Ultra boob utec tuning Q

[DuckRide]

Hey All,
I got my UTEC installed it (was a breeze) and started running the stock
mode and running the logger to get a feel for all the data that I could see
before runing any tuning runs (either on the dyno or on the street. I have
some basic questions (which were not satisfactorily answered by the manual
or by searches on NASIOC, clubwrx or i-club). Hoping someone here will be
able to help me out.

My basic understanding on how one should go about WRX cardio tuning:
1) Retard the ignition timing by three or 4 notches to take care of 91
octane and any boost spike issues which might cause lean outs

2) incrase the fuel throught just a little bit (maybe 0.3 or 0.4 points) to
be extra safe. Both the ignition and the fuel maps will be fine tuned after
the boost map has been bolted into place

3) Now get the boost map in good shape. First by setting the ABC
approximately and then fine tuning stuff by dinking around with the boost
map to reach the right boost levels at various RPMs and TPS values. Here is
where I am a little ignaramus
a) I have TXS Stg2 with an autospeed flex uppipe. Planning to run open
loop boost control and stock tuning parameters. What are the right boost
values for this? what is the general guideline to vary boost across a load
range (at const RPM) or across a RPM range (for a const load)? I figure the
"guidelines" comes to one from tuning experience? The manual recommends some
boost values for a stage 2. Are these the values I should strive to acheive?
And the only way to figure the actual boost acheived is by using an external
gauge right? Because the logger only shows me the boost solenoid duty cycle.

4) Now once the boost map is in the right place. I could start tuning the
fuel map to get rid of any rich or lean spots. Correct? Here again, I wonder
what the right AFR values are for the various RPM/Load points. Any help will
be appreciated

5) Now I dink with the ignition timing. And I go through multiple iterations
of tweaking the ignition map and the fuel map alternatively to reach the
level of timing aggressiveness that I need on the ignition map and to remove
any lean and rich spots on the fuel map.

Is this general strategy good? or am I just a dumb bloke when it comes to
tuning. My logic is, even if I get someone else to do this for me, I want to
be able to understand what's going on, and appreciate the beauty of it
all.....

Any help/suggestions/comments will be greatly appreciated
Thanks all for reading this through !
Duckride

[hippy78]

I'm not an expert, but I have a few tips for tuning boost. I really just use the boost gauge to make sure that I am not overboosting, I dunno if this is normal, but it works for me. Depending on what log you use, you can see different things. Recording logs from your runs is good and can help you work out many different bugs in your maps and what not. Some of the log modes do actually show manifold absolute pressure, this is more accurate than your boost gauge. Also, some things to node in the logs are the load site, being 0 10 20 30 40 50 and so on upto 100. This tells you what part of the timing and boost map the utec is using when you are at that rpm and what not.

Puting more load on your car while tuning it will give more reliable results for multiple load situations. This means that putting a bunch of weight on the floor in the back seat or having a bunch of people in your car while you are logging will bring on some problems that wouldn't happen if you didn't have the extra weight, and once those problems are ironed out, you are ready to move onto bigger better things....

Now, using open loop boost control is not optimal if you want to get consistent boost control in different gears and weather conditions. Closed loop boost control lets you set a target boost and a rate at which the turbo spools to that boost. Once closed boost mode is tuned right, changes in temperature should not effect boost, and you should be able to tune it so you see more boost in more gears earlier than open loop mode. Just some food for thought. I mean, you are just starting to tune it, and I figure why waste all the time learning how to tune open loop mode, when you can spend the time tuning closed loop since you will probably want to switch to it later on anyways. Also, the boost that turboxs recomends is optimal(the psi not the duty cycle). There are many reasons not to exceed it.

peace

[DuckRide]

Agreed. Doesn't this make more sense for track use though? for street( read "everyday) use won't different weather conditions imply that the though the boost itself is the same the MAF value is different? (or is the boost always proportional to the MAF value?) and if the MAF value is going to differ according to weather, we might want to let the boost value itself slide and adjust to the weather. When I am writing this, I am thinking, "when the weather is really hot for street driving maybe I want my car to boost a little less anyways" Don't you think?

Duckride

[Hot_Dog]

Originally posted by DuckRide
(or is the boost always proportional to the MAF value?)

The boost and the MAF are not a 1:1 relationship. The equations involves the compressor efficiency. If you have a really efficient turbo, the heat generated will be less, and the MAF will be higher for the same boost.

It all relates to the ideal gas law: PV=nrT where P is your boost, V is the MAF, and T is the temperature (n and r are constants). So if your temperature is lower, you can move the same V at a lower P.

[hippy78]

you are reading the wrong thing on your log. the map is the manifold absolute pressure. That is what you should adjust your boost to....

peace

[DuckRide]

Sorry!! Typo...I mean MAP

[hippy78]

well, the map is better than gauge boost pressure, because the pressure inside the manifold is what you want to adjust your setting to anyways............

[DuckRide]

right.....so coming back to my original question...how seriously can closed loop boost control get affected when the temperature changes? As opposed to open loop

Cause unless I am understanding this wrong....if the temperature goes up, the air will become rarer for the same boost. Is this a good or bad? On one hand...since fuel is injected based on MAP values we will have a richer mixture, right? so that's ok...but then the charge will also be hotter....which is not all the good....leads to pre-ignition? Just trying to understand the dynamics here.....

on open loop, the boost itself will be lower and i iwll be operating on a different point on the map for lower boost.

Am I just getting confused?

Manoj

[hippy78]

well, I'm not one to ask about that. I mean, I have been running clb for a few months now..... I've been having a little boost creap problem that I attribute to my crappy downpipe(which I am replacing but the new one hasn't come yet)... Anyways, I used my car in ny at 40 degrees, and in florida at over 100 degrees in high humidity, and the boost is very conssistant(even though mine always creaps)..... I am sure there are lots of other people on here that would recomend clbc over olbc......

in open loop mode, since you are using a solonoid duty cycle, when the weather gets cooler, you will overboost because the turbo will be pushing more air with the same duty cycle. Conversly, when it is hot, or at altitude, you will underboost. With closed loop, the utec is trying for a specific boost pressure.....which means that if it is set correctly, and the system is good, weather and altitude should not affect boost preassure if you system can put out.

peace