belt drive 2nd starter mod for P&G? (like mild hybrids)

[stillsearching]

I did my first experiment with P&G recently and I came to two conclusions... i'm not comfortable with the risk of killing my only starter (reliability means more to me than a few more % of fuel efficiency), and i'm not comfortable restarting the engine by the clutch either, it's really jerky.

I've driven a Saturn Vue redline, which has some kind of small assist hybrid motor which is made to automatically restart the engine, after it auto-stops at street lights. I'm wondering what the feasibility would be of hooking up either something similar (which I assume is a stouter motor than a typical starter for how effortlessly it gets the engine back up again - it's under a half second instead of the 2-4 seconds normal) or simply crafting some kind of DIY mount and using a normal but robust starter (like from a pickup, even though it's starting a 4cyl compact engine) to have a 2nd way to start the vehicle thats alot easier to swap out from the top side of the engine.

I'm sorry but it really just feels like i'm abusing my car otherwise with the engine shutdown/restart cycle, whether I use clutch or starter. I dont want to go through the work of putting in a clutch prematurely (with how hard it was last time) and I don't want to in the middle of winter have to be swapping out a starter just to get to college in the morning when I no longer have use of the garage. >_< With 200,000 miles and not having the money for a replacement I have to baby it. I don't mind adding on some 2nd part that, if I break it, no harm no foul I just stop P&G-ing. Or I can swap it with little hassle just by opening the hood and undoing a few bolts where I design it myself to be an easy-easy swap.

Any suggestions of what the best way to go about this would be welcome.

[jakobnev]

it's really jerky

Did you see this?

[California98Civic]

I sympathize with the reliability issue big time. I am modding my daily driver too. When I am wrenching on the thing, getting to work gets complicated. But....

Are you sure this is really so much the easier approach? To do what you describe, you need to design it, acquire the parts, and install, test, and perhaps modify/refine what you have done. On the other hand, I bought a junkyard starter for <$10 and got it tested for free at my autoparts store (they do that regularly). And the install into my Honda is just a couple wire connections and bolts. I can't imagine your proposed second starter set up would be much easier.

For what it is worth, I just did the transmission swap on my Civic, DIY. Two friends with experience inspected my clutch with me. With 200,000+ miles on it, it just did not look worn-out. I am the second owner of this car, and I have driven it since the car had a mere 27,000 miles on it. I've been very gentle on the car and 30,000 miles of bump starting it scores of times a day has not destroyed the clutch. Key starting at long lights has not yet necessitated a new starter. Now, you have a new clutch in your car, so if you drive it gently and become very good at the gentle bump, I would think your engine will wear out before the clutch.

[stillsearching]

Yes but due to the quirks of the Saturns clutch I still don't seem to be able to get it smooth, maybe practice will enable me to do it but i'm still worried about it wearing the clutch out faster - I put in the last clutch - what a horrible nightmare. I hope my current one will last me through college and grad school/do NOT want to do that again. >_<

[nemo]

P&G can be engine off or on. While off will get you better mileage, with engine on you won't need to worry about restarting.

[stillsearching]

How much of a mileage difference is it for on vs off?

Another quirk I noticed in my experiment was that my engine doesnt like to spool down at all - after accelerating up to 75mph, I push in the clutch, it takes a good 5-6 seconds to slow back down to idle. Since my glide time (unless I go really slow) isn't much longer than that, I can't see getting any mpg saving at all unless I shut it off the moment I push the clutch.

[WesternStarSCR]

While I can't add anything on the tech side of your question, you are absolutely correct in putting reliability and safety before fractional FE gains. Any cost of premature wear on components, or being in an unsafe situation will cost more in time and treasure than your gain. EOC is a great method for FE gain, but has to be done in ways to allow quick reaction times. I have to imagine most experienced people doing EOC drive a particular route mostly and are in a car that they are comfortable with having a bit more wear on the clutch and or starter. Safety first. Reliability, then FE gain.

I can add that a OEM found that a mild hybrid concept like that Vue you drove can gain about 10% FE if using it for EOC at speeds > 15 Kph and < 100 kph. So to finish my thought, yes there are mild hybrids OEMs are still going after, low hanging fruit with reasonable costs.

But adding extra component like you mention is a good idea, just not sure it is bang for buck. Like your clever idea though. Cheers, Sean

[stillsearching]

Well i'm not worried about a safety issue - I have manual steering and plenty of braking ability. I'm as comfortable swerving or braking with the engine off as otherwise.

It's mostly a reliability and maintenance issue. My experiment with P&G and EOC over 100 miles recently gave me an eye-widening fuel efficiency increase - I didn't measure it but I was very intrigued. I did a very wide get up to as high as 75mph when downhill then coast to 40mph routine engine off, or maybe 65mph straight and level.

What I dont want to do is to have to put in a new clutch sooner or a new starter during any winter when I can only work outdoors currently and not in the garage. Even if it may involve some hacking to put on a 2nd starter that is a nontrivial amount of work, the peace of mind knowing that "P&G killed my starter and thats why i'm either paying a pro to change it or late to work today" is an insurance policy i'm willing to put a little work into, at least on a future vehicle if not necessarily this one. Hell i've wanted dual starters (maybe even an air start?) on off road deep wilderness vehicles before to go with the dual alternators that are easy to add for a long time... since one future vehicle I hope to P/G on will be a pickup i'm not averse to that kind of tinkering.

[nemo]

Can't give you any information on the fe difference. It's going to be vehicle and speed dependent. If you are worried about the longevity of your car and don't have the time, place or money to repair it as others have said don't do it.

For fe just slow down try 65 instead of 75, it will help you out in the repair department also.

[stillsearching]

I would if I didn't need to find a way to reduce my fuel costs. : P The fuel savings was so huge on my test I couldn't believe it, I could swear I did 90 miles on barely over a gallon, maybe 1.5 gallons max suggesting 60mpg as the fuel gauge barely moved at all, I really want to test it later. One reason I never slowed down much is because it never gave a big FE improvement. This did.

I'm as worried about my unaffordable gas bills as I am about the other things, it's why i'm struggling so hard to figure out a total system that actually works for me and my situation. If I can get the fuel bill down enough, that could well pay for other improvements which bring it down further.