20v SIlvertop, huge HP missing, please Help!!

[byd1380]

I have just installed a 20V silvertop in my 1972 MG midget, I have been running a large port with ITB's for a while. I did the swap over the last week, car running driving etc, seems to be pulling better than the large port 16valve. I drove the car to get setup up last night. We were using a Dynapack system, bolts directly onto the rear hubs, excellent setup. But basically the silvertop made 90bhp at the wheels!! Yes, 90 BHP at the wheels!!!! We didn't spend alot of time on it but really just got the fueling sorted out. I run a standalone ECU and just used the map from the 16v running ITB's. All it did was trim back the injectors.

The power starts as normal and is making 70bhp @ 4000rpm approx, then it goes flat and rises again at 6500-7000rpm.

What ignition curve should I be running, my original map had it running up to 38 degrees advance, we changed this to 30 and it didn't make any difference to power. But as I said, we didn't get a chance to look at ignition, but I don't think it couldbe hiding 40+ hp. I left the car, and he is going to play with it today.

Could somebody please post/email a image of a standard ignition map.

thanks

Ivan

[email protected]

[robokill]

your VVT-I ins't working. Without this the 5 valve engine will run as a 4 valve and has smaller ports.

The trigger of vvt-i is a single signal to the trigger so that it will use 5 valves.

[byd1380]

I have the ecu triggering the VVT @ 4400 rpm the same as factory setup, but wondering if the ignition timing needs to be adjusted to compensate for the advance with the cam timing once VVT is activated.

Ivan

[Ozone]

You loss in power coincides with the VVT trigger. Are you sure it is triggered correctly i.e. is it going off-to-on at 4,400rpm instead of on-to-off?