TOPIC: Use more Throttle, Save More Gas!

OK, so Ron has enlightened us of the merits,even Need. of using the Power, to get the gains in MPG's. Yesterday I re-Grooved the TB on a '06 Subaru Forester, 2.5L, auto trans. On the re-learn drive, after the low speed sequences, I began to use throttle more aggressively than ever before on the re-learn drive. I had my scantool plugged in, mainly to monitor the ST/ LT fuel trims.

the Forester started out at 16 LT. After I had powered up to 35 from 25 MPH a few times, the LT went into the 15's. I kept the sequence up, using full throttle several times. I never did get on the freeway. But I got onto a 3 block long street with only Industrial businesses along it, and little/no traffic. I nailed it and held it there at WOT, reaching 65 MPH from a short roll 3 times. Headed back to my place, getting in two more hard accelerations on the way. Back in the driveway, LT had dropped to 12.3. A few times I saw the ST go to -9.4 as well. And, with a Large Groove, this Forester runs Very Strong!

So, I think it's time to accentuate the Positive with the Grove's effects. We can say that because you will have more Power, that the Reward for using it judiciously will be better Economy and Reduced Emissions!

This Really is like--You must Eat Your Cake, to Have it Too!

Tracy G

I like the idea of using the power how long will it take to get it to reset it self also I'm wondering if any one has tried moving the egr in front of the throttle body some how.i read something about a stainless natural gas hose some were

Miles I don't know how long. I think the way to view this idea is- it is a process, not just a one time thing. Think of it as a change in driving habits. When possible use more throttle to accelerate than before. Not to be a speed demon, just get deeper in the throttle as long as reasonable. Ya gotta have common sense here.

Ron said to me yesterday that getting it to downshift is even better. I suggest for example, using WOT, along w/ a downshift ( auto trans) on a freeway onramp, or when passing someone. To me, it's not about hauling A** everywhere- rather driving normally, yet looking for the right situation to open it up, even if only for a short moment.

This does require a mental adjustment. It seems against common sense- yet I saw evidence if it yesterday working, on my scantool. It's real. But if you just drive normally, "Grandma-style" then the ECU will always want to return things to higher ST and LT numbers. Meaning back to mediocre mileage.

Tracy G

Awesome that you clicked the link to the EGR defeat/reroute thread, Miles.
I've never done it (I've worried about melting my intake tube), but re-routing hot&moist air from the exhaust to back into the intake should have a positive effect on fuel trims as far as we're concerned, meaning leaning out fuel delivery by shortening injector pulse durations. Silicone hoses used by people who build their own intake plumbing have a better tolerance for high temps as I understand things; the real trick is mating the stainless steel pipe you mention to a silicone intake. It would definitely have to be downstream of a MAF sensor...

Intercooler Pipe Fabrication
Rubber Material Reference, Neoprene, EPDM, Buna-N, Silicone, SBR, Butyl, Natural Rubber, Gum Rubber, Hypalon, Urethane, Viton, Fluoroelastomer, Fluoro silicone, Hydrogenated Nitrile, Carboxylated Nitrile

Interesting Tracy. 2 points I am pondering and would like your comment(s) on:

- Instead of high throttle, what about just driving in lower gear / higher rpm (1 or 2 gears below normal)? wouldn't this provide the same effect without having to launch-off at high acceleration as frequently?

- In Ron's youtube video where he explains with a white-board what's happening to the air 'clusters' that catch and spin in the groove when throttle is almost idle, doesn't this mean, it's beneficial to first be at low throttle in order to build up the air 'clusters' in the groove first and then after enough vacuum pressure is built-up (and air clusters condensed ) you THEN dump it down the header with open throttle? I guess I'm asking, isn't it necessary to first allow the air-clusters to build up in the groove first (at low throttle) before giving it a lot of throttle because the air reaching the combustion-chambers would have time to condense making the the high-throttle more efficient?

Wes, I wouldn't want to drive like that. I prefer to just drive normally, while looking for the opportunity to floor it when it's reasonable. Part of this is that the TPS will tell the ECU that it's at WOT. And, especially w/ an auto. trans, if it can downshift at the same time, then as I understand it, this is when the ECU does the most adjustment of fuel trims. Ideally, WOT and a downshift are done in a high load situation, like climbing a hill, or a freeway onramp. Someplace where you can see all around well so it's safe.

