For months my fuel pump had been whining from the turn of the key until I turned it off. The whining was getting progressively louder and I thought I could sense some 'hesitation' at WOT and full boost.
After considering the options I decided to take JonnyDangerous's suggestion of a Walbro replacement pump.
My options were: New pump from OPC - £450ish, 2nd hand from breaker £200, or walbro for £120. You are not able to source the pump on its own even from the pump manufacturer VDO.
The 996 fuel pumps are 'in tank' and are enclosed in a swirl pot which is permanently filled with fuel so that even during hard cornering the pump is not starved of juice.
There is a variation in the pumps across the 9*6 range even though at first glance they look similar. There is also a difference in the swirl pots as the 2 wheel drive cars have a large fuel tank and need one venturi tube to suck the fuel in. The 4WD cars have effectively two small tanks straddling the prop shaft and therefore need 2 venturi tubes.
The 996 turbo fuel pump has a maximum output of 5 bar. The 996 carrera fuel pump is 3.5 bar.
The Walbro E85 pump I chose has a maximum output of 455 L/h at 8.0bar.
As I intend to tune my car to approx 650bhp an upgraded fuel pump is recommended and this seemed like the ideal time.
I took a lot of instruction and inspiration from this thread: http://www.6speedonline.com/forums/996-turbo-gt2/324376-diy-tank-fuel-pump-upgrade-pic-heavy.html
Towards the end of the thread the author starts machining out the ports from the swirl pot to further increase fuel flow but fails to subsequently increase the diameter of the rest of the tubing. Therefore this seemed completely pointless to me.
old pump:
New vs Old:
New pump secured into top of swirl pot by large jubilee clip. Small piece of tubing used to connect to the Y connector and some staggered rewiring done (just awaiting the finishing of the heat shrinking):
I'm not sure if its placebo but the car feels more powerful, is a LOT quieter and the hesitation at WOT has gone!
I would say this job is a 2/5 in terms of difficulty and is a viable option when looking for a fuel pump replacement.
:judge:
After considering the options I decided to take JonnyDangerous's suggestion of a Walbro replacement pump.
My options were: New pump from OPC - £450ish, 2nd hand from breaker £200, or walbro for £120. You are not able to source the pump on its own even from the pump manufacturer VDO.
The 996 fuel pumps are 'in tank' and are enclosed in a swirl pot which is permanently filled with fuel so that even during hard cornering the pump is not starved of juice.
There is a variation in the pumps across the 9*6 range even though at first glance they look similar. There is also a difference in the swirl pots as the 2 wheel drive cars have a large fuel tank and need one venturi tube to suck the fuel in. The 4WD cars have effectively two small tanks straddling the prop shaft and therefore need 2 venturi tubes.
The 996 turbo fuel pump has a maximum output of 5 bar. The 996 carrera fuel pump is 3.5 bar.
The Walbro E85 pump I chose has a maximum output of 455 L/h at 8.0bar.
As I intend to tune my car to approx 650bhp an upgraded fuel pump is recommended and this seemed like the ideal time.
I took a lot of instruction and inspiration from this thread: http://www.6speedonline.com/forums/996-turbo-gt2/324376-diy-tank-fuel-pump-upgrade-pic-heavy.html
Towards the end of the thread the author starts machining out the ports from the swirl pot to further increase fuel flow but fails to subsequently increase the diameter of the rest of the tubing. Therefore this seemed completely pointless to me.
old pump:
New vs Old:
New pump secured into top of swirl pot by large jubilee clip. Small piece of tubing used to connect to the Y connector and some staggered rewiring done (just awaiting the finishing of the heat shrinking):
I'm not sure if its placebo but the car feels more powerful, is a LOT quieter and the hesitation at WOT has gone!
I would say this job is a 2/5 in terms of difficulty and is a viable option when looking for a fuel pump replacement.
:judge:
