TOMS BARREL EXHAUST SYSTEM TITANIUM TAIL FOR TOYOTA GR COROLLA 17400-TEA14

 

TOMS BARREL EXHAUST SYSTEM TITANIUM TAIL FOR TOYOTA GR COROLLA 17400-TEA14

The TOM’S Barrel 17400-TEA14 is a premium exhaust system developed specifically for the Toyota GR Corolla GZEA14H / G16E-GTS. 

TOM’S lists it as a stainless-steel system with titanium tail sections and a variable valve, rather than a full titanium exhaust. 

🔧 Technical breakdown

Feature	17400-TEA14
Engine	G16E-GTS 1.6L turbo 3-cylinder
Construction	SUS stainless-steel exhaust
Tail material	Titanium
Main piping	76.3 - 60.5 - 50.8 mm
Valve	Variable exhaust valve
Tail design	200 mm + 120 mm titanium oval outlets, offset L/R
Reference close noise	94 dB
OEM reference	93 dB
Installation	Rear TOMS diffuser required

🧠 Why the variable valve matters

The clever part isn’t simply the big titanium tips.

The system uses a variable valve architecture that changes the exhaust flow path according to operating conditions. In practical terms:

Low load / quieter driving
→ valve strategy helps control exhaust sound

High load / acceleration
→ greater exhaust-flow path opens
→ less restriction through the rear exhaust
→ sharper, more aggressive G16E-GTS character

That is particularly appropriate for the GR Corolla because its 1.6L turbo triple has a distinctive pulse character that can sound much more aggressive when the exhaust system allows it to breathe.

🏎️ Why TOM’S chose 76.3 mm → 60.5 mm → 50.8 mm

This isn’t simply “bigger pipe = more horsepower.”

The graduated diameter is part of the exhaust-flow design. The 76.3-mm upstream section provides substantial flow capacity, while the downstream reductions and split routing allow TOM’S to package the muffler/valve system and control exhaust velocity and sound.

For a relatively small-displacement turbo engine, excessively large tubing can also hurt exhaust-gas velocity and make the system unnecessarily loud. TOM’S is therefore balancing:

flow capacity + velocity + acoustic character + valve control.

🔥 Titanium tail — the prestige element

The titanium isn’t being used throughout the entire exhaust. Instead, TOM’S concentrates the expensive material where it has the greatest visual and enthusiast appeal: the exhaust outlets.

The result is the classic high-end Japanese performance aesthetic:

SUS304 exhaust body → engineered valve system → titanium oval outlets

The titanium tips can also develop the characteristic heat coloration associated with titanium exhaust hardware.

⚠️ Important installation point

This exhaust must be installed together with the TOM’S rear bumper diffuser. TOM’S explicitly specifies this requirement, and its rear diffuser is designed around the Barrel muffler. 

So this isn’t quite a simple “swap the muffler and go” modification—the exhaust and rear aero package are effectively engineered as a system.

🏆 The verdict

TOM’S Barrel 17400-TEA14 = 9/10 for OEM+ performance character

Its philosophy is different from an all-out race exhaust:

• Variable valve → controllable character
• Large-flow architecture → appropriate for the G16E-GTS
• SUS304 construction → durable structural material
• Titanium outlets → lightweight/premium visual finish
• TOM’S diffuser integration → factory-like aesthetic
• 94 dB reference → deliberately aggressive rather than ultra-quiet

The most interesting aspect is that TOM’S isn’t trying to make the GR Corolla merely louder. It is packaging flow, valve control, acoustic character and rear-end styling into one integrated system. 

TOMS BARREL EXHAUST SYSTEM TITANIUM TAIL FOR TOYOTA GR COROLLA 17400-TEA14

KAKIMOTO RACING EXHAUST CLASS KR FOR TOYOTA GR YARIS GXPA16 T713177

 

KAKIMOTO RACING EXHAUST CLASS KR FOR TOYOTA GR YARIS GXPA16 T713177

The Kakimoto Racing Class KR T713177 is the more aggressive 4-tip version of Kakimoto’s Class KR exhaust, developed specifically around the pre-facelift GR Yaris GXPA16. 

Kakimoto lists it for the 2020/9-2024/4 RZ/RZ High Performance 6MT, with the G16E-GTS 1.6L turbo and AWD. 

🔧 Technical specification

Item	T713177
Engine	G16E-GTS 1.6L turbo
Chassis	4BA-GXPA16
Drivetrain	4WD/AWD
Transmission	6MT
Applicable years	2020/9–2024/4
Configuration	Class KR 4-tip
Construction	All stainless steel
JQR	JQR20212025
Idle noise	70 dB
Near-exhaust noise	91 dB
Japanese MSRP	¥247,500 incl. tax

🏎️ Why the Class KR matters on the G16E-GTS

The GR Yaris’ G16E-GTS is a compact, high-output turbo three-cylinder. Its exhaust system has to handle rapidly changing exhaust flow as the turbo moves from low-load operation into boost.

The Class KR’s objective is therefore not simply “make it louder.”

Think of it as:

Turbocharger → freer exhaust path → reduced restriction → sharper exhaust response → stronger motorsport character

The 4-tip arrangement also gives the rear of the GR Yaris a much more visually substantial performance-car appearance.

🔥 T713177 vs T713176

This is an interesting distinction:

• T713176 = Class KR conventional configuration
• T713177 = Class KR 4-tip
• T713177 is rated at 91 dB near the exhaust.
• T713176 is listed at 87 dB. 

So T713177 is the choice for someone who wants the more dramatic four-exit Class KR presentation and stronger acoustic character, rather than simply replacing the factory exhaust.

