Just wondering which fuel rail kit was better Visnu or perrin. And why

 

if your going to tune with the vishnu stuff like the xede then get the vishnu cuz its all designed for eachother.

 

parallel fuel rails are parallel fuel rails. the only really important thing is that they are parallel instead of series (like the stock rails). i haven't seen the vishnu rails, but the perrin rails are nice and balanced. even the fuel lines from the "T" section to each rail are equal length.

 

yup.

 

Yup I use perrin ones they work great

 

Both make great products, so go with the one that is cheaper.

 

pardon the noobass hijack, but are aftermarket fuel rails required to get enough fuel into the motor after a turbo swap (say an IHI turbo for example, nothing crazy), or are the stock rails adequete?

 

They aren't required, but there's speculation that at higher horsepower levels fuel pressure in the rails can start to oscillate and get uneven. No direct evidence of it though.

 

what kind of levels are we talking about, higher than stock? or say, around ~400whp...

 

Yeah, 400hp+ is a good guess. Like I said, there's not really a quantified point where the rails start having defined flow issues, it's just speculation and anecdotal evidence.