interesting performance mod, a bargain!

[hhspunter]

so i went on ebay and looked for chips for my m44 and all i could find was something called a "performance module". after asking what exactly it does and where it connects, it alters the intake air temp sensor into thinking it's cold. the ECU then adjusts air/fuel ratios(i think, i know it alters SOMETHING because it thinks it's cold) and you get a little more power. they claimed 10-18hp. probably a little exxagerated, but still, it's better than nothing. they wanted 28 bucks. i realized the product is just a resistor, and i found another brand that gave the exact resistence: 4390 ohms, for three series from 1990-2005. they claim the optimum temp is 69 degrees, and that's what that value resistor signals to the computer. so i went to radio shack and paid a dollar for five 4.7K ohm resitors. unplug the air temperature sensor (it think, it's the one that plugs into the airbox). it should have two connectors inside, bridge the two connectors with the resistor and that's it. i know 4.7K ohm isn't exactly what they said, but i drove for about a half hour and the car felt quicker. so really i got a few horsepower for 20 cents. not bad. and it was really really easy to do... and it works pretty darn well for a 20 cent part. i highly reccomend a trip to radio shack. i remembered some stuff from physics class and bought some 2.2K ohm resistors, if you put resitors in series they just add. so two 2.2K ohm resistors in series should give 4.4K ohms which is way closer than 4.7K ohm. i tested it with an ohm meter to be sure, and it was off. then i remembered two identical resistors in parallel decreases the overall resistence by half. so two 4.7K ohm resistors in parallel is like one 2.35K ohm resistor. that in series with a 2.2 K ohm resistor should act like 1 4.55K ohm resistor. but i knew the predicted values were high. so i did it and checked with an ohm meter and it came out to 4350 ohms.... which is as close as i would probably be able to get to the desired resistence. so i put that in the car, but i haven't driven it yet. i'll post back and tell you how it feels. and i'll put up pictures of the whole process. if it even gives you 5hp, it's worth it. the resistors cost 20 cents each and i used three. that's sixty cents for a few extra horsepower. i think it's worth a shot. like i said i'll put up pictures of how i did it really soon, and tell you how the car feels. oh yeah, and you can undo the whole thing and go back to stock in like 10 seconds

[DustenT]

This is a terrible idea. Your car DEPENDS on an accurate signal to adjust fuel/ignition for the best performance.

Tell me what happens when the temp drops below 69 degrees? The car thinks its still warm out but the air is really thick, your car runs lean and you blow it up. Your ECU compensates for extreme heat, but without the temp sensor it won't.

DON'T DO THIS!!!!!!!!

[hhspunter]

Originally Posted by DustenT

This is a terrible idea. Your car DEPENDS on an accurate signal to adjust fuel/ignition for the best performance.

Tell me what happens when the temp drops below 69 degrees? The car thinks its still warm out but the air is really thick, your car runs lean and you blow it up. Your ECU compensates for extreme heat, but without the temp sensor it won't.

DON'T DO THIS!!!!!!!!

it's the summer, i live in florida, it doesn't get below 80 degrees out. no lights have come on yet, if they do i will simply take it out and plug the temp sensor back in. if it starts doing ANYTHING abnormal i'll take it out in a heartbeat. so far it's run fine, the temperature gauge in the dash it the same as it has always been. if the car is running lean, will it run hot? i'm definately listening to everything everyone on here has to say and taking it into consideration. my dad has worked on cars his whole life and i told him all about it and he didn't object. i trust him with my life, so no question about trusting him with my car. i'll tell him what you said to see what he thinks though. the last thing i want is a blown engine. but so far everything has appeared okay. unlike most teenagers i always look at my gauges and pay attention to what the car is doing

[hhspunter]

as far as air/fuel ratio goes, i will be running richer because the ECU thinks it's colder. that's as long as it stays over 69 degrees out, which it will for me. i'm not sure about the timing though. neither is my dad. i'll do more research. i'm gonna drive with it in tonight, then go back to the sensor until i find out that it won't hurt anything. which i may never find out. my dad said i'd be safe driving it tonight, and then taking it out. so yeah, my initial enthusiasm is gone... but hey i appreciate the advice. i was just excited that i figured out how to calculate the resistence and i built it and it seemed to work, i was excited and wanted to share the good news. but i take it back DON'T DO IT! cause i don't want anyone's car getting killed because i gave bad advice. i'm not sure if it's bad advice yet... well it is bad advice if you live somewhere cold. i'm not sure about if you live somewhere hot though... but really please don't anyone do it. too risky

[hhspunter]

i got served.... but thanks for catching my error dustin t... i'll admit that i was probably wrong

[DustenT]

Your ECU takes the reading from the intake air temp and compares it to a fuel and ignition map. Your car is tuned by BMW to run the best it can in all conditions. It's a complex fuel injected car, not an old school carburated car.

