CUSCO CROSS MISSION FOR HONDA CIVIC EG6 EK4 9 317 028 AR

 

CUSCO CROSS MISSION FOR HONDA CIVIC EG6 EK4 9 317 028 AR

The CUSCO 317-028-AR is a close-ratio gear set designed for the Honda Civic EG6 / EK4 / EK9 transmission family. CUSCO lists it specifically as TYPE-R. 

🔧 The key idea

It isn’t simply a stronger gearbox. Its main purpose is to reshape the gear ratios so the engine loses less RPM between shifts, keeping a naturally aspirated B-series engine closer to its useful power band.

Gear	CUSCO 317-028-AR	EG6/EK4/9 STD
1st	2.533	3.230
2nd	1.944	2.105
3rd	1.590	1.458
4th	1.280	1.107
5th	STD	0.848
Final	STD	4.400

CUSCO’s published specifications confirm those ratios. 

🧠 Why TYPE-R is interesting

The really clever part is the 2nd–4th gear progression.

The standard gearbox has relatively large ratio changes. The CUSCO set makes the middle gears substantially closer:

STD:
3.230 → 2.105 → 1.458 → 1.107

CUSCO AR:
2.533 → 1.944 → 1.590 → 1.280

So during a hard acceleration shift:

Engine RPM ↓ less → engine stays nearer its torque/power zone → acceleration resumes sooner.

That’s particularly attractive for a high-revving B16A/B16B because these engines reward keeping RPM high.

⚡ What changes on an EG6?

Think of it this way:

Standard gearbox

1st → big RPM drop → 2nd → bigger drop → 3rd → 4th

317-028-AR

1st → tighter 2nd → tighter 3rd → tighter 4th

The trade-off is that the 2.533 first gear is much taller than the 3.230 standard first gear. So the car gives up some first-gear multiplication in exchange for a more motorsport-oriented progression.

This is why I’d characterize the AR as a circuit/spirited-driving-oriented ratio set rather than an automatic “more acceleration everywhere” modification.

🏁 AR vs AC vs AS

CUSCO offers three different concepts for this Civic application:

• 317-028-AS — TYPE-S: 3.417 / 2.412 / 1.714 / 1.231 / STD
• 317-028-AC — TYPE-C: 2.533 / 1.944 / 1.590 / 1.280 / 1.032
• 317-028-AR — TYPE-R: 2.533 / 1.944 / 1.590 / 1.280 / STD

The AR is especially interesting because it keeps the standard 5th gear, whereas the AC also changes 5th to 1.032.

Key takeaway:
317-028-AR = less about “making the gearbox stronger” and more about turning the B-series drivetrain into a closer, higher-RPM acceleration machine. 

It makes the most sense when the engine, differential/final drive and driving environment are all chosen around the new ratios.

CUSCO CROSS MISSION FOR HONDA CIVIC EG6 EK4 9 317 028 AR

TOMEI COMPLETE BLOCK CPB-2J36H FOR TOYOTA SUPRA JZA80 TOYOTA ARISTO JZS161 2JZ 216011

 

TOMEI COMPLETE BLOCK CPB-2J36H FOR TOYOTA SUPRA JZA80 TOYOTA ARISTO JZS161 2JZ 216011

The TOMEI POWERED CPB-2J36H (P/N 216011) is essentially a pre-assembled high-performance 2JZ-GTE bottom end designed for JZA80 Supra and JZS161 Aristo applications. 

TOMEI introduced this High-Comp version in 2025, using a higher-compression forged piston. 

🔧 Core specification

Component	CPB-2J36H
Base engine	Toyota 2JZ-GTE
Bore	87.0 mm
Stroke	100.0 mm
Displacement	3,565 cc / 3.6 L
Pistons	TOMEI forged Ø87.0 Hi-Comp
Connecting rods	TOMEI forged H-beam, 139 mm
Crankshaft	TOMEI forged full-counterweighted
Main bearings	TOMEI Competition
Rod bearings	TOMEI Competition
Main fasteners	ARP reinforced studs
Main caps	TAITAN billet reinforced
Cylinder block	Standard 2JZ block
P/N	216011

These specifications are confirmed by TOMEI’s current catalogue. 

