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9 hours ago, hypergear said:

ATR43ss1 will do nicely for Rb20dets in T3 .63 rear housing. Last run done was a pretty responsive 243rwkws on pump fuel.

 power.thumb.jpg.0c69e3e39ccddb1ed0be574ce0d41751.jpg

boost.thumb.jpg.9987a738cef3fea99bfc3d75bcbfd3e6.jpg

Thank you, currently getting parts together for a build. anything even a little less power but way more responsive?

Edited by Adz2332

Hi Tao,

Question on the comp housing machining vid. Is it fair to assume that you first chucked up the housing using something bolted to the holes on the back, so you could machine the outside of the inlet snout true to centreline, before turning it around and chucking it up on the snout?

cheers

The Rb20det result above is on 19psi, thats a very good result, depending on supporting mods and engine condition, I usually seeing them making around the 225rwkws with the same turbo. Its already a very small turbo in the range of a G25-550, I don't think I can get it any better in response, I've had one in my R32 gts4, its was very responsive.

With comp housing preliminary machining. The casting had no bolt holes. It was pressed to a chunk for back plating surface machining, so that is the center. It was then flipped to cut the outer of the inlet snout before onto a rotor table to drill and tab bolt holes.

 

  • Like 1
1 hour ago, hypergear said:

With comp housing preliminary machining. The casting had no bolt holes. It was pressed to a chunk for back plating surface machining, so that is the center. It was then flipped to cut the outer of the inlet snout before onto a rotor table to drill and tab bolt holes.

 

Ta. I see. Your "start from scratch" to create the centre was one whole step further back than I imagined.

On 16/01/2023 at 10:42 PM, hypergear said:

ATR43ss1 will do nicely for Rb20dets in T3 .63 rear housing. Last run done was a pretty responsive 243rwkws on pump fuel.

 power.thumb.jpg.0c69e3e39ccddb1ed0be574ce0d41751.jpg

boost.thumb.jpg.9987a738cef3fea99bfc3d75bcbfd3e6.jpg

 

do you know the other mods that went into this result?

Would cams help in anyway etc?

Just now, GTSBoy said:

Gears more than cams perhaps. Bigger cams may make more power, but usually at the expense of the low end, and that is where the hole is on an RB20.

very true! defiantly dont want to shift any power away from the low end. just putting together a list of items i want

On 20/01/2023 at 11:13 AM, Adz2332 said:

 

do you know the other mods that went into this result?

Would cams help in anyway etc?

Engine is standard with ARP Head studs

550cc injectors, Nistune ECU, 600x300x76mm front mount cooler, 3 inches turbo back exhaust, 3 inches metal intake pipe, Split fire coil packs. Thats pretty much it. 

 

  • Like 1
  • 4 weeks later...
Sharing result of a recently built ATR43SS-3 Turbocharger on an Rb25det R32 Skyline.
 
Built details are:
R32 GTST Manual
Rb25det Engine
Cp pistons
Spool rods
Cam tech 264 cams. 0 , 0 on Cams gears, No VCT
Hypergear ATR43SS3 turbocharger in T3 .63 rear
Freedy intake
6 Boost T3 Single entry exhaust manifold
Valve springs
1650cc injector
Haltech ecu
389rwkws @ 20psi, Full boost @ 4000RPM.
Pump 98 / Ron 93 fuel. NO E85 this time.
 
331649005_2126697534194726_5116472742497761640_n.thumb.jpg.09f86193a5cbb597d074439c059549a0.jpg
 
331812784_1206937897375212_6998443198651292934_n.thumb.jpg.261aac1f59dc4c65e26b5a34993c3088.jpg
  • Like 2
  • 2 weeks later...

Moving on to RB30dets while my Rb25det getting a fresh up.

Engine's built specs:
Rb30 Turbo A8 block + S2 25DET Head
OEM Crank
N1 Oil pump w/ billet gears
85 pound valve springs and Ti retainer
CP Forged Pistons
Spool H Beam Rods
ARP mains and head studs
ACL race bearings
VCT oil-feed mod
Franklin engineering head drain

Final result so far is 442rwkws @ 26psi E85 fuel, Result shown Rb30det with stock Rb25det cams VS Rb25det with Kelford 262 cams. I will be dropping in a set of Kelford cams to the Rb30det shortly. For now 300rwkws with 725Mn definitly feels good to drive.

