WOT shifting for autos

[SVOboy]

I seem to be the only on here that believe in the merits of WOT shifting; I also happen to drive an auto so I can't practice it much.

However, since I no longer am able to use my kickdown cable (tells the tranny when to shift based on pedal pressure) I can rig it up any way I like. I plan to stretch it only as much as needed so that it always shifts at 1800, no matter what. This will allow me to just floor it through all the gears and keep my rpms low, hopefully I can test this theory well.

What does we thinks?

[krousdb]

I look forward to some results.

I plan of accelerating more briskly on this tank, although not WOT. There is a point in 5th gear, at 17 in hg and higher that my instantaneous FE spikes. The sooner I get to speed the sooner I can cruise in this high FE zone.

[SVOboy]

I have been doing it in my mom's car but our driving styles are just too different to compare. I hope it does work, have you seen the insight forum quote about why it's supported over there?

[krousdb]

No but I would expect that it is for the same reason that I mentioned above. WOT means less time accelerating and more time cruising in lean burn. I think that the benefit of lean burn might outweigh any drawbacks of WOT.

But for those without lean burn, WOT may not work as well. WOT means open loop, which means less than stoich.

I dunno, just my opinion. meh

[SVOboy]

Run a search for my original thread on it and you will see the quote. The idea is mainly that you reduce pumping losses enough that in combination with getting to speed quicker you're still saving. You're prolly at 13.5:1 or so when you're at WOT, it could prolly be tuned down a bit also.

[krousdb]

Yes, the target afr at WOT (for my ecu) is about 13.5. I plan on changing that to 14.7 so that I won't have a WOT penalty. In that case, I would agree with your WOT theory.

[SVOboy]

Well, even with that decrease the fuel injected at WOT will still be a large amount above greater vacuum. Also, there's a lot of blown up engine issues when you mess with WOT afrs,

[krousdb]

Originally Posted by SVOboy

Also, there's a lot of blown up engine issues when you mess with WOT afrs,

Hah! A blown engine will give me a good excuse to go Z1. The holy grail! :-)

It reminds me of when I bought my dad's 68 Rambler American in the early 80's, my first car. It only had 83k miles on the 199 cid inline six, three on the tree. I ran that engine in first gear, WOT for miles and miles. I could not get it to blow. Finally I had to tell a white lie to my dad that the engine blew. Thats when I put in the 401 cid and a chrysler 8 3/4 rear end. Ahhhh those were the days. NOw I am in persuit of the ultimate measure of performance... FE! :-)

[Compaq888]

Originally Posted by krousdb

Yes, the target afr at WOT (for my ecu) is about 13.5. I plan on changing that to 14.7 so that I won't have a WOT penalty. In that case, I would agree with your WOT theory.

The max you could go for WOT a/f ratio is 13.5:1, anything leaner and you can easily blow your engine.

[zpiloto]

I've tried this with the scan gauge and there is a sweet spot where MPG drops from 6 to 2.8 with out much increase in acceleration. When I ran my 41 mile test loop(rolling terrrain with 15 stops but no traffic) the increase in MPG between each trip was an increase of .4 MPG using the near max acceleration. I do not shut the engine off(which would yeild better results) when coasting but shift into neutral. I'd be interested in the results of the lower shift point and the effects on MPG. My point is 2500 RPM.