⚠️ Important compatibility point

This SKU is not the correct part for the facelift GXPA16 from April 2024 onward. Kakimoto explicitly states T713177 is for the pre-facelift vehicle and that installation on vehicles from 2024/4 onward is not possible. 

It is also intended for cars equipped with the GR rear bumper spoiler. 

For the later GXPA16, Kakimoto lists T713193 as the corresponding Class KR application for 2014/4-2026/4 cars. 

🧠 Performance interpretation

T713177 is best understood as an exhaust-system upgrade that balances four things:

1. Flow — less restrictive downstream exhaust architecture helps the turbocharged engine evacuate exhaust gases.

2. Thermal management — the exhaust carries extremely hot post-combustion gases away from the turbo/engine.

3. Acoustic feedback — the 1.6L three-cylinder’s unusual firing character becomes considerably more apparent.

4. Motorsport identity — the four-outlet design visually reinforces the GR Yaris’ rally-derived character.

Bottom line:
T713177 = Class KR + 4 exits + stainless construction + JQR certification + pre-facelift GXPA16 fitment. 

It is particularly attractive for an RZ/RZ High Performance 6MT owner who wants the GR Yaris to feel and sound more like a serious performance machine without moving to an uncompromising competition-only exhaust. 

KAKIMOTO RACING EXHAUST CLASS KR FOR TOYOTA GR YARIS GXPA16 T713177

JUN AUTO GT SURGE TANK FOR MITSUBISHI 4G63 LHD EVO7-8 2015M-M003

 

JUN AUTO GT SURGE TANK FOR MITSUBISHI 4G63 LHD EVO7-8 2015M-M003

This is a high-performance intake manifold / surge-tank assembly developed by JUN Auto Mechanic for the 4G63 turbo engine in left-hand-drive Mitsubishi Lancer Evolution VII–VIII (CT9A). 

JUN lists the 2015M-M003 specifically for LHD Evo 7–8 applications. 

🧠 What the surge tank actually does

Think of it as the air-distribution chamber between the throttle body and the four 4G63 cylinders.

Turbo → intercooler → throttle body → JUN surge tank → runners → intake valves

The key engineering problem is air distribution. A highly tuned turbo 4G63 can demand substantially more airflow than the original intake system was designed around.

JUN’s philosophy is interesting: bigger isn’t automatically better.

• Too small: pressure distribution between cylinders can become less uniform.
• Too large: pressure fluctuations become excessively smoothed, reducing the beneficial inertia/ram effect.
• Correct volume: balances plenum pressure stability with useful pressure-wave behaviour. 

🔬 Why JUN’s internal design matters

JUN describes its surge tanks as being designed around several variables:

Collector/plenum volume + runner cross-section + runner length + engine displacement

The internal geometry is intended to promote efficient air entry and distribution rather than simply creating a large empty chamber. 

JUN specifically discusses a curl/funnel-shaped internal form intended to improve the efficiency of air entering the runners. 

For a 4G63 being pushed toward serious boost and high RPM, that can mean a more suitable airflow architecture than simply enlarging the factory manifold.

⚙️ Important installation requirements

This isn’t a simple bolt-on replacement where you retain every factory component.

JUN states that:

• Injector and throttle body are NOT included.
• It cannot be used with the stock ECU.
• Intercooler piping must be prepared separately.
• The kit requires a suitable throttle-body arrangement. JUN’s documentation identifies the relevant throttle-body adaptation, while current specialist listings specify a Nissan N15 70 mm throttle body for this application. 

So this part belongs much more naturally in a properly engineered 4G63 build than a basic street modification.

🏁 Evo VII vs Evo VIII

The application is particularly interesting because the listing covers:

Application	Engine	Chassis
Evo VII	4G63T 3rd generation	CT9A
Evo VIII	4G63T MIVEC	CT9A
Steering	LHD only	—
JUN Part	2015M-M003	—

Specialist fitment data confirms Evo VII 2001–02 and Evo VIII 2003–05 applications. 

🔥 Where it makes the most sense

I’d classify the 2015M-M003 as a high-output airflow-management component, not a cosmetic intake upgrade.

Best matched with:

Large turbo 4G63 → high-flow intercooler → 70-mm-class throttle body → JUN surge tank → appropriate injectors/fuel system → standalone/programmable ECU → calibrated ignition & fueling

The surge tank itself doesn’t create horsepower in isolation. Its value is that it can become part of a better-controlled intake system when the engine’s airflow demand has moved beyond the factory hardware.

⭐ Technical verdict

Area	Rating
Air distribution potential	⭐️ ⭐️⭐️⭐️⭐️
High-RPM airflow	⭐️⭐️⭐️⭐️⭐️
High-output 4G63 suitability	⭐️⭐️⭐️⭐️⭐️
Street plug-and-play practicality	⭐️⭐️
Motorsport/tuned-build suitability	⭐️⭐️⭐️⭐️⭐️
Installation complexity	⭐️⭐️⭐️⭐️
Rarity	⭐️⭐️⭐️⭐️⭐️

The big story: JUN didn’t simply make a larger intake manifold. They engineered the plenum volume, runner geometry and airflow path as one system. 

That is why the 2015M-M003 is particularly interesting to serious CT9A 4G63 builders.

One important current-status point: JUN officially discontinued its 4G63 GT Surge Tank production in February 2022, and JUN’s current catalogue marks 2015M-M003 as discontinued.  

This makes genuine examples considerably more interesting to collectors and period-correct Evo builds.

JUN AUTO GT SURGE TANK FOR MITSUBISHI 4G63 LHD EVO7-8 2015M-M003