Can I put on a MAF meter calibrated for 24# injectors without using a Tweecer?

Pokageek

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#1

• Jan 17, 2006

• #1

Straight forward question. Let's say I have 24# injectors and a MAF calibrated for 24# injectors. Do I need a tweecer??

 

G

Green 94 5.0

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#2

• Jan 17, 2006

• #2

if the MAF is calibrated to the injector size, you do not need a tweecer. the car should run fine.

 

Pokageek

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#3

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Thanks man!

 

BlackVert

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#4

• Jan 17, 2006

• #4

you don't NEED a tweecer, but ...

you are still "fooling" the computer by letting in more air than the computer thinks is coming in. the extra air is compensated for by the injectors, so it should run fine.

most of the decisions the computer makes are dependent on the perceived load. it uses the amount of air reported by the maf to determine the load.

in your case, the actual load will be higher than the load the computer calculates, so its decisions (like spark advance and target a/f ratio) will be less accurate. specifically, a/f could be targeted too low and spark may be advanced too far (because the computer thinks there is less load then there really is). this could result in detonation.

that said, the difference in load is probably not enough to cause real problems, epsecially if you have an afpr. then if you do get detonation in the higher load ranges, you can up the pressure to get around it (but then you are probably too rich down low).

 

Don 95Vert

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#5

• Jan 17, 2006

• #5

BlackVert said:

it uses the amount of air reported by the maf to determine the load... in your case, the actual load will be higher than the load the computer calculates, so its decisions (like spark advance and target a/f ratio) will be less accurate.

Click to expand...

This is about 99% correct - the 1% wrong part is with a calibrated MAF, load will be lower than it should be - and at lower loads the spark is higher. With an NA car with 24# injectors - as stated, it probably won't be an issue, because at 90% load the spark (without considering adders/subtractors) is 25* - with a 24# calibration load would be reduced to about 71% spark would be about 27-28* - still pretty safe for a NA car. Although with a 94-95's propensity for pinging this COULD be an issue. This also assumes the ability to get to 90% load, which it probably would not do - so the spark might be still higher.

Don

 

BlackVert

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#6

• Jan 17, 2006

• #6

Don 95Vert said:

... load will be lower than it should be ...

Click to expand...

that is what i said, just the other way around, isn't it? i said "the actual load will be higher than the load the computer calculates", which means the computer's load will be lower than it should be.

maybe i'm not following you.

 

Don 95Vert

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#7

• Jan 17, 2006

• #7

Lost in translation.. LOL!! I see what you meant!

Don

 

BlackVert

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#8

• Jan 17, 2006

• #8

Don 95Vert said:

Lost in translation.. LOL!! I see what you meant!

Don

Click to expand...

 

Pokageek

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#9

• Jan 17, 2006

• #9

Going with a custom tune BTW. Tweecer is up for grabs. It is a base but can be sent in for an upgrade. Great for someone who likes to tune it themselves. I went custom chip.

 

zkillrr

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#10

• Jan 25, 2006

• #10

Well guys i bought a pro m about 2years ago cal for 24# injectors and it took some of my low end power and I don't feel it up top either. I wonder is it b/c i don't have a ajustable feul pressure reg. Any comments.

 

final5-0

Mustang Master

Apr 6, 2003

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#11

• Jan 25, 2006

• #11

zkillrr said:

Well guys i bought a pro m about 2years ago cal for 24# injectors and it took some of my low end power and I don't feel it up top either. I wonder is it b/c i don't have a ajustable feul pressure reg. Any comments.

Click to expand...

Is it possible your heated wires in the maf electronics need to be cleaned.

Grady

 

zkillrr

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#12

• Jan 25, 2006

• #12

Its funny you say that b/c it was like that the first day i put it on. I had to look at the box to make sure they sent me the right one . All the #s match up but who to say the didn't put it in the wrong box. How do i clean it and could it have come dirty?