Money burning a hole in my pocket!

[Rick_RS4]

my inlet mani has had so much time smoothing and porting every time i carbon clean it (once a year) so id say beyond stage 2, whilst it is like a kangaroo when cold once its warmed up its fine

[MikeFish]

Dave, anyway to find out which version ( 0090 or 0080) the car is running other than taking it to the dealer?

Is this not visible through the VCDS software when plugged into the car?

[PetrolDave]

Dave, anyway to find out which version ( 0090 or 0080) the car is running other than taking it to the dealer?

Connect to either of the engine ECUs (at addresses 1 and 11) using VCDS (VagCom) and it will display the version number.

[marc1]

Thanks Dave, much appreciated. OT but... Will be thinking about adding in AMI soon, hoping there might be a guide on here somewhere as I remember you did it some time back. That U.S. Forum seems to be down unfortunately.

[sar]

And Marc, I'm pretty sure there is a very good explantion on here (possibly by Petrol Dave) explaining the effects of what will happen if you remove tumble flaps and I'm prety sure it is exactly what Ross has described.

The job of the tumble flaps is to direct the air going into the cylinders at part throttle openings through only 1 inlet valve, as that's offset from the centre of the cylinder that will generate more swirl and hence richer "spots" within the lean mixture. Those will act as starting points for the burn when the spark plug "fires" and hence make for a more thorough and more even burn of a mixture that really should be too weak to burn properly.

So without the tumble flaps you've got a more homogeneous mixture that's really too weak and hence burns slowly and incompletely - which will cause poorer drivability on part throttle.

The effect should be more noticeable with engine SW 0090 which implements a more "lean burn" strategy, why is why mpg is approx 10% better with 0090 than 0080.

the rs4 has four valves a cylinder, i think you are describing a s4 (five valves a cylinder) with the one off set inlet valve.

i thought the tumble flaps are open and shut dependent on rpm?, i have never heard of them being controlled by throttle position?.

everything i have ever read says they are in the tumble/restricted position until 3500rpm after that they are full open. before 3500rpm the flaps are in tumble mode no matter what the throttle position is, so without the flaps you should have a poorer drivability/burn regardless of throttle position. after 3500rpm there is sufficient intake velocity that the flaps are no longer needed for a thorough burn and they slide out of the way, and they stay open regardless of throttle position.
so i cant really see the general correlation between a stage 2 manifold with the tumble flaps removed and poor part throttle driveability.

a rs4 without tumble flaps should drive exactly the same (part throttle/full throttle) as a rs4 with tumble flaps above 3500rpm.

i dont doubt that un mapped rs4 could drive horribly below 3500rpm with the tumble flaps removed, but thats where mrc do their thing and claw back the driveability whilst adding power. after all you would only buy a stage 2 manifold from mrc if you were getting their stage 2 map that accompanied it.


the question is, is mrc clawing back enough driveability?..... for me and what seems the majority of mrc's stage 2 manifold/map customers yes they did, for ross it fell short of what he was willing to compromise on.
different strokes and all that.....

[PetrolDave]

the rs4 has four valves a cylinder, i think you are describing a s4 (five valves a cylinder) with the one off set inlet valve.

No I'm describing the RS4 4 valve engine - think about it the valves will be "in the 4 corrners" of the cylinder, so air only going into 1 inlet valve will swirl round the cylinder more than if air is going into both inlet valves.