Which mass air for Tweecer?

Discussion in '1994 - 1995 Specific Tech' started by cjrpony, Mar 13, 2010.


  1. cjrpony

    cjrpony Member

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    I just got a Tweecer RT and LM-1 wideband and I am reading all the different stuff about setting it up and using it. Currently I have a 73mm Vortech mass air for 30lb injectors. Some of the things I have seen suggest using a Ford meter like the 70 or 80mm and using the Tweecer to set-up the calibration. It looks like the EEC Analyzer and the CalEdit both have preset mass air units in their software. It doesn't look like the one I have now is on either of those lists. I know I can still use it, but I would think I would have better results if I use one with known MAF values. Any suggestions on what works best with the Tweecer.
     
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  2. BlackVert

    BlackVert Mustang Master

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    i have (and like) the 90mm LMAF. the maf transfer function for that is well known. it needs an adapter, but the wiring is simple and i made my own in 10 minutes with a couple dollars worth of parts from radio shack

    but it still can vary depending on the way it is clocked and if there are bends in the tubing before the element. mine is a straight shot into the fenderwell with 4" PVC and no bends.

    if you are interested, i can snap a couple pics of my setup for you
     
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  3. cjrpony

    cjrpony Member

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    Thanks, some pics would be cool. By 90mm LMAF, you mean the Lightning unit?
     
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  4. BlackVert

    BlackVert Mustang Master

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    yep, lightning. unfortunately, the homemade adapter is not visible as it is in the fenderwell.

    i enlarged the hole to the fenderwell and slit a fuel hose lengthwise and lined it with the hose. then i made a tube with pvc from home depot and painted it silver. i'm happy with it

    [​IMG]

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    the old bends before the meter ... they caused havoc with the readings
    [​IMG]
     
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  5. cjrpony

    cjrpony Member

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    Thanks for the photos! I got the Tweecer hooked up yesterday and tested it out. I did the read on the EEC (T4M0) and copied it to all 4 positions to make sure nothing funny was left in it. I got the car running but it didn't run very good. I am guessing maybe because I had the battery unhooked it needs to relearn. I still need to put it back to 10 degrees timing too. I did play around with the idle speed a bit to make sure the Tweecer was working. I'll play around with it some more today and hopefully get it running smoothly again. Any tips on setting this thing up would be appreciated:D
     
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  6. BlackVert

    BlackVert Mustang Master

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    do you have any air flow figures for the maf?

    if not, then since it is calibrated for 30# injectors, multiply all the flow numbers in the stock maf transfer function by 1.579 (which corresponds to 30/19).

    in the scalars tab, set the engine cid to 331, the low and high injector breakpoint values to 30

    do all this at the same time.

    and set that timing back to 10!
     
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  7. cjrpony

    cjrpony Member

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    Thanks again for the help. I don't have any numbers for the mass air sensor, so I am looking to get a different one with known air flow numbers. In the mean time I will put in the numbers you suggest in the MAF transfer function. Its nice out today so I am going to get out an make these changes and see what happens:D
     
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  8. BlackVert

    BlackVert Mustang Master

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    any update?
     
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  9. cjrpony

    cjrpony Member

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    I got a 76mm C&L mass air and the new o2 sensors put on and have done a few datalogs. I tried using Caledit and Calcon but ended up getting BE and EA a few days ago. I just took it out yesterday for a datalog on the road. It idles well and runs ok up to a point, but anything more than about half throttle I am getting some missing and hesitation. I just ran the datalog thru EA a little while ago and I am going to double check some things on the motor before I give it another go. Any suggestions on a order in which I should procede would be helpful. Right now I am just winging it. Not really making any major changes yet, just seeing how everything works.
     
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  10. cjrpony

    cjrpony Member

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    Another update, I checked over some mechanical things today to figure out the hesitation and lack of power and found my timing to be way off. When I put the timing back to 10 degrees, I must have goofed up because it was at 10 degrees ATDC! OPPS:stupid: Its hard to see down there! Anyways, I set it back to 10 BTDC and it runs awesome now! Now I can get to work on really getting it tuned in.
     
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