Making An R34 Gtt Plenum Forward Facing

[jase_c]

Did a search but came up with nothing, so has anyone made their stock 34Gtt plenum forward facing by blanking the original entry point and making a new throttle body mounting plate on the front? Would this actually work or be bad in regards to flow? would like to get rid of the excess pipework across the front of the engine, along then across the engine to the throttle body and the aftermarket FF plenums sound like a P.I.T.A gettting the AAC and everything else connected and working.

Fors and against please guys, and if anyone has done it pictures please.

[WMDC35]

proper forward facing only, no one is talking about the chop job because it's crap

[jangles]

The response is in the standard system.

[jase_c]

proper forward facing only, no one is talking about the chop job because it's crap

reason being?

[GTSBoy]

Because the standard plenum was designed (by some very clever Nissan engineers) to have the air enter from the side and distribute it evenly to all 6 cylinders. That is not a trival exercise, given the shape that the plenum is. You can bet your last buck that there's some rather clever design ideas hiding inside there. It's not just a box.

Chop and change it the way you describe, and despite the people out there who have done it and therefore have a vested interest in defending the results (so they don't look stupid) or are actually ignorant of the results (poor air distribution), what you will inevitably do is wreck the distribution between cylinders. The box was designed to receive air from the side, now it's getting it jammed in from one end, and the box has NONE of the design features that you'd expect to see in an end-fed plenum.

[jase_c]

Ok, that's sort of what i was thinking but wanted confirmation. So my only real choice is to fork out heaps of $$ for a FFp and new throttle body and the dramas that come with fitting one i am guessing.

[wolverine]

You can just leave it.

[discoPumpkin]

dunno what GTS kid just said but look at the GTR, those clever little engineers at Nissan designed the forward facing plenum and that didn't cause "uneven air distribution" as he described.

I agree don't chop it tho, leave it or get a good greddy copy instead

[jase_c]

You can just leave it.

If I leave it I wont ever be able to put a high mount exhaust on.

[jase_c]

dunno what GTS kid just said but look at the GTR, those clever little engineers at Nissan designed the forward facing plenum and that didn't cause "uneven air distribution" as he described.

Seriously, are you just following GTS around trying to flame him? No relavance to GTR plenum, his comment was regarding forward facing the stock Gtt plenum.

[wolverine]

Why not? You can run a cooler pipe Gibson style from the drivers side over the top of the cam covers.

[iruvyouskyrine]

dunno what GTS kid just said but look at the GTR, those clever little engineers at Nissan designed the forward facing plenum and that didn't cause "uneven air distribution" as he described.

I agree don't chop it tho, leave it or get a good greddy copy instead

This is the epitome of retarded. Yes, you are correct, Nissan did design a forward facing plenum and yes it does work. But he is quite obviously talking about the RB25 inlet plenum, as is everybody else because that is what the thread is about. He is talking about the uneven air distribution that is created when you convert a standard RB25 side feed (for lack of a better name) plenum to a forward facing one. He is not talking about a the RB26 plenum which was DESGINED to be forward facing.

Using your logic converting the RB26 plenum to side feed would not have any "uneven air distribution"

Anyway, to OP, yes you are better off leaving the standard inlet plenum as it is or puchasing a greddy/plazmaman etc one. As has been stated a standard converted plenum often leans out cylinder 6. Using a forward facing plenum you get power loss in the low/midrange.

Edited June 16, 2013 by iruvyouskyrine

[wolverine]

Link to pics of Plazmaman cross over pipe

http://www.skylinesaustralia.com/forums/topic/213098-plazmaman-intercooler-kits/#entry6630302

Edited June 16, 2013 by wolverine

[jase_c]

Why not? You can run a cooler pipe Gibson style from the drivers side over the top of the cam covers.

Cheers Wolverine I will google/search Gibson style, is it similar to gangnam style?

Thanks for the input guys.

[jase_c]

Thanks for the link!

[discoPumpkin]

He is not talking about a the RB26 plenum was was DESGINED to be forward facing.

Um if u look at the RB26 plenum, the 1st 3 cylinders get the majority of the air according to GTS boys theory because its forward facing, but this isn't true. All the cylinders do get even airflow despite the forward intake being closest to the 1st 3 cylinders.

Anyway it was a silly idea by OP, i wouldn't mess around with plenums, get an aftermarket one if that's what u wish

[jase_c]

Ah, no, it wasn't a silly idea by me, without asking questions no gets answers and I have now been given ideas as to different directions to take to achieve what I wanted.

[iruvyouskyrine]

Um if u look at the RB26 plenum, the 1st 3 cylinders get the majority of the air according to GTS boys theory because its forward facing, but this isn't true. All the cylinders do get even airflow despite the forward intake being closest to the 1st 3 cylinders.

Anyway it was a silly idea by OP, i wouldn't mess around with plenums, get an aftermarket one if that's what u wish

You are totally missing the point and comparing apples to oranges. It has even air distribution because it was DESIGNED, i repeat, DESIGNED to be forward facing, unlike a modified standard plenum that was DESIGNED to be side-feed and has been modified to be forward facing, hence having uneven air distribution. If you cannot understand this, then i truly feel sorry for you.

Sorry OP, as i said before your only real options are

- Standard plenum

- Std plenum with different crossover piping as shown by Wolverine

- Plazamama/Greddy forward facing plenum

[jase_c]

Thinking option B if that massive stock throttle body allows it

[iruvyouskyrine]

If you already have a NIStune or aftermarket ECU, and are willing to give up traction and cruise control then you can use an RB25DET Series 2 Throttle body, and it will work fine with your car. The standard 25 Throttle body is exactly the same as the one in the post wolverine made, and will allow you to run that crossover piping no worries

Edited June 16, 2013 by iruvyouskyrine