[McLuVan]

does the exhaust flap(golf tee mod flap thing) close ALL the time? because when I accelerate from a dead stop it sounds like it's open and closes around 10mph or so

[Year's_End]

Not sure. Doesn't sound like it to me.

[e46e92love]

Originally Posted by McLuVan

does the exhaust flap(golf tee mod flap thing) close ALL the time? because when I accelerate from a dead stop it sounds like it's open and closes around 10mph or so

Nope, it actually is there for when your car is cold and warms up. When you first crack her up for emissions and one other reason I think (can't remember) the flap closes and allows exhaust to only flow through one side. If you started your engine up in the cold and just let her idle (which you SHOULD NEVER DO!!!) you would see the exhaust coming out one side for a bit, then the engine note would change a bit, then a bit later it would change again along with a change in the exhaust note and you would see exhaust then coming out both pipes.

Cheers,
e46e92

[cmurphy335e92]

e46e92love

Your saying that I shoudlnt start my car in cold weather and let it idle?? I dont think your correct about that....

[thekurgan]

Originally Posted by McLuVan

does the exhaust flap(golf tee mod flap thing) close ALL the time? because when I accelerate from a dead stop it sounds like it's open and closes around 10mph or so

The default position is open when the engine isn't running, it stays closed to warm the cats and opens slightly after they are warmed, after that, it's mostly closed until you hit around 2500 rpm or get into the throttle.

[bavarian335]

There is no way you are right about the engine idle. It lets the oil temp rise and gets the engine closer to operating temp before you start revving it.

[McLuVan]

I'm pretty sure it's closed while driving
I had the golf tee mod and it was MUCH louder

[e46e92love]

Originally Posted by cmurphy335e92

e46e92love

Your saying that I shoudlnt start my car in cold weather and let it idle?? I dont think your correct about that....

I am correct

Hate to crank the newbies, but this has been discussed 1000 times back in 2006 when the 335i first came out (I owned one of the first 335i out of the factory). Idling your car is the worst thing you can do because at idle the oil doesn't run through the engine as well because it is cold and thicker, viscosity is not optimum. So, by sitting there and letting it idle, you are more likely to get wear and tear from friction. The proper warm-up is to turn her on, wait a few seconds, and drive off, but to keep the rpms low and to be very easy on her for a bit and as the temp gauge moves closer to operating temp you can drive her harder. This ensures the oil rises to the preferred viscosity in the shortest amount of time and good pressure is supplied. This is the one time I am not expressing my opinion but fact.

[Dubbedoutbimmer]

yea I did the golf tee mod and mine sounds so sick when you fire it up it gurgles and growls I get morning wood on the way to work hahah

and yea BMW says just get in and drive but drive kinda easy till upto temp

[///AFRO]

[darkphantom]

so are there any backfires to the golf-tee/exhaust mod? I mean there has to be a "greater" reason than just to warm up the cats right? Or am I just blowing smoke?

[nospleeny]

In the manual, it says to not let your car idle.. but instead drive away after turning the car on but keep the engine speed low as this is more efficient to let your engine heat up.

So I have to agree with e46e92love.

It's in the BMW manual.

[to_riffic]

Originally Posted by e46e92love

Nope, it actually is there for when your car is cold and warms up. When you first crack her up for emissions and one other reason I think (can't remember) the flap closes and allows exhaust to only flow through one side. If you started your engine up in the cold and just let her idle (which you SHOULD NEVER DO!!!) you would see the exhaust coming out one side for a bit, then the engine note would change a bit, then a bit later it would change again along with a change in the exhaust note and you would see exhaust then coming out both pipes.

Cheers,
e46e92

really? dont let it idle? so drive off even wen its cold?

[to_riffic]

Originally Posted by nospleeny

In the manual, it says to not let your car idle.. but instead drive away after turning the car on but keep the engine speed low as this is more efficient to let your engine heat up.

So I have to agree with e46e92love.

It's in the BMW manual.

Originally Posted by Dubbedoutbimmer

yea I did the golf tee mod and mine sounds so sick when you fire it up it gurgles and growls I get morning wood on the way to work hahah

and yea BMW says just get in and drive but drive kinda easy till upto temp

i guess that solves my question, haha. thanx guys

hm....but wat if i needa hit the freeway to get to skool, i relaly wouldn't be able to keep it easy...

[tintivilus]

Originally Posted by ra2fanatic

i guess that solves my question, haha. thanx guys

hm....but wat if i needa hit the freeway to get to skool, i relaly wouldn't be able to keep it easy...

You can get on the freeway without bouncing off the rev limiter.

Btw, it's not a new or 335i thing; my E34 (1990 525i) manual said the same thing. BMW has always advised against idling because cold running is bad and the engine warms faster if you actually drive it.

[darkphantom]

this is the general rule of thumb, turn your vehicles on, and drive slow-moderate speeds to warm up the engine+tranny

[StarrDlux]

dude every german car i've ever owned said unless the conditions (say an inch of snow/ice on the windshield = danger) permit. Start the car,idle, and begin driving in 30-60 seconds. do not lug nor load(high rev) the motor. the light load cause all parts to achieve operating temps faster (there's diff/trans/motor/power steering) fluids.

99% of emissions is due to cold start since you need to spray mad gas to keep the motor running so the longer the period of warmup the more emissions, more gas in oil, more greenhouse, more wear. yadda. pretty simple man. its no different for jap or american just the laws of physics. maybe a prius might be different.

gotta RTFM on this one its in every owners manual for every car i've owned american/german/japanese.

the engine uses vanos to create a rich overlap during first start it takes about 30-60 sec to light the cat(s) tops with them hanging of a pair of hairdryers probably even faster since a little juice in the exhaust stroke into the turbo's would get them toasty real quick.

that is why there are very very few (malibu?) cars that come with factory remote start. it is bad for emissions, and bad emissions = engine wear.

you know the mapped cooling system works too? its PWM the ecu controls the temps all the time but what you don't see is the fact that if you set it on cruise at say 70mph the engine will bump the engine temps to 220-240F (!!!) but the aluminum block can use this to its advantage to burn cleaner (low load) to get that better mpg. when you get on it the ecu maps the cooling down to prevent detonation. every german car in the last 7 years has had this either with electronic thermostats or variable speed water pumps.

[alex2112]

Originally Posted by tintivilus

You can get on the freeway without bouncing off the rev limiter.

Btw, it's not a new or 335i thing; my E34 (1990 525i) manual said the same thing. BMW has always advised against idling because cold running is bad and the engine warms faster if you actually drive it.

+1

Even my old Honda Civic manual said this. Don't idle to warm the car up, just drive it. Its not even a BMW thing.