Some of us have the AMS unit because it's cast. DP installation on the X is such a pain that having something durable in there makes a whole lot of sense. Someone from Cobb wrote a piece on DP design a while ago that explains all the compromises that must be factored in for an optimal design. In a nutshell, keeping the wastegate flow separate from the exhaust flow is better for performance. But, packaging, durability, space, etc all play a role.

 

Unfortunatelly for me, AMS doesnt make for RHD vehicles

 

Widemouth DP's have one key performance advantage over divorced.
When those pressurized gasses enter the Wide part of the DP, they are allowed to expand and cool, therefore making the gas more dense, and allowing it to flow better gradually down the progressively smaller tube.

Cooler& denser is better. Less backpressure is better.

 

I've had two widemouth styles; UR isn't a separated housing chamber, but it's a lot bigger near the outlets than the AMS. As a result, the UR actually runs leaner stock, plenty of farting and backfiring, relative to the AMS unit. Under steady 3000 rpms they seem comparable, but the UR's bigger volume right at the origin of the exhaust does give it more power.

Too bad the UR unit is welded bent SS piping. Welds seem to fail. If it's not the welds, it's at the piping where the bends stress and stretch the metal making it subject to eventual failure.

The AMS is cast, big sturdy thing that will last a lifetime I hope.

 

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KIT CONTENTS *

■OUTLET COMPONENT ■FLANGE NUT M12 * P=1.25
■GASKET (TURBO SIDE) ■STICKER (EXPREME)
■GASKET (CATALYZER) ■BOLT SMOOTH PASTE
■CLAMP BAND ■INSTALLATION MANUAL
■BLIND PLUG ■STICKER (TOMEI)
■COPPER WASHER ■WARRANTY CARD
■STUD BOLT M10-40 P=1.25 (THREAD 12/26)
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PART NUMBER : 433001　　　MSRP $450.00 (USD)

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After testing a variety of shapes and pipe diameters here at Tomei R&D Lab, we found the optimum tuning point for the best performance balance. This design will extract the full capabilities from the EVO 10 4B11 engine. The design also retains the original layout to help with the ease of installation and compatibility for other exhaust parts.
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■ WIDE MOUTH



The smooth flowing design, without steps from the turbocharger. Manufactured with the lost wax process, combines both strength and beauty.

■ 3 INCH PIPE



After numerous tests, the 3 inches (76.3mm) greatly increases both power and torque.
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■ TORQUE & POWER


Wide mouth & 3 inch piping. Achieve large power & torque gains over stock.




Direct bolt on that retains the original stock layout.
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Lost Wax casting process for maximum durability,
precision without welds.



Larger in size and diameter, smooth
without any steps.
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The larger curve design makes it possible
for a much larger capacity.



Improved efficiency through with
a more linear layout. .

MATERIAL
PIPE DIAMETER (Φ)
PIPE LENGTH (mm)
FLANGE LENGTH (mm)
WEIGHT (kg)
TOMEI
SUS304
76.3
1.5
13-12
4.8
（With Accessories）
STOCK
STEEL
64.5
1.5
12-12
5.2

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GOOD DESIGN FOR TOOLS
O2 SENSOR BOSS FOR AFR GAUGES

The wide mouth was designed to be easy to install with the general common work tools.

The mouting boss is an M18, which makes it easy to fit the AFR sensor. Comes with a blind plug to seal the hole when not in use.
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FLEXIBLE PIPE DESIGN
MIKALOR HIGH GRADE BANDS

Easy to install with minimal risks to cracking the stainless steel exhaust manifolds from vibrations.

The Supra Bands made by MIKALOR is what we have chosen to use, since they maintain the strongest torque to secure a proper strong connection. We also used Nejiname bolts.