Originally Posted by Jeff20B

So I recently found out the bus trans has a drivetrain loss of around 20%. This is due to the hypoid gears they use which are less efficient but stronger than what's found in a bug trans. This means if I'm aiming for 100HP to the wheels, I'd need 120 to 130 HP at the flywheel with my bus trans. I was told 100 at the wheels is plenty. You can do a lot with just 100HP, they say. I don't doubt it, and I could have a peak HP at that level with a stock ported R5 13B pretty easily, but they were also assuming an air cooled VW engine. Those things make great low RPM torque. The HP is just the way they measure power over there for some reason. I thought you measure... torque? Problem is the rotary doesn't make that kind of torque at the same RPM. I need a way to get the low end grunt of a 2332 without the cost. So stock S5 turbo? I worked out some numbers. See if you can follow my math. 150hp x .2 = 30 150 - 30 = 120hp 160hp x .2 = 32 160 - 32 = 128hp 162.5hp x .2 = 32.5 162.5 -32.5 = 130hp For example, if the turbo makes a max of 150HP, with a 20% drivetrain loss, I'll have 120HP at the wheels. Likewise if I get 162.5HP at the flywheel, I'll have 130HP at the rear wheels. I think 150 to 160 HP is pretty realistic, actually, considering the stock S5 turbo made 200HP in an FC at stock boost levels and stock T2 spec intake and exhaust ports with a top mount IC. My baja engine has smaller ports and most likely won't have an intercooler. So I'm going from 200HP under factory intended conditions down to 150 to 160. Then factoring in a 20% drivetrain loss I'll get about 120 to 130HP at the wheels. I think that's realistic. And that's being generous. I think the actual numbers will be lower still. Like 100 to 110HP (but plenty of low end torque!). Thoughts?