Batman we have lean burn! 49.6 mpg!

[cfg83]

cheapybob -

Originally Posted by cheapybob

The device I have is an Ultraflow III Stoichiometric Air/Fuel Ratio box with 10 LED's going from Lean to Rich. When I did the HAI and IAT mods, we added an output from the O2 sensor which goes to the interior where I can clip onto it an alligator clip from the Utraflow III box.

I guess its similar to the device you pointed out as far as how it works. It did react to the resistance being changed when I'd flip the switch. I didn't try hooking it up on the T/A because the O2 sensors on it are not convenient to get to like the Saturn's.

Ok. Most excellent test. The devil is in the details. Just knowing you monitored the A/F makes the resistor mod a slam dunk, IMO.

With the Scangage, if you watch IGN, you'll see it drop and feel the engine get real sluggish if actual air or water temps get above about 210. I think that's because it was retarding spark significantly when it detected preignition. It also seems to happen if I try to run it tricked to 242 degrees before the intake air is up to 80 or so, so I usually run it straight from the sensor a few miles to warm up before switching it to 242.

Thanks. I am not good at interpreting the scangauge IGN parameter, so I haven't been able to extrapolate the timing.

Interestingly, the T/A seems to have no problem starting and running happily with it at 224 to 231, on 87 octane regular, no less, which is surprising given its higher compression ratio.

Did you try your test?

I am hoping to do it this or next weekend.

One other comment. Without filling the tank to the same level at each fill, you can't really tell if the scangage has fuel usage calibrated correctly, and therefore, nor can you tell what your actual MPG's are. I try to go to the same station, same pump, and aways fill to the 3rd time it shuts off, with the last couple times filling very slowly. It doesn't overfill, and I get consistent results that way.

I agree that you are doing it the best way.

I set the scangauge to the engine size and look for relative changes in my MPG runs. Since that is my operating condition for all my runs, I think the my claims of *relative* MPG gains/losses are valid.

I have chosen to look at the "90 day outlook" instead of the tank by tank, because that should reduce the overall error over time. For example, in the last 90 days I have driven 4570 miles for a 38.87 MPG average. Since the sample size is large I think the adjusted odometer based MPG is accurate.

When I see a "relative gain" with a mod over time, the mod stays.

I just can't afford the time to use the same pump. I am a commuter with a messy 1.5 hour one way commute. At best, I try to keep to the same station, but use whatever pump is available .

There's one fellow who records the station and the pump # in his gaslog. Maybe I'll do the same.

CarloSW2

[cheapybob]

I'd guess that pumps that were on the level at the same station would be the same model and therefore give pretty good results. I think the key is to have it on level and finish the fillup slowly, hopefully the same way each time. If you get it within 8 oz of the same point each time and are filling at 1/4 tank left, your mpg accuracy will be high. Relative gain is "nice", but real, believable results for each tank are "priceless". You can always calculate a 90 day average if you have accurate fill and distance data.

I think the IGN number it shoews is probably spark advance in degrees, so the higher it is, the better, and when you see it dropping abnormally, I'm guessing it has sensed ping and is retarding spark to compensate.

Anyway, that's a long commute, so any improvements will payback quickly. If I were you, I'd definitely switch that trans at first opportunity.

[cfg83]

cheapybob -

Originally Posted by cheapybob

I'd guess that pumps that were on the level at the same station would be the same model and therefore give pretty good results. I think the key is to have it on level and finish the fillup slowly, hopefully the same way each time. If you get it within 8 oz of the same point each time and are filling at 1/4 tank left, your mpg accuracy will be high. Relative gain is "nice", but real, believable results for each tank are "priceless". You can always calculate a 90 day average if you have accurate fill and distance data.

I think the IGN number it shoews is probably spark advance in degrees, so the higher it is, the better, and when you see it dropping abnormally, I'm guessing it has sensed ping and is retarding spark to compensate.

Anyway, that's a long commute, so any improvements will payback quickly. If I were you, I'd definitely switch that trans at first opportunity.

I have an SOHC/MP2 5th gear set sitting in my lap right now, but I'm waiting for a good price from a transmission installer dude. I got the SOHC 5th gear set because of what I read in saturnfans :

Re: MAD!! gear swap
http://www.saturnfans.com/forums/sho...3&postcount=45

Who else sells those gears, i think i will fix it so i can watch and calculate..cheapybob has me VERY interested in this gas saving adventure!! What i think would be nice is to come up with a set of cams for the DOHC that will move the powerband lower in the rpm range and swap in an entire mp2, that way you will still have the power of a twin cam but the easy cruising of the mp2..
As for how im liking my 5th gear swap..im loving it!! I know i have no way of calculating the mileage at the moment, but my gauge is definately NOT dropping as quickly as it did..and I dont think the 'most power' is made within the rpm's that they claim it is with the DOHC engine..My son-in-law hates it because he cant outrun my car with his sl-2, if im behind him and he takes off flying through the gears, i can run right up his butt, letting him know that i CAN pass him if he were to move over, well, today, he tried it again, me having the new mp2 5th gear, i was running up his butt, i shifted into 5th at 4000 rpm, let out the clutch and about 5 seconds later, he shifted his to 5th (i could hear him because he has a fart can exhaust) and i STILL was running up his but and he finally got frustrated and backed off..Im pretty tickled with this setup!! Dont underestimate that DOHC engine, its still got plenty even with that gear.

