Plazaman Rb26 Plenum 72Mm Stb Or Greddy And Itb's ? Help Me Decide?

[BLITZ-26]

Hey guys i am in a brain debacle and i have searched and read and re read and blah blah

Short history

Rb26 built motor say 2.7 litre comp ration is 9.1

big blitz turbo setup (around garrett GT35R) for similar comparison

cams will be tomei 270 10.25mm

ports stock chambers cnc'd

So i have a greddy plenum looks the goods and that issue is the throttles, they wont seal to my standards i have applied tomei throttle paste etc and i am just just totally happy

so option is to either at $770 enlarge my stock throttles and have them all referbished to say 48mm or what ever more so to fix the sealing than anything else.

or sell the plenum setup and go a plazaman with a 72mm single throttle

i can see many pros and cons for both but can i get some real word advise and or experiences?

Thankyou

[BLITZ-26]

no one has any useful information ?

[Blackkers]

Well, either will do. Both are a headache though. Have you considered using the factory plenum? It will be fine for a GT35 sized turbo setup.

270 degree cams are probably on the big side duration wise too. have you bought/installed the cams yet?

[BLITZ-26]

I have the greddy plenum already, I have a stock one but I have it so why not use it.

Main issue is I do t know whats going to work better itb's or single throttle

No there zis hks 256 cams in there atm but from looking at where I wanted the setup to go those tomei 270pro cams were the best option to run with to suit the setup motor and comp level

[GTSBoy]

What is the usage model for the car? Drags? Street? Dyno queen?

[34GeeTeeTee]

What is the usage model for the car? Drags? Street? Dyno queen?

Its Ryan, so drag queen for sure

But i am pretty sure he would want and all rounder, drift, drag, circuit and fun

[Piggaz]

Have you looked at the Hypertune duel fuel rail jobbie ?

[GTSBoy]

Drift, drag, circuit and fun implies throttle response desirable. Which implies ITBs.

Having said that, not many RB25s have ITBs and they get used for drift, drag, circuit and fun also. So provided the plenum is not too large and the TB is not too large, then using the Plazmaman and single TB won't likely hurt anything.

If it were me, and I had the Greddy plenum already, I'd spend the money getting the ITBS dolled up and made good.

[BLITZ-26]

street car and drift and circuit will be the main aim.

this is my big issue i have looked and just dont know which was is going to be better to go atm, the throttles are going to cost be 1k to get them where i want, but them ppl are saying if i enlarge them to 48mm i will loose response anyway?

so after i get everyting coated up i am expecting to spend 1k-1300 to get it working ... or sell the greddy and go the plazaman for a bit more.......?? anyone swapped and have some figures to run off ?

[BLITZ-26]

thanks guys for current responses... and i have looked at the hypertune one as well but limited info after changing to it ?

[GTSBoy]

You won't lose response by upgrading the throttles to 48mm. What does happen is that you lose fineness of control at low throttle openings. ie, smaller movements of your foot result in bigger changes to throttle open area and hence flow. makes it a bit more a blunt instrument.

But then, the only reason to upsize the throttles is if they are too small for the amount of air you want to flow. If they are, then go for it. If they aren't then don't.

[Piggaz]

Stock throttle size will shit in a 35R sized turbo without any sweat. Why change at all?

[Mick_o]

Geez you still ain't finished that thing yet mate?! Have you got my old Alcons on yet?

[BLITZ-26]

So to reply to above answers the throttles arnt sealing so its either rebore them to start again (for a better seal ) or fork out the $1200 odd dollars for a new set of throttles

This is why I dont know which way to go both have the same costing but will I loose from going single throttle or gain or will the itb's be far superior is so why do they single tb at all ?

And no I havnt fitted the brakes or finished her yet life and houzes got in the way but I am not giving up this is the last peice before trail fitting of the motor

[GTSBoy]

This is why I dont know which way to go both have the same costing but will I loose from going single throttle or gain or will the itb's be far superior is so why do they single tb at all ?

Single throttle conversions date back to the bad old days of Jap tuning where they couldn't get a reliable MAP signal with big cams and ITBs. So they'd just throw even more of the original 26 gear in the bin and put on a single throttle plenum to make it easy. This was back when they couldn't cope with trying to tune with or upgrade AFMs either!

The practice hangs around.

[BLITZ-26]

Ill be running a map sensor no afms

Everywhere says different conflicting information has anyone done a swap or has something thry can give me a seat of the pants feel to work with ?

Either way is going to cost me bulk coin.... I just w

Dont want to spend it twice sort of speak

[ido09s]

Whats the Plazmaman inlet worth?

The version 2 Hypertune which Piggaz has referred to above is $4500 with rails and single throttle body. A later version is about $3500

Who said your TB's are leaking and whats it doing? I havent seen throttle bodies cause major issues in all the time i worked with them.

Power wise they will shit it in. We make close to 500rwkw on a standard plenum and TB's. I could probably make some more if i switched, but maybe a little later, its got enough in it now

[BLITZ-26]

Its a a discounted rate but rrp is $1900 for the plenum.

I can see light passing through the throttle blades pretty bad and even after applying throttle paste still gaps not as bad but on a few still not great.

I know the stock tb will make the power, but its the cost of having them reco or new ones vs a whole new plenum both equal abour the same money henfe why I am tossing up between the 2

[ido09s]

makes perfect sense to go after market really. You need to factor in some pipe work but its not that expensive

[BLITZ-26]

Pipe work hasnt been fabricated yet so either isnt an issue

I was just reading a loss in response and and toqure etc than with itb's and so much info off the web.

Some real world figures or advise would be amazing