The 100 mpg carb - Does it really exist?

[DavidVizard-GFN]

Originally Posted by John Gervais

David, first, thanks for everything you've done for us. I really enjoyed reading this article when it was recently published in Mini Magazine. I'd toyed with the idea of installing a water injection system in my 'warmed-up' 998cc mini, as I too can see the many benefits.

Think I'll ring that UK company and hear what they've got to offer...

John,
I would lole you to keep us updated on any progress you make with Aquamist. they lok to have a really good product.
DV

[DavidVizard-GFN]

Originally Posted by Brian P

Well, at a risk of speaking in someone else's place, if it were ME doing the testing, I'd find engine RPM and load settings that correspond to (say) 60, 80, and 100 km/h "road load" (i.e. part throttle), and measure BSFC at those operating points without the gizmo, then measure it again with the gizmo, then measure it again without the gizmo. If you really have sophisticated testing apparatus then you could use one or more of EPA's prescribed driving cycles on a dyno. But, that's just me.

A while back, on another website, we had someone touting an economy gizmo of some sort (I've forgotten what it was). That one got to the point of showing up at a dyno testing facility and the promoter got a chance to talk to everyone involved - none of the rest of us were about to stand up for any BS. There were some dyno equipment problems when the test was first attempted and we had to book it for another date. At that date ... no show.

I've also witnessed the tail end of a private dyno operator doing a test of an economy gizmo - but the methodology used was not valid. In that case, the dyno operator was (in effect) showing the promoter of the gizmo what he wanted to see, presumably in the interest of getting paid. "Independent test results" - Ya right.

I have my own opinion of those "HHO" or "Brown's gas" or other such systems. I'm thinking DV isn't going to get a response to his offer ...

Brian,

We seem to have had similar experiences but it would be nice if these hydrogen generation guys could show some results. i for one would be happy to save fuel.

As you can see I have had a response so let us see where this all goes. Mean while watch out for our Econmy Forum - its only days away now.
DV

[FlowSpecialist]

Originally Posted by Billzilla

Quick thread hijack.
VW are seriously looking at producing a 282mpg car in a couple of years.



Laugh at High Gas Prices With a 282-MPG VW | Autopia from Wired.com

Brilliant concept. I was astonished looking at the picture of this because it's exactly what I'd envisaged for the 100 mpg car I've designed only this takes the weight saving and aerodynamics even further. I'd come up with a realistic and cheap to manufacture steel and aluminium 1500 lbs vehicle with a 15 square foot frontal area, passenger or luggage sitting behind driver and a very achievable Cd of 0.26. Engine would be a 40 bhp direct injection diesel for 125 mpg at 60 mph or a similar powered petrol one for less weight and cost but about 100 mpg at 60 mph.

Top speed would be 100 mph with 0-60 in 17 seconds. Enough to easily keep up with other traffic. Cost would be no more than any other cheap small car.

Running the calcs for the VW I get 275 mpg at 60 mph so their claims seem spot on. The cost of getting down from 1500 lbs to 660 lbs is extreme though. Not worth the extra fuel saving IMO.

I was contemplating writing a series of articles in here on the design and maths for economy vehicles (or any vehicle really) and how to calculate their mpg with a simple spreadsheet as you change the design parameters. If there's enough demand I'll do it.

Dave

[Pinhead]

Having thoroughly examined Chris's v6 electrolyzer (at OUPower, I've been a member there for quite a while) I have absolutely nothing against his design. However, I'll have to speak from my experience with electrolyzers as a means for saving fuel.

If the engine/vehicle baseline is found, and then the hydroxy gas added with no other modifications, you will likely lose mileage. It is only in conjunction with tuning will you see any MPG gains. This is almost wholly caused by the oxygen sensor; if you watch the sensor signal while the engine is running, and then "turn on" the hydrogen, you'll see the signal almost flatline, reading "lean." This tells the computer to add fuel and will completely negate any increase of efficiency that you may have seen.

With your v6 electrolyzer will you be including a EFIE or any other means of adjusting the oxygen sensor signal?

IMO the only way to "quantify" the results would be to first run engine to get a baseline BSFC figure at cruise. You would have to note lean burn misfire limits, EGT, AFR using a wideband sensor, and ignition timing requirements. Then add the hydrogen, and note how all of these previously recorded data points are effected. After all of that, you would have to re-tune the vehicle in order to take advantage of the increased flame velocity (change ignition timing) and extended lean burn limits (tune for leaner AFR's).

99% of the time, just adding hydroxy gas does blip for gas mileage (as is stated and pointed out by all of the experts). Tuning is the key, and is the only way to get any meaningful data from the test.

If it were me (and I had the time, money, and facilities) I'd do it this way:

1) Find driving parameters (speed, load, etc).
2) Put the car/engine on the dyno and set up for the same conditions, checking BSFC.
3) When at the steady state condition, tune it as lean as the engine can handle, noting how far it will go before either a power loss/lean misfire is found or the EGT's go to an unsafe level. Do the same with ignition timing, noting optimal timing requirements
4) Return to stock settings and add hydrogen, noting BSFC
5) Re-test for lean burn limits/EGT temps/ignition timing requirements with the additional hydrogen.

This will at least quantify the changes that the hydrogen has on combustion. The BSFC after injecting hydroxy and all of the tuning would tell you what your final MPG figure is.

[rookie]

Then the next question would be, how will you make any of this work with an OBD2 or CAN system?

[Brian P]

Makes sense to me. I'd be interested also in seeing what the effect on NOx is ...

[maxc]

Problem posting.

[maxc]

[quote=rookie;5033]Then the next question would be, how will you make any of this work with an OBD2 or CAN system?[/QUOTE ]
Best too do it on a carbed engine first. Sometimes OBD2 adaptive memory is hard to beat.
I have a speed Demon 650 that will be modified to run 60 to 1 AFR's with HHO and water injection.
But a cam lobe just worn out bad on my 351C.

[Pinhead]

Originally Posted by rookie

Then the next question would be, how will you make any of this work with an OBD2 or CAN system?

Tuning for Mileage by MPGMike

[maxc]

Here's some power and using way less gas. Directory:Gun Engine - PESWiki
I know a guy who ran direct cly injection of water at 300C and 3000psi. Almost blew the head off the engine(streched headbolts, wasted the head gasket,cracked pistons).