Getting explosions on overrun, is there any way to stop it as engine running great but bangs getting on my nerves.

slightly rich?, excess fuel burning in hot exhaust.?

who did your mapping?

only a bang ?

i get flames

(1) Check the exhaust system (especially the manifold) for leaks and pinholes.
(2) Check the idle speed

Three or four bangs spaced out evenly. me and paul f have done the mapping. I am in the process of putting forged pistons and steel rods in a new engine, when i have done it i might get it rolling road-ed.

Exhaust ok.

[Edited on 12/4/08 by madteg]

Kev
try turning on the overun fuel cut , it is a setting in the more settings menu.
You will need to put in the revs at which it becomes active and the vacuum at which it is active.it needs to be set up so as it cuts the fuel with the throttle closed but switches back on just before idle speed.
Paul.

The explosions are almost certainly caused by unburnt fuel igniting within the exhaust, can be caused by an airleak into the exhaust (usually there isn't enough oxygen to allow fuel to ignite). If the exhaust is very short you can get sufficient oxygen to ignite the unburnt fuel just from the exhaust outlet.
It suggests that your overrun mixture is quite rich - obviously if you can engineer an overrun fuel cut this will probably eliminate the problem.HTH

What paulf said

Make sure the rpm limit is at least 500rpm above your idle speed, otherwise you get some odd things happen if you coast down to too low an rpm. Similarly make sure the kPa set point is well below your idle kPa, otherwise it'll kangaroo at really light throttle.

[Edited on 12/4/08 by martyn_16v]