ITB mode on my 2276 MS2

[UKLuke72]

Hi,
I've been running my 2276 on VW Speed shop 36mm ITBs
MSII batch fired running the VW Speedshop crank trigger too
Trying to get ITB mode working

It worked crudely in Alpha-N but I want this to behave well as a street car not just full throttle.
I tapped the manifolds for vac takeoff and made a little manifold to merge all 4 pulses and ran speed density.
It idled at around 63kPa so is pulling a good vacuum to be able to work the speed density side of ITB mode but the injector pulse width is really erratic, The smooth idle I had is now surging, unsteady AFRs
Full throttle goes lean.

Overall it's not very happy.
Not sure how to attach logs/maps here but they're available on MSextra at the bottom of the page Log and tune

Any thoughts much appreciated.

Cheers

[Chip Birks]

Strange that Alpha-N gave bad results. I actually really found a ton of drivability once I switched to Alpha-N on my turbo car. I only used it until manifold pressure went positive, then switched to SD, it worked way better than straight speed density for me.
I had a giant cam that basically gave no vacuum signal.

[UKLuke72]

I had an issue with the intake valve guide breaking up and making a mess.
Rebuilt, with an FK10 this time.

Tuned ITB mode in quite nice now that the switch point has been tweaked.
Tempted to go full speed density though.
Not sure I need ITB mode at all.