[craneboy]

Anyone done a carbon/vapor delete on their 335i?

Juts wondering??
Got some ideas for the space that could become available......

Andy

[BMWsky]

What is it? Are you talking about the valves?

[craneboy]

Carbon/vapor canister.
Bottom left in pic below.
See below, the 2 black cylindrical items.

[Dave W.]

I did it on my race car (of course). I can occasionally smell gas fumes since the vent on top of the tank is open to atmosphere instead of going to the can. I wouldn't do it if you're using E85 since it'll absorb moisture from the air. Those are the only drawbacks I've seen.

[Dave W.]

Oh wait, I just saw the pic, those are the vacuum cannisters that control the wastegates!
The carbon cannister for gas tank evaporative emmision control is located next to the tank behind the rear wheel.

[MDORPHN]

Originally Posted by Dave W.

Oh wait, those are the vacuum cannisters that control the wastegates!
The carbon cannister for gas tank evaporative emmision control is located next to the tank behind the rear wheel.

+1.

I really wouldn't remove them....


Neil

[craneboy]

Vac cans for wastegates?

Wow, it's a new one on me. Guess I'll have to do some reading on that one.

Why on earth do we need vac cans for wastegate control?
What happened to good 'ole boost control soleniods? LOL

Andy

[Tzu]

Acts as an accumulator to alleviate unnecessary stress on the vacuum pump. Consistant volume and vacuum pressure supply.

[craneboy]

Vacuum pump on a petrol car?
It get's stranger! LOL

[JamesM3M5]

Originally Posted by craneboy

Vacuum pump on a petrol car?
It get's stranger! LOL

Turbo car, low manifold vacuum, possible loss of vacuum supply to the turbos and more importantly, the brake booster.

These cars control boost backwards - the ECU uses solenoids to pull vacuum on the wastegates to close them and build boost. It is able to shut down boost entirely by never supplying the WGs with vacuum. Pretty ingenious for a road car if you ask me.

And all Valvetronic engines require a vacuum pump to pull a vacuum for the brake booster. This includes N52, N55, N63, etc.

[craneboy]

Originally Posted by JamesM3M5

Turbo car, low manifold vacuum, possible loss of vacuum supply to the turbos and more importantly, the brake booster.

These cars control boost backwards - the ECU uses solenoids to pull vacuum on the wastegates to close them and build boost. It is able to shut down boost entirely by never supplying the WGs with vacuum. Pretty ingenious for a road car if you ask me.

And all Valvetronic engines require a vacuum pump to pull a vacuum for the brake booster. This includes N52, N55, N63, etc.

All my other turbo'd cars have never had a vacuum pump, seems pretty over-engineered, but could be genius
Unless you were braking under accleration I can't see there being a need for it as an aid to the brake servo (booster).

Very interesting to know about the boost control though. Cheers!

Andy

[Dave W.]

I think they did it this way so if something broke the wastegates would automatically open.
Also, with electronic throttle control they needed to make sure the brake booster always has vacuum, if the E-throttle malfunctions and opens at the wrong time there won't be vacuum in the intake mani.
Unfortunately the wastegates tend to rattle badly configured this way.

[boostaholic786]

wow and this is why I get on this site probably twice a day... always learning something new and very innovative. Thanks for that info!

[JamesM3M5]

Some Audi gasoline turbos also had a auxiliary electric vacuum pump to ensure vacuum assist for the brakes.