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Old 02-24-2003, 03:38 PM   #1
Scooby Newbie
Member#: 32433
Join Date: Jan 2003
Location: Pasadena, Ca
2005 STi V370

Default UTEC map question -regarding knocks and lean

If someone has a brief moment and would like to pass along info I would much appreciate it.. My two questions are

(easy one first I think)
1 - during shift points I actually get a lean indicator for just one log line. This only happens during a shift point. Is this normal?

2 - 1st thru 3rd gear I can mash the throttle at any point and hold until red line and I get mostly rich and more importantly no knocks. However, in 4th and 5th gear this is not the case.. I can get serveral knock counts in the 3k-4.2K range. I kinda assume that I should just keep adding a wee bit of fuel and reduce timing in those areas. But why does this happen only in the higher 4th and 5th gear? Stronger load?

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Old 02-24-2003, 03:42 PM   #2
Scooby Specialist
Member#: 10186
Join Date: Sep 2001
Chapter/Region: MWSOC
Location: some kind of bmw tech...

I get lean too

You get knock in 4th and 5th because of more load.
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Old 02-25-2003, 12:26 AM   #3
Scooby Specialist
Member#: 13704
Join Date: Dec 2001
Location: Chester Springs, PA
2006 EVO MR
Apex Silver


You have to provide some logging with your setup (Mod List)!

It seems to me that you are running considerably "LEAN" around max torque area... I am not sure what map you are using but I would definately add more fuel by .1 or .2 (That is only if you get 1 or 2 knocks).. However, if you are getting harsh knocks where knock counts exceed 3 or more in a given RPM, I would definately pull the timing by -2 degrees at minimum...
But then again, it could be a bad gas that was causing the detonation....

The knocks you mentioned on 4th and 5th gears are due to the heavy load where car would not acceleration fast enough through the RPM zone.... Normally you would get higher than optimal boost in these area and that leads to the knock conditon. It is typical with the OPEN loop boost control where the solenoid duty cycle turns on and off continuously at certain interval... So, longer you say in that RPM range, the more boost you will build/get... Typically, you have specified probably 80 or higher in these RPM zone (Open loop from 2500 through 3500 RPM).. So, if you stay in that zone for couple of seconds or longer you will see your boost creeping up to beyond your desired max setting... (The boost builds slowly then suddenly jumps to max boost and beyond....)

To remedy these situations (4th and 5th gear knock from stepping on the GAS), reduce the boost for 2750, 3000, 3250 RPM zone only if you are using open loop boost control.. Try lowering the value to 70, 75, 80 respectively... (If you drive hard in 1, 2, & 3rd gear, you would be always above these RPM zone. So, it is not really a big deal..)

However, the best solution will be to use "CLOSED LOOP" boost control with 2.5b firmware... If you already are, then use ABC to tune boost as well so that stock solonoid is not pushed to the limit to build high boost..

I certainly do not have any kind of problem with all gears driving in any conditions with closed loop boost control...


Gain: 50
Boost MAP: Closed Loop - TXS stage 3.. ABC closed all the way (I did not have boost spike or irregularities getting 16.5 max boost.. So, I just left ABC closed all the way)

upto 2500 RPM @ 500
2750 @ 480
3000 - 5250 @ 380
5500 - 6250 @ 375
6500 - rest @ 370

I hope this helps..

Dan from PA.

BTW, if you have catless uppipe & downpipe installed, please add more fule into the 2500 and 2750 RPM. I would add +0.8 and +1.2 respectively if you are using the stock injectors.. This is to accomodate the shift of the boost curve due to the catless pipes.. (This is based on larger TMIC as well but you would want to run a littler richer than lean to cause a knock)..
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Old 02-25-2003, 05:13 PM   #4
Scooby Newbie
Member#: 32433
Join Date: Jan 2003
Location: Pasadena, Ca
2005 STi V370

Default thank you

Thank you that is very useful.

I am using closed loop with the ABC open about 1 turn. I'm starting to get concerned though as my timing is now going to 13-15 units in some areas (3k-4k range on the timing map) and I have added fuel to this area twice now (total of .5 to .7).

I started with stage4 base map dropped the timing 2-3 degrees and added .2-.3 fuel. I have the following sti injectors, uppipe, Vf34, fuel rails, , injen air intake, larger top mount intercooler. Only thing I don't have that I really should is a larger turbo back (down-pipe to exhaust), because I think I am probably storing too much heat in the turbo (hoping it will cause faster spools)..

Trying to just get about 16.5-17psi max.. just want to hold that for as long as possible. I also don't want to be running on the ragged edge (at all as a matter a fact).. I know people have setups similar to mine that are running 350+hp, but honestly I think 290-310hp is as much as someone should expect with 91 octane (if engine life is a concern)..

At any rate thank you for your feedback..

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Old 02-25-2003, 07:04 PM   #5
Scooby Specialist
Member#: 4329
Join Date: Feb 2001
Location: Cleveland, OH
2005 LGT Wagon 5MT


doesnt just about every tuner say NO, NO, NO to CAI's???
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