bump starting after engine off coasting

[kalifornia]

Im new to hypermiling. If you know you can engine off coast for awhile, do you bump start the engine to get it back on?

[MetroMPG]

I do.

But you don't just dump the clutch (arguably that's harder on the drivetrain).

Instead, the smoother way is to spin up the engine using a higher gear than called for by your current road speed and immediately depress the clutch again, then rev-match/engage the clutch in the correct gear and off you go.

It takes practice to get smooth at it. A passenger shouldn't notice the re-start.

FYI: http://ecomodder.com/forum/showthrea...gine-1141.html

Also: be warned that with the engine off, you only have a couple of brake pedal applications before the vacuum reservoir is depleted, and then you have unassisted brakes that take a lot more pedal force to use. Also, you lose power assist in the steering while the engine is off. In some cars it's no big deal; in others it could be a problem.

[kalifornia]

could you mark the speedo with some tape for each gear, thereby showing you when to dump the clutch? Would that work everytime or am I missing something?

[MetroMPG]

You're missing something. You should never dump the clutch. I mean, some people do, but it's not smooth for the driver/passenger, and it's harder on the car.

Did you get a chance to look at that Ecomodder thread?

[kalifornia]

yes i read it. Im just wondering if rev matching could be made by looking at some "hash marks" placed on the tach & speedo or if it can only be done with experience

[kalifornia]

basically if I know 3rd gear reengages smoothly @ 34mph. couldn't you adjust to that speed and disengage the clutch in one motion?

[Daox]

Nothing will reengage super smooth unless you rev match. Its not that big of a deal, you just have to get used to it. When you start learning to bump start, its hard enough to get used to without looking down at tape marks on your dash. Its much more of a feel thing that you'll figure out quick enough.

[kalifornia]

got it, do you guys find you do more dfco gliding anyway?

[Daox]

Heck no, you can't coast nearly as far while in gear.

[kalifornia]

man you guys are hard core