The easiest, cheapest way to address this would be to use a vacuum can with a one way check valve. High performance cars with lopey cams don't build enough vacuum to operate power brakes and stuff, so these cars usually use a simple vacuum can to provide vacuum for the brakes.
If I were an aggressive EOC'r, I would install a vacuum can on my car.
deer bastards thats the main thing that stops me from eocing all the time. i have taken out to of um this year (wasent eoc they just jumped out way to fast on the higway) at least my car won both times.
i think i'll leave EOC for a while now, just put it out of gear when i want to coaste. i'm still quite shaken so i'll try to keep my mind devoted to traffic for now. a
as sidenote of course the cause of this accident is not EOC alone. i think it's no a coincidence this happenes on a friday evening after a stressfull week, it was on the way to my girlfriend and i was almost there. apparently you're more likely to have an accident on familiar roads than on unfamiliar ones.
anyway, i'm really really glad i didn't cause any more havoc. my first thougths where how incredibly lucky i've been i didn't hit anyone...but if i keep going over what could have happened i'd probably never drive again. so all i can do is try to always be carefull.
i don't take this lightly and i'm not to proud of this little stunt eigher, but i'm glad it ended the way it did so i hope i can keep improving my FE in a safe way....
afterall i'd hate to wreck a car that get's better FE than a brand new one.
landspeed. I disagree that the handbrake is the best. At most you are only using 2-wheel brakes with the handbrake.
You are more more familiar with cars than to believe you are going to burst your brake lines!!! You do not put additional pressure in the brake lines or cylinders than before vacuum depletion, just additional pedal pressure is required.
I repeat, EOC is not for sissies. Push the damn pedal!!!!
I don't use the handbrake, but if you need to do tiny jabs at the brake pedal, using up all the vacuum, maybe it is best. My handbrake is not good at all (it gets through the MOT, but is just an old design).
I once took a Primera through an MOT. There was only one person there so I had to press the brakes for the brake testing. I saw that on the meter the brakes weren't working well enough to pass, so I pressed the pedal hard. In fact I put my entire weight (85kg) onto that pedal, and my upper back was against the seat, the rest of me was like a bridge between the two points. The result was a flexible hose burst at the front right caliper (it was the rear brakes that were a bit dodgy). The one hose, bursting at a corner of the car, took out the whole brake system and nothing was left.
In one of my other cars you can press the pedal down hard, with no vacuum, and stopping isn't too difficult. My current car is different, you get very little braking without the vacuum. I think EOCing with no brake vacuum is dangerous. If mine runs out, I just spin the engine slightly (and slowly) in 5th gear for a second, in order to regen the vacuum without wasting any fuel
__________________ Team GasMisers5 - #1 for first three rounds of the original GS Fuel Economy Challenge
Miles displaced by e-bike since 1 Jan 2008: 62.6 (0 kWh used)
http://www.gmcmotorhome.com/tech/vacuum_pump/index.html Go to a you-pull-it yard on their 50% off day and grab an electric vacuum pump. Could be cheap. I think I can get one for $10 at the salvage yard near me. Also someone on ebay is selling one for a little over $100 to your door. Or get a new one for $300, many places do a search.
Electric vehicle conversions use them, also lopey race engines use them. That web page says they turn on at 5 psi vacuum. I plan on getting one this week. Another option is to use both pump and can, with check-valves, for insurance.
Some vehicles are worse off than others with the vacuum all depleted. The ZX2 holds its vacuum a very long time with EOC. I tested the caprice by EOC an pumping the brakes to rid the vacuum. Still could lock up the wheels if i tried. (I usually don't EOC b/c it is an automatic)
85 Chevrolet. 30 MPG or bust!
P.S. Is there any way a vacuum gauge could be fitted to the brake vacuum chamber to see the state of the vacuum? That would be good
Yes. Insert a T for the gauge on the brake booster's vacuum line between the booster and the check valve. Make sure all your connections are tight, or your gauge installation will bleed away your brake vacuum while EOCing.
Originally Posted by omgwtfbyobbq
Or just switch to a manual booster. More stopping power than a vacuum booster with vacuum, but less than a vacuum booster w/o vacuum. And it's always like that, so there's no need to compensate for any changes, less to fix too...
Care to elaborate on the operating specifics of this "manual booster" thing? If there's no power input, it's not a booster. You could play around with master cylinder sizes to alter the driver's leverage over the brake system, but then you have to find a comprimise between pedal effort and travel. With a booster, you just use a large bore MC to keep pedal travel short and an appropriately sized booster to keep effort to a minimum.
Good info. I was wondering where the electric vacuum pump suggestions were as I was reading down the thread. It occured to me that you could use the brake light circuit to control power to the pump, but it sounds like those pumps will switch themselves on and off depending on pressure.