i have simtek on 2.1 stroker mapped for 99 ron,local shell had no vpower so filled up 1/4 of tank with 95ron +octane booster intermittent stutter in lower rev range on accelerating have refilled with vpower can you reset simtek as per oem ecu as this seems most likely cause??
martin

 

could be a few different things, mine has a slight stutter and turned out to be the plugs. Best bet get it looked at by a specialist who can try a few different things. Its one of those things you could chase round the engine bay

 

Yeah i had a similar problem and it turned out to be plugs

 

+1

 

SimTek has no reset facility Martin as it has no self learning facility.
I would get the plugs out and check you haven't melted a tip.

Martyn

 

neutral position sensor?

 

Wouldn't he have a CEL if that was knackered or settings were out?

 

Mine threw one up for NPS, but no codes recorded.

 

sounds like plugs then-due oil and filter change anyway after recent knockhill track-what plugs do you recommend martyn seeing how you built engine!love the new S206 mods mmmmm
martin

 

PFR7B plugs gapped to .7mm.
You had your Billet conversion carried out yet ?

 

not yet-420bhp is more than enough for me so very understressed engine lol
love the type ra gearbox so run 320 bhp on road most of the time as aware gearbox is weak spot and dont really fancy 6 speed gearboxso far 12 laps knockhill including 1 backward moment! and 6 1/2 laps ring-engine did not miss a beat although plenty of bits falling off rest of car lol
martin