GT-R R35 Plenum Test Fitment on my VQ37HR
 

Hello from Germany :-)

following a suggestion from a member of this forum I update this first post with the most current information about the status of my project !

as Facebook deletes picture links after a period please visit my album to see all pictures from the very beginning until today.

I will start a list of parts here you need to install the GT-R IM Conversion - this will be updated until the project is finished:

from ChrisUR Germany
1x lower GTR_2_Z34 Manifold Adapter
4x fuel rail holder for stock or aftermarket rails
2x 10mm to 6mm Hose Connectors
Xx Hose to connect to all vaccuum and water ports on the R35 plenum

from Nissan (I can also supply them with the kit)
1x - R35 Intake Manifold Plenum*1
1x - R35 Engine Cover*2
6x 16618EA000 - Z34 O-Ring Injectors
6x 166188J000 - Z34 O-Ring Injectors
1x 1661810V10 - Z34 O-Ring Fuel Pressure Regulator
2x 16175ET80A - R35 Throttle Body Gasket
1x - R35 Manifold to Plenum Gasket
2x - Z34 Head to lower Manifold Gasket

*1 you may also use 3rd party products e.g. GReddy, BoostLogic, etc. (fitment not verified yet)

*2 optional you can buy a carbon fiber cover like this from eBay

Chris

just gauging interest - after doing some test fitment of the GT-R manifold this weekend I think about designing my own lower intake adapter to mount it to the VQ37HR cause GTM seems to need some more time to reveal theirs and as there is no ETA still for months I don't want to wait for them.

Just so you have an idea I will construct and calculate it via CAD and run some virtual dynos with it. The final product will be made out of aluminum, the flanges will be CNC'd using 5-axis and the welding will be done professionally here in Germany by the same company who welds for Airbus.

If there is enough people ready to buy I might produce it as a cast unit (also done in Germany in aircraft quality, no chinese crap), but that depends on how many units I can sell as the initial costs for a cast form are very high.

all testing will be done on my own N/A 370Z first so the primary goal for the construction is adding some HP to the stock naturally aspired engine, but of course it is very clear that this mod will help the FI people the most as this is a FI manifold.

please let me know !

Chris

sunds interesting....

I might be in depens on the results, its hard to say im in for 100% sure because if it was that easy, GTM could have done it loooong time ago.

But props for you for trying :tiphat:

its absolutely not easy and I guess I know why GTM takes so long, because this is in no way a P'n'P solution ! There are a lot of clearance issues and you need to extend a sensor wiring plus replace some hoses with shorter/longer ones plus modify the mounting position for the intake pipes on the throttlebodies etc. - when I'm done with the prototype I will do a full photostory of the installation or maybe a video for ease.

Just to make clear I'm building this for my car definitely because I WANT to do it ;) just wanted to see how many other people are interested.

So not a 1 hour job like with the M370 but hey, this is something completely different not just a stock part mystically modified ;)

Chris

Subscribing

cant see pics, work is probably blocking it, but this looks like a fun build!

If you have solid numbers to back it up. Subscribed.

In for updates

subd' good luck!

Very interesting. If you can make the part at a reasonable cost, and especially if it helps w/ NA, I'd imagine you'd get enough takers. Keep in mind (as I'm sure you're aware) the "extra" connections we have on our stock plastic manifold that need to be dealt with as well, e.g. the brake booster vacuum, the MAP sensor, the PCV vacuum connection(s), etc.

Even if you don't end up mass producing the part and just do a one-off for yourself, at least it will give us some independent data on the utility of the GTR manifold. Thanks for putting this up here :)

Sweeet...very interested!

In for future updates and results :tup:

:eek: :tiphat:

subscribed

I have of course checked at first if all connections for hoses, sensors, etc. are available - and luckily you will miss nothing when the conversion is done, but as written above its not just completely P'n'P - will detail in the installation documentary later !

I cannot tell if it will get HP, even though the lower manifold is not just bolted together with some spare metal pieces but constructed and rendered with the same software manufacturers use and build to meet and exceed OEM quality and fitment.

First calculations show it will be very hard to gain HP on N/A's throughout the whole power band because of the VVEL but I'm positive we can do at least much better than the M370. Maybe you will need a proper retune to take full advantage but this will all be tested from start to end and documented very detailed as soon as the construction and building part has been a success.

