[Greg Jones]

I am very skeptical of any sort of set up like this without enough positive ventilation of fresh air such that it would defeat the purpose. In my youth I rigged up such an exhaust system with a hose clamped to the tail pipe. I then mostly shut the garage door and started the engine, and fiddled away doing my mechanical stuff. After a period of time I got up from under the car and blacked out. Fortunately a friend had just shown up (that is why I was getting out from under the car). The heat and vibration on the clamp rattled the pipe off the tail pipe -not completely but enough to have a huge CO leak. Thank God for friends stopping by. And CO poisoning is an awful feeling but it wasn't my day to die of stupidity. Be very very careful.