Lets say you replace the sensor and trick the car into thinking its 69 degress when it's really 90 degrees. Your car will try to run the ignition and fuel map for that temp(69), but in reality the air is 90 degrees, so you don't get the right power because you are running to much ignition and end up detonating. In the end, your o2 sensor will see a rich condition and back off the amount of gas anyways, so it's VERY self defeating.

Any car with a computerized fuel injection system is tuned primarily off temperature (intake temp and collant temp). Don't screw with it, you're just asking for problems. Is the extra power (i doubt there really is any) worth wrecking your car over? Do you think your mod is better than anything BMW could have come up with?

Anytime you do something to your car, remember that BMW puts MILLIONS of dollar into R&D, they know what they are doing. Don't fix it if it isn't broke.

[hhspunter]

Originally Posted by DustenT

Your ECU takes the reading from the intake air temp and compares it to a fuel and ignition map. Your car is tuned by BMW to run the best it can in all conditions. It's a complex fuel injected car, not an old school carburated car.

Lets say you replace the sensor and trick the car into thinking its 69 degress when it's really 90 degrees. Your car will try to run the ignition and fuel map for that temp(69), but in reality the air is 90 degrees, so you don't get the right power because you are running to much ignition and end up detonating. In the end, your o2 sensor will see a rich condition and back off the amount of gas anyways, so it's VERY self defeating.

Any car with a computerized fuel injection system is tuned primarily off temperature (intake temp and collant temp). Don't screw with it, you're just asking for problems. Is the extra power (i doubt there really is any) worth wrecking your car over? Do you think your mod is better than anything BMW could have come up with?

Anytime you do something to your car, remember that BMW puts MILLIONS of dollar into R&D, they know what they are doing. Don't fix it if it isn't broke.

chill out! i already said i'm gonna take it off! i realize that now! i just got kinda distracted before because i was happy that i did something with my hands.... and i already said to NOT do that to your car.... so we are pretty much in agreement... no need to get upset with me. i tend to get carried away on stuff. i'm an ambitious teenager who thinks he knows everything... you were probably one once too. so take it easy on me. i admitted i was wrong. i don't want to come off as disrespectful. you have had a 318 way longer than i have, so you know a lot more than i do about them. that doesn't mean i'm not trying to learn.

[DustenT]

Originally Posted by hhspunter

chill out! i already said i'm gonna take it off! i realize that now! i just got kinda distracted before because i was happy that i did something with my hands.... and i already said to NOT do that to your car.... so we are pretty much in agreement... no need to get upset with me. i tend to get carried away on stuff. i'm an ambitious teenager who thinks he knows everything... you were probably one once too. so take it easy on me. i admitted i was wrong. i don't want to come off as disrespectful. you have had a 318 way longer than i have, so you know a lot more than i do about them. that doesn't mean i'm not trying to learn.

Sorry, I didn't see the other posts. It took me like an hour to write that last post.

Seriously, I got sidetracked by a chicken ceasar salad and I didn't refresh.

No harm.

[hhspunter]

Originally Posted by DustenT

Sorry, I didn't see the other posts. It took me like an hour to write that last post.

Seriously, I got sidetracked by a chicken ceasar salad and I didn't refresh.

No harm.

haha alright. so what can i safely do to the car besides forced induction? and doesn't cost much... like i know i could probably do cams and some other stuff, but that's pretty expensive. if i really feel the need for insane power i'll save up and do an engine swap... maybe a nice low-mileage M30... i love that engine... it sounds so nice

[Tyler]

If it sounds like he's being a dick he's not,he's just telling you what your doing is not a good idea and when you come back and say my engine blew we all would've said we told you so. Please don't by any products off Ebay that say they will give you more power,i said this earlier but you get what you pay for.

[DustenT]

Originally Posted by Tyler

If it sounds like he's being a dick he's not,

Hmm, I hear this a lot...

[Tyler]

Originally Posted by hhspunter

haha alright. so what can i safely do to the car besides forced induction?

If you have a m42 engine you can get a chip,on the m44's you need to reprogram the ecu. There isn't really any mod you can do to get a big increase in power unless you do what Dusten did,but a DASC. Somebody posted on here earlier that Dinan is having a 50% off sale on ecu's and chips. Check out the site at www.dinancars.com and see if there is anything on there that you might like.

Originally Posted by DustenT

Hmm, I hear this a lot...

I should've added that you know your stuff on there, and that you help who you can with your knowledge. Oh Well.

[hhspunter]

i'll say it again, i really appreciate you guys watching out for me.

[hhspunter]

my 318 has 180,000 miles on it... i don't want to do anything serious to it. i need it as a daily driver. it's really hard to take it easy on the car, it redlines so easily.... but i'm trying. i drive responsibly, i don't do stupid stuff. the first ticket i get i don't drive for six months, parents orders. that doesn't mean i can't go through first and second fast though... it's so hard not to...

[robcarync]

www.dinanbmw.com works too! cool i never knew they had ttwo domain names!

lol sorry pointless post....