Evap/Emissions System Question

[RETed]

First, having the vacuum source deep into the runner on a single rotors will induce pulsations due to the physics of the running motor...
It's a question if this is significant or not.

If your MAP sensor is damped, then this would not matter too much.
For very sensitive MAP sensors (or signals), this can cause headaches.

FPR's are not as important, but don't be surprised to see pulsations of + or - 5 to 10psi in some cases - verify by monitoring fuel pressure.
The effects can be minimized by the tune - tuning slightly rich will "fix" this.

If you want a more stable vacuum source / signal, you really need to run a plenum...
This is why most intake manifolds have a (collected) plenum - to minimize all the weird pulsation in the intake tract.
If this is not possible, you can cheat and run a vacuum manifold, which acts like a mini plenum by collecting multiple source of vacuum into a single space; be careful with such a system, as making things "too big" can cause more pulsations in the system!

Your brakes might be perfectly fine drawing off just one rotor - this goes into brake performance theory, but that's a whole 'nother ball of wax!


-Ted

-Ted