Comprised of a 2.5-inch mandrel-bent aluminum pipe, the AMS performance hot pipe is a simple-to-install piece that can reward your Evo with added horsepower. The factory Evo plumbing was designed by Mitsubishi as a cost effective way to interlink the inlet and outlet piping. Unfortunately, the soft rubber hose the factory provided is considered less than ideal for any performance vehicle. The soft rubber hose has a tendency to expand when under boost. This expansion causes an increase in air turbulence and deflection, which can cause a loss in both horsepower and torque. The AMS Evo X upper intercooler pipe was designed to flow more air than the stock unit using its 2- to 2.5-inch transition for maximum performance. Using the factory location core support strap, the AMS hot pipe can be installed by even the most amateur mechanic.

While installing the unit is a no-brainer, the larger-sized hot pipe diameter was a minor concern when attempting to reattach the factory radiator cover shroud. Although the hood clears without an issue, we suggest trimming the plastic to accommodate the new pipe.

Dyno Test Results
With the new hard pipe in place, the rollers were spun once again. We found an increase from 4,400 rpm to redline with the largest gains occurring at 4,730 rpm with an increase of 12 hp and 10 lb-ft of torque. As the boost level increased, the gains were obvious as a 5 to 9 hp and 4 to 8 lb-ft of torque margin was seen from 5,600 rpm to redline.

What began as a baseline dyno run of 237 hp and 247 lb-ft of torque was quickly revamped with our final run of 282 whp and 262 lb-ft of torque. A gain of 45 hp and 17 lb-ft of torque was established with some of the basic bolt-ons more commonly used on the street. Upon dyno testing the Evo X and the new 4B11, we barely touched the surface on the true potential of this motor. Stay tuned in the near future as we plan to take this engine to the next level.

Baseline 5Zigen ZZ
ARK Design
Advanced Boost
Hot Pipe
237 @ 5,570 rpm 241 @ 6,390 rpm 252 @ 6,250 rpm 276 @ 6,894 rpm 282 @ 6,905 rpm
Peak Torque 247 @ 4,330 rpm 251 @ 4,443 rpm 263 @ 4,210 rpm 262 @ 4,110 rpm 264 @ 4,115 rpm
178 183 191 194 194
Average Torque 199 203 213 217 217
Final Power
Baseline +4 hp
+4 lb-ft of torque
+11 hp
+12 lb-ft of
+24 hp
-1 lb-ft of torque
+6 hp
+2 lb-ft of torque

Total Gains
+45 HP
+17 LB-FT Of Torque

Parts MSRP
5 Zigen Border
ZZ Cat-Back


AMS Upper
Pipe/Hot Pipe

ARK Design
Advanced Boost

Total MSRP $2,100

Dynamic Autosports

5Zigen USA

AMS Performance

ARK Design