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LaurelPWR

Rb26 oversized itb's... has anyone actually done it?

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love what you're doing and being different, massive props. Love all the mods and the way you are/am/have been going about them...
Just one question, money doesn't seem to be a massive issue so i'm curious why with all the quality of parts you've used in most areas you haven't gone with a nice modern say B/W EFR turbo etc that would almost certainly achieve your desired 'under the curve' results!?!? The HTA definitely has it's positives but in this day and age isn't exactly a modern piece of kit?!?
Edit: some more reading about the HTA turbo's, they seem to be a good thing that I possibly haven't heard too much about being more an Evo turbo upgrade etc...
Keen to see your results...


Honestly man, I really want an efr 7670 as I know for a fact it will do what I want no problems hahah....
BUT, I purchased this turbo like 4 years ago and I’m a stubborn bastard and want to do what no one else did with this turbo first haha...it’s silly, I know....
I have seen one other dyno result almost identical to the 7670 curve seen on rb25’s at almost 550whp peak and it was actually on a built SR22 and was a normal gt3076 with a true twin scroll twin gate setup...to add credit, it was tuned with my tuner (Matty Spry) who is a well known trusted tuner and his dyno considered a heartbreaker..
I figure, if an old gt3076 can do that on a 4 cylinder, the hta should do what I want on the rb25....
We shall see anyways.

Thanks for the props man, I do very much appreciate the understanding.
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Going all out may as well put in a decent computer while at it [emoji6]


Your not an emtron guy are you......
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Never heard of them?
 


If not Emtron, I’m guessing Haltech ?

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Halaltech ah the good old E6GAY  :)  those were the days. Almost as memorable as these below, btw are they still around ?

 

microwreck 1.jpg

microwreck 2.jpg

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Halaltech ah the good old E6GAY  :)  those were the days. Almost as memorable as these below, btw are they still around ?
 
509572635_microwreck1.thumb.jpg.742ca1d7d58d07c11c3c1cafe5ff7650.jpg
209336785_microwreck2.thumb.jpg.b4e90408cfc91c69020b7f8bc9e539ab.jpg



No one uses microtech anymore hahah

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On 4/13/2019 at 1:47 AM, LaurelPWR said:

 

 


Hey man apologies for the late reply....
I had an engineer shop cnc my nismo plenum.
He clamped it the the bed and made a program to suite....he probably still has that program and could do the same for any plenum depending on if garage ito offset the throttle centre slightly like efi hardware did for mine to retain more meat around the shaft seals.

Even if the ito centres are slightly different to mine, I’m sure he could slightly modify the program to cut any centre...

 

 

Thanks so much for the reply mate, really appreciate it.

I never even thought about whether the centres would be offset. I ended up contacted Naprec to get these done and will be sending them the injector plate too, so I'll ask them about the offset centres.

 

I'm based in the UK so I may try to find a machine shop that can do the same for the plenum.

Appreciate the guidance mate, thank you.

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Thanks so much for the reply mate, really appreciate it.
I never even thought about whether the centres would be offset. I ended up contacted Naprec to get these done and will be sending them the injector plate too, so I'll ask them about the offset centres.
 
I'm based in the UK so I may try to find a machine shop that can do the same for the plenum.
Appreciate the guidance mate, thank you.



No problem my guy, are you going 48 or 49mm?
I thought NAPREC and Garage ITO only do the 48mm to allow enough meat around the shaft seals etc...


But awesome anyways mate, good to see others spending money needlessly on cool shit hahahaha [emoji4][emoji4][emoji4]

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Update:

 

Because the 49mm throttles were bored out with offset centres, the flange plate that was made to be welded to the rb25 s1/2 runners also has the same offset centres (obviously to match the throttles) but this has made the miss alignment to the rb25 s1/2 runners a bit worse than it normally is for the cut’n’shut process.....which meant the fabricator was going to have to make up small short runner sections for each runner individually to line up the throttle bores with the runner bores.......

IMG_5268.thumb.jpg.be1cec2e018500d1d358aee64bba47ef.jpg&key=5c8407a436e7cc2cc5cd0063a7ffa434e26c2b746f92fb7908c8ccde6dffee5b

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This all seemed like time wasted time and effort when I had another adapter made for 45mm throttles in the exact same fashion but using Rb25det neo runners.....SO!....we ended up using the neo cut’n’shut I had made in NZ by R.I.P.S over 9 years ago....it’s been sitting collecting dust in a display shelf that whole time so we decided to put it to use rather than making a new adapter....this was originally made for, and will eventually go on my forged rb25/30neo I have waiting in a safe place...

