Explorer swap sensor confusion!!

[charlien]

Hey viper...use a conversion factor of .5 (divide kg/hr in half) and convert the kg/hr to cfm and replot them if you don't mind...let's see what that looks like.

 

[charlien]

------A9L ---- 94-95 Cobra ---- 94-95 GT
1V ---- 15cfm ---- 15cfm ---- 15cfm
2v ---- 50cfm ---- 50cfm ---- 50cfm
3v ---- 130cfm ---- 125cfm ---- 125cfm
4v ---- 265cfm ---- 255cfm ---- 255cfm


This is supposed to be a table....not much difference huh...


If it supposedly take 1.6 cfm to make 1 hp, and a stock motor is a little over 200hp, then you would only need 125cfm or 3V....and there is less than 4% difference at 3V between the A9l and 70mm 94-95 MAF.

 

[Viperwolf1]

Hey viper...use a conversion factor of .5 (divide kg/hr in half) and convert the kg/hr to cfm and replot them if you don't mind...let's see what that looks like.

The chart would look exactly the same except the scale on the y axis would be halved.

 

[charlien]

http://classicbroncos.com/forums/showthread.php?t=169420&highlight=running+lean

Stretch started with the 70mm MAF, but had issues and switched to the 55mm MAF and solved all of his problems......all the numbers look close, but it didn't work for him.

He has the 98 explorer 5.0 with explorer TB.

 

[Viperwolf1]

http://classicbroncos.com/forums/showthread.php?t=169420&highlight=running+lean

Stretch started with the 70mm MAF, but had issues and switched to the 55mm MAF and solved all of his problems......all the numbers look close, but it didn't work for him.

He has the 98 explorer 5.0 with explorer TB.

He also didn't mention exactly what 70mm MAF it was.

 

[lars]

I have the Explorer 70mm transfer function on my computer at home. I'm using it with a Tweecer on my A9L. I'll try to overcome my ADD long enough to sit still when I get home and post it here.

As for the comment about surging with mismatched MAF & ECU, that was me, once. I couldn't get my engine (5.0 Explorer, orange top 19 lb injectors, etc) to run right with anything other than the Mustang 55mm MAF. Even with the Tweecer and the Explorer MAF I still had to do some MAF curve tuning to settle the idle- probably due to my non-stock cam.

 

[lars]

2000 Explorer MAF curve

As promised.

0 0
0.71338 10.777
0.83569 13.946
0.948 17.116
1.085 21.553
1.2021 25.991
1.4172 35.183
1.481 38.352
1.564 42.79
1.7205 51.982
1.8572 61.174
1.96 69.098
2.0771 78.29
2.1848 87.482
2.2629 95.089
2.439 113.16
2.5806 129.95
2.7175 148.02
2.8347 164.82
2.9424 181.62
3.0547 200.32
3.2405 234.55
3.5728 303.97
3.7585 346.76
3.9395 390.82
4.1006 434.56
4.3794 520.77
4.6287 608.25
5.0049 754.69


The 64 thousand dollar question is what units those are. I'll confess I didn't do my due diligence but the numbers should be scalable.

 

[charlien]

I sent him a private message...............

Re: MAF question

--------------------------------------------------------------------------------

Quote:
Originally Posted by charlien
When you were having problems with your MAF...you said you were using the 70mm MAF to start..was this the explorer MAF or the 94-95 70mm MAF? and when you got a new one, you said it fixed your problems....what size/model was your new one?

All of this is from your running lean post.

Thanks,
Charlie

Over the last couple of years I've managed to collect enough EFI parts to convert three Broncos, so it is difficult to say where the MAF came from. I believe it is from a Cobra, I know it's not from the Explorer. This is the one that gave me problems with the A9L ecu.
I believe the new one is from a 92-93 mustang 5.0. Once this was installed, the lean conditions went away.
I hope this helps.

Brian

 

[Viperwolf1]

As promised.

0 0
0.71338 10.777
0.83569 13.946
0.948 17.116
1.085 21.553
1.2021 25.991
1.4172 35.183
1.481 38.352
1.564 42.79
1.7205 51.982
1.8572 61.174
1.96 69.098
2.0771 78.29
2.1848 87.482
2.2629 95.089
2.439 113.16
2.5806 129.95

The 64 thousand dollar question is what units those are. I'll confess I didn't do my due diligence but the numbers should be scalable.

Assuming those are cfm numbers, this is the comparison.

If they are Kg/hr numbers look at the 2nd chart (maf3.jpg).

Charts are updated. I think it's clear those are Kg/hr numbers so the 2nd chart is correct.

 

[charlien]

Can you really compare those numbers, since the computers were matched to the MAF and they all used different computers??????

I think the proof is there...both Stretch and Lars tried the larger MAF sensors and they didn't work (without a custom tune in Lars' case).

I guess the real question is, Has anyone used the larger MAFs and had it work?????

 

[Viperwolf1]

Can you really compare those numbers, since the computers were matched to the MAF and they all used different computers??????

I think the moral of this story is, if you're using a A9* ECM a '94-'95 mustang MAF is more likely to give you better results than an explorer MAF.

If stretch was using a '94-'95 mustang MAF that's only one data point.

 

[charlien]

Hey viper...what MAF are you running?

 

[Viperwolf1]

'88-'93 mustang

 

[charlien]

Viper....."If stretch was using a '94-'95 mustang MAF that's only one data point"

I'm not sure what you mean by this?

 

[Viperwolf1]

Viper....."If stretch was using a '94-'95 mustang MAF that's only one data point"

I'm not sure what you mean by this?

I mean you're right, we need more people to fess up and let us know if they've tried it. For all we know stretch's MAF could have been damaged.

 

[charlien]

Or maybe the 70mm MAFs just DON'T work.......(without a custom tune)!

 

[lars]

I mean you're right, we need more people to fess up and let us know if they've tried it. For all we know stretch's MAF could have been damaged.

I should point out that I grabbed that data from the Tweecer (caledit) software which is known to suck. I find it odd that the curve stops at 2.58 volts. Clint Garrity's software is infinitely superior to the bug-laden product supplied by Mike Glover of Tweecer fame, and it may well be that there is a scaling factor error in the numbers I posted (there definitely is in the software). Which reminds me that it's time to get off my arse and finish my tuning. But first, must... finish... airplane... project...

 

[lars]

OK, it's me that sucks. I failed to notice the curve points past 2.5807 volts, which were hidden in plain sight in Caledit. I added the values to my earlier post.

 

[Viperwolf1]

Charts are updated above.

 

[Broncobowsher]

That updated chart really shows the difference of the Explorer MAF compared to the mustang MAFs. Don't have the time at the moment to really analyse it, but with the mustangs having a spread of 8% (from prior math) That Explorer has to be WAY different.