FAS'ing and engine temps
 

I'm been trying out FAS'ing lately:) and have a couple of questions. Since starting a cold engine is one of the hardest things you can do to your engine. Do you wait until engine temperature is at normal operating temp before shutdown. It takes about 3-5 miles to get up to normal engine temp but there are a couple of spots before then that I could get a good 10-40 second FAS out of. Also a couple of light that I could shut down at also. Thoughts?

On the way to work, my first FAS is after about 10 seconds, just long enough to get up my driveway and to the peak on my street. Then bump start and then 20 seconds of hill climbing before my second FAS. At that point I am at .66 kilometers and .066 liters used. That second FAS lasts about 2.5 km and then two more FAS's by the time I am 4 km into the drive to work. Then no FAS's for the next 5 km when my engine finally reaches normal operating temp.

On the way home, my first FAS is after 5 seconds, then a bump start and burst to build up speed for 10 sec then another FAS for about 1 km. Then a quick bump for 3 sec then a FAS for another km, after which I'm at 2.65 km with only .044 liters used. Another 2 FAS's by the time I am at 5 km. Then 5 miore km with no FAS when my engine reaches operating temps.

In all cases except for the initial starts, I am able to bump start as long as I time things correctly. At low speeds I bump start in 3rd and drop to 2nd for accelerating.

I use Mobil1 0W-20. No apparent issues yet.

I also typically kill the engine within either 5 seconds or about 20 seconds after a cold start, depending on which way I turn out of the driveway.

If I'm not mistaken, the wear of a cold start is caused mainly by lack of oil (which has drained down while parked for an extended period). So while all starts are technically cold until the engine reaches operating temps, only the very first one has the oil issue.

I'm also running full synthetic.

That is my understanding also. That is why I am not concerned.

Damn you Metro! I thought that I was the only one FASing so often. I have no tricks left up my sleeve. Looks like I need to remove my alternator belt also. One advantage you have is your kill switch and you dont have to turn the key off and on again to restart the fuel pump. I loose prolly 1/2 to 1 mile per day while I ign off long enough for the engine to die and the VSS isnt outputting a signal. But that is just a small thing. You will not see a 100 MPG segment out of the Del Sol. Methinks my low 80's segment is the wall. I just have one cylinder too many. I would love to get my hands on the Blackflea for a shot at a 110 MPG segment.:D

Dan, why don't you do the kill switch? I'm telling you that the fuel pressure stays for much time after the engine is shut off, so you don't need to worry about that.

I did the kill switch. The engine would not bump start unless I keyed off and back on again. I read that the fuel pump is shut off as soon as the ECU senses that the engine has stopped turning. That defeats the purpose of a kil switch so I removed it. Is it different with yours? Maybe it is a OBD1 thing?

Eh, I've been obd1 for a long while, I dunno, we'll see, I guess, but whatev even so.

I told you: I've been driving like a crazy person. :o

Though you're still likely a bigger nutbar, and I would only be mildly surprised to see 110 on the old ScanGauge with you piloting the Flea and FASing it mercilessly.

As for alternator belt - I got the data today, and it's pretty much what I thought.

EDIT: actually, it's better than I thought, now that I've looked at the numbers closer. See the alternator experiment thread: Alternator v. no alternator

While fas'ing in my 91 civic hatch std, my power brakes went out.

Only happened once.

Did it happen because of a certain time window, or

Because I was using the brakes while fas'ing more than usual?

Could have been either, budomove.

Eventually the vacuum will be lost if the engine is off for a long time. How long probably depends on how well sealed the plumbing is in each particular car.

If you brake while FASing, you use up the reserve eventually. On the rare occasions that I have to brake several times with the engine off (you notice it as the pedal firms up), I'll re-start it to "recharge" the vacuum, then kill it again.

Man...I knew I need to be more aggressive with my FASing...you guys start right away! Still, some of the distances you mention are amazing. I'm lucky to get in a 1 km glide (.61 miles) before an incline or before I've got traffic on my tail.

I'm serious, I don't think there's a level section of road in the city. Everything is .5% inclines and declines. If rolling resistance (and red lights) wasn't an issue I could probably roller-coaster it all the way to work (just have to power up one hill).

Looks like the "FAS" term is going to stick ... I was generally avoiding it, since it's not really FAS on a non-hybrid. (I don't have Auto Stop to begin with, so I can't force one :o ) - Ah well, FAS it is.

Hills are to your advantage if you pick a good route - you can get better FE by FASing in hilly terrain than you can on flatland. Ask Dan about that.

Aim for the steeper uphills with more gradual descents, rather than the other way around if you can. Search for Dan's Prius hilly route comparison.

this is how i get to school and this nets me a 50 + mpg segment cold start of course assuming temps are around 50 F + here is how i get to school and this could score a 55 mpg segment if i score 80% through the lights.



- ROll out of my driveway, looking left and right

- roll into position facing the direction I want to go to

- Key on!

- REvs rise, immediatley clutch into 1st.

- The lightest accleration you have ever done towards 2000 rpms

- shift and then baby accel again till...

