MAC Fenderwell Cold Air Question

[RedbirdGT]

So I finally got around to making a couple more mods...

Background Info and FYI:
After a long debate over what intake (if any) I would buy. MAC won it out due to local availability at Dallas Mustang. Install was super easy, except for the filter itself. The way the thing gets seated and held in place is by pulling the filter though the fender hole in the mounting bracket, while prying the inside wall of a channel (which is built into the filter's tube), such that the filter is held securely to the bracket. The difficulty comes with the fact that the channel and tubing on the filter part is a hard urethane, and the walls of the mounting channel are rather tall, meaning a lot of prying with a flat tip to get it through... Other than that, everything went smoothly. I fired her up, and after making sure I didn't manage to acquire any idle issues, went out for a lil' test drive. I can honestly say that throttle response was improved without a doubt, and it's very well possible that there are a couple extra ponies in the upper RPMs (4K+).

The Question:
I noticed that there is a hole on the upper steel tube in the kit. Check out: http://macperformance.com/store/PDF/3296.pdf
You'll notice that it has a black rubber bushing in it from the picture on the left. The question is... What goes in here? The original stock tubing / box only have the two obvious lines w/ the plastic MAF housing between...

Then there is what appears to be a little black plastic cap that came in the hardware bag. Nothing about it on the instruction sheet, and no ideas what it was intended for.
Note: It doesn't fit the extra hole in the steel tube...

CORRECTION: That cap does in fact belong here on any cars where the intake air temp sensor is located in the MAF assembly. Simply remove the rubber bushing and pop it in.

The car ran beautifully (as always) in my test, but having an open hole (albeit a small one) in the tube doesn't seem right at all.

What am I missing here?

Thanks!

 

[stangGT97]

I'm glad you enjoy your MAC cai, I did not have the same experience you did so thats why I'm back to the stock airbox.

To answer your question, the inlet air temperature sensor (IAT) is supposed to fit into that rubber grommed. This relays air temp info to the computer, so it can adjust for ignition timing. You have to put this sensor back in - it looks like a small loop with the sensor hanging down in the middle. Install it such that the plane of the loop sits perpendicular to airflow, ie, the loop does not block the air flow to the sensor.

The fact you have a gaping hole in your air tube means you have unmetered air entering your engine, probably causing you to run lean... this may be where your extra power is coming from, depending on how lean you are.

View attachment 447796

Edit - your car may have this sensor built into the MAF. If that is the case, then just plug this hole and you will be golden.

 

[COramprat]

My car fell flat on it's face when I forgot to replace the sensor one time. Ugly...

 

[stangGT97]

My car fell flat on it's face when I forgot to replace the sensor one time. Ugly...

yeah i can't imagine that would do you any good... unmetered air leak, plus the temp sensor would be taking readings from the engine bay. The fact that his car isn't running like crap is making me think that this temp sensor is integrated into the MAF (this just came up in another thread, kind of interesting)

 

[streethorse]

I had the same CAI on my 99 gt, mine had no hole at all for the temp
sensor so I just had it hanging in the fender well near the filter. Anyway
it ran good like that for a couple of years. I was going to drill a hole for
it but never did. On my 04 I am using the stock set up with a K&N and the
silencer removed but will probably put the Mac on when the outside temp
gets cooler. That chrome tube just stays too hot in the summer.
It is definatly a pita to install or clean that filter.

 

[ADRENLN]

well if anyone else wants a used mac fender cai, i have one with 2 filters. mac and k&n. its just going to waste laying around. ill give it up super cheap. i realize this isnt the classifieds but i thought one of you could use it.

congrats on the install though. once you install and uninstall the mac a couple of times it gets easier. also keep an eye on the filter and make sure it dont pop of in the fender.

 

[Susky]

I'm dreading having to reach in there to take off the filter for cleaning.

 

[RedbirdGT]

Thanks for all of your input.

I will pull that part off the CAI and check around the engine bay for an additional temp sensor. I had read an install guide for a V6 car before I even bought the thing that mentioned one going into that hole. However, I didn't see anything of that sort in my car the first time around. As before, the stock tubing only had two connections going out of it.

I'll check it all out and let ya'll know what then end result is.

 

[RedbirdGT]

So as it would turn out... That little black cap that I mentioned does fit rather snugly in the hole (after you remove the ruber bushing), and the air temp sensor is located in the MAF assembly.

Phew. No more paranoia...

 

[stangGT97]

So as it would turn out... That little black cap that I mentioned does fit rather snugly in the hole (after you remove the ruber bushing), and the air temp sensor is located in the MAF assembly.

Phew. No more paranoia...

okay good to hear everything is resolved