What is this?

[sokat1989]

I installed a custom short ram intake and there were a couple of things attached to the factory airbox that I dont know what to do with. There is a fat hose that goes to a cylinder looking thing near and under the MAF's right side. Another is some sort of sensor attached to a wire. I'll attach pics so someone can tell me what these are and what I should do with them.
Thank you

[aceyx]

I think you're looking at the temp probe and secondary air pump, respectively.

[spidertri]

I have seen people put a small filter on the fat hose that looks like its own tiny short ram. I'm pretty sure you will need somehow get that sensor into the airflow of your short ram, not sure what happens if its not in there.

[spidertri]

Check post #9 in this thread for a picture of both the sensor and the fat hose on a SRI.

http://www.318ti.org/forum/showthread.php?t=16355

[sokat1989]

I think you're looking at the temp probe and secondary air pump, respectively.

I have seen people put a small filter on the fat hose that looks like its own tiny short ram. I'm pretty sure you will need somehow get that sensor into the airflow of your short ram, not sure what happens if its not in there.

what is the purpose of the temp probe? im guessing measuring air temperature? but how does it use that data? and ive put temp probe near my cone filter so i guess there shudnt be a big difference in temperature. do i really need to put it in my pipe? and if the temp data is used for the air/fuel mixture is it possible to play with wat the read out on the probe is as compared to actual air temp being sucked in to fool the ecu to giving me more power? :eyebrow:

[aceyx]

what is the purpose of the temp probe? im guessing measuring air temperature? but how does it use that data? and ive put temp probe near my cone filter so i guess there shudnt be a big difference in temperature. do i really need to put it in my pipe? and if the temp data is used for the air/fuel mixture is it possible to play with wat the read out on the probe is as compared to actual air temp being sucked in to fool the ecu to giving me more power? :eyebrow:
Air density (amount of O2) changes with air temperature since volume is the same. I think it's Bernoulli's law, but I could be mistaken.

In any event, the ECU uses this information along with other data to maintain the stoichiometric (air/fuel) ratio. You could mess with it, but I do not suggest it unless you're running some other tuning AND know what you're doing.

If you think you know more than German engineers and the millions of dollars in research they've put in to the M44, go ahead. The mere fact that I had to explain the above hints that you might not.


That's not meant to be a disparaging remark; more of a warning and that I don't want you to grenade your motor.


EDIT: my guess on what would happen if you omit the probe is that: because under-hood temp is usually greater, your engine will run lean and predetonate. If you remove the sensor altogether it may run in limp mode.

[sokat1989]

Air density (amount of O2) changes with air temperature since volume is the same. I think it's Bernoulli's law, but I could be mistaken.

In any event, the ECU uses this information along with other data to maintain the stoichiometric (air/fuel) ratio. You could mess with it, but I do not suggest it unless you're running some other tuning AND know what you're doing.

If you think you know more than German engineers and the millions of dollars in research they've put in to the M44, go ahead. The mere fact that I had to explain the above hints that you might not.


That's not meant to be a disparaging remark; more of a warning and that I don't want you to grenade your motor.


EDIT: my guess on what would happen if you omit the probe is that: because under-hood temp is usually greater, your engine will run lean and predetonate. If you remove the sensor altogether it may run in limp mode.

yea i wasnt really planing on messing with it. it was kind of a joke :wink:but in any case it makes sense about the higher temp in engine bay. i should probably stick it in the intake

[cooljess76]

Short ram intake = Hot air intake

Even a CAI or shielded cone filter won't give you any beneficial performance gains. My suggestion is, save your factory air box because you're going to need it when it comes time for smog inspection.

[sokat1989]

Short ram intake = Hot air intake

Even a CAI or shielded cone filter won't give you any beneficial performance gains. My suggestion is, save your factory air box because you're going to need it when it comes time for smog inspection.

I did keep it. smog inspections? I don't think we have those in Missouri, I guess we probably do in some form or another but a replacement of the airbox with the cone filter will make me fail emissions? hmm i did not know that. When i bought the car I looked at the sheet and they didn't even test the cat. I asked the guy and he was like don't worry you passed. got me to thinking, test pipe??:eyebrow::icon_evil

btw If anyone has state specific info, it would be helpful to know or where to get info on what will and will not make me fail emissions. I skimmed through the dmv site but didn't come across exactly what i was looking for.

[Marv17]

that probe has to go in the tubing or housing of the short ram intake. it MUST be in there.
and that second hose is the secondary air pump. i think i have a pic here somewhere to show what i did with mine.


okay found two. this is what i did. hope it helps out.

6680
6681

[CarCraze]

and that second hose is the secondary air pump.

6680
6681
second hose is one with smaller cone filter? Why BMW needs a secondary air pump?

[nyle]

The secondary air pump provides extra air to the catalytic converter while it is still heating up.

[sokat1989]

The secondary air pump provides extra air to the catalytic converter while it is still heating up.

hmm i always wanted to do a cat delete/test pipe. does that mean i can do a SAP delete as well?

[nyle]

without a cat a SAP would be worthless. but you dont HAVE to get rid of it. The problem is with the computer though. because it expects it to be there so it calculates accordingly.