though? so our RB20 half of the adapter is different to the RB25 half which is where the issue is in both of our cases. I still maintain its a shit design.

A dude i know actually designed and built a single piece adapter that just truly bolts on and works. He is a fitter and turner by trade and was able to knock it up himself. It is a true bolt on affair, no extra gaskets or sealants etc. I have been harassing him for years to sell it or at least make another couple but he said it was very difficult and tie consuming to make and can't really be f**ked making another one. 

Maybe with enough interest he may relent?

His is superior as its one piece, and doesnt require cutting and welding of lower runners or any of that rubbish

[Ben C34]

7 hours ago, iruvyouskyrine said:

I also purchased mine in 2017 so not sure about that. I believe you are running an RB25 though? so our RB20 half of the adapter is different to the RB25 half which is where the issue is in both of our cases. I still maintain its a shit design.

A dude i know actually designed and built a single piece adapter that just truly bolts on and works. He is a fitter and turner by trade and was able to knock it up himself. It is a true bolt on affair, no extra gaskets or sealants etc. I have been harassing him for years to sell it or at least make another couple but he said it was very difficult and tie consuming to make and can't really be f**ked making another one. 

Maybe with enough interest he may relent?

His is superior as its one piece, and doesnt require cutting and welding of lower runners or any of that rubbish

I may be able to make them, I haven't looked at the designs to see what is even possible but does seem there is a niche market here.  

[iruvyouskyrine]

every video/post i make on my car i get approximately 6342 americans message me asking how i did it.

I just stopped replying as its actually overwhelming and they dont like it when i use the words 'flamin mongrel of a thing' to describe it 

[iruvyouskyrine]

today i learnt the forum changed c|_|nt t flamin mongerel

[Scottyd 240z]

I cut down a 25 manifold, redirected the runners to suit the itb inlets and welded plates on. I recently purchased a tig ( so don’t expect much and you won’t be disappointed ) I want to do it myself.

[jmknights93]

4 hours ago, Scottyd 240z said:

I cut down a 25 manifold, redirected the runners to suit the itb inlets and welded plates on. I recently purchased a tig ( so don’t expect much and you won’t be disappointed ) I want to do it myself.

That looks sick!

[Jordie Lewis]

On 4/26/2021 at 8:59 PM, iruvyouskyrine said:

I also purchased mine in 2017 so not sure about that. I believe you are running an RB25 though? so our RB20 half of the adapter is different to the RB25 half which is where the issue is in both of our cases. I still maintain its a shit design.

A dude i know actually designed and built a single piece adapter that just truly bolts on and works. He is a fitter and turner by trade and was able to knock it up himself. It is a true bolt on affair, no extra gaskets or sealants etc. I have been harassing him for years to sell it or at least make another couple but he said it was very difficult and tie consuming to make and can't really be f**ked making another one. 

Maybe with enough interest he may relent?

His is superior as its one piece, and doesnt require cutting and welding of lower runners or any of that rubbish

For the record I am Canadian 😆. 

 

I am still waiting on my spare lower manifold to show up then will be cutting and welding adapters on. Do you have any pictures of your friends adapter? Maybe there is an easier way. Like I said before, I'm a mechanical designer by trade and play around with 3D CAD for 8hrs a day.  My current company has full machining capabilities as well so we might be able to get something done!

[iruvyouskyrine]

Ill annoy the f**k out of him again then and see if he relents after about 4 years 🤣

[Jordie Lewis]

Bumping this thread to keep the dream alive.

Finally got cracking on this yesterday. 

Cut the runners off with a bandsaw and machined the runners flat. 

The plan is to retain these two sensor locations. But remove the steel insert, cap the end and thread a nipple in which will go to an aftermarket swirlpot.

The lower coolant runners will have to be cut and modified after seeing where everything mounts up.

Hopped on the computer and measured up the flanges. They have been sent to the waterjet and should be back in a couple days. 

Ill update when the parts get here. 

-Jordie

 

[Dose Pipe Sutututu]

jesus, that's some solid determination!

One would think just running a Plazmaman complete intake manifold/plenum with a DBW throttle would be miles ahead of what that RB26 ITB setup would/could offer with all it's mid century fittings.

[Jordie Lewis]

On 1/5/2022 at 8:41 PM, Dose Pipe Sutututu said:

jesus, that's some solid determination!

One would think just running a Plazmaman complete intake manifold/plenum with a DBW throttle would be miles ahead of what that RB26 ITB setup would/could offer with all it's mid century fittings.

I 100% agree that another intake setup would be better performing but I like the uniqueness it brings to the build. I am not paying someone to do the fabrication and this has become something I want to figure out. Call me stubborn for being sold a "bolt-on" adapter plate.

The waterjet has been down so it was quicker to machine them. I had one of my machinists at work (who is enthusiastic about making car parts) to give me a hand over the weekend.

We started with .75" scrap we had kicking around and profiled out the shape. 

I transferred over the studs from the balance tube for a test fit. There is a slight interference caused by the distance between the top and bottom studs being off by .75mm.

Not a huge deal as the split pins which locate the throttle bodies are on the bottom holes and they fit perfect. I just oversized the top holes on the ITBs to accommodate my stupid error in measurement

You can see the difference in the ITB spacing vs the OEM RB20DET runner spacing here. The plan is to fill it with weld on the inside and weld on the outside as well. I can then smooth out the transition. 

-Jordie