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redracer311
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redracer311 Sep 19, 5:04pm - #46471 
2000 Red Toyota Celica GT
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2000 Toyota Celica GT

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St Louis Mo, South County
Is this a crazy idea?

As far as I know they do not make aftermarket MAF sensors for our cars. I was wondering what exactly it would do if you took the stock MAF and mounted a funnel shaped piece onto it so that it would collect more air at that point and force it onto the sensor that recieves the "signal" of how much air is flowing into the engine. My guess would be that It would trick the MAF into thinking that there is more air and in return richen the air/fuel mixture. Does anyone know for sure if thats what would happen. And yes I do know that there are Devices made by Greddy and Apex that can richen the mixture. So give your two cents. Is this A. a bad idea or B. a good idea or C. who the f&*k cares?
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trog2233
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trog2233 Sep 19, 5:05pm - #46472 

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Don't think that would work...good thinkin though thumbsup
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Steven
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Steven Sep 19, 6:53pm - #46473 
2001 Spectra Blue Mica Toyota Celica GTS
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I believe it's the O2 sensors that control air fuel ratios, NOT the Mass Air Flow Sensor (MAFS).
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chameleon
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chameleon Sep 19, 6:58pm - #46474 

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2000 Toyota Celica

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Michigan
I'm thinking that this kind of a setup would not work. You would be unable to know exactly how much of an alteration of percentage of fuel enrichment is occuring. Also, you would be unable to make fuel trim adjustments at individual engine RPM increments, any adjustment you would make would be flat across the entire engine RPM range.

Another questionable factor with this set up is how the air will react to the funnel. I see your logic with the funnel concept. Basically, one end of the funnel is much larger than the other end, which will result in a greater surface area of ambient air being forced into the smaller opening at the other end, which is where the MAF will be and where it will take it's reading. But what other factors will come into play? Due to the overall shape of the funnel (a narrowing tunnel) the air will increase in velocity. It's possable that due to the obstruction at the end of the funnel (the MAF sensor) a lot of turbulence will occure which will result in the MAF taking a lower air reading then it did with out the funnel. This would of course result in the ECU making the engine more lean.

Finally, this is just another form of trying to "trick" the ECU with a false MAF signal. This will not work with our cars because the ECU relies on more than one sensor when applying air fuel ratio's. I made a super LONG post a little while ago that explains how the ECU reacts to false MAF signals, you can read the thread if you want to know more about it.
Super chips?

Any way, it is a good and creative idea though. If you decide to try it, be sure to post your results! smile
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chameleon
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chameleon Sep 19, 7:13pm - #46475 

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2000 Toyota Celica

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Originally Posted by Steven
I believe it's the O2 sensors that control air fuel ratios, NOT the Mass Air Flow Sensor (MAFS).


The O2 sensors are located just before and after the catalytic converter in the exhaust system. The ECU can not use these sensors to control air fuel ratios because once the ECU has received a reading from them, the combustion process has already occured. In order to control air fuel ratio's, the ECU needs to know how much air is present AS it is entering the engine, and this reading occurs from the MAF.

I just think that you were confused because the O2 sensors is where people get their readings to adjust the air fuel ratio's. But like I said, if the ECU got it's air reading from there, it would be too late to add any fuel.
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Steven
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Steven Sep 19, 7:14pm - #46476 
2001 Spectra Blue Mica Toyota Celica GTS
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Where did you get that info Cham?
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redracer311
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redracer311 Sep 19, 8:01pm - #46477 
2000 Red Toyota Celica GT
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2000 Toyota Celica GT

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St Louis Mo, South County
That was pretty informative. I like this forum because there are some guys out there that are like text books. I probably won't mess with anything then. Oh, I did just get in a factory ecu for my car so it won't be long before I dyno it with and without the jet chip. I will definetly post the results.
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chameleon
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chameleon Sep 19, 8:04pm - #46478 

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2000 Toyota Celica

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confused

It's not some thing I read in an article or any thing like that. It's all just stuff I have learned from being really involved with the 7th gen Celica, I bought my 2000 GTS some time in late 1999 and I immediately started modifying it. Primarily because I was modifying the car, I wanted to learn every thing there was to know about it, so have been reading up about the car on forums/articles for the past 3 years and almost every available modification has been personally done to my car, so I just know a lot about this stuff in general. Most of the information that I have learned about the Celica was from NC.org.

In the specific case of the ECU over riding the SAFC, I remember first becoming aware of the problem when NC.org member cool2mike was trying to use SAFC to tune a custom fabricated turbo system on his GT. He did 30 dyno runs trying to tune his car which proved to be an impossible task because the ECU kept compensating for the adjustments. Because this compensation was visibly proven on all the dyno run print out's, people could no longer ingnore the possibility that the SAFC was, in fact, worthless on a 7th gen Celica. Through other multiple posts that were made over time, people figured out what was actually going on in regards to false MAF votages and OBD11.