🧠 Why the 3.6L configuration is interesting

The important number isn’t simply “3.6L.” It’s the combination:

87 mm bore × 100 mm stroke

versus the standard 2JZ’s approximately 86 mm × 86 mm geometry.

That extra 14 mm of stroke substantially changes the engine’s character:

Longer stroke → greater displacement → more crank leverage → stronger low/mid-range torque → broader usable powerband.

The 3,565 cc capacity also gives a large turbo more exhaust-energy support without requiring extremely high engine speed to generate torque.

TOMEI specifically describes the 2JZ-36 concept as producing a wide torque band with strong response, including the ability to support large single-turbo configurations. 

🔥 What makes the 2J36H different?

This is where the H matters.

The regular CPB-2J36 uses a TOMEI forged Ø87 mm piston, while the CPB-2J36H uses a Hi-Comp forged piston. Everything else in the major rotating assembly is essentially built around the same 87 × 100 mm architecture. 

Think of it as:

CPB-2J36

3.6L + forged rotating assembly + relatively broad compatibility with high-output turbo builds

CPB-2J36H

3.6L + forged rotating assembly + higher compression + greater emphasis on response, torque and competition-oriented performance

TOMEI specifically warns that the High-Comp version requires high-octane race fuel or ethanol-blended fuel to control knock. 

⚙️ The really clever part: the bottom-end architecture

The CPB-2J36H isn’t just a collection of aftermarket parts.

TOMEI supplies the pistons, crankshaft and connecting rods already assembled, turning the product into a prepared tuning block rather than making the builder source and assemble each major rotating component individually. 

The architecture is:

87 mm forged piston
↓
139 mm forged H-beam rod
↓
100 mm forged full-counter crank
↓
TOMEI Competition bearings
↓
TAITAN billet reinforced main caps
↓
ARP main studs
↓
2JZ-GTE block

The reinforced main-cap arrangement is particularly important because increasing displacement and cylinder pressure raises the loads transmitted through the crankcase.

🧬 Why the 100-mm stroke is significant

The 2JZ is famous partly because its original architecture is extremely robust. TOMEI takes that foundation in a different direction:

86 × 86 mm → ~3.0 L

becomes

87 × 100 mm → 3.565 L

So the engine gains approximately 18% displacement.

That means you don’t necessarily need to chase enormous RPM to generate impressive output.

A simplified way to visualize it:

3.0L 2JZ

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3.6L 2JZ

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The additional displacement effectively gives the turbocharger a larger “engine behind it.”

🏁 CPB-2J36H vs CPB-2J36

Characteristic	CPB-2J36	CPB-2J36H
Displacement	3.565L	3.565L
Bore × stroke	87 — 100 mm	87 × 100 mm
Forged piston	Yes	Yes, Hi-Comp
Forged crank	Yes	Yes
H-beam rod	Yes	Yes
Billet main caps	Yes	Yes
Compression	Lower	Higher
Response	Excellent	Potentially sharper
Knock margin	Greater	Lower
Fuel requirement	More flexible	High-octane/ethanol-oriented
Competition focus	High	Very high

TOMEI’s own positioning is essentially that 2J36H is for applications seeking additional low-speed torque and a broader powerband, particularly competition use. 

• Listed weight: approximately 110 kg

🧠 Takeaway

The CPB-2J36H is best understood as a 3.565-liter, forged, high-compression evolution of the 2JZ-GTE bottom end.

Its engineering philosophy is not simply:

“Make the 2JZ stronger.”

It’s:

“Make the 2JZ larger, increase its torque density, increase response, strengthen the rotating assembly, and make the engine a better foundation for a serious turbo system.”

The particularly interesting combination is:

87 mm bore + 100 mm stroke + Hi-Comp forged piston + full-counter crank + H-beam rods + billet main caps + ARP studs.

That makes the CPB-2J36H one of TOMEI’s most sophisticated modern interpretations of the legendary 2JZ-GTE architecture.  

TOMEI COMPLETE BLOCK CPB-2J36H FOR TOYOTA SUPRA JZA80 TOYOTA ARISTO JZS161 2JZ 216011