Project EVO IX Part 2 More Engine Tweeks


WORKS EVO resonated race pipe
The WORKS resonated race pipe is one of the reasons why our car is so quiet

To keep things quiet, we used a WORKS resonated race pipe to link the downpipe to the exhaust. With a 3” super free flowing perforated core resonator, the race pipe is probably the reason why our exhaust system is pretty quiet. In fact installing these free flowing parts seemed to make our car less noisy than it already was. The race pipes all stainless construction matched the rest of our systems high quality.

WORKS Downpipe and Race Pipe for EVO

Our complete turbo back exhaust in place

EVO’s are known to top out there fuel pumps capacity even with bolt on mods. Although the EVO IX has a higher capacity pump than the EVO VIII, it’s pump still can get maxed out with bolt ons. To solve this problem before it happened, we installed what is rapidly becoming the industry standard fuel pump for turbo performance applications, a Walbro 255 liter per hour fuel pump. The Walbro pump is an easy direct bolt in that takes only about ½ hour to install. Walbro is a QS9000 certified OEM supplier so expect that this pump will be extremely reliable.

Walburo 255 pumpEVO fuel pump location
A Walbro 255 lph fuel pump ensures that we won’t run out of pump capacity soonThe pump is easily accessed by removing the rear seat and unbolting this access hatch in the fuel tank
EVO fuel pump locationEVO fuel pump carrier
The fuel pump carrier can be easily removed like thisThe Walbro unit easily replaces the stock unit, snapping into place in minutes

Since we plan to use our car for track days, we knew that cooling was an important issue. To help keep our thermal situation under control, since we had to remove the radiator to install the O2 sensor housing, we installed an ARC radiator, radiator air guide and cooling system pressure regulator while we were at it. The ARC radiator is a very high quality unit using all tig welded construction in the aluminum end tanks to withstand high pressures coupled with a super efficient core. The radiator cools much better than stock but is no thicker, a good deal if you are installing a big turbo. The unit bolts directly in including the stock fans making installation a snap.

EVO ARC radiator
Our hand fabricated TIG welded ARC radiator is a visual work of art that will help keep our engine cool on track days

If a cooling systems pressure is kept higher, the boiling temperature increases, with less localized boiling in the head and less cavitations of the waterpump, the cooling system works much better. To increase our cooling system pressure, we installed an ARC cooling system pressure regulator between the radiator and the coolant overflow tank. The regulator allows us to adjust the cooling systems pressure from the stock 1.1 bar to slightly over 2 bar.

ARC Cooling system pressure regulatorARC Cooling system pressure regulator
The ARC cooling system pressure regulator ups our pressure from 1.1 to 2 bar to reduce localized boiling and improve cooling within the engineWe installed the regulator by the coolant overflow bottle

The ARC air guide is a simple plate that helps prevent air entering the grill opening from pilling over the top of the radiator. Although it is simple in concept, being cut from titanium, it is probably one of the more esoteric parts on project EVO IX.

ARC EVO air guide
The Titanium ARC air guide helps make sure that most of the air going through the grill opening is forced through the radiator. The use of Titanium for this part is pure bling but bling is cool if it’s functional

Since we were upping the pressure of our cooling system, we thought that it was prudent to upgrade our coolant hoses was well. Nukabe sent us some of there molded 4 ply silicone hoses for us to evaluate. Silicone has much better temperature resisting properties than rubber and 4 plies is twice as many as stock. These heavy duty features means that the Nukabe hoses will sport a much longer service life over the stock parts.

Nukabe EVO Silocone raidator hoses

Nukabe’s silicone radiator hoses are much tougher and longer lasting than the stock parts, important since we boosted our cooling system pressure


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