CarloSW2

[skewbe]

That saturn 5th swap can be done in the car. The most expensive part is the gasket (kit), but it's just a cover so you can improvise. I wound up using kite string and rtv on the shifter cover of mine and it is has worked well so far.

Cheapie, you gotta try a kill switch and some P&G sometime. You'll be all like "Dang, why didn't I do that sooner"?

[cheapybob]

Originally Posted by popimp

I took the van for a test drive using the 330 ohm resistor which is 260F. I think the SG2 uses the IAT to compute fuel usage. While driving to Home Depot my MPG was 35.5 with cruise control set at 30mph. I took it on the highway and was getting between 45-50 mpg going 50mph. The SG2 has to be flawed because I doubt this hack would boost the numbers by this much especially on a minivan.

260f is too high. Get it down to 220f or so to run it reasonably lean. I get about 15% better mpg running lean, but I wouldn't want to try to push it beyond there. If you had a GM you'd be setting a code because it would be trying to run way too lean. Just my opinion, and I'm not responsible for any problems. I'd pull a plug and check it. Running way too lean is bad for the engine, IMO.

Also, the SG2 uses the injector pulses as reported by the computer to accumulate fuel usage, I think. Otherwise the fuel used when filling the tank wouldn't match what the scangage thought was used.

[cheapybob]

Originally Posted by skewbe

That saturn 5th swap can be done in the car. The most expensive part is the gasket (kit), but it's just a cover so you can improvise. I wound up using kite string and rtv on the shifter cover of mine and it is has worked well so far.

Cheapie, you gotta try a kill switch and some P&G sometime. You'll be all like "Dang, why didn't I do that sooner"?

I don't "hypermile". I just want my car to get great gas mileage driving from point A to point B without having to do anything extra to accomplish it. I just think its TERRIBLE that we consume so much fuel in this country, and eventually our gluttony will come back to haunt us. I don't want to go slow or have to monkey with it all the time. I get about 45 mpg doing 70-75 mph in the SC1 out on the road, and that meets my objectives. The fuel I save driving my Saturn 98% of the time eventually gets used to fuel my race car and tow van, or the Trans Am, but I'm proud to be able to do that and still use less fuel than the average American because of my efficient Saturn.

What is "P&G"?

[popimp]

I tried using the IAT mod again at 260F. I think it's tricking the SG2 more than anything. The Gauge reported a 30mpg tank while the actual tank was 23mpg. I did use a lot of burn & glide and shutting off the engine at long stop lights.

[cfg83]

popimp -

Originally Posted by popimp

I tried using the IAT mod again at 260F. I think it's tricking the SG2 more than anything. The Gauge reported a 30mpg tank while the actual tank was 23mpg. I did use a lot of burn & glide and shutting off the engine at long stop lights.

I was hoping to post an update to this tonight, but all the data was garbage. I had my wife "film" the scangauge and A/F meter with our digital camera in order to try to gather multiple data points (MPG/IGN/TPS/MAP), but the damn scangauge screen was illegible. Damn glare and inadequate focus in the camera !

CarloSW2

[cfg83]

cheapybob -

Originally Posted by cheapybob

...

What is "P&G"?

http://www.gassavers.org/showthread.php?t=1088

P&G > Pulsa and Gluide. Its roots go way way back in FE driving. But its claim to fame has been in hybrids. Its also alot of work IMHO. But in certin cars can produce steller results. Lets say your on a stretch of road thats flat as a board. Our target speed is 60 mph. We get to 60 mph and then we begin a bleed say down to 55 mph. We then start speeding up to our 60 mph target. But we do it very very slow. In some hybrids you pick up some very lite assist from the electric motor and dont really use much of the pack. And then we start bleeding again. This is a very repetative driving style and not for the faint at heart. It takes alot of conctration and throttle control. It has alot of varibles that can be played with for diff. cars and over all driving styles. Used alot on hwy's and in city driving. The challenge for hybrid drivers is to know when to loose a P&G cycle or two to get the pack recharged.

CarloSW2

[popimp]

cfq83:

Did it work for you?