Charlescrown wrote: ↑Mon Feb 17, 2025 4:26 pm
Who says he's got any left. I know my brain now needs a holiday.
Ha, yes I reckon I might have aged a few years but the feel of the turbo surge is addictive. Just need to change fluids and get it down the 1/4 mile. Then a wastegate adjustment and back to the dyno. I also need to see where valve bounce comes in and if it is within the rev range of the cam. I reckon a change to beehive springs might squeeze a couple of extra hundred rpm out of the top end.
Cheers
I never would have thought that a fuel pump could even pressurise air? That threw everyone off track for sure.
I know my cars def have no pressure when the fuel runs out, I have removed hoses before to confirm fuel flow/pressure and where there is nothing in the tank, the pump doesn't even push air against my finger over the end of the hose. So it must be unique to certain pump designs/brands?
A typical pump forces out about 70-90psi before regs, so you'd def know if there was air even a fraction of that pressure, mine simply make noise but nothing comes out at all if they are not submerged in fuel, even if they have fuel but start to suck air when low, they lose all pressure but a dribble. So the car won't run if it sucks some air.
I'm the director of VSH (Vlad's Spec Holden), because HSV were doing it ass about.
vlad01 wrote: ↑Tue Feb 18, 2025 8:18 am
I never would have thought that a fuel pump could even pressurise air? That threw everyone off track for sure.
I know my cars def have no pressure when the fuel runs out, I have removed hoses before to confirm fuel flow/pressure and where there is nothing in the tank, the pump doesn't even push air against my finger over the end of the hose. So it must be unique to certain pump designs/brands?
A typical pump forces out about 70-90psi before regs, so you'd def know if there was air even a fraction of that pressure, mine simply make noise but nothing comes out at all if they are not submerged in fuel, even if they have fuel but start to suck air when low, they lose all pressure but a dribble. So the car won't run if it sucks some air.
I have a lift pump to a surge tank and then on to the high pressure pump so not sure if this why I was getting a pressure reading on the gauge. When I cracked the fuel line to the rail it was definitely under pressure but of course no fuel came out.
On another matter should I be able to write an unstacked 12P Bin to a Winbond W27E257 - 12 chip? or did I need the W27E256 - I couldn't find one on ebay only the 257.
I keep getting write failed and probably bought the wrong chip thanks
Finally got the tune and setup back to its old self again. On full throttle from about 20 kms an hour and When the turbo spools up this thing wants to go sideways at 60kms. The boost is only about 6 psi.
I have no idea what the exact change was but last week and even this morning it would stumble and backfire if you dumped it at say 40kmh. I reinstalled the AFR gauge to see what was happening as I suspected it was leaning out under load and tapped the power feed and earth off the wideband loom and at the same time hooked up the narrow band dummy feed wire to the wide band controller. This involved pulling apart the existing power feed and earth and using new connectors. I also reduced the fuel pressure as I had split a high pressure fuel hose. After all this I took it for a run and no stumbling just full torque and power response. How would this be with no change to the tune. The original connections to the wideband seemed ok and can’t imagine that would have made a difference could it have simply been the reduction in fuel pressure? Anyway a very productive day, Cheers
