GM maff translator and rain any problems??

[GstRacer]

are any of you guys running a GM maff and when it rains does your car act funny or any problems??? just let me know your expereinces

 

[tstkl]

i don't drive my car in the rain, but it is a KNOWN FACT that water will screw up your gm maf

 

[DSMcamaro]

It probably has something to due with the drop in air temp. Correct me if i'm wrong, but I believe the GM MAS doesnt compensate for outside aire temp. like the stock DSM MAS would. I usually end up leaning out the WOT more and more as the outside air temp gets colder. Otherwise I run into some sputtering/ jerkyness anywhere above 4,000 RPMS.

 

[ivanr4g63]

The GM Mass doesn't have a IAT (intake air temperature) so the MAFT translator has that value fixed at 80* f, so that the ECU see the same value all the time.

I drive my car on all kinds of weather like days, and like most turbo cars I can tell you that the pull on WOT is different depending on how cool the weather is, but I don't recall any major issues like yours since I installed the Maft. if anything a little lag on very hot humid days, but other than that I don't have issues with my maft.

Maybe a vacuum leak in your intake path?

 

[project_tsi]

Besides that, unless you have a leak/hole somewhere, how is water going to get into the Maf? Like others have stated, your car's going to react differently in diff temp and humidity conditions, but unless water is actually getting inside the maf, water itself wouldn't affect its performance. Undertand?

 

[JOEY A]

Maybe that little control box is what is acting up, moisture might get into it. Just a idea, could be were its mounted?

 

[GSntncT]

No, I've personally have not had any issues with my MAF-T when it rains.

 

[slipstream808]

No, you should be fine providing there are no ways to get into the intake other than the air filter, and the air filter is in the stock location. Now, relocate the air filter and you might get some issues (say where the stock SMIC is).

The MAF is called a "hot-wire" MAF. Those little wires are platinum and heated to 212 or 240 farenheit. As air goes across them, they cool. More air, the cooler they get. The ECU (or in our case the MAF translator) supplies power to them to keep them at a consant temperature. More power to them = more air going into the engine.

You get them thar wires wet and woohoo. Things get messed up! FYI, keep the cover on the MAFT box, and that thing should be fine. If you are paraniod, then you can just silicone it shut, I've done it before.

 

[Dream On]

So I take it water injection with a GM Maf is a bad idea? I was planning to do that sometime down the road...I thought of doing 2 nozzles, 1 after the intercooler and 1 at the throttle body elbow. I suppose just 1 larger one at the TB elbow would be ok...?

 

[Jetblack]

That's right, no water or nitrous before maft .

 

[selmerguy]

I have had no problems with my maft in the rain. And correct me if I am wrong but you would inject water or nitrous after the maft anyway, right?

 

[Jetblack]

Correct and I only had an issue with mines when I routed the filter in stock sm location and it rained.

 

[Mike1992]

Correct and I only had an issue with mine when I routed the filter in stock smic location and it rained.

Ditto, although I still run my air filter where the stock sidemount is and just don't drive in the rain anymore.

 

[Jetblack]

Correct and I only had an issue with mines when I routed the filter in stock sm location and it rained.

 

[wret]

The GM Mass doesn't have a IAT (intake air temperature) so the MAFT translator has that value fixed at 80* f, so that the ECU see the same value all the time.

The GM MAF does use intake air temperature as part of it's air mass measurement. In fact it works by temperature differential, measuring the current required to keep a wire hot against the convection of intake air. It will be somewhat affected by humidity as humid air contains less oxygen.

 

[Eclipsethis90]

I have had no problems driving in the rain with my MAFT.

 

[JayRolla]

My mechanic uses the MAFT and he hates it. Our outside temps change so much here in Colorado he says he finds himself retuning everyday. He says its a pain in the ass and thats why he directed me to the 2gmaf. I think he has upgraded to the evo maf which he says he loves and flows awsome. I think he has almost 600whp through it.

 

[DROOPY209]

I've never had a problem....

but I do notice that my car got better gas mileage when the outside air temp was around 80 degrees.

 

[fulanititoo8198]

No problems here. In fact that hurricane Ernest or whatever is around and I'm going driving right now to play in the rain.

 

[tstkl]

My mechanic uses the MAFT and he hates it.

I hate it too, and even though it may use intake air temperature in its calculations, it DOES NOT have a fluxuating intake air temperature output to the ecu, which effects the maps the ecu uses. The weather effects my car like crazy, and tuning is INSANE. Don't be surprised when I go to a full map sensor set up, or hack an aem intake air sensor into the wiring harness on my maft. I can't take it anymore.

 

[slipstream808]

If you are using a DSMLink, you can lock out any temperature inputs and the ECU only sees a fixed temperature.

 

[Kevin Jewer]

The MAFT doesn't use the IAT in it's "calculations" because it doesn't have to calculate it, it actually measures it The amount of heat that is carried away from the wire will be directly related to pressure, temperature, and speed. All things are accounted for. This is why the Temp and Pressure outputs are clamped. They are not needed, but the ECU needs to see something so it doesn't flip out.

Water does a very good job of removing heat from that hotwire. Some cars are more sensitive to it than others. My car never had any real problems, though the WBO2 would read a little richer in very humid or raining weather. Others get all kinds of sputtering and other issues related to running too rich. Still others have trouble with air-liquid ICs since the temps drop so low that the humidity condenses inside the IC pipes and MAF, . This is a fairly common side effect for these units, though some poeple get away with it, like me. I had much bigger things to worry about when I ran the MAFt however, like the unusually choppy airflow signal giving me proportionaly choppy WBO2 traces, but that's another topic.

 

[GstRacer]

well ya the rain deff efects mine, DAM IT!!!! good thing its not a DD. i have dsmlink so i can tell the maff to think its always a certain temp that will end this problem???

 

[Kevin Jewer]

There is nothing you can do to remedy this problem that does not inlcude changing things to try to keep the MAF dry. With my intake in the stock location with no way for water to get at it, I had no major problems. Just a slight change in AFR due to the extra humidity.

 

[92 GSR-4]

Yes, rain CAN affect it. I have had some issues with heavy rain, and my buddy had issues with his using a CAI on his GSX.

Basically, the GM is a hotwire MAF. What that means is that the little wires inside the MAF (look into it, you will see them) are held at a certain temperature at all times. When more air comes in, it cools the wires down. The MAF calculates how much air is coming in based on the temperature drop/voltage it takes to keep it heated up. SO, if a water droplet or a mist of water comes in, the wires inside will cool down ALOT and the maf will "report" an assload of air coming in, thus you will run very rich. I have witnessed this phenomenon logging before. Basically I would run around in the rain, and then suddenly during a pull it would hit fuel cut. This was very erratic as well, which was confusing me, and only happened in the rain.

My friend had a CAI using a FP3065. He was having the same problems even on dry days following the rain. One time when it was raining he pulled his car in his garage and checked the filter, which was wet. This lead him to remove his FMIC and sure enough he was able to pour a little water out of it. He ditched the CAI and the problem went away. The water that remained in the FMIC after the rain was getting swept up in the intake when he was boosting, causing the same rich conditions I was having.