Microtech LT-8 altitude compensation? -Severe lack of power at Wakefield

[WHITCHY]

Does anyone know if the Microtech LT-8 has any sort of altitude compensation setting?
I was down at Wakefield on Friday, and heading down Thursday night, I noticed a massive loss of power about 3/4 of the way there, and it stayed like that all Friday, we put on the wideband 02 sensor on the way home today and the engine was running ridiculously lean (16:1 - 18:1) under heavy acceleration.
Thinking it was just a blockage or busted fuel pump or injector(s) I just drove home avoiding heavy acceleration, keeping my eye on the mixtures the whole time.
Then on the way home in roughly the same spot the car lost all its power I put my foot down and it accelerated normally and the mixtures were normal!
I have tried searching the net to find out the altitude differences between Castle Hill and Golbourn, and also if the LT8 has any altitude compensation, but I can't find anything!
Thanks for any info!
Cheers.
-Whitchy-

[Billzilla]

If it's running lean then it's something else, as increasing altitude means less air, and (depending on how the engine senses load) it'll still dump in the same amount of fuel and so be running rich.
So I'm guessing fuel pressure or the like.

Goulburn is about 1500' - 1800' I think, Castle Hill is maybe 100' - 200'.

[thechuckster]

unless the ecu has a second MAP sensor, it can only do barometric correction at startup not continuous.

i vote fuel system - possibly even something in the fuel tank (was level in tank at about the same spot when you had the power-loss episode?).

[WHITCHY]

Well then, maybe it was just a blockage, and it was a complete fluke that the power loss and re-gain happened in a similar spot?
I'm not really sure about the fuel levels, cause my guage is stuffed, but it was the same at full tank, and even after thrashing it around the track down to about half a tank, and then filling up to full again?
The only difference to normal was I was running Shell V power instead of BP ultimate, and I was also running a bottle of that Wyyns Octane Booster because it was pinging slightly.
Then late Friday afternoon I changed the fuel filter and put in a bottle of petrol system cleaner for good measure.
Guess I will just never know for sure untill I head back to Wakefield!
Cheers.
-Whitchy-

[oldcorollas]

just thought i'd add these i found when looking for answer

http://home.earthlink.net/~jcgebhart/megabaro.html
http://www.diyautotune.com/catalog/m...ion-p-117.html

[AbaddonMR2]

I was under the impression you don't need altitude compensation with a map sensor.

Yes the air pressure is lower... so the wastegate does not open as much and the turbo works a little harder but the pressure in the manifold ends up being the same.

My bike has a sensor for it uses the TPS for the main load sensing and a MAP for low speed and idle.

Rep me pls!

[YLD-16L]

I was down at Wakefield on Friday, and heading down Thursday night, I noticed a massive loss of power about 3/4 of the way there, and it stayed like that all Friday, we put on the wideband 02 sensor on the way home today and the engine was running ridiculously lean (16:1 - 18:1) under heavy acceleration.

I don't think it will be an altitude issue as my car runs near the same on the dynos in Canberra and Sydney and I have never noted any real performance difference from the coast all the way up to Charlottes Pass (which is about as high in altitude as you can drive in Aus).

I have a MTX-8.

As other have eluded to I think the issue won't be altitude related.

[chris davey]

V power is 2.5% oxygenated IIRC so that is going to lean your AFR's out a bit. On mine it was about .7-1 point different.

I don't think that is the sole reason though.