Tutorial: How to scale your MAF [pics]
Scaling will be near impossible to set if you cannot get the MAF to read below 40Hz at idle. Try pulling the MAF further away from the turbo with a longer coupler. A method that worked for me was to install a 3" coupler inside my HKS pipe to make the pressure drop after the MAF dissappear. The pressure drop occurs becayse of the large size of the HKS pipe.
Another thing to try with the MAF is to adjust out the plug on the bottom. There is a dab of silicon on the bottom. Peel it out. You will find a hex head plug. Screw it out until when you look through the MAF the plug is flush. This will open up the bottom portion of the MAF allowing more air to bypass the MAF sensors and lower the HZ reading at idle. Also will allow more airflow at higher RPM, which is always a good thing.
Lastly, any time you make an adjustment on an 03 VIII you need to disconnect the battery and clear the residual memory from the ECU. Then, the car will re-learn and start adjusting trims once again.
Paul
Another thing to try with the MAF is to adjust out the plug on the bottom. There is a dab of silicon on the bottom. Peel it out. You will find a hex head plug. Screw it out until when you look through the MAF the plug is flush. This will open up the bottom portion of the MAF allowing more air to bypass the MAF sensors and lower the HZ reading at idle. Also will allow more airflow at higher RPM, which is always a good thing.
Lastly, any time you make an adjustment on an 03 VIII you need to disconnect the battery and clear the residual memory from the ECU. Then, the car will re-learn and start adjusting trims once again.
Paul
His ETS intake is 3" all the way I believe, so the drop should not exist, correct?
Interesting note about the screw, I never knew that! I figured it would be difficult to dial them in correctly without it being in range.
On a side note I rescaled the idle portion of my MAF today a bit to get rid of the 6% total enrichening the ECU was doing. That put ST and LTFT Low at 2% combined. Mid was less than 1 so I left it.
Installed 780cc injectors with scaling from the thread and haven't touched them from there yet. Total(LT+ST) trim is within 4%.
Interesting note about the screw, I never knew that! I figured it would be difficult to dial them in correctly without it being in range.
On a side note I rescaled the idle portion of my MAF today a bit to get rid of the 6% total enrichening the ECU was doing. That put ST and LTFT Low at 2% combined. Mid was less than 1 so I left it.
Installed 780cc injectors with scaling from the thread and haven't touched them from there yet. Total(LT+ST) trim is within 4%.
If the ETS is full 3 inch the issues lies in the tube design. The stock turbo has a 2.5" inlet, so the tube need to be 2.5" up until the MAF where it will taper to 3". Look at the stock rubber tube and the Perrin tube. Thus they both work great.
Try placing a 3" to 2.5" reducing coupler on the MAF and insert it into the ETS pipe. This might just solve the problem....It worked for my HKS pipe.
The other option is to get the car to idle at below 900 rpm. This will slow the air enough to get the Hz down. With big cams this could be a daunting task.
Try placing a 3" to 2.5" reducing coupler on the MAF and insert it into the ETS pipe. This might just solve the problem....It worked for my HKS pipe.
The other option is to get the car to idle at below 900 rpm. This will slow the air enough to get the Hz down. With big cams this could be a daunting task.
If the ETS is full 3 inch the issues lies in the tube design. The stock turbo has a 2.5" inlet, so the tube need to be 2.5" up until the MAF where it will taper to 3". Look at the stock rubber tube and the Perrin tube. Thus they both work great.
Try placing a 3" to 2.5" reducing coupler on the MAF and insert it into the ETS pipe. This might just solve the problem....It worked for my HKS pipe.
The other option is to get the car to idle at below 900 rpm. This will slow the air enough to get the Hz down. With big cams this could be a daunting task.
Try placing a 3" to 2.5" reducing coupler on the MAF and insert it into the ETS pipe. This might just solve the problem....It worked for my HKS pipe.
The other option is to get the car to idle at below 900 rpm. This will slow the air enough to get the Hz down. With big cams this could be a daunting task.
Not to mention they use a 3" coupler from the pipe to the MAF, so you already have to stretch the coupler some to get it over the MAF.
There are no other ways to cure the issue?
The car runs and drives fine with the stock injectors. Possible to get the hz down, dial them in, then remove the piece to let it back to normal and it still run ok?
I see no need or have the desire to tackle the SD.
I see no need or have the desire to tackle the SD.
well I put the stock injectors back in and the car runs great! The idle trim still won't move cuz its still idling at around 50-60hz, but the mid trim is pulling 12 percent fuel, and the short term 20ish. Its actually causing it to throw a p0172.
That doesn't make much sense to me, as I thought it had to trim rich, not lean with this intake? Plus that means most the scalings I tried with the 1k's weren't right, as the car never ran that well with them but fine with the stockers...
That doesn't make much sense to me, as I thought it had to trim rich, not lean with this intake? Plus that means most the scalings I tried with the 1k's weren't right, as the car never ran that well with them but fine with the stockers...
I can't help but think your injector scaling is pretty far off causing most of the problems. With a bigger intake pipe the hz reading I always thought would be lower due to the larger diameter of pipe the air travels slower. Not sure maybe others can chime in. On my car the idle hz are lower than stock not higher
Last edited by fostytou; May 4, 2009 at 10:59 AM.
His car is on stock injectors right now with the ETS intake. The MAF hz is almost 50 I believe, if not a little higher. The VC vent is routed to the intake just like stock and everything.
Its wierd that the ECU is pulling so much fuel with just the stock injectors and scaling with only the intake.
Its wierd that the ECU is pulling so much fuel with just the stock injectors and scaling with only the intake.
Going from a cut OE airbox to an open filter lowered my idle airflow by ~10hz (back to between 18 and 25). I then test fit a 3" hard intake pipe with the open filter and my idle airflow went >40hz... though this was with the VC breather open to air. I'll try to report back once my catch can comes in and I can get all of the air metered.
Car runs great in almost all conditions, the only thing I'm having trouble with is a lean then rich spike when coming back to idle. It hangs at the desired RPM for a split second but stays lean, can't tell if this is just wideband delay. It then goes way rich and settles at perfect after a second or two.
The other is when running the car WOT I get rich during shifts. I suspect that this is backflow from the BOV.
When you say breather you are talking about connecting the intake tube to the valve cover, correct?
I have mine connected and have nevr gotten idle Hz to be below 33Hz since puttin in my cams and raising idle RPM to 1000.
I have mine connected and have nevr gotten idle Hz to be below 33Hz since puttin in my cams and raising idle RPM to 1000.
Correct. My idle is still at stock levels since the S1's idle nice 'n pretty, but I would have gone with the S2 if I could do it over again.
FYI, I'm hosting the doc that was copied from this here:
http://thefrost.net/randomfiles/tuni...%20intakes.doc
and adding it to the wiki also
credit to oldevodude for hanging on to it
http://thefrost.net/randomfiles/tuni...%20intakes.doc
and adding it to the wiki also
credit to oldevodude for hanging on to it