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Hey all,

Due to a Turbo upgrade (Going High-Mount Exhaust Manifold) & my Intercooler being a Blitz Return-Flow, I've realised I will most likely be better/should run a FFP. My first pick is Plazmaman but I've since come across a new (I think) Manifold made by a company called Otaku Garage. They claim to out-flow a genuine GReddy but idk the legitimacy of that.

Anyways, just wondering if anyone has heard of/used these Inlet Manifold's and can let me know what the go is with them. They do look like good quality from what I can see, but I don't want to have to spend money twice cos the product is bad etc.

Car is an RB25 R33 (S1), although would be good to hear back from anyone that has used the Inlet Manifold

Link is here - https://www.otakugarage.com.au/product/otaku-garage-intake-manifold-forward-facing-plenum-rb25det-series-1-2-neo/

Thanks!

Only heard about these a few weeks ago.

Wonder how the CPC or Plazmaman go in comparison.

Alright guys, here is all the testing & results on our manifolds. Head to our online store to grab one: https://www.otakugarage.com.au/shop/intake/

Notable observation, rumour has always been that the GReddy intakemanifolds caused cylinder 6 to lean out. It had always been speculation that perhaps that was incorrect, only because the flange angle direction and distance from the throttle body that i would receive the least amount of air. So far we have completed cylinder balance testing on our intakemanifolds, and the RB25DET GReddy. Before the test we were discussing what our expectation was going to be and we assumed well.

First let's start with the GReddy manifold, as I would have assumed cylinder six was quite the opposite of what people always say. Number six was actually the cylinder that received the least amount of air movement. The cylinder that receive the majority was actually cylinder two followed by cylinder three. This can also be traced to its design where the throttle flange angle points directly on cylinder number two. Unfortunately thesemanifolds are not cast identically between cylinders and the runner lengths are different. I had never realised how much of a deviation that these manifolds had until now. It is actually a very poor design in respect to balancing.

Our manifold did a better job of spreading the balance. The longer equal length CNC design off of the common collector provided for better distribution with a much lower deviated average between the cylinders. However the scenario was the same where the runner at the centre line of the throttle flange is the manifold that receives the most amount of air movement. However on this particular unit number five is the highest number and number one is the lowest. However the deviation to average is minimal in comparison.

Otaku Garage RB25/RB26 Billet CNC Intake Manifold

200 CFM source
Average flow 2950 feet per minute using , Highest (5) 3087 fpm, lowest (1) 2991 fpm

Greddy gasket ported RB25 manifold
200 CFM source
Average flow 2790 feet per minute using , Highest (2) 2988 fpm, lowest (6) 2690 fpm

For the testing process that we used a calibrated 200 CFM electric motor fan and a eGMP rated and calibrated hot wire anemometer. The measurements were taking at each individual runner and recorded at a 10 second average. Each number was recorded three times.

Pressure Tested at 50PSI no leaks or issues at all.

I used to have that style of manifold, but after several years swapped back to the standard lower runners with a MX Performance/SME plenum top (similar to plazmaman).

The shorter runners really kill the torque and also increase the spooling time of the turbo - unless it's a dedicated race car there's no way I'd consider a short runner manifold (like the Otaku Garage one) again.

Do you have any pics/link/info on your plenum?

The manufacturer of my plenum now operates under the name "Sydney Motorsports Engineering", the best way to check them out is on Facebook. I had a quick look and there's a post on 12 Feb 2015 which shows the plenum, or you can check out my build thread (for more pictures) in the projects section on here.

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