As previously stated, the neo adapter had the extra runner pieces made individually for each runner because the neo has different runners to s1/2 rb25’s, this made the alignment with the throttle flange completely different to begin with before adding the offset bores of the 49mm throttles...funnily enough, the 49mm itb’s lined up slightly better than on the s1/2 runners hahaha...

In these pics you can see the original 45mm alignment issue and remedy pretty clearly;

IMG_5263.thumb.jpg.7f840d4ea16a08730e8512ac526cc946.jpg&key=cfe7303b423d0a0a517d868cae36890585b87c70ec839050492331ab8dac5488

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We bored out the neo adapter flange in each bore by only a few mm on each runner and the throttles open freely...

IMG_5262.thumb.jpg.f0bd38b17e8a8262ceb59b54363118e2.jpg&key=92e98e2af4a8642357351074ca55f3499aee9f0689c041ef953f974312c0d9fc

So then I purchased Bosch 1650cc short injectors with 11mm half height fuel rail adapters because I got talked into using them instead my HKS 1000cc garden hoses.

And, sure enough, they didn’t fit in the neo injector bores because neo uses full height injectors... the electrical clips fowl on everything [emoji849] to get around this, I did away with the female loom connectors completely and then used a dremel to relieve some excess meat around the injector bores and also ground down the outsides of the injector plug fittings and made them fit....12volt Performance wiring specialist will be potting the injector plugs with the new wiring and putting new connectors out away from everything.

I refuse to use 1600cc injectors as they’re known to be no where near as good as the 1650cc’s and my tuner specifically asked me to go the 1650’s if I upgraded.

IMG_5021.thumb.jpg.28fc64dc710991ff3948a1991efe39de.jpg&key=9711bc2bc3fded90f9432f0d5756b8be764be8ad11575846c3b00c8a40b59560

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Then welded some new threaded machined aluminium mounting bosses to the runners for the HKS fuel rail to mount to, because the existing neo top feed fuel rail mounts are also way off...also welded a barbed push lock nipple under each runner for vac signal that will eventually go to the vac manifold that will be mounted in the firewall.

IMG_5041.thumb.jpg.a8adf4675786c45f639e6af2fb84ca64.jpg&key=16d9bdab975c15e376aaade9587cefd5d033b3b49ad4757c803006a6c649307c

 

 

 

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There's a few people running 800 plus HP with stock size ITB's without too much issues.  I wouldn't be worrying too much about it.  I had the same questions when I did my build.

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There's a few people running 800 plus HP with stock size ITB's without too much issues.  I wouldn't be worrying too much about it.  I had the same questions when I did my build.

 

 

There’s cars all over Australia making 800-1000whp+ with 45mm and 48mm throttles....

 

Im not worried about peak numbers my dude.....please read all of my previous posts.

My turbo isn’t capable of anywhere near that power. The most I’ve seen anyone make with a hta3076 is Buschur Racing when he ran 40psi through one at the request of the owner of Forced Performance turbos and he nudged just over 600whp on his 2.3L built evo 8 and his was a .63 TiAl open scroll rear housing.

 

Obviously I won’t be running 40psi but I do plan on running 30psi and I’m using a 1.01ar twin scroll rear but seeing as I’m running mine on a 2.5L 6cyl, I believe I’ll most likely see the turbo max out and I’ll be stoked if it makes 550whp with bulk early and midrange torque and power.

 

My car only made 470whp with my last hks 2835 pro S setup but was fairly responsive with 22psi at 3700rpm and 325whp at 4000rpm and in an s13 with the full works suspension under it and 315/30 NT01’s under the rear, it kept up with 650whp gtr’s no problem.

My main aim is to have same or better response and make as close to 550whp as possible (or more haha) so I have gone above and beyond with all the supporting mods to eliminate anything holding the turbo back [emoji1365]

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I have the Hypertune the NAPREC 49mm throttles with cooling plate ported to match.

Currently N1 Block Carrillo rods 87mm mahle pistons, HKS 2530's, Head is a NAPREC High Response head, Block machined by NAPREC. NISMO surge collector and Step 1 Vcam, 600cc NISMO, ported stock exhaust into some Titanium all the way to the tip , and a CTG TOURQLINE Carbon Fiber drive shaft, and AUTO GALLERY Double Synchro Tranny with modded transfer case  

 

The car from Top Secret was my friends car, BNR34 WANGAN RUNNER, We ran the BAYSHORE Route together  

Video is from inside of the Top Secret 34 and BCNR33 is me, and a flyby clip.

Install is next month

1375E432-BD26-4064-9F27-47827EB32911.jpeg

80EB63C0-4AA0-42E6-B7D0-831D5408C89E.jpeg

Edited by Asphalt Jet
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