MichaelTT

After talking to Altered Atmosphere this morning (Monday) I have some clarifications/answers to a few issues that were brewing yesterday on the TT forum:

1. Dyno runs were done in 3rd gear is that in low HP engines (talking sub 350 hp engines) with AWD 3rd gear is used. AA guys have done over 1000 dyno tests and most on AWD drive cars ranging from our group to track ready 700 hp+ Mitus VRs and Stealths. They stand by methods and experience in AWD dyno testing and get consistently correct data.

2. 'Boost overshooting spikes' are common on turbo cars on dynos...specifically when starting the run the turbo spikes VERY momentarily (thus spiking shows to the charts as a brief occurrence) until boost control moderates and brings back boost into spec (whatever the ECU allows...on OEM TTs it is 1 bar and on the MTM ECU it is ~1.4 bar). AA guys say they see this phenomenon routinely and as such don't treat the spikes and related max hp/torque reading as the real output for the vehicle. Reading the entire chart/readout showing performance through the rpm ranges is much more important than the max output numbers.


3. Typically from run to run there can be a 3-5% variation of readouts on the same vehicle...engine temp (cold to optimum running temp for car) being the main cause for variation.

4. Based on some additional computations looks like 118% factor for wheel to crank conversion might be closer and little more conservative.

Auto Union Jack

So which chip set up performed more admirably in your opinion?.

Jenner

to 20.3 psi.

With my K04 turbo and chip I am running 1.1 bar or 15.95(aka 16psi) and producing on the dyno 256crank, 223 wheel horsepower. You are right in the same area with the MTM, yet running much higher boost. Where did you get that 1.4 BAR spec without a boost gauge? From MTM?

Just wondering. If it is true that the MTM chip produces the said hp at 1.4 bar then the GIAC setup is doing it with less boost, and in my opinion that is better programming...

I'm a big fan of MTM, I hope this isn't true.

Let me know. Thanks.

MichaelTT

torque is the number that jumps out to me...the number that makes you go. At 300 lbs I think there is a relationship to boost psi...different view?

john s

Wastegate takes almost 2 seconds to become fully active. MTM is holding higher midrange pressure so sounds reasonable that spikes could go higher.

MichaelTT - how many seconds to go from 1500 to 6600 on dyno?

Chaka

MTM and can confirm that it is 1.4 bar.

PanTTher

My GIAC peaks (momentarily) at 1.4bars as well.

PanTTher

When did you get chipped?

john s

Stock chip as in the original Audi chip.