- ...the hill dips down a bit and then immediately shift into 4th and revs will be still high (kinda strange really, but i guess the ECU doesn't allow revs to drop below a certain number on a very cold start) 100 feet later i have a big bump followed by a right turn.

- 1/4 pulse up to 50 km/h (30mph) albiet slowly and then first engine kill and coast up to first stop sign.

- turn right bump start into 3rd, rev rise and then shove it into 2nd gear, no rev matching!

- accelerations get a bit more agressive now, rowing through 3rd, and 4th over some mild inclines and then a FAS towards the 4 way stop sign.

- slow down towards the 4 way, bump start into 3rd, while still slowing down (i can bump start while i'm slamming the brakes in case an emergency manuver) by the time the rev rise and settles i shove it into 2nd and then roll away from the 4 way :P when there are is a car in the OPPOSING direction (not in front but left and right) then I will stop and then shove into 1st gear. Stop signs are a plauge of life but these are my local stops so I just know when to roll and when to stop... judge it from there....

- up a incline and greeted by another stop sign already! instead of hardcore fasing for 5 seconds and then bumping again i just slowly accel towards 2000 rpms in 2nd gear and then N coasting it towards the stop sign. The hill should stop me without me using any brakes.

- Look left, coast is clear, take a left and then up towards a small incline and then over the bridge of beautiful highway 1 where my road begins to merge with the highway boys! so from 1 lane it turns into 3. Now get this I have to get on the very right lane with tons of highway boys just exited in! As soon as I get over the mild incline and the road drips very low I FAS and then try my best to get on the very right lane. Where I dip for around 200 feet or so then.

- A sharp right I must make, followed by a merge bump start before the turn, and rev match into 3rd to enforce engine braking. Normally a driver would take this turn at 2nd gear but I follow a racing line hoping to minimize any tire screetching and making the turn with 3rd. Look left quick to see no cars will t bone me (one accord ran a red while I was FAS and I had to slam the brakes/bumped and waited for him to past at a very high speed)

- up the moderate hill while i drive with load in 3rd gear at 1700 rpms the hill will start to dip down and left when i reach the top. This is where I look on the opposite side of the road, if i see cars then proceed through the hill and down where I will see a light (meaning it was green for awhile) but if I don't see any cars (ghost town on the opposite side) then that means the apex corner will be greeted by a red light. So I FAS at the top of the hill and proceed slowly around the bend with all these lights going to greet me.

- Past one light, 10 feet later past enough one, when the hill starts levling out i have to bump to get my pulse on towards the 3rd light i will turn left.

- A somewhat flat 1/4 mile towards another light which I try to predict the light. If green far away FAS (by the time i get there it will red), or if its red now just 5th gear towards it hoping by the time i get there it will turn green.

Play the game like that for 3 more lights.

Then take a right and this part of the road is a long stretch that dips down. I can see why people love to past me and just rip it up this road but in the very end of it followed by a blind apex to the left. There is a light, and using the road as my prediction I can tell if the light around the corner is going to be red (no cars on the opposite side of traffic) or it is going to be green (mobs of cars after another on the opposite direction) . Either or I always FAS towards it because that light is very picky and only turns green for a limited amount of time (since the other road is a highway so it has higher light priority).

If i'm lucky I can fas through it, down some more apexes, maybe make it that light! road dips down and then up (like a roller coaster!) and maybe get lucky and past that light too! more dips and a big main intersection where I have to make a left.

- make that left, as I'm turning left (its a big road) as soon as I get to 2000 rpms 2nd gear cut the engine and roll towards another light, then make a right, past a bump and hopefully just enough momentum into a free parking lot!


55 mpg. over 5 .2 miles

60 mpg if i hit all the lights on the way, but lol that's rare I have to stop on 1 or two evenually. If i can predict that green light will turn green and FAS all way to it then the mpg hit isn't as hard, if I can FAS through it then the mpg hit will be blessed ;D Just it sucks when your FASING and the light turns yellow on you... but no one is looking :)

when i get to the third stop sign my engine temp needle is starting to climb and engine water coolant temp is at 60 degrees C. I"m not on synthetic by the way, but I did had my oil filled not to the max lines.

How about FESing (Forced Engine Stop)?

As for hilly terrain, I'm pretty limited with my route choices. I think I just need to be more aggressive with the engine-off overall. Yeah, I know, and I need a MID.

at load or off!

https://img174.imageshack.us/img174/930/fas7cg.th.jpg

Red line is on my way to school (as described above)

The blue dots are the FAS points

The blue line is on my way home, notice the change in direction?

The green dots are the FAS points on my way home

Now you're talking! Arguably more important than an exhaust system.

FES... I don't know, isn't it kind of uncouth to talk about FESes in public?

Sort of like the short-lived name of the Canadian Conservative Reform Alliance Party...

Neat map, Phil.

It underscores yet another similarity between regular "high performance" (i.e. fast) driving and high performance efficiency driving: lap times get better as you learn a race track's optimal line and braking points.

MPG gets better as you figure out the ideal FAS points, light timing and other factors on regularly travelled public roads.

