[Isimmo]

Originally Posted by Tim C

Thought I had better answer this here rather than infect Ian's thread .

Nothing major this year, lots of little things that will hopefully go along way.
Some of which are:

Bigger wastegate and pipework to try and combat the boost creeping up at higher revs.
Some 034 uprated engine mounts (the 90% stiffer ones not the solid ones), it was still on the originals !!

Upgraded the ECU, from Emerald K3 to K6 to enable us to use coil packs. The old K3 didn't have enough outputs to support 5 coil packs. Up until now we have had to limit the boost and revs because of spark blowout. The single coil didn't have enough time to regenerate and produce a decent enough spark for the boost after about 6000rpm, so it used to start missing. Now with some meaty coils on each cylinder we should be able to let it rev a bit further, maybe with a tad more boost .

The main reason for the map tweeking is the result of some inlet manifold balancing. On a jerry-rigged flowbench we found that No.3 was getting less than half the air of the others and No.s 1 and 5 getting more than the other 3. The problem is more obvious at lower air speeds (i.e. low boost) but still evident at higher air speeds (high boost).
So after some very time consuming engineering and re-measuring on the manifold they are now almost even.
As a consequence, No.3 is no longer running rich, so the fueling measured at the lambda in the downpipe (as an average of all 5) shows the engine is now running leaner.
It's not been quite as easy as shifting the fueling map up a bit, but the lambda is fed into the ECU and can be datalogged along with revs, throttle position and fueling map position. So with a bit of driving around, reviewing the datalog graph and adjusting the appropriate fuel map site where it is running lean, it seems to be getting there.

I'm only trying to get it drivable and safe (from detonation) to use next weekend and then I think it'll need a session on the rollers. Up until now we've been up to Emerald themselves for mapping, to see Dave Walker.

With the nice strong spark and all 5 cylinders theoretically getting the right air/fuel ratio and working properly it feels a lot, lot stronger, especially low down pick up .

With risk of hijacking a thread you've clearly attempted to avoid hijacking... (If you get my drift).... John (at JMR,) was adamant 'NOT' to modify the AAN inlet manifold, as Audi had spent hundreds of hours working out the manifold air flow balance to each cylinder and 'cutting' the manifold would compromise this flow and any water cooling the AAN inlet manifold jacket provides around the throttle bodies. Johns' approach is pretty much 'Audi knew best' for the engine air passage/delivery (the AAN standard inlet manifold delivers the air mid-manifold)... Which is easy for a 20vT convertee, but groundbreaking for a 10vT.

The brave take the more challenging path...