96" Harley Turbo...1990's Era
Without a properly designed intercooler your Harley is going to detonate, stick a ring or hole a piston and by properly designed we don't mean some shit-ass thin oil / transmission cooler passing itself off as an intercooler. Intercoolers can lower the inlet charge temperature dramatically, often 75 to 150 degrees or more! Under boost the compressed air leaving the turbo can easily be greater than 200 degrees Farenheit...and depending on the outside temperature and how fast you are going, you can cut this figure easily in half!
The intercooler pictured dischages into our 8" diameter plenum chamber that acts as a surge tank and eliminates any "direction" the air may have before it enters our 56mm throttle body. The air chamber features an idle air control motor, an inlet temperature sensor for the RSR Fuel Injection, and a sophisticated dual function valve that both vents turbo pressure when you close the throttle as well as by-passing the turbo under vacuum conditions to aid throttle response. No, we are not going to show you the valve. The plenum is all billet in construction for safety reasons. Castings will fragment if there is an explosion, ours will simply expand like a balloon. Details, details details. Nothing like 20 years of experience to get it right. This sophistication means power and reliability.
bike pictured was a low compression S&S 96" that made 132hp @ only
5 pounds of boost. At 10 psi the figure climbed past 170hp. Beyond this
things go exponential as the turbo would put out 30psi and the power
keeps going up, past 300hp. This particular bike was ridden daily for
over 5 years and the owner kept it to 5 to 8 psi which seemed enough to
outrun everything he came up against. The turbo was eventually removed
as the bike was sold and coverted back to normally aspirated. We
recently took the engine apart to put in some new higher compression
pistons and the old turbo pistons looked perfect...more than 10 years
If you want to race or be a 300hp Dyno hero be prepared to upgrade your engine and not do anything stupid or your pushrods will be in China because turbos do not know when to quit. If you don't have a rev limiter, get one.