That's because the stock heads are typically very poor on the intake side. Show me a stock head, and I'll show you a ≤80% E:I flow ratio.

You can get lazy with the IVO because you have supernatural pressure from the FI, but in my opinion you'll be better off getting the EVO event sooner, leading to higher exhaust duration.

 

For what its worth I ran a 218/230 with my 408 and tvs1900, and will run a 236/230 with my 410 and pt88

 

That's the cam I run. Does good in town and like you said breaks tons of sheet on boost. I have wondered what I'm leaving on the table running it that small on my 408 though.

 

I don't think my little Isky 215 runs all that bad

 

I run something similar on a TVS1900....224/230 114...alittle less lift....580ish its comp 54-444-11....sounds nice at idle at speed sounds stock

 

What do you know newb....come back when you've actually done something

 

Can I come back now?

 

thanks for all of the info guys but maybe i should have worded my question differently.

Can someone explain what to look for in a FI cam? FI cam theory i guess you could call it.

 

Not all Forced Induction is created equal as far as cams go. Overlap plays a vital role in any FI applicaton though. A supercharged application is more tolarant of overlap as the pressurized intake charge will blow out the spent exhaust gasses. This can be benifitual in getting a full clean intake charge but in excessive cases you would get boost bleed off. In a turbo application where the exhaust backpressure could be greater than the intake pressure, overlap can cause reversion where the exhaust backs up into the cylinder inhibiting a clean intake charge.

 

What 76mm turbo are you running? As said above the optimum cam for a turbo setup is a bit different than that of a supercharger. For a TC, or a master T76 I would be looking between 212 and 225 @ .050'' single pattern, or a couple deg reverse split. No more than 6* forward. 112~116 LSA. On a 6.0L the power is likely going to peak in the mid to low 5K range due to the small exh wheel not the cam. Cam it too big you are going to loose low end, and not pick it back up on top. If you are running a GT, GTS, or S400 turbo it will pull past 6K and make better use of a larger cam. Also with boost valve control is just as important as lobe intensity. Too aggressive of a lobe can cause valve control issues with boost blowing on the intake valve...