ROFL - FESes...and I forgot about the CCRAP party (I don't like politics anyway)...lol...:D

Okay, how about COD (Coasting On Demand)?

As for the MID > Exhaust argument...Yeah, I'll debate on that one for a while. I suppose I just have to PM Yoshi if I decide on the MID?

I have another suggestion for the abbreviation. How about Engine Off Coasting?
When I take my wife to work I have already done more EOC(:p ) than engine on in a 5.8 mile trip. I roll down my driveway(engine off) bump start and accelerate for 1/4 mile then kill the engine and coast for 1/2 mile up to the stop sign. I then bump start and accelerate for another 1/4 mile then kill the engine and coast for 3/4 mile to the next stop sign. I then bump start and accelerate to 50mph in about .4 miles and kill the engine and coast for .6 miles to the next stop sign. I then bump start and turn onto a state highway. If I'm lucky and there is no traffic, I can run 45 mph until the speed limit drops to 45 a mile later. After 1 more mile,(2 altogether) I can, if the traffic and lights work out right, kill the engine and coast for 1.1 miles all the way to the door of my wife's work. I have recently been able to acheive a 61+mpg segment by doing this. Before the head mods I was lucky to see 54-56.

Obviously that makes much more sense. COD was my lame attempt at a joke. Even though it could be extended to CODFISH - Coast On Demand Forced Ignition SHutoff...might be a good name for a marketable engine-kill switch. :D :rolleyes:

On a more serious note I just returned from a lunchtime drive and definitely proved that I just need to be more aggressive with my EOC. I was able to coast much more often, though I have to admit I was worried about the slow speeds and time and had to accelerate much sooner than I would like to accomodate traffic.

I think I like yours better.:D A couple of weeks ago, I was coming home from PA from getting my cam timing re-adjusted and I used my kill switch on a 3 mile downhill grade of about 8%. I noticed that the temperature guage dropped noticeably during that segment.
My kill switch is a relay that was spliced into the fuel injector wiring. When I activate the relay, it opens the contacts and the engine dies instantly. Luckily my engine will re-start without having to key-off first.

thank you, i'm just trying to inspire those that don't have the courage yet. It took me a lot of "getting over" to FAS as much as say I did a month ago.

Experience counts.

Oooo, that's a good one Metro95. CODFISH it is! :D I wasn't sure if it was a continuation of the Canuck theme of the acronyms or not.

Have you got one for engine-on coasting? :confused:

You liked that one, huh? Well, I was born in NFLD and my entire family tree is from there...thankfully we escaped mostly accent-free. So, yes, it was a continuation of the Canuck theme.

At the moment I'm lost on a Canuck related engine-on acronym, but I'll come up with something...:D

On my way to work, I start the ICE and let run it for 5 sec to circulate the oil before engaging the clutch. After 3 sec of power to clear my driveway, I FAS and coast for 3/4 mi, restart and climb a 300 feet high hill (3/4 mi), FAS down the other side (1/2 mi), ICE on for 1/4 mi, FAS for 1/2 mi, ICE on for the next 6 miles (1300 foot climb) and so on. As far as power brake issues, I find that I have 2-1/2 to 3 pumps of the brake petal before I lose the power assist and then it only takes a half second pop and release of the clutch (ignition off) to work the pistons enough to recharge the vacuum. The vacuum pressure holds steady even after the 4 mile FAS that I do on my way home from work.

Just a question to all you FASers/CODFISHerman - what kind of speeds are you coasting at and what do you do about traffic?

I was thinking about the FAS misnomer today also. CODFISH is nice but long. I like EOC.

My CODFISH speeds range from 60 down to 30 normally but if I am approaching a stop, the speeds are obviously lower. I find that in traffic, as long as I leave a reasonable buffer in fromt of me, no one would notice my EOC./CODFISHing.

I think CODFISH is more of a running gag for the day - no one has made it official yet. :D

Are you talking mph for speeds or km/h?

As for traffic, I'm more concerned with who/what is behind me than what's ahead...how do you deal with that?

I quote speeds in MPH but FE and distance in km/L and km. That is just because of the SuperMID.

I find that keeping up with traffic on my route isn't an issue. On two lane roads, they either have very light traffic (I can go slower if need be) or the traffic is heavy so speeds are slow anyway. On the highway portion of my route it is 4 lane and I just hang in the right lane. I am also lucky that the speed limit is 55 MPH for half of the time and 45 truck speed limit for the other half due to hills and sharp curves. In Pittsburgh, there is not much aggressive driving. I don't get many complaints or road rage. Just every once in a blue moon.

if that line is true then you know what that means??!?!!?!? I got it out of the toyota prius wikipedia.

now we just got to get rid of the raw fuel posioning the catalytic converter during a bump start reason and then we should be in the clear!

even more info! from danman32 from priusonline.comINTERESTING INDEED :D I mean all your doing is using the EV motor to spin the magnetic engine to a certain revolution. Then by itself it should automatically start firing because it has momentum. Just like when bump starting the momentum of the wheels push the engine into motion and that motion ALONE starts the car.No wonder its so much smoother than a RERERRRERERR BROOOOMMMMM!