Rear Turbo Weber 32/36 fuel curve sorted - dyno this week
Turbo Mini Forums

Took some fiddling, but the Weber 32/36 now runs very well under boost. Narrow-band O2 sensor shows ~800mV under power. Took some doing to get the last flat spot out. I wound up shimming up the spring on the power valve to make it come in sooner and also stay on more under boost at part throttle.

No power measurements yet, but this afternoon it buried the 95MPH speedo and was still pulling. This is with 8PSI boost. Don't think I'll turn it up any higher as the engine is standard so far as I know. I'm also running 91 (R+M)/2 octane fuel, about 95RON. No pinging, but pinging must be somewhere nearby.

As a point of reference for others, here is the jetting:

idle 65 primary, 70 secondary (going to try bumping the secondary a bit when the jets come in)
main 145 primary, 140 secondary
air correctors 120 primary, 100 secondary

I think the key to getting the fueling right without a restrictor at the carb air inlet is the very small air correctors. These richen up the high airflow operation.

1275 with Back Door Turbo

cool, any pics of this setup? what mods are needed to the weber for turbo use? cheers

If you search for my username (fortfun), you'll find the previous threads that have photos. The only mods to the weber were to remove the choke linkage and seal off the hole with epoxy putty and to shim up the spring on the power valve. Other than that it was rejetting only. No obvious leaks around the throttle shafts.

1275 with Back Door Turbo