JCviggen Posted March 11, 2010 Report Share Posted March 11, 2010 I used an old MAF in a 3" custom housing thanks to Raf No clue if an ME 7 could be used or not.. Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted March 11, 2010 Report Share Posted March 11, 2010 Seems like a chunk of 3" intercooler piping and some epoxy should do it. Scale the fuel values up by the same % difference in cross sectional area per the 3" pipe vs the stocker and it should easily be close enough to drive and re-tune. Quote Link to comment Share on other sites More sharing options...
JCviggen Posted March 11, 2010 Report Share Posted March 11, 2010 That's fine, except that he has no idea how much airflow is increasing as he adds boost after the point where the maf maxes out, and it still doesn't explain why the timing is not what is has been mapped to. I agree on the timing. M4.X is a tough nut to crack when it comes to understanding timing advance and what it does with the tables. If he has an AFR gauge he can see exactly how much fuel he needs to add or take out of the map at full boost, regardless of the MAF being maxed out. You don't need to know the airflow, boost vs AFR is all you need? The trouble only starts when M4.X uses that amount of fuel from the moment the MAF maxes, so it's only correct at full boost but not at less boost (but still maxed maf) Quote Link to comment Share on other sites More sharing options...
BlackT5 Posted March 11, 2010 Report Share Posted March 11, 2010 looking at the wiring diagrams, I don't think the ME7 sensor can be rewired to work with M4.3/4. The ME7 unit receives a 5v,12v,signal,signal ground while the M4.3/4 gets 12v,power ground, signal, signal ground. Also the signal voltages are different. Idle voltage for ME7 is 1.7v while M4.3/4 is 0.9v Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted March 11, 2010 Report Share Posted March 11, 2010 No point in trying to adapt a different sensor. It sounds like a job for a 3" piece of aluminum pipe, a drill, and some epoxy. True enough on the afr vs fuel map value JC. Same can be said for map sensed systems where the desired boost pressure is slightly higher than the max the MAP sensor can read - you set the values to whatever is correct for max boost and it's just a bit rich/retarded for the few psi before that. Getting some numbers at 15psi, and at 18psi or something like that has been mentioned by a few folks now and to re-cap, I'd say that is good advice. Even 12, 15, and 18. Try to get a feel for what the car does as boost increases. Determining if/how/when the motor starts to underperform as boost is added will help narrow down what the issue(s) is(are). Quote Link to comment Share on other sites More sharing options...
lookforjoe Posted March 11, 2010 Author Report Share Posted March 11, 2010 Seems like a chunk of 3" intercooler piping and some epoxy should do it. Scale the fuel values up by the same % difference in cross sectional area per the 3" pipe vs the stocker and it should easily be close enough to drive and re-tune. So, if the area of the stock opening (61mm) is 2922.46cm2, and I have a slightly bored out housing, (64,5mm) the area of which is 3267.45cm2, then I get the difference of 344.99cm3 which is 11.75%. I would then scale my maps upwards (moving the higher load values lower down the map) by that percentage? 3" MAF has 71mm opening, so that would mean an area of 3959.19cm2, a difference of 1036.73cm3, and a 35.45% difference, assuming my math is correct. EDIT: fixed my incorrect units of measurement :rolleyes: Quote Link to comment Share on other sites More sharing options...
98 s70 t5m Posted March 11, 2010 Report Share Posted March 11, 2010 So, if the area of the stock opening (61mm) is 2922.46cm3, and I have a slightly bored out housing, (64,5mm) the area of which is 3267.45cm3, then I get the difference of 344.99cm3 which is 11.75%. I would then scale my maps upwards (moving the higher load values lower down the map) by that percentage? 3" MAF has 71mm opening, so that would mean an area of 3959.19cm3, a difference of 1036.73cm3, and a 35.45% difference, assuming my math is correct. Wouldn't your ratios be in cm2 not cm3. first ratio would be (64.5^2)/(61^2)= 1.118, second ratio would be (71^2)/(61^2)=1.354 Looks like you math is correct, your units are just wrong. Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted March 11, 2010 Report Share Posted March 11, 2010 Sounds about right. Make sure you move the timing values as well. Quote Link to comment Share on other sites More sharing options...
