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Title: LDRQ0S and calibrating for tighter WG spring Post by: userpike on May 28, 2013, 11:09:12 PM So who has done this and how much did you increase the value in the map?
I want to change mine for a 12lb spring but don't know how much to add to the value. I don't want to add too much but I also don't want to add too little to even be noticed... Title: Re: LDRQ0S and calibrating for tighter WG spring Post by: nyet on May 28, 2013, 11:11:21 PM Q0 isn't going to help you
most of your work will be in KFLDRL, KFLDIMX, and Q2 Title: Re: LDRQ0S and calibrating for tighter WG spring Post by: userpike on May 28, 2013, 11:48:07 PM Q0 isn't going to help you most of your work will be in KFLDRL, KFLDIMX, and Q2 I have both KFLDRL and KFLDIMX where I want them at this point. I have yet to modify Q2 and don't know what is too much increase and what would be too little. Is a 50% increase across the board safe? Title: Re: LDRQ0S and calibrating for tighter WG spring Post by: nyet on May 29, 2013, 08:13:25 AM Yea. Q2 is pretty insensitive to large changes
The biggest problem you will see is that it is almost impossible to tune properly without a LITTLE overshoot, or you will find undershoot under a lot of conditions, and a subsequent oscillation. Alternately, if you have set up KFLDRL and KFLDIMX *just* right, you can leave Q2 alone... but it is tricky w/o an engine dyno. Title: Re: LDRQ0S and calibrating for tighter WG spring Post by: userpike on May 29, 2013, 11:16:47 AM Yea. Q2 is pretty insensitive to large changes The biggest problem you will see is that it is almost impossible to tune properly without a LITTLE overshoot, or you will find undershoot under a lot of conditions, and a subsequent oscillation. Alternately, if you have set up KFLDRL and KFLDIMX *just* right, you can leave Q2 alone... but it is tricky w/o an engine dyno. Being that the 12lb spring is more than double the stock tension, do you think changing KFLDRL say after 3000rpm to half the duty cycle of what I put down in the maps prior? Will it better my overboost problem? I'm thinking it should. I used elrey's "linear" KFLDRL map for k04 1.8t Passat and used audi TT 225 BEA engine code KFLDRL map columns for up to 3000 rpm. So I'm thinking anywhere where its 95% DC for example I would cut in half or even more and put those values in the map. So then anything that was @95% would now be @ say 47%. Is this at least a good start or am I totally wasting my time? Is there a map that adjusts for "vacuum lag time" from the WG because of the added spring tension? Title: Re: LDRQ0S and calibrating for tighter WG spring Post by: nyet on May 29, 2013, 11:24:23 AM So I'm thinking anywhere where its 95% DC for example I would cut in half or even more and put those values in the map. So then anything that was @95% would now be @ say 47%. Is this at least a good start or am I totally wasting my time? You're on the right track. The tricky bit is that you really want 95 to be 95 at LEAST during spool (if not everywhere else).. The problem is, you are near the map limit, so you have to limit WG somehow... if you do it via KFLDRL (on the 95 row), you might pull wg too soon during spool... but if you do it via KFLDIMX, you might need to turn off IMX adaptation (at least upwards adaptation) since the map limit will interfere with proper trimming if you overboost/underboost. Quote Is there a map that adjusts for "vacuum lag time" from the WG because of the added spring tension? Q2 will do this.. you just need to add Q2 a bit earlier (both rpm, and lde - i.e "down" (higher lde) and "left" (lower RPM) when tuning Q2 MAKE SURE YOU TRY IT UNDER A LOT OF DIFFERENT CONDITIONS (gear, temp, uphill/downhill etc)! peak boost does not always hit in the same place.. Tuning the PID is more art than science if you do not have a proper engine dyno setup... Also, this is all *my* opinion, it could be very wrong, so take it all with a grain of salt. |