I'm sorry that I don't have a specific article to refer your to, or a specific source of information to support what I am saying. I will say this - I would never submit any information unless I felt that it was all 100% accurate because I know how false information can effect the end user, especially in regards to making important and some times expensive decisions when modifying your car. I am honestly just trying to help people out here. wave

I'll bet that cool2mike, for example, would have appreciated knowing about this before he spent all the money on 30+ dyno runs. grin
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Steven
ECelica Staff
Steven Sep 19, 10:34pm - #46479 
2001 Spectra Blue Mica Toyota Celica GTS
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I understand your position Cham, and I'm not calling you a liar or anything but I didn't think that's what the MAFS was for. I'll do more research to back up my info.

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Steven
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Steven Sep 19, 10:48pm - #46480 
2001 Spectra Blue Mica Toyota Celica GTS
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I just talked to a toyota tech and he said that the mass air flow sensor measures how much air is flowing in the Intake tube along with other things like air Intake temperature and uses that information along with the information that the O2 sensors gather, like EGT to a determine air fuel ratios. that is one long sentence.
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chameleon
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chameleon Sep 20, 2:19am - #46481 

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2000 Toyota Celica

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That was a long sentence! smile

Yes, you are correct about that, both sensors do influence air fuel ratio's. The MAFS is where the ECU gets its readings for primary fuel enrichement. The O2 sensors then takes readings to determine the effeciency of the resulting combustion process and then applies trim settings that are stored in the ECU. This allows the ECU to compensate for various engine malfunctions, such as a vacuume leak or a sticky valve which would cause an otherwise optimum air fuel ratio to be ineffecient.

I didn't mean to make it sound like the O2 sensors had absolutely nothing to do with the air fuel ratio. When I went back and re-read my post, I realize that it seems like that was my point. My appologies. frown
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Steven
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Steven Sep 20, 2:51am - #46482 
2001 Spectra Blue Mica Toyota Celica GTS
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don't worry about it cham! thumbsup
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Michael Aristide
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Michael Aristide Sep 20, 3:11am - #46483 
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Miami/Daytona Beach
Why would you want to richen the air/fuel mixture if you're N/A?? I could understand if you had full bolt-ons including cams, aftermarket Intake manifold etc and wanted to go all-motor. In your current state of tune, you will actually lose power because the stock ECU already runs very rich in open-loop mode.
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hybridcelica
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hybridcelica Nov 30, 2:22pm - #46484 
2000 silver/blue Toyota Celica
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2000 Toyota Celica

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virgin islands
i might be wrong,but i think the maf sensor is caliberated to compensate for a set range of air temperatures and volume.(i know usually in the area of 10%)since its responsible for air/fuel ratios(ecu controls injectors by the way of info from the maf)i think it would be easier to up the fuel by changing injectors or even changing the flow pattern.(if you trick the maf,it can only be tricked to a certain %! if you leave the maf as is and deal with the injectors,you can richen the air ratio without narrowing the tolerances of the maf,with the "slightly bigger injectors" you would have to make provision for the extra fuel to be burnt,or the o2 sensors would pick up on the extra fuel and compensate.its easier and better to let the o2 sensor handle the compensation of the extra fuel(that the maf doesnt know about cause they are slower to act and have a wider tolerance than the maf)egs. the second you exceed the set tolerance(or do anything that would cause a dramatic increase/decrease in anything to do with the maf,the check ingine light would come on.it would take a much longer time for the light to come on if it was the o2 sensor!the ecu is much more touchy with the stuff that is going to happen/coming into the motor,than with stuff that has already happened/coming from the motor(as long as the maf readings are in good tolerance the ecu would have a harder time throwing a code based on 02 readings.that is, if injectors are increased "within reason" 5% to 7%
ps:we used to screw with the mafs on the turbo celicas/supras even used the lexus maf on a celica to compensate for more fuel,but as i said the more you can richen the system without letting the maf know about it and not screwing with the o2 the better.

HYBRID:resulting from the combination of two or more mechanically dissimilar origins!
"...... code":every man is a shadow,let him be treated as such,until proven otherwise by a show of character or code!
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Rave669
Senior Member
Rave669 Dec 1, 1:06am - #46485 

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2002 Toyota Celica

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Lisle, IL
Originally Posted by Steven
I believe it's the O2 sensors that control air fuel ratios, NOT the Mass Air Flow Sensor (MAFS).


MAF does play a part in a/f ratio, it measures the volume of air coming into the cylinder head.

Most aftermarket Intakes already have a funnel of some sort on them (they are called velocity stacks, btw) THey must be placed at the point where the Air Filter attatches to your Intake system.

A larger MAF housing will do more in terms of performance. Most Intakes have a larger, integrated MAF housing on the piping, so that is also a moot point.

Hope this helps,

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