Current best dyno power figure:
218.7 kw @ rear wheels
Current best quarter mile:

15.0 seconds @ 98mph

 

 

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Now that I have have almost maximised the potential of the standard T25G, it is time to move to a bigger turbo. I was going to get a ball bearing T28 from a JDM model S15 Silvia, but the sale fell through. This turbo came up for sale on the same day, and I purchased iot very quickly.

 

Specification

Details for this turbo are hard to find, as little testing has been done on them in Australia. I will conmsider myself to be the pioneer of some sorts by trying this turbo on a SR20DET.

 

 

 

Research

Not a lot is available on the net on this turbo or its variations, but I can work out a fair bit from translated Japanese pages. I do know that in T25 flange ther is only one model of AX53B60 that exists, the P25 trim. Other models include the P18, which seems to be a popular bolt on turbo for naturally aspiratred Hondas, and is rated to 300ps.

The followings links are to pages that contain information about the turbo.

http://babelfish.altavista.com/babelfish/urltrurl?lp=ja_en&url=http%3A%2F%2Fwww.k-style.gr.jp%2Fdemoca%2F..%2Fnewpage9.htm

http://babelfish.altavista.com/babelfish/tr?url=http%3A%2F%2Fwww.axia-sports.com%2Faltezza.html&lp=jaen&intl=1&tlb=1

http://babelfish.altavista.com/babelfish/tr?url=http%3A%2F%2Fwww.geocities.jp%2Fdraghistory%2Fapextabin.html&lp=jaen&intl=1&tlb=1

http://www.kendo-tuning.nl/01c1bd9412110cd07/000000944a0943701/01c1bd9412111cd0f/000000944a095a514.htm

The follwing is taken from Takakaira, which won't allow me to link to them so I chopped up my own copy of the page:

 

FUNCTION

  • The Apexi turbo kit is a complete bolt-on to the factory turbo kit location & fittings.
  • All items are specially made in-house by Apexi inorder to optimize & maximize turbine performance, (except for the turbo center section).
  • The Apexi logo is casted onto the aluminium compressor housing depicting that the unit is a genuine Apexi part.
  • Apexi managed to acheived the zero clearance for air flow due to its unique airick system to smoothen the airflow in the turbo housings.
  • All turbo models utilizes the reinforced spring actuator.
  • Apexi's turbo units adopts the reliable & proven IHI's water cooled ball bearing turbine.
  • For ease of installation, and to ensure enhanced durability of the turbo kit, all Apexi kits includes stainless steel mesh hoses.

By creating a new airick for the compressor housing during manufacturing, the tip clearance between the impeller and the housing reduces to a nominal value of 0.06 mm (almost zero!). This improves the compressor efficiency in the entire area by approximately 5% - 6%. In addition, this system reduces compressor exit temperatures by a theorectical value of 10 degrees Celsius. In actual driving conditions, the compressor exit temperatures could be reduced by as much as 20 degrees Celsius when the engine is performing at maximum power. Due to this system, an improvement in peak power is realized, and even boost pressures could be increased as a result of improved turbo performance efficiency. The latter also improves the torque output of the engine.

All Apexi models include a built in reinforced spring actuator.

Turbo kits includes a spring actuator as a standard equipment to tweak the supercharging pressure. For Apexi, it adopts a tie rod like strengthen spring for such tuning adjustments.
 

 

A:
Apexi turbine with the new airick system provides a tip clearance of almost zero, ensuring that there is no compressed air backlash.
B:
On turbine kits from other manufacturers, there is a tip clearance thats creates a compressed air back lash which causes air turbulence. This air turbulence creates friction, and as a result, created a hot spot in the turbine housing due to increase frictional temperatures.

TURBINE PERFORMANCE CHART of Car Model Silvia S14

    1:APEX 53B60/70 TURBINE, GT Camshaft (250dgree) -Boost 1.2kg/cm
    2:APEX 53B60/70 TURBINE, Standard Camshaft -Boost 1.1kg/cm
    3:Other Maker same spec turbine, Standard Camshaft - Boost 1.1kg/cm
    4:S14 Standard turbine, Standard camshaft -Boost 1.1kg/cm
    5:S14 Standard turbine, Standard camshaft -Normal Boost

 

 
AX TURBINE
MODEL
Type

Control Unit

Output

(PS)

 Compressor Wheel Compressor Housing Turbine Wheel Exhaust Housing Actuator
Trim

Inlet Diameter (mm)

Outer Diameter (mm)

Inlet Diameter (mm)

Outlet Diameter (mm)

A/R (mm)

 Trim

Outer Diameter (mm)

Outlet Diameter (mm)

 Inlet Flange Outlet Flange

A/R (mm)

 Material

Bypass PorteDiameter (mm)

 Type

Pressure Setting (mmHg)
AX53B60 Standard Ball Bearing Actuator 340 57 46 60 60 50 19 82 53 48 T25 SR20 Exclusively use S14） 22 High Silicon 26 Standard 570
25
13.4 T25 RB26 Exclusively use 18 26 570
21
20 EJ20 exclusive use EJ20 Exclusively use 20 24 570
Racing 13.4 T25 RB26 Exclusively use 18 Nickel-Chromium Steel 27 Strengthening 750
21
AX53B70 Standard Ball Bearing Actuator 380 57 53 70 60 50 19 82 53 48 T25 SR20 Exclusively use (S14) 22 High Silicon 26 Standard 570
25
13.4 T25 RB26 Exclusively use 21 26 570
19 T3 RB20/25 Exclusively use 22 24 570
25
19 EJ20 Exclusively Use EJ20 Exclusively use 18 24 570
Racing 19 T25 SR20 exclusive use (S14) 22 Nickel-Chromium Steel 28 Strengthening 750
25
For AX53B series turbine, specification may differs in according to different kit.

 

From this I can see that the turbo is rated at 340ps, even though k-style claim 350ps from their orange S13 ute. The power ratings for most japanese companies are for at the wheels, not the flywheel. 340ps is about the same as a HKS 2535, but from what I've heard the response is as good as a 2530, which is the turbo I always wanted. Should be interesting then to see how it responds compared to the factory turbo, and how much boost is needed to break 200rwkw. The condition is very good though, apparently only being a few months old. The wheels spin freely and have no shaft play, freely enough that if you blow into the exhaust inlet they will spin. I will probably run 14psi at a minimum, and possibly up to 18psi depending on how this effects power. I'm guessing the most I'd ever hope to make with this turbo is about 240rwkw, but only on higher boost than I'm probably prepared to run.

 

 

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