diga -tron data aquisition systems dt 50

[mdw471]

mark        whar air temp is it salt flats when you run.  you should talk to flyin9 he has a wide band o2.

How does the o2 sensor get along with premix?

From memory the air temp ranges between low to mid 60's to tall 90's.....depending on the time of day and which event.

I am definitely interested in what flyin9 has experienced, but I spoke to a couple of different companies before deciding on the Digatron kart stuff..........

Only one seemed to think that the O2 sensors would get along with pre-mix. I had one of their engineers on the phone and he explained that they had got an O2 sensor to work, but it wasn't easy. Some of what he mentioned included using shrouded or unshrouded sensors, false readings due to an 'errant' drip of oil, the un-spent exhaust that is pulsed back across sensor by the chamber, position of the sensor, etc. The guy that designed the instrament and is also an engine tuner had his work cut out for him with the O2.

It didn't take long for me to remember that I am not a software designer or an engine tuner. I am personally more interested in using a 'table saw' to build stuff as opposed to figuring out how to mount a circular saw upside down on the kitchen table......

I look at the Digatron as a 'way' to take Stewart to the salt with me....or at the very least send him a graph over the internet!

Mark

[kaw rider]

I would upgrage to these egt sensors. These are what we ran on are sled motor 10 years ago. Plus they come with a 3 year warranty.

Hyper Response, Exposed Tip. Accurate enough to see a single misfire at 8,000 RPM's.

[stewart]

diga-tron plug-head temp installed and rpm  is blue wire on plug wire

[stewart]

diga tron mph sensor on front wheel  notice round magnet  drilled and pressed in hub

[Larry Wiechman]

Can you add another wheel speed sensor (rear wheel) to calculate how much wheelspin at speed on the salt?

[stewart]

Can you add another wheel speed sensor (rear wheel) to calculate how much wheelspin at speed on the salt?

yes we are just finishing a rear bracket

[stewart]

here  is head temp under plug ..a balmy  65 degrees        it checks with in 2 degrees of my infer-red  temp gun screen says cht  ...cylinder head temp

[kaw rider]

Mark & Stewart
You will like the data logger deal. It will make you faster, You should try a dyno section with cht clamped to pipe body. That way Mark can gear for same surface pipe temp on dyno then he out on the flats. Pipe temp will change as much has 500 rpm.

[DoldGuy]

Stewart,
Had a chance to run the bike yet? I am curious to see what EG temp it's getting up to with it "On The Pipe"

[kaw rider]

Doug
On a stock build it should get up there around 1050*-1300*.

[stewart]

picture at 7000 rpm of head temp and exhaust  temp on dyno today working out inductive tach interfence  problems

[flyin9]

nice pics stewart.

hey guys sorry i didnt check this thread sooner but this g** d*---- snow in october is making everyone who owns a boat freak out that their stearn drives are going to freeze. but on to motorcycles. mdw471=mark i would assume. what are you looking for and EGT or a wideband AFR O2. big diffrence. EGT = temperature and WB O2 is for air fuel ratio. most of the time the AFR is used in the powersport industry to tune an engine to give the engine what it wants for fuel. its kind of like how do you make a woman happy?  give her what she wants! same is true with an engine. most people will ask a question like, What jets do i need at 65*F at 1265' above sea level to tune my engine? and you will get a resposne like pilot 55, 170 main 2nd clip on the needle... that is a fine and dandy for trail riding, im not trying to rip on anyone about questions like that so please dont rip on me, when you are looking for every last inch-lbs of torque and HP out of your machine you need to go to the n'degree of detail.  not all engines are the same so to the jetting Question you need to look at AFR to see what your engine wants. most tuning is done in a controled setting IE. DYNO! run your tests use your ARF to pick and chose jets, needles, slides, ect to make your engine happy, you will see a nice smooth AFR curve and that will tell you what it wants. always get close on the dyno fist then test in real world conditions. the WBO2 system that i have records real time data and allows you to plug in to your laptop to retrive the data. check out www.daytona-sensors.com and check out the wegoIII WBO2. thats what i run. i have a LCD readout in the cockpit of my kart that i can glance at just to make sure im in check, then i plug in to my laptop and review my realtime data. for racing, i think that this is a must. I will be more than happy to talk to anyone about it. This is what i love to do so please feel free to contact me. if i made a mistake somewhere someone please correct me, i dont want to give false info to anyone! BTW after all of my STEWART mods i made 54 HP on the dyno, , 12% came from tuning with ARF. stewart thanks again for working on my engine it still runs like a top. i will never have anyone other than him modify another KX 500 of mine! Jared

[flyin9]

sorry i forgot to mention, the O2 sensors last 2-10 hours depending on the location. i would sugest welding 2 bungs in to your pipe then while onthe dyno test both, (they make plugs for a bung that is not used, so dont worry about a hole in your pipe) one close to the exhaust port of the engine, for use while on the track, the other one further up the pipe =midpipe or so. test them both on the dyno to check accuracy, use the mid pipe one for on the dyno, the O2 will last longer. the O2's are between 100-150$ each but with a little thinking and the help of an older VW rabbit O2 i belive it is your should be able to make your own for about 50$
jared

[stewart]

whay kind of tourqe  numbers  and at what rpm did you see in your testing jared ..i have found that since dynos maesure tourqe  and calculate horse power a few things became big factors  number one the checking of the calibratyion of our tourqe arm  ,,it sets at 50 pounds in our case then zeros ..and found that any interferance in rpm reading from calibration or inductive issues caused varying hp totals  as well as our pulse settings.....thanks for your input   as i hope your racing is going good..are you getting rear wheel numbers or out put shaft

[flyin9]

I ran a load test on my kart at 12%, it was run in 4th gear, i had to keep the engine at close to 6000rpm's to start the runs because anything below that on the dyno my kart would shake so viloently that it just about threw me out of the seat. so the curves didnt cross at 5252 like all graphs do, do to the fact we started at 6000r's but the torque # was falling from about 58to about 48 from 6000-9000, we found with a stock silencer it alowed the torque curve to pull sery smooth from 6500-8500 compared to a modified silencer. we used both, an inductive tach and then we tried an optical tack on the tire with all of the calculations put in to the computer both were within .1'ths of eachother. if your using an inductive make sure it is only touching the plug wire, if it bounces off the engine or frame rail. interference can happen very easy. these numbers are all SAE Trq and SAE RWHP, it was done on a superflow dyno.
jared