14B VS. EVO VIII 16G Photo Comparison
Recently I installed an EVO VIII 16G turbo on my 6-bolt 4G63 engine swapped 1989 Dodge Ram 50 truck. Since I love seeing how things work, I decided to take them apart and compare them. As you can see in the pictures below, the EVO 8 turbo is a twin scroll and the 14B is not. The wastegate is far larger on the EVO turbo as well, which is very good news because the 14B internal gate is less than impressive. Naturally the compressor and turbine wheels are a bit more elaborate on the 16G as well.
My Hypothesis: Math says the EVO VIII 16G should flow about 50% more air than the 14B did, which means more air at less pressure, less heat soak, and twin scroll should make the spool time between the 16G and 14B negligible.
Results from the butt dyno: The 14B was set at 18PSI and was a lot of fun, because it could break the rear tires loose in 1st and 2nd gear when the turbo spooled. With the new turbo on and the wastegate plugged directly into the intercooler piping (stock actuator pressure is about 12psi I believe), the truck was neeeearly as fast as the 14B at 18PSI. It spools at about 150 rpm more than the 14B, and the boost came on so much smoother. Once I got used to the new turbo, and made sure everything was functioning properly, I cranked the boost up to 20 to see what would happen.
Tire spin in 3rd is what happened.
Traction Bars: Somewhere in the back of my mind, I had a vision of my rear differential wrapping up and ripping my driveshaft apart. I knew that my truck’s suspension wasn’t exactly designed for 250+ hp, and since I know my stock / lowered suspension was on borrowed time, I decided traction bars would be a smart idea. Not only would they prevent my truck’s axle from flipping over backward and turning my driveshaft into a pogo stick, but, it might actually provide traction through my Z rated 255/45/18′s! In went the new traction bars.
As if by some miracle, almost all of my missing traction was back again! I couldn’t believe it! These things really work! Now I can keep traction in 2nd gear (if I want), and spinning the tires in 3rd just plain won’t happen no matter how hard I try.