MAF Cliping with Turbo Kit

[Giupo]

Hi, I have a Yaris 1nzfe with:

Greddy turbo
Greddy emanage ultimate with sensor pressure
Injector 380cc
Fuel pump
Cp pistons 9:1 cr
Pauter roads
Cams
Greddy elettronic overboost


I have mapped with 18 psi turbo pressure but the MAF between 3500 - 4500 rmp is cliping.

Could I eliminate the toyota Maf?

Thanks

[cali yaris]

Please post pictures, especially of the cams, and dyno chart.
Where did you get the head studs for your build?

[Giupo]

Sorry but I don't have a dyno charts because i want eliminate the Maf sensor because it is a problem at 3500 rmp the car is block and i want know if the problem is the MAF or O2sensor under 10psi the problem don't have but up 10 psi have this problem.

Thanks

[scioncrew]

I dont think the Greddy emanage will lit you bypass the MAF it kinda needs it. Im not an expert with MAF sensor's but i think to fix your problem your going to need a bigger higher flowing MAF. Your only other option that will eliminate the MAF is to go with a full standaloan EMS. ( AEM,MOTEC,HYDRA ect.)

Regard
Arthur

[Nexus1155]

Yeah I highly doubt it is the O2 sensor, most likely it is the MAF sensor. It is scaled for only so much air, unless you can install a larger MAF and scale the curve for the added g/s of airflow, then you need to lose it and put a MAP sensor in there...

Good Luck!

[Giupo]

Thanks for your answer..
The problem is the MAF sensor, with greddy Emanage Ultimate I can eliminate the MAF sensor with "Airflow Output" map but I have need of the values of the MAF sensor with stock engine ( volt at all RPM).
Someone could help me?

Thanks

[cali yaris]

I have need of the values of the MAF sensor with stock engine ( volt at all RPM).

Don't know that curve. Someone will know the range though.

[Giupo]

Who knows the 1NZ-FE MAF voltage range?

Thanks

[kurokoma-kun]

You mean just the normal operating range? The manual says its between 0.4 V and 2.2 V

[Russelt3hPirate]

where in the turbo routing did you mount the MAF?

what size is the MAF housing?

it's possible you're maxing out the MAF's readings and you need to go to a larger diameter MAF housing and retune.

or you could be having issues if it's
A.) too close to the turbo inlet
B.) Blow thru (after the turbo outlet)
C.) bad maf

[CTScott]

You mean just the normal operating range? The manual says its between 0.4 V and 2.2 V

From what I've seen the MAF voltage vs RPM plots are pretty linear, so based on the normal operating range of 0.4 to 2.2, you could start with the following:

100 0.4
200 0.430508475
300 0.461016949
400 0.491525424
500 0.522033898
600 0.552542373
700 0.583050847
800 0.613559322
900 0.644067797
1000 0.674576271
1100 0.705084746
1200 0.73559322
1300 0.766101695
1400 0.796610169
1500 0.827118644
1600 0.857627119
1700 0.888135593
1800 0.918644068
1900 0.949152542
2000 0.979661017
2100 1.010169492
2200 1.040677966
2300 1.071186441
2400 1.101694915
2500 1.13220339
2600 1.162711864
2700 1.193220339
2800 1.223728814
2900 1.254237288
3000 1.284745763
3100 1.315254237
3200 1.345762712
3300 1.376271186
3400 1.406779661
3500 1.437288136
3600 1.46779661
3700 1.498305085
3800 1.528813559
3900 1.559322034
4000 1.589830508
4100 1.620338983
4200 1.650847458
4300 1.681355932
4400 1.711864407
4500 1.742372881
4600 1.772881356
4700 1.803389831
4800 1.833898305
4900 1.86440678
5000 1.894915254
5100 1.925423729
5200 1.955932203
5300 1.986440678
5400 2.016949153
5500 2.047457627
5600 2.077966102
5700 2.108474576
5800 2.138983051
5900 2.169491525
6000 2.2

[Giupo]

where in the turbo routing did you mount the MAF?

what size is the MAF housing?

it's possible you're maxing out the MAF's readings and you need to go to a larger diameter MAF housing and retune.

or you could be having issues if it's
A.) too close to the turbo inlet
B.) Blow thru (after the turbo outlet)
C.) bad maf


The MAF housing is 2.20"

[Giupo]

For CTScott
thank you very much for the value but my toyota MAF sensor is 0,2v at 4,9v.

