VICTORY_OR_BUST

for my 100" v-twin FI motor what do you think is a good turbo to have i want to gain throughout my RPMs but for the most part past 3k, my bike revs to 5600 stock but i can get it reprogrammed to 6300 im new to this but im just wondering what boost and components you recommend on my v-twin, i see lots on high reving rockets but not much for my twin

busa4

thats a big vtwin. i plotted your engine and it recommends a t3 turbo. see what turbo you can find. the most popular is the t3/t4 but see what you can find. i wouldnt boost any more than 6 psi. if your engine is air cooled then i would boost it lower than 6psi.

AaronZ34

You ran a airflow calculation on an engine you know nothing about? All you know is displacement and redline.

busa4

yes. is a basic calculator. engine displacement, how many cylinders and how much boost. it gives a general idea of what you should look for. thanks for your input but i have done this before. im not a 18 y/o kid.

AaronZ34

Dang. Here I thought displacement meant nothing without volumetric efficiency.

busa4

displacement increases as boost is added. ex: a 1000cc engine n/a is at most 80-90% ve. which makes it ~800-900cc engine. when boost is applied that ve goes up over 100%. most boosted application are 120-130% ve. which would make the 1000cc engine like a 1200-1300cc engine. this is all just a calculation. nothing major needed to figure out what turbo is required for a specific engine displacement and how much boost wanted.

AaronZ34

Except VE is not a "guess," it is specific to every engine, and is a critical factor in turbocharger sizing. Unless you want to tell me that the 5.0l found in a 1980s GM diesel demands the same turbocharger as that found in today's 412hp Mustang GT.

busa4

i understand its not a guess. the calculator does all the work. you put in the engine displacement, bore size, stroke, boost level and rpm. it gave options of turbos and the compressor maps looked like a match with the t3 turbo's. based on his requirements he wants mid to high rpm power and with his engine displacement and low boost level a t3 turbo will work good for his application.

AaronZ34

So the calculator doesn't even use VE?

Odd, consider that's more important than the engine displacement.

busa4

wow! i guess your not understanding. boost is VE