The actual question is for my brothers VL turbo but I'll ask here as those spankers at calasiturbo couldn't organise a root in a brothel and all they do is crap on about the bresciani and rajab workshops instead of coming up with proper technical answers so here goes.

The car is a pretty much standard 1986 VLT with the only mods being a 600x300x76 delta fin front mount cooler from Just Jap, 2.5" cat back zorst and a boost tap allowing it to theoretically hit 17psi with the standard turbo. I do know that the injectors run out of puff with standard fuel pressure at around the 12psi mark. What I want to know is what rate fuel reg should he get for it to run a safe 15psi boost pressure without maxing the injectors out as well as having good part throttle driveabillity (who cares about top end as long as it pulls hard like a train and doesn't ping then its all good) and decent fuel economy. He recons a 2:1 mallpassi would do but I was thinking maybe a larger rate fuel reg. What do you guys reckon? And please, no sell the VLT and buy an XR6T comments as this car is a project between myself and my brother and neither is too keen to let it go unless someone offers the right $$$.

Gee guys thanks for your help. He ended up buying a malpassi (don't know what rate it rises at) and will have it fitted by the end of the week

I would use a Sard reg...
I would also fit a larger fuel pump...
The higher pressure you use the harder it is on fuel pumps to supply, in quantity....

How much do they retail for? Anyway we fitted it last night and the car runs like a dream. Should have it dyno tuned by the end of next week.

yes my sard reg is far far better than my old malpassi.