IMG_20230301_191227.thumb.jpg.9ca4bfe6b7cc0d3fe6045a9c212c9b91.jpg
 
-747641043775935446.thumb.jpg.d9c3f8001c8fd856f065ea7c5ba66b4c.jpg
 
4761095188555901129.thumb.jpg.5d2f3e7884daf186fe3483ef30a46aea.jpg
  • Like 5
  • 4 weeks later...

Hi Tao,

Would a RB25 OP6 high flowed to the SS1 (380hp) profile be capable of supporting 250rwkw and still retain good response?

Thanks

35 minutes ago, Sir Lord Van Von Vader'ham said:

Hi Tao,

Would a RB25 OP6 high flowed to the SS1 (380hp) profile be capable of supporting 250rwkw and still retain good response?

Thanks

That would seem like an excessively small profile for an RB25 highflow. That profile is intended for RB20s. The stock RB25 Neo turbo is capable of not much less than what the SS1 profile can do. Specific example; mine (stock) is ~190rwkW at 12 psi (which is somewhere north of 320 engine HP). If I could run that to say, 16-18 psi (without the ceramic wheel becoming chips) then it would want to be up around that sort of number (mid to high 300s engine HP). Thus you wouldn't really need to highflow a Neo turbo to get to that sort of power - just do a steel wheel conversion. But if you're going to do that.....then of course you highflow as well, to get benefit from time and money spent.

What is not clear from Tao's site is the difference between the "RB25DET Neo SS2 450HP" and "R34 GTT OP6 G3 450 HP" profiles. It's fairly obviously "the difference between SS2 and G3", but they produce the same peak power number with one costing more than the other. There are 4 relevant dyno results on Tao's website (Neo highflows) and they all have the same shape, making it look like the different options behave quite similarly. Tao's many many posts in this thread many years ago probably contain the info required to understand, and I would have read it all back then as it happened.....but now I've forgotten and can't be arsed going back to look. Maybe Tao can enlighten us again.

Anyway - one of those is where I think you should be looking. However.....if the G4/SS2PU profiles don't suffer any extra lag compared to the earlier ones, then you'd obviously look to one of these. All of these want the high pressure actuator and don't really want to be run below ~18 psi (according to Tao's site).

Thanks @GTSBoy

Reason i ask is i have a 21U that im about to send off for either a G2 or G3 highflow. Ideally id like around 250kw and as near to factory response as is able.

But ive found a OP6 down here as below, and am wondering if thats the fit im after.

"R34 OP6 turbo with a mild SS1 high as flow from Hypergear. Billet compresser wheel and steel turbine, rated to 380HP. Great for a upgrade over factory RB25 turbos for a mild power upgrade and better reliability/boost than the factory ceramic turbine unit.
Used but only on wasetgate pressure, and has been stripped and rebalanced by Hypergear prior to sale."

Weird. Someone paid Tao to make that? It's a waste of an OP6 housing. It'll struggle to make 250rwkW. That (250rwkW) scales up to well over 400 engine HP, approaching 450HP, depending on the dyno.

For your power target you really do want the G3/SS2/SS2PU/G4. The larger of those only if they maintain response compared to the smaller, which is a question for Tao.

As to whether these highflows give away much response compared to the factory turbo.... the response of the factory turbos is pretty shit anyway. They are really lazy compared to modern wheel designs and housing profiles, even with the benefit of a light ceramic wheel. Remember, they originate in the 1980s. They are old tech. Here's on result on a 21U turbo, G3. Makes more than your target on only 19psi. Makes 9 psi by 3000rpm. Can't really hate that sort of response.

https://hypergearturbos.com/images/dynosheets/hiflows/271rwkw21uhf/power.jpghttps://hypergearturbos.com/images/dynosheets/hiflows/271rwkw21uhf/boost.jpg

 

Whatever you do, do not do a G2. Too tiny for an RB25. Or are you perhaps putting this onto an RB20?

Edited by GTSBoy

So, wrt the question above about whether we're talking RB20 or RB25, I see your thread

and without reading into it too deeply, I shall presume that an HR31 is still an RB20. So....perhaps I shall reverse my objection to the OP6 SS1. It will probably work well for you, although it will still struggle to go near 250rwkW, especially on a 20. But an RB20 in the low 200s rwkW is the fun zone anyway. A 250-260rwkW RB20 is a lightswitch. Nothing nothing nothing nothing nothing alltheboost wheelspin.

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