05-25-2009, 01:43 AM
Join Date: Jun 2006
Total Cats: 3
MX-5 Miata Forum - Turbo Timers
Originally Posted by Corky Bell
I am not fond of the idea behind the turbo timer. In my view it is largely useless.
1. Turbos do not spin very fast at idle. 100/200 rpm. Loads are near zero.
2. Oil does not drain out of the bearings when sitting still. Oil only leaves the bearings when new oil is forced in from the pump.
3. Turbos do not "wind down"... the Aerodyne being an exception. As soon as the engine goes to idle, the turbo will be at idle in a second or two.
4. Water cooled center sections keep oil cooler than the charring temperature.
5. Synthetic oil has a charring temp so far up the scale as to be .... safe.
6. When oil begins to suffer some damage from high temps, change oil. That works out to be about a 6,000 mile interval in my best guess. (synthetic)
7. If no water cooled center section is present, change oil every 3,000 miles.
8. No turbo racer uses turbo timers. Slightly different deal, but the Audi Diesel that just won Le Mans ran just about an equivalent 3,000,000 street miles, and they didn't even change the oil.
9. When stopping immediately from use of boost give the engine 30 seconds at idle then turn off.
10. When parking in your own driveway, turn it off and walk away.
11. NEVER turn it off while under boost.
12. Be careful with excessive ignition retard, as that can drive exhaust gas temperatures beyond imagination. Some of which will eventually get to the oil.
13. Porsche does not use a turbo timer, and I'll copy them anytime.
I'd urge that many better ways exist to spend a buck. Margaritas, for example.
In 30+ years of playing with turbos, I've not failed a single one. I've never mustered the patience to even do as I have suggested above.