Dominic Posted March 12, 2010 Report Share Posted March 12, 2010 You're looking for are (cm^2) not volume (cm^3) witch is what you have there. . maybe it's just a mistake in typing as i didn't do the math, but just throwin that out there Quote Link to comment Share on other sites More sharing options...
lookforjoe Posted March 12, 2010 Author Report Share Posted March 12, 2010 Wouldn't your ratios be in cm2 not cm3. first ratio would be (64.5^2)/(61^2)= 1.118, second ratio would be (71^2)/(61^2)=1.354 Looks like you math is correct, your units are just wrong. You're looking for are (cm^2) not volume (cm^3) witch is what you have there. . maybe it's just a mistake in typing as i didn't do the math, but just throwin that out there You're right - I'm just bad at math :rolleyes: Quote Link to comment Share on other sites More sharing options...
GeraldJ Posted March 12, 2010 Report Share Posted March 12, 2010 This has turned into the epic thread for tuning info. One question, isnt the beauty of the TT, the fact that users can share tunes? Could Jan email his tune in a file for you to try out when you do get a 3inch MAF? Then you would have all the changed values, you would just have to massage the fuel and timing maps for the smaller turbo. But then again, is the 4.3maps compatible with the 4.4? Quote Link to comment Share on other sites More sharing options...
lookforjoe Posted March 12, 2010 Author Report Share Posted March 12, 2010 This has turned into the epic thread for tuning info. One question, isnt the beauty of the TT, the fact that users can share tunes? Could Jan email his tune in a file for you to try out when you do get a 3inch MAF? Then you would have all the changed values, you would just have to massage the fuel and timing maps for the smaller turbo. But then again, is the 4.3maps compatible with the 4.4? Users can share tunes, but not if they are based on maps extracted from other vendors (Woth, MTE, etc...) those are tied to the TT license one purchases. ME.4.3 tunes can be imported either way, they just need converting to the appropriate scaling. Quote Link to comment Share on other sites More sharing options...
maciekb2002 Posted March 12, 2010 Report Share Posted March 12, 2010 Always problems ,where do I know that story from ? Quote Link to comment Share on other sites More sharing options...
lookforjoe Posted March 12, 2010 Author Report Share Posted March 12, 2010 Always problems ,where do I know that story from ? I know. Another issue in the saga is oil in the intake tract. This 20g has always deposited a fair bit of oil into the intake & IC plumbing, so in trying to address every conceivable issue with my tune, I'm figuring oil in the intake charge ain't so great. On the dyno, when the IAC hose ruptured, you would have thought it was an oil leak, from the spray. SO, I'm looking into oil restrictors to drop the pressure in the CHRA, and therefore on the compressor side seal. The stock banjo bolt is M12, with 5mm orifices opening to 7mm bolt ID. Hahn said one option is to use a .060 nitrous jet as a restrictor, but that would mean a reduction of 2/3 the current orifice. Not knowing what the line pressure that is delivered to the CHRA, I don't know if that much of a restriction is excessive, or not. So, has anyone here ever measured the line pressure to the turbo? Any thoughts on the restrictor port? I also don't know what the optimal CHRA oil pressure is. Basically, I'm just gonna take the banjo bolt & add an inner sleeve with smaller ports, or fill the existing ports & re-drill accordingly Quote Link to comment Share on other sites More sharing options...
Captain Bondo Posted March 12, 2010 Report Share Posted March 12, 2010 What does your inlet tract into the turbo look like? The turbo can make vaccuum in the compressor inlet if the air filter/etc are too restrictive. This will suck oil into the compressor inlet. Quote Link to comment Share on other sites More sharing options...
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