R75 2.5 v6 Petrol Engine/ECU Re-Map

[SD1too]

Originally Posted by geofftl1000r

I have the 2.0 v6 and the extra torque at the lower rpms would be very nice!

Originally Posted by kaiser

ANY extra torque would be nice ... You really have to whip that poor engine to within an inch of its life to draw any meaningful response out of it.

Gentlemen, have you borrowed the club's VIS actuator tester? If your balance actuator is faulty and/or the flap is stuck (a common fault), you will get exactly the symptoms you describe. This was the case with my engine.

Simon.

[amableson]

It is interesting to note that the vis valve 'kicks' are not present on the graph, although mine do work properly, I believe this is due to the fact that the ecu operates the vis valves and only responds to certain driving criteria in lower gears as the power tests are only performed in 5th gear.

I only detect the 'kicks' in 2nd or third on hard acceleration.

I'm sure somebody will be along to disagree in a mo, but i still think my theory is correct.

[SD1too]

Andrew,

There's an unofficial graph around which suggests that VIS actuator operation is determined by engine speed and the angle of the throttle butterfly.

As to "kicks" on the graph, I think the idea was that the VIS valves smooth out pre-existing dips in the graph. But that's just my theory and it may be wrong.

Simon.

[rrobson]

Originally Posted by SD1too

Andrew,

There's an unofficial graph around which suggests that VIS actuator operation is determined by engine speed and the angle of the throttle butterfly.

As to "kicks" on the graph, I think the idea was that the VIS valves smooth out pre-existing dips in the graph. But that's just my theory and it may be wrong.

Simon.

it was the other way around, the vis system gives higher torque at set engine revs and throttle position. this video explaines everything:

http://www.youtube.com/user/kv6coupe.../1/05Wl0dkoQwc

the torque curve is shown at 3.30 mins

[StevenWilliams]

Here is another members graph with a superchips mod.




I haven't had mine shipped yet but my figures after 10 years of use are

Power at flywheel 165.6 bhp @ 6591 rpm
Power at wheels 140.5 at the wheels
Maximum Torque was 147.8 lb ft @ 6827 RPM

Teh car was due a service at the time so I'd expect a little extra after that.

For me the Torque consistency is the main reason for a mod rather than just an increase in BHP.

I notice that the Torque on the other mapping shots shows quite a drop off whereas the one above does not.. I wonder why considering they are from the same chip supplier?