Hypergear Turbochargers and High flow Services Development thread

[hypergear]

25 minutes ago, silviaz said:

I thought that the high flowed rb25det turbos were a lot more responsive than the stock one? Would that mean better low end torque?

Greater amount of energy is required to turn larger wheels up to speed, there for laggier. However bigger wheels are capable of flowing greater amount of air through both housings, let the engine burn more fuel and makes more power that way.   

[silviaz]

1 hour ago, hypergear said:

Greater amount of energy is required to turn larger wheels up to speed, there for laggier. However bigger wheels are capable of flowing greater amount of air through both housings, let the engine burn more fuel and makes more power that way.   

That makes sense.

[SeanR32GtSt]

Got my 34 gtt dyno tuned with the G3 turbo (the one rated for 450). Dyno reads 8% lower than actual numbers. Car made 309 whp on 14 psi. Stock manifolds. 650 injectors. Walbro pump. Mac valve boost controller. Haltech ecu. 

[Dose Pipe Sutututu]

On 23/12/2024 at 12:29 PM, SeanR32GtSt said:

Got my 34 gtt dyno tuned with the G3 turbo (the one rated for 450). Dyno reads 8% lower than actual numbers. Car made 309 whp on 14 psi. Stock manifolds. 650 injectors. Walbro pump. Mac valve boost controller. Haltech ecu. 

Is your VCT working?

That curve looks like your VCT isn't engaging 

[SeanR32GtSt]

2 hours ago, Dose Pipe Sutututu said:

Is your VCT working?

That curve looks like your VCT isn't engaging 

That’s a good question. I’m not sure. It feels laggy for sure. How can I diagnose that?

[Dose Pipe Sutututu]

1 hour ago, SeanR32GtSt said:

That’s a good question. I’m not sure. It feels laggy for sure. How can I diagnose that?

Unplug it and see if the car makes a difference 

[hypergear]

Might also needs a stronger actuator with the right preloading. With older 2019 built bush G3 units, BB upgrade or 21U housing down size makes a pretty decent gain in response as well. 

[SeanR32GtSt]

31 minutes ago, hypergear said:

Might also needs a stronger actuator with the right preloading. With older 2019 built bush G3 units, BB upgrade or 21U housing down size makes a pretty decent gain in response as well. 

I know this one’s the BB one. My tuner did make mention about the actuator. I am curious about the VCT as well

[hypergear]

Updating results from our ATR43SS-1 turbo in T3 .63, OEM bolt dump pattern. Not a big number but pretty sweet for a stock Rb20det. Car's managed to pull 220rwkws at 20psi, perfect boost control internally gated with EBC and excellent mid top end power band as they usually skydive after 5.5K. Usual bolt on supporting mods and inlet plenum and factory location exhaust manifold. Pump 98 fuel was used (Ron 93). 

 

 

[hypergear]

                     

I’m doing some side developments on SR20det S13 engines, its one my hobby cars used it to compare flow capacity of some smaller size wheels. SR20det is one of another JDM legendary engines I'm sure there are plenty of SR enthusiasts on this forum, I will share results some common turbo configurations here.

a quick run down of what the car is:
Wide body 180sx Type X with black top engine (blue). It has:
Stock bottom end
Haltech 1500 ECU
5-0 motorsports trigger kit
Kelford SR20DET Beehive Spring with Titanium Retainers
Kelford Cams SR20DET S13 188-B 268/272 Cams
G25-660 Turbocharger in T2 .64 rear housing internally gated
ARP Head studs
MLS head gasket
1000CC ID injectors
Walbro 450L Fuel pump
Front mount cooler kit
JJR’s 3 inches turbo back exhaust (its too short for the 180sx it had to be extended)
Pump 98 fuel
Hub Dyno tune

So far made 270rwkws at 22psi full boost by 4500RPM. Engine is very knock limited hence a pretty bad looking top end. From previous experiences it seems like SR20dets are happier with bigger size turbine, some thing like a GT30 would make way better top end, but on same time response is lost. It won't be a problem with S15 VCT engines. I'll be testing alternative turbine housing, turbine wheel and possibly dump pipe options for extra flow to resolve the problem and of course E85 would resolve all the issues.  

