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i currently have an issue where the car leans out with anything over 8psi boost.

Mods are:

3 inch exhaust

Front Mount Intercooler

Apexi pod

Blitz Dual stage boost controller

Walbro Fuel Pump

All plugs, fuel filter are new and AFM is clean. There is no vacuum leaks.

I had it on the dyno today to check fuel mixtures and everytime we start adding boost it leans right out.

We cramped the return line hoping it something stupid like a fuel reg issue but that didnt make any change.

Power output at 8psi is 167kw at rears tyres

How much boost and power are ppl getting and does anyone have any thoughts on whats causing it to lean out like this?

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https://www.sau.com.au/forums/topic/354817-problems-making-power/
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how did you wire up walbro? when i put one of these on my car we had same problem and found fuel pressure was dropping when coming on boost, i ran a 10g wire from back of alternator through 20amp fuse and to a 20amp relay switched on by factory fuel power feed and no more fuel issues

The fuel pump i used is that same in my racecar which has 270kw at rears with no fueling issue.

Though i might try hard wiring with a decent gauage cable to see if it helps.

I will have access to the dyno again tomorrow so the more ideas i have to try and fix it the better

Injectors should do more than 200kw at least. Maybe your race car has battery in the boot? Walbro flow drops right off when boost increases and needs all 14v to function properly. Replaced the filter in the engine bay? Time for a Nistune chip!

rather than jumping straight into rewiring the pump, try putting a multimeter across the terminals and see if you're getting a voltage drop - but i'd say upgrading the wiring and running it off a relay is a good safety measure anyway.

and if you want to do some forward planning, use Amp wiring OAWG or similar - run it to your boot and into a distribution block - then run some thicker wiring like 8AWG off that for your pump (dont' forget to fuse it).. bit of overkill, but then if you want to add amps later, you're set!

Edited by SMOKEYC34

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