Conventional snowmobile turbo builders have always placed the turbocharger in the most convenient location on the snowmobile. However, this is not always the best location.
All turbochargers have some lag because of the time it takes the turbo to spool up and produce boost pressure. Lag is determined by the time it takes to move hot exhaust gasses into the turbocharger. Longer exhaust manifolds and charge piping increase turbo lag. This is why you don’t see the turbo on your diesel pickup located near the tailgate.
Impulse Performance set out to build an all-out performance front mount turbo system specifically designed for aggressive mountain riding. Impulse’s Yamaha Nytro and Apex turbo systems are engineered for throttle response, reliability, weight centralization, fuel capacity and power. Both systems are available with a choice of the Garrett ball bearing GT2860RS or GT2871R turbochargers, which are supported in the frame. The 321 stainless steel shorty exhaust manifolds are built to provide instantaneous boost and maximum reliability. Large intercoolers are mounted tipped up to optimize airflow through the stock hood.
A high-flowing cold air intake filter exits out the stock fuel cap location, minimizing snow and ice buildup. The under-seat fuel cell is filled from the rear and has more than 10 gallons of fuel capacity. The fuel system is plumbed through a front-mounted surge tank, allowing complete use of the fuel in the tank without the motor sucking air and cutting out. Premium 91 octane pump fuel can be used up to 12 psi boost, which nets about 240 hp on the Nytro and 260 hp on the Apex.
A blend of 50/50 110 octane and premium or straight 100LL aviation fuel can be used up to 15 psi and 100 percent 110 octane up to 19 psi.
New for 2009, Impulse will introduce the Nytro Race System. This kit combines a hybrid Garrett GT2871R turbocharger and a highly responsive Tial turbine housing with an external 44 mm wastegate. A 3-inch stainless downpipe exits the turbo and a 1.75-inch separate downpipe exits the wastegate. The 50 mm Tial Q blow-off valve keeps the turbo spooled in on and off throttle situations. Larger fuel injectors supply adequate fuel for boost pressures beyond 25 psi.
Contact Impulse Performance (801) 870-1587 or www.impulseturbo.com.