[CTScott]

For CTScott
thank you very much for the value but my toyota MAF sensor is 0,2v at 4,9v.

The output of the sensor can go from 0.2 to 4.9, but the "normal range" goes to 2.2 V.

[CTScott]

Have you measured the MAF voltage where the clipping occurs?

[Giupo]

yes is 3,94 volt at 4200rmp

[Giupo]

I have use the "Boost limiter cut" map but the engine between 4000 and 5000 rpm refrains slightly.. the A/F ratio is good

[CTScott]

yes is 3,94 volt at 4200rmp

OK. So, it that case I would scale it from 0.4 to 3.90 volts:

100 0.400
200 0.459
300 0.519
400 0.578
500 0.637
600 0.697
700 0.756
800 0.815
900 0.875
1000 0.934
1100 0.993
1200 1.053
1300 1.112
1400 1.171
1500 1.231
1600 1.290
1700 1.349
1800 1.408
1900 1.468
2000 1.527
2100 1.586
2200 1.646
2300 1.705
2400 1.764
2500 1.824
2600 1.883
2700 1.942
2800 2.002
2900 2.061
3000 2.120
3100 2.180
3200 2.239
3300 2.298
3400 2.358
3500 2.417
3600 2.476
3700 2.536
3800 2.595
3900 2.654
4000 2.714
4100 2.773
4200 2.832
4300 2.892
4400 2.951
4500 3.010
4600 3.069
4700 3.129
4800 3.188
4900 3.247
5000 3.307
5100 3.366
5200 3.425
5300 3.485
5400 3.544
5500 3.603
5600 3.663
5700 3.722
5800 3.781
5900 3.841
6000 3.900

[changchewsoon]

Giupo,

I'm currently using the E-Manage Blue for my turbo, and the MAF volt is clamped at 4.95v.

Do you have a MAP sensor as well? If budget permits, you may want to add a MAP sensor as another input for your Ultimate and tune your car off its reading as well. You can achieve a much more accurate tune with a MAP sensor rather than relying on the TPS readings. But in your case, you have the boost harness as well, which is cool.

If you don't want to go standalone but yet you want to remove the MAF altogether, you could consider using the HKS F-CON V Pro. It allows you to remove the MAF physically.

[Giupo]

For CTScott

Excuse me but my MAF arrive at 4.9v..Thank you very much

[Giupo]

Giupo,

I'm currently using the E-Manage Blue for my turbo, and the MAF volt is clamped at 4.95v.

Do you have a MAP sensor as well? If budget permits, you may want to add a MAP sensor as another input for your Ultimate and tune your car off its reading as well. You can achieve a much more accurate tune with a MAP sensor rather than relying on the TPS readings. But in your case, you have the boost harness as well, which is cool.

If you don't want to go standalone but yet you want to remove the MAF altogether, you could consider using the HKS F-CON V Pro. It allows you to remove the MAF physically.


I have the Greddy E-manage Ultimate and use the Greddy sensor pressure..I can eliminate the maf with this greddy ecu but I need the Maf value..

[CTScott]

For CTScott

Excuse me but my MAF arrive at 4.9v..Thank you very much

If I understand correctly, it goes up to 4.9v, but the clipping starts when it is at 3.94v?

[Giupo]

ok, the maf sensor arrive at 4.9v at 6000 rmp but at between 4000-5000rpm the Maf value 3.94v I avvert the slightly engine brake but the A/F ratio is good..

[CTScott]

ok, the maf sensor arrive at 4.9v at 6000 rmp but at between 4000-5000rpm the Maf value 3.94v I avvert the slightly engine brake but the A/F ratio is good..

Tomorrow I will have time to connect a voltmeter to mine and see what a normal one reads at various RPM. I suspect that it will follow with the 0.4 to 2.2 normal operating range.

The question is why does yours clip between 4K and 5K, but then stop clipping above that?

