O2 sensor for PCIIIUSB
 

the PCIIIUSB specifically designed for BMW's has a datga port that accepts several devices. Dynojet has an A/F meter available that plugs into this port (I believe the BMW-specific PC is the only one currently with this useful feature as the saled guy at dynojet waws confused about it until I said BMW).
Neat, and you don't need multiple bungs:)
Part# is 76950408, $111.00 with shipping.
Mine's on the way.
With an AF meter and a gforce, I don't need a dyuno....

I'll be interested to see what you get from that. I've found all the g measurement systems too inconsistent for a bike, so far. Hope this one works. I haven't worked too hard on it yet, as I'm still working some rpm pickup issues, and building a plug-in tps pigtail out of an old tps and harness segment. Let us know what you see.
thanks
Roger

dumb question: what's a gforce?

y'know, an accellerometer with microporcessor.
tells top speed, accelleration, lateral g's...all that good stuff; calculates HP;
I'm not interested in empirical accuracy here as much as the ability to do an accurate before-and-after comparison.
scenario:

deserted road or airstrip;
brought laptop, have default map saved as the baseline.
run bike; look at gforce data
fire up laptop, tweak map richer or leaner depending on data run iinterpreted by gforce
do another run; look at gforce data; ws this run better, if so, the map's closer
was this run worse, go the other way with map; keeping careful notes and tweak till you get best accelleration and top end numbers from gforce, taking into consideration what the AF meter says (max hp will do no good if the af is so lean you get a 1700F egt and a ventilated piston)
somewhere in the middle is a compromise between best performance, best fuel mileage and an AF ratio that won't detonate/hole pistons.
YMMV< FYI< FWIW<LMAO<CIA<NSA<LSD<LDS<LSMFT

We'll try to forgive you ... :cool:

http://www.gtechpro.com/

http://www.gtechpro.com/images/hp-image.jpg

Sure, tweak all the figures in a 60 cell map table based on a single run?

what makes you think I'm going to just do a single run?
My method has worked for 2+ decades....you do things your way, I'll do mine my way:)

Jony,
Sounds real similar to tweaking a Holley "pro injection" unit...
Is it???

very.
I have a 4bbl 950 commander on my 383 chebby boat motor.
In fact, the 950 commander CPU would probably be a better unit than the moronic with PCIII; it has all the sensor inputs including a wideband O2 sensor (I don't run my boat closed loop for various reasons, mainly due to the fact it's a wet exhaust; I like quiet boats and not the insane bellow of open headers).
A day or two spent comparing back-to-back runs and data gleaned from them, combined with the AF meter reporting 'rich' or 'lean' and I ahve no douobt I'll get as close as a dynojet dyno, especially considering tuninglink doesn't work with a BMW-flavor PCIII (!!!!!! WTFO, DYNOJET, THAT WAS ONE OF THE MAIN SELLING POINTS; DYNO INTERACTIVITY!!!!!).

> as much as the ability to do an accurate before-and-after comparison.

Yes, but that is exactly what I hold the g-forces are not worth a crap on on high Cg / short wheelbase vehicles like a bike.
Mounting it close to the Cg would of course help.

If you can get about 10 runs to match each other as a good baseline, I'd trust it, but at the mag a few years ago (an abandoned article given the crap success) the units just weren't repeatable.

You're right, the absolute numbers don't matter a whit.
The repeatability, which I failed to find, matters a bunch.
I dont' think I was able to mount a unit close enough to Cg.
Maybe focusing on that will give you better results than me.
That's certainly where I'd start.

Hey Rog;
Isn't there a g-force thingie specifically for motorcycles?
My buddy has one and I've had it in my cage one day 'sperimentin and it was pretty cool. I hear ya about the short-wheelbase hiCG thingie.....hmmmmmm.
might be back to having to compare 1/4 mile times and speed in gears with a radar gun. buddy's got an older Kustom Kraft ex-state trooper unit.....

now i reeeelly reeeelly want to do a PC3 for the 1100s, but i need to finish theother 2 ikes first, must get others back together,

I think that's what you'll find Jony, but definitley decide for yourself.
I would get reading from time to time with >10% variance, even after throwing out some obvious flyer datapoints. Just about no tweak anyone would make would be sufficiently above that noise floor.
But again, you might do better with a better unit, and better unit placement. 1/4 mile times are tough for comparison what with reaction time and clutchplayout and overall launch playing too big of a role.
I bet your speed-in-gears would be a better indicator. Also, roll-ons from some given speed in a given gear (from bottom of 2nd and 5th maybe?) could give good comparisons of low and high rpm performance.
You know the deal. Like any tool, the use and techinique are often a bigger deal than the tool itself.

later
roger