The other custom intake manifold

Like I said in the ITB's project, there's another intake manifold coming up. As the 300zx is still in my driveway, it will serve again as a test and dyno mule.

With the ITB manifold everything was designed for maximum performance explaining the large plenums and custom intercooler pipes. This time the manifold should be easier to fit by making use of more OEM parts, and being much cheaper to fabricate. Modifying the valve covers, fuel rails and ignition coil brackets is still required though. The length of the intake runners is just as long as the ITB manifold, around 39cm which is a good value for what most vg30's are tuned to.

This manifold has smaller plenums that hook up to OEM throttle bodies. The plenum volume is roughly 1,5 liters per side, only slightly larger than stock. However, due to the improved design and more central TB location going any bigger won't really do any good. I milled the TB flanges to 58mm in case it's being tested on a car with enlarged TB's. The TB's will be linked by cables requiring some work to them. I'll have to fit the manifold to the car and check fit and clearance for the lever setup in the final stages.

The TB's sit at a 45 degree angle and face downwards about 10 degrees. By using just a 60mm 45 degree hose it can be directly hooked up to a hard pipe kit. For a 'soft' hose connection, a short 45 degree aluminum bend can be fabricated.

So far it has come to what you see in the pics below. The Border fuel kit fits without problems after I mill the excess material away. The stock fuel rails require new fittings fabricated at the ends, and removal of the original hose fittings. Welding the fuel rails is a bad idea I've learned so they must be hard soldered. This project should go much faster and the modifications to the coils, fuel rails and valve covers are already done. The welds may look a bit odd around the plenum cause of polishing residue.













This manifold is also going to fit with top feeds. The bolts that hold the velocity stacks in place first bolt into the plenum floor and are again secured once the manifold is welded shut. The heat from welding destroys any sealant put around the bolts so after it is fully welded additional nuts are screwed up and sealed against them.

-Rutger

 

Realy, realy like your work.
Very nicely done.
Would look great if smoothed and polished.

 

Awesome work rutger!

 

Like those trumpets! Looks nice

 

Thanks everyone Expect a dyno vid soon

It is possible to smooth the welds but this does make them much weaker. The bends used for the curves at the sides of the plenums are only 1,5mm thick for lesser weight...

The velocity stacks/air horns are identical to the ITB manifold. Made by jenvey they're the best bang for buck, I haven't come across anything better.

 

I finished the other side manifold an now in the process of linking the TB's, and fitting the AAC unit along with a balance tube. Just like the ITB manifold, the weight saving is substantial. I estimate the complete system will remove around 7kg from the engine. The air regulator will be removed as well, useless device. The AAC can easily hook up for the cold start.

it looks so small doesn't it?













I didn't want to remove the timing belt again due to the lower manifold swap, so I made a special fixture to hold the timing belt pulley in place. It braces itself to the underside of the intake pulleys and pushed down in a triangular shape upon the belt pulley. By applying the right amount of pressure on the pulley, it worked so well I could remove and install the bolt that holds the pulley by hand. It didn't move a millimeter.

 

That sure is a handy little tool you have made for the timing belt pulley!

 

Yeah it works great, the problem is that it won't work that well when the OEM stud is still in place. Nissan glued it into the manifold, the only way I've been able to get them out is by welding the nut onto it and than loosen it.

 

awesome work !! how are you going to link those 2 throttle bodies ?

 

Great stuff - I'm a fan of your work

I have a couple of questions I am hoping you can answer - I dont think I missed anything before - so I'm curious about a few things:

1. What is your endstate (what do you want to specifically achieve at the end after doing all this) e.g. build a 700hp motor for example or manufacture and sell parts to others or even just design and build parts for your own motor etc

2. Did you build this ITB to replace the other given its smaller as stated or was there other reasons as well?

3. What do you plan to do with the other ITB - Do you have only the one VGDETT?

4. Have you ever considered manufacturing parts like ITB's for others?


Once again - good job - looks really great and I like that tool you made up for the timing belt as well.

Regards
Jamie

 

always wondered how these came out, ever since my one broke it has been set up like yours with a bolt and I much prefer it this way.

 

Can be done in several ways, I want to try to modify as little as possible to the OEM TB's. I can use 1 TB to hook the throttle cable up to and link it with a wheel on the TB shaft through another cable to the other TB. Another way is by leading the throttle cable to a separately mounted wheel from which 2 cables hook up to the 2 TB's.

 

Hi Jamie,

This car belongs to a friend, I do the testwork on the engine in trade for a timing belt job and other small things the car needed. I have a S13 with a vg30det which is also fitted with Jenvey 45mm TB's. Because that car is being build up from the ground I used the 300zx ITB project as a test mule so I could learn how to properly set the ITB's up. I also use these manifolds as a way of learning about the effects on performance.



I'm currently working out the bumps from the ITB project, everyone makes mistakes the first time so the next time there won't be any. As I do plan to sell the ITB manifold as well as this one as full production items. I estimate I can build this 'R35 style' (as someone called it) manifold setup for around 1200 euro's depending on what the customer requires.

The ITB's themselves are very difficult to replicate. The housings and shafts would have to be CNC'd, plus the costs from making the spring and lever setup. The throttle plates are not round, with angle cut tips and very difficult to produce. In the end, the Jenvey product is cheaper.

 

Starting to get there. Finished the intercooler pipes and the idle hook up welded to the balance pipe. I don't really like the 'bends' within the balance pipe like this but weld elbows this size (25mm) cost 50 euro's for a pair. A bit too much for something not that important. The bends for the intercooler pipes have a short radius. It would have been possible to use a wider radius but this would have looked odd and not improve the airflow.








I'm now in the process of hooking up the 2 TB's, it's a lot more difficult than I had expected. But I will get there, hope by tomorrow.

 

Single pull cable from pedal to a dual pull cable adapter a-la-motorcycle.
Something like this:



Easy!
E

 

Thanks for the idea Tass, I looked into a way to use that splitter but I found no way to use it. This is how I eventually did it. The pics explain how it works. The wheel in the middle has a bronze bearing. The cables were designed as brake cables for bikes, even Jenvey uses simple cables like this so no doubt this will work perfect.

The cruise control lever can be installed later on opposite to the regular throttle cable, because it normally spins freely on the throttle shaft, it needs it's own bearing and spring. Too much works at this point, but worse, the cable kinks as it's not of the right length. I would have to rotate the entire unit. Maybe next time.





The 90 degree steel bends are filled with teflon liner, the were a very tight fit underneath the manifold. The aluminum wheels were all made by hand.

 

Damn I need to start working on my ally welding skills

Looks awesome mate.. Lots of inspiration here and especially with the ITB manifold

 

I love this work. I make no secret of it. Particularly the ITB setup.

I particularly like the look of both systems. Just looks the business.

However, I just cant ignore the slight and niggling little voice in my head that gently and persistently speaks to me highlighting the "why " factor with this twin TB setup which is more or less the same as stock save for significantly shorter inlet runners.
Along the lines of "Why bother climbing mountains? Because they are there"! Kinda thing.

Rutger may be doing this setup purely "Because he can"! Or just wants to- because he can!!!

In no way am i criticising this wondeful bit of ingenuity and fabrication, quite the opposite in that I applaud it loundly, but Im having a little trouble with getting past the "why bother" bit when the stock clobber works just fine and has been optimised to exploit low down torque!!!

Just me!

I look forward to more updates on these two creations!!!!!

E

 

Love your work

Love your work and you must have a passion for it. BUT??? why??

 

Is that Q directed at me or Rutger??

E