[Giupo]

I don't know because the maf clip between 4000 and 5000 Rpm, before 4000 rpm e after 5000 rpm the engine is good... I suppose that between 4000 and 5000 Rpm the engine is at max of Tourque.

[Russelt3hPirate]

I don't know because the maf clip between 4000 and 5000 Rpm, before 4000 rpm e after 5000 rpm the engine is good... I suppose that between 4000 and 5000 Rpm the engine is at max of Tourque.

the turbo is most likely flowing the most volume of air at the RPM and maxing out your MAF.

do you have any datalogging showing your MAF logs based on load and RPM?

[Giupo]

Hi Guys :)

*The problem has been resolved* The maf clip because it was too much near the turbo downpipe and the heat annoyed the Maf sensor. I have moved the Maf support more near the air filter and the problem has been resolved :)

picture before the support maf moved:
http://img151.imageshack.us/img151/3567/dscn1699z.th.jpg (http://img151.imageshack.us/my.php?image=dscn1699z.jpg)

[CTScott]

Hi Guys :)

*The problem has been resolved* The maf clip because it was too much near the turbo downpipe and the heat annoyed the Maf sensor. I have moved the Maf support more near the air filter and the problem has been resolved :)

picture before the support maf moved:
http://img151.imageshack.us/img151/3567/dscn1699z.th.jpg (http://img151.imageshack.us/my.php?image=dscn1699z.jpg)

I'm glad to hear it's resolved. Excess heat makes a lot of sense for what was happening.

[Giupo]

Thank you very much :)

[PHXDEMON]

Hi Guys :)

*The problem has been resolved* The maf clip because it was too much near the turbo downpipe and the heat annoyed the Maf sensor. I have moved the Maf support more near the air filter and the problem has been resolved :)

picture before the support maf moved:
http://img151.imageshack.us/img151/3567/dscn1699z.th.jpg (http://img151.imageshack.us/my.php?image=dscn1699z.jpg)
Great to hear it was fixed :thumbup: I'm assuming that turbo kit is full on custom? Do you have anymore pics?

[Bluevitz-rs]

Bump... I never noticed this thread. Might be useful.

[Bluevitz-rs]

I'm getting this same problem. Has anyone ever data logged the MAF voltages on a NA engine?

I'm getting clipping at random RPMs but I did a log and if I floor it, the MAF spikes to 3.9V and that's when the hiccups occur. This can be anywhere from 2000 to 5000 RPM. Odd thing is, the MAF will still read all the way up to 4.4V without any hiccups sometimes.

[kou]

I'm getting this same problem. Has anyone ever data logged the MAF voltages on a NA engine?

I'm getting clipping at random RPMs but I did a log and if I floor it, the MAF spikes to 3.9V and that's when the hiccups occur. This can be anywhere from 2000 to 5000 RPM. Odd thing is, the MAF will still read all the way up to 4.4V without any hiccups sometimes.

Are you using aem fic or greddy e manage?

[Bluevitz-rs]

FIC

I haven't tried building a MAF voltage table yet. Haven't had time.

[kou]

FIC

I haven't tried building a MAF voltage table yet. Haven't had time.

Only maps you should be using are the o2 and fuel maps. Maf clamp is in the setup menu and should be set at 4.95. unless you have the maf in a bigger or smaller pipe that is what the maf table is for. aem does not really go over this and it causes alot of people problems.

[Bluevitz-rs]

Only maps you should be using are the o2 and fuel maps. Maf clamp is in the setup menu and should be set at 4.95. unless you have the maf in a bigger or smaller pipe that is what the maf table is for. aem does not really go over this and it causes alot of people problems.

I have it set to 4.9v. The problem is I can get it to produce 3.9V at as low as 2000 rpm. I'm thinking the computer sees this as a problem and cuts ignition or fuel.

The MAF table allows you to set the voltage output based on the voltage input.

So you can have it read exactly as it should up to the point where the turbo starts drawing in more air than a NA engine would and makes it freak out, clamping the voltage at a set RPM.

I've had this problem even before I had an FIC installed. I've even run the car without the O2 sensor hooked up and just the FIC making fuel adjustments.