PCV Autotune Target AFR Values

Evening,

Any of you with Autotune - what target AFR values have you entered?

I've been chatting with Dynojet UK and had a base table sent to start with so working with that.

Bike is a 1200 GSA DOHC with just a Remus header pipe.

Thanks in advance.

Oz

The standard bile runs very weak so you could just start with 14:1 and go from there.

I used to try to run 13.8 to 1 with the Autotune and PCV.
I say " tried" as I found it very unstable ( I was measuring the AFR with an Innovate Dual channel LM2).
I think the problem was that with disconnecting the lambda sensors the BMSK could not do its job and was unable to adjust to the variables.
When the Autotune was first launched I was under the impression that I could dial in an AFR and the bike would run to it. I soon found out that was not the case.
Probably the new versions are different ?
I have been using AFXIED`s for many years now as these do exactly that.

My PCV runs fine open circuit but TBH it is an engineered bodge. The AFXIED sorts the problem closer to source and a remap sorts the daft map that causes the problem anyway. Yer pays yer money, etc

I wonder why BMW control the bike almost as two single cylinders rather than as the one engine that it actually is.

Thanks. I don't think I'm too far off then. Maybe a bit rich.
The AFR table Dynojet made for me is from 13.6 to 13.2 with a bit of a cruise range of 13.8 at 10-20% throttle 3500-5000rpm. I wonder if it's just better to pay my £165 and have it set up on a dyno - just be nice to find one that's done GS's before.

If a set of AFXIED's come up for sale 2nd hand I'd be keen to try them!!

All the best

Oz

Bendy toy said:

My PCV runs fine open circuit but TBH it is an engineered bodge. The AFXIED sorts the problem closer to source and a remap sorts the daft map that causes the problem anyway. Yer pays yer money, etc

I wonder why BMW control the bike almost as two single cylinders rather than as the one engine that it actually is.

Click to expand...

Up to and including the R1150, that was what they did.

For most engines one O2 sensor and a single control works great. The clue is that each cylinder gets the exact same throttle opening.
On the boxer twin engine the throttle for each cylinder is operated by a cable, and cables stretch. The singel control 1150 suffered from potential vibrations due to one cylinder running slightly richer than the other. They both got the same amount of fuel, but since the throttle opened slightly different due to inaccuracy from the cables operating the throttle, this could make the engine run less than perfect.
Adjusting the amount of fuel individually according to each throttle solved the problem.

knutk said:

Up to and including the R1150, that was what they did.

For most engines one O2 sensor and a single control works great. The clue is that each cylinder gets the exact same throttle opening.
On the boxer twin engine the throttle for each cylinder is operated by a cable, and cables stretch. The singel control 1150 suffered from potential vibrations due to one cylinder running slightly richer than the other. They both got the same amount of fuel, but since the throttle opened slightly different due to inaccuracy from the cables operating the throttle, this could make the engine run less than perfect.

Adjusting the amount of fuel individually according to each throttle solved the problem.

Click to expand...

TBH, a less error-prone throttle control system would have done the same thing. They also have only one throttle position sensor.

If we look at the power outputs of many sub 2 litre car engines, they are not far off the same per cc as the R1200. The cars have only one throttle body which seems to have no negative effects on the engine power. The bike has one for each cylinder, which begs the question - Why? It's certainly not to boost airflow - the filter inlet tube delivers a huge restriction to mass air flow.

Fiat's 1746cc twin cam as used in the Punto HGT (and others) is a single spark version of the Alfa Romeo Twin Spark 1.8. In power terms, nothing special but no slouch (and very tune-able with new cams). Even with two power sapping pre cats in the manifold, it makes 130bhp - about 75 bhp per litre. The bike with no power sapping pre cat only gives 85bhp per litre. Let the car engine breathe and it would easily be up there with the bike. All with one ECU and one throttle body.

I'm illustrating a car engine more or less contemporary with to the 1150. The 1200 should have been even further on.