I'm glad you like this project, motivates me to bring it to live as soon as possible :tiphat:

Chris

Love seeing people who pursue what they really want, the best of luck Chris!

This is awesome. Best of luck to you.

Awesome build, good to see someone going for it.

Subscribed! Hope it works out and shows some nice gains.

today we found out a very tricky issue: the lower intake manifold is also used to hold down and bolt on the fuel rails. As the GT-R intake needs to sit higher than the stock manifold you cannot simply make the holes for the fuel rail bolts in the upper flange.

Those 4 holes need to be below the other holes used to bolt on the new upper plenum. So this needs to be designed and cnc'd and makes the whole build much more complicate - perhaps another reason why nobody else has done it yet but we will face and master the challenge - will keep you posted !

GTM's retrofit kit also requires custom fuel rails.

The oil cap is a pain as well. The GT-R valve cover has a simple hole for oil, and a tube attached to clear the intake plenum.

I still have the plenum and engine cover for sale for anyone who want it... I'm opting out since the house stuff is more important after getting the turbo kit installed.

my kit will work with the stock fuel rails and the stock oil cap or aftermarket oil cap like the NISMO I have installed on my car.

we try to keep the whole design and installation effort as simple as possible.

Just to make clear this build is not intended as an offense against GTM - I very appreciate their work and the products they offer and will definitely buy their TT kit very soon.

But after following the thread about the GTR manifold retrofit kit for several months without any significant movement I decided to try on my own.

Chris

im very interested in this, so keep me updated. Any guess on what pricing would be?

Interested as well. In for results. Good luck!

Subbed.

wow, this is seriously impressive work, any idea if this will fit the VQ35HR as well or no? I would be willing to test this product for if you make one for the HR and wants see result of it with GTM stage 2 SC

ChrisUR: Is that a NACA duct in the roof of the car? For a driver ventilation system I'm guessing?

no, sorry thats just the key case I left on the roof ;)

Excited to see where this goes.

Are you affiliated with any shop or garage in Germany?

Thanks for going for it... it really is great to see someone doing something new. Even if the results turn out to be not worth it, it's progression in at least one direction!

Good luck!

:excited::yum:

well, what I can say for sure is that this uprade will help everybody who goes or went FI - for the NA guys (like myself currently) it will be a surprise if and how it improves or not.

All I can say is that you have very little room to play cause the position of the plenum is quite pre-defined by the valve covers, hood, oil cap, etc. - so the way we are building it is plus minus a few 0. inches the only possible solution.

We try to make the piping of the lower manifold as big as possible / as close to the GT-R runner diameter, so with FI you will absolutely see gains because of the higher volume and better flow.

The fuel rail issue I worked on today is really a PITA - we will see later on if keeping the stock rails really is the best solution or if it wouldn't be easier to design new fuel rails which also have a larger diameter - which also would help those with bigger injectors, etc.

But for the prototype I will constuct the adapter to use stock rails, so we can do the first test runs asap.

Chris

Sub'd for results. :tup:

(*everyone on forum scoots up to edge of seat)

What type of tuning are you going to do with this setup when it is complete?

Did you dyno your car before this so you have something to base it on?

Doing all of this work to say, "it feels faster" doesn't really do anything.

biting nails in anticipation

what are the potential gains from this?

Really depends on how much volume this adds to the collector.

yes, I made some dyno runs before - stock car - only exhaust (Topspeed catback) - catback + stillen gen3

so I have a good idea if the manifold will gain or loose when we do another dyno with it installed.

the main region I hope to see gains for NA cars with this conversion is that our design combined with the excellent gtr mani has a greatly improved airflow as the runners are now round instead of square and the runners are longer and going independently into the tanks and there are no sharp edges inside the manifold like with the stock one.

I guess that is the reason why the M370 looses power in the high rpm range. My guess would be that they cut the runners inside going into the plenum to enlarge the volume but this sacrifice the airflow.

Haven't seen the M370 in person but after looking at the stock manifold that is about the only thing they really can do as this is a plastic piece and you cannot really enlarge or polish anything like you would do with a cast unit.

Chris