But, as when I was doing the re-learn drive on the '06 Forester, I went to an industrial area street after hours, and did several WOT runs from a rolling start. followed by another on a long boulevard. Just after the last WOT run, I checked the scantool, and LT had dropped to 12.3 from 16 at start of the re-learn drive. These streets were all level ones.

Talking about how the Groove works- the process of air compressing/releasing in the Groove is far faster than we can manually control. If I understand you, you are speaking of a way to get RPM's up higher. But the idea is to get the engine under a higher load at WOT.

Wes, if you have a scantool or etc. then hook it up and go try your idea, and then tell us here. Compare different ideas, see what works best!

Tracy G

I have a gauge, but I've mostly been using the instant mpg to monitor fuel usage just because it's the simplest. I haven't actually taken the time yet to understand how to interpret the fuel trim readings. is the instant mpg unreliable?

Also I drive a 5 speed AT and since I put on the groove, keeping it D (5th) gear generally requires more gas and load at speeds below 60mph. I've found keeping the gear box at 4 (instead 5/overdrive/D) everything works more efficiently if under 60mph...

When you say WOT that literally means flooring it? So, in order to maintain the good fuel trims you're getting by doing this, you'll have to always keep flooring it? Or just during the ECU relearn?

PS I will get around to posting about the whistle on the other thread.

Thanks!

The ECU is actually programmed on most vehicles to read MORE miles/km per hour than the vehicle is actually travelling by around 10%, give or take. This means your computer will automatically read that or more in error. And there are other variables in play, also (see the document on Tuning Your Spark Plugs for Maximum Power) that case variables in the calculations.

The best way is also the oldest, although it's still going to be off some of actual distance travelled. Take miles on the odometer and divide it by the fuel used. For KM/L calculations, it's the opposite: Fuel/Distance.

As to "WOT" suggestions, I'm not sure I recommend that. Just at the higher RPMs The Groove does seem to perform better. But for tuning the ECU (and KEEPING the thing tuned!) you need to change your habits, and forever.

But who DOESN'T like using the power you PAID for???

Ron

My experience so far re: using WOT is from both my and a cudstomer's Subarus during re-learn and one subsequent test on my Subaru. I realize that WOT is not something I or most folks do very often. But I did see the drop in LTFT numbers on both Subaru's immediately following using WOT.

I think what I need is some kind of digital readout display I can stick in view on my dash, to let me monitor fuel trims and other data. I don't have a smart phone. Does anyone have any suggestions?

Using WOT is definitely counter-intuitive. And it seems cynical if the OEM's design things this way, if it is true that it's WOT when the most changes to fuel trims occurs.

Would using a somewhat heavier than normal "foot" be just as good?

Whatever the case is, it seems evident to me (from a small sample admittedly) that driving like Grandma can lead to the same old crappy fuel economy. Maybe a mix of the two styles?

Hmmm....

Wes, I advise searching 'round on youtube for some tutorials about Short term and long term fuel trims. I'm sure there are such videos there! And if ya would, when you find a good one, could you post it in the Forum? Thanks!

Tracy G

Right Ron, so if the groove works better generally at higher RPMs, would you advise those with AT to either keep overdrive off or do do more manual shifting at lower speeds, if the car permits?

On my 5 speed AT, I can move the lever and select the highest gear available in gear box, D->4->3->2->L ... If I keep it in D, the car basically tries to keep the RPM's under 2000, so by 40mph it's already auto-shifted into 5th gear ...

Is there a simple suggested rpm range to maintain when cruising? Perhaps stay above 2000?

Tracy, if you want something simple that plugs into the obdii port, easily customizable and sticks on your windshield, I'd recommend the (wired) ultra-gauge ( UltraGauge OBDII Scan tool & Information Center ). You can have the LTFT/STFT display in real time if you prefer along with a couple hundred or so more different gauges to choose from.

I currently have showing on the 1st page: instant mpg, rpm, relative throttle position, coolant temp, engine load %, mph

Thanks, Wes! I appreciate that, I'll go look at that one!

Tracy G