Astra Coupe Turbo 273bhp, but 25bhp less power with WI.

[ashtal]

Originally Posted by MikeWarner

No, because I will have two maps which will be switchable. The low level sensor on the tank would automatically change the map to the safe version which will be designed to run without WI.

I take it this wont be on a standard ecu ! Will it ?

[MikeWarner]

It will be a piggy back ECU on the standard ECU.

[Richard L]

Here is all three dyno pulls of the day. The power didn't seem to suffer after the ramping up period. The engine seemed to enjoy running on WI +M only. Wonder why putting all those fuel there in the first place. We should have been brave and run the last pull all the way to red line.

I will get a time scale plot from Gary to ensure the RPM scale is matched to the previous pulls. The above picture is only a guessed fit.

[Richard L]

Originally Posted by MikeWarner

Ok, am I am going to think out loud here.

When tuning a turbo engine, you want to fuel in relation to the torque, not the horsepower. So, at high torque areas, you should runng a bit rich and as the torque drops, you can move the mixture to a lambda of around 0.85.

If you look at the graph from 2800rpm to 4000rpm (B to D) you can see that with WI the mixture was richer at this point and too lean without it. As a result, there was more power with the WI.

The extra rich mixture at the top end (G to J) is impacting on the torque hugely. As you can see, the WI was making it too rich because of the methanol content (was running 50/50). The run without WI got better results at the very top end. I think that if the graph went up to 6800rpm (limit) we would have seen it rise further.

I really can't work out what is going on sections E to G. It is possible that the AMM was not giving consistant results to the ECU and was fuelling differently on each run. Or maybe the cooler inlet charge helped keep the mixture leaner for longer when WI was running.

I am sharing the same thoughts - it would be so nice whenyou have got your Wide band sensor, an in-car dynometer to take all the guessing game away.

Amazing how afr affect the torque reading - only running a small amount of water/methanol relatively.

Richard

[Richard L]

Mike, got your toys yet?

Richard

[MikeWarner]

Hi Rich. Yep - got the toys. Not had much time to play though. I still think there is an issue with the car, so I will be getting it checked out soon. I'll let you know when the car is ready to try again.

[ashtal]

I have seen an astra turbo with an EGT sensor in the manifold (with in car guage). Would this help the trimming device and the dds3 ?

[JohnA]

Originally Posted by ashtal

I have seen an astra turbo with an EGT sensor in the manifold (with in car guage). Would this help the trimming device and the dds3 ?

Although you can expect detonation when EGTs become excessive, you can also have detonation with EGTs in the 'normal' range for that engine.
So the EGT signal is not the best single indicator out there.

[Richard L]

ashtal, what has happened to your pictures?

[ashtal]

Originally Posted by Richard L

ashtal, what has happened to your pictures?

Account was closed. i will send them to you if thats ok ? Or do you know of any other hosting sites for pictures ? If not can i have your email address.