When is it required? DOes it makes sense to upgrade on the stock injectors. Will it do any good on stock injectors with a Walbro 255?

 

Nope fuel rails are a mod that happens when you get to pretty extreme flows don't worry about it especially if you're not going with e85.

 

If you will upgrade in the future......
Get this
https://www.evolutionm.net/forums/ev...fuel-rail.html

 

the stock fuel rail, lines and regulator worked fine until I got right at 700awhp on Q16 with PTE 1000cc and buschur twin walbros. Glad to see you asked the question before wasting your money, some others could benefit from this thread.

 

Good info mellon

 

Great! That's what I though. Just want to confirm because I was at a local tuning day where AMS were tuning Evos and GT-Rs and sobody was telling me to upgrade to the AMS fuel rail and showed it to me. It was really big compared to stock but for my power and mods the added flow will never be used. BTW it was not the AMS guys telling me to upgrade. It was someone at the shop. That's good info.

 

the stock rail opening is about as big as a pencil whereas a sharpie might fit in an upgraded rail. So one could make a compelling argument for the upgrade based on the visual.