  

 

  

 

[Dose Pipe Sutututu]

5 hours ago, hypergear said:

From previous experiences it seems like SR20dets are happier with bigger size turbine, some thing like a GT30 would make way better top end, but on same time response is lost

Here's one I help build and tuned a decade ago, Garrett  GTX3071R Gen 1, T3 twin scroll 0.83 rear housing. Went from larger 272 cams down to smaller Tomei Poncams to help with the low end. S13 non VCT motor. Car was purpose built for the track, hence low down was the focus.

Note the actual dyno chart shows lower boost, however the EBC and boost gauge showed 1.9Bar

(Ignore the torque, I was young and didn't know how to set derived torque)

 

[Watermouse]

On 14/11/2024 at 8:49 PM, hypergear said:

We've been working on all sort of different types of turbos with majority of work load shifting towards Euros in the last few years. The Skylines are more of a hobbie then a daily, at least its like that in Australia. I will update photos from some of our latest RB jobs. Whats recent is G30 turbine housing externally gated plumb back kit using T3 .83 geninue housing. It can be made to suit G35, G40 and G42 units. External gate optional. 

 

That’s a beautiful setup Tao,

Have u done any development with the new Turbosmart 40mm electronic straight gate, especially in this G30 configuration?

[hypergear]

Not yet. The current 45mm Gen 4 gate is already a tight fit. I don't think the EWG 40mm is going to squeeze in that spacing. 

[Watermouse]

Ahh ok, thanks again for your valued insight Tao

[Watermouse]

Another question sorry,

what stainless do u use in the turbo external WG plumb back piping? Is it 321, 316 or 304?

[hypergear]

Sharing results from recent Liberty Walk R35 GTR, since they are still considered as somesort of a V36 Skyline. We do them turbos too. This are high flowed SS-1 models with ball bearing conversion done. 

Car have managed to pull 485awkws @ 20Psi so far pushing limitations of factory built engine. The build list for R35 GTR enthusiasts as follow :
HyperGear high flowed stock turbos in SS1 (G25-660 specs)
Custom titanium intake pipes.
Vspec performance titanium front pipes.
Vspec performance 4" titanium exhaust.
Upgrade fuel pumps.
1200cc injectors.
Ignition coilpacks
Hks intake plenum.
Hks intercooler piping.
Greddy intercooler.
Greddy bovs.
Top-secret coolant reservoir.
Emtron ecu.
Straight E85.
Built gear box.

 

Edited February 7 by hypergear

[hypergear]

Result of another R35GTR build. Similar specs as above except this is running our bigger size SS-2 profile option. Made similar power except this car runs on Pump 98 fuel. Build specs are:

Nissan R35 GTR 2015 model stock engine and box.
ETS street intercooler
boost logi intercooler piping with tial bov, boost logi turbo inlet pipe
ID 1050 injector
DW 300C fuel pump
Decatted oem down pipe and y pipe& HKS exaust
3inch intake pipe
Upgraded actautors
HyperGear SS-2 high flow option
Final result is 639whp / 477wkws hubs, Ron 93 / P98 fuel at 20psi.

 

[hypergear]

Updating results following our SR20det project. Data collected form improves future turbocharger making and high flowing services. So far differences between G and GT series turbine wheels, we are in the process of making a new turbine, the aim is for better mid top range flow without gain too much lag. 

Result is back to back comparison of G25-660 and GTX2867 spec turbochargers on the same car, nothing changed apart from turbocharger. Both tuned to knock limit from pump 98 fuel (US Ron93). GTX2867 was about 400RPM more responsive making 255rwkws while G25-660 made 17 extra Kws with wider spread of torque after 4500RPM finishing off at 272rwkws.

 

[jdmser]

On 1/16/2025 at 6:43 PM, hypergear said:

Updating results from our ATR43SS-1 turbo in T3 .63, OEM bolt dump pattern. Not a big number but pretty sweet for a stock Rb20det. Car's managed to pull 220rwkws at 20psi, perfect boost control internally gated with EBC and excellent mid top end power band as they usually skydive after 5.5K. Usual bolt on supporting mods and inlet plenum and factory location exhaust manifold. Pump 98 fuel was used (Ron 93). 

 

 

How does this compare to the internally gated g25-550 in terms of power production at same psi and spool

[hypergear]

14 hours ago, jdmser said:

How does this compare to the internally gated g25-550 in terms of power production at same psi and spool

Consider it as a G25-550 in a T3 .63 rear housing. So performance wise will be very similar.