Digatron Data Comparison & Questions

[PilotSniper]

I went riding with Odykid in the corn fields for the first time yesterday after a three-month complete rebuild of the bottom end, top end, K-fab head change, PowerBloc clutch change, PowerPros rev pipe change and Keihin 39mm PWK carburetor change. Naturally, after all of these changes, it becomes necessary to monitor your vital signs with a Digatron data acquisition computer. The Digatron Pilot kit that I purchased from Ludedude (a huge "THANK YOU" once again to Ludedude for doing all of the legwork for all of us Pilot owners) comes pre-loaded with average limits for water temperature (H20), tachometer (RPM), top speed (MPH) and exhaust gas temperature (EGT). The best part of the Digatron computer is that if any of these thresholds are broken (either under limit for H20 or over limit for RPM, MPH or EGT), the rev limiter kicks in automatically in order to save your a$$ and avoid a poofkaboom scenario.

Side Note: For my maiden voyage yesterday, I did not hook up the MPH, REV limiter or VOLT meter leads. Odykid was bugging the hell out of me :wink: and nightfall was approaching quickly.



Quick bunny trail: You loan your Pilot to your friend, who doesn't realize that you need to warm up the engine before you punch it.

Without the Digatron: Your friend cranks up the Pilot, immediately punches it and fries your engine! Now, you're pissed at your friend (who is now an ex-friend) and you need to spend hundreds of dollars on a rebuild!!!

With the Digatron: Your friend cranks up the Pilot, tries to punch it, but the water temperature has not yet reached the safe "punch it" temperature of 85 degrees. Your friend sits there with a silly face wondering why the Pilot won't fly, all this while Commander Digatron is barking orders to Private REV Limiter as he quietly does his thing and your engine is saved!!!

Personally, I'd rather have the Digatron...  :lol:



Back from the bunny trail, I'd like to find out from others who have the Digatron what their experience has been as far as the average threshold settings for a modified Pilot.

Water Temperature (H2O): My H20 readings never exceeded the 178 degree point. I attribute this to the over-sized, major-heat-dissipating design of the K-fab head (awesome job Skeeter!!!). What is everyone else getting as a high reading for H2O?

Tachometer (RPM): My RPM readings were excessive, in my opinion. I have a modified CDI, but I hit a maximum of 8,870!!! What is everyone else getting as a high reading for RPM?

Exhaust Gas Temperature (EGT): My EGT readings were off the charts, in my opinion. I was hovering above the 1,300 degree mark quite frequently with an all-time high reading of 1,371 degrees! The only thing I can think of is that my piston crown was coated by Bore-Tech's ceramic coating. This is supposed to keep the heat away from the piston and in the exhaust gases, right? Is this a good reason as to why the temps are so high? What is everyone else getting as a high reading for EGT?

Well, I think I've bored everyone enough. If you do have a Digatron and do respond to this thread, please note your Pilot modifications. This will help (I hope) to shed some light on how certain mods affect certain temperature areas.

Thank you all in advance for your time and efforts!

[Moskito]

Water Temperature (H2O): My H20 readings never exceeded the 178 degree point. I attribute this to the over-sized, major-heat-dissipating design of the K-fab head (awesome job Skeeter!!!). What is everyone else getting as a high reading for H2O?

Tachometer (RPM): My RPM readings were excessive, in my opinion. I have a modified CDI, but I hit a maximum of 8,870!!! What is everyone else getting as a high reading for RPM?

Exhaust Gas Temperature (EGT): My EGT readings were off the charts, in my opinion. I was hovering above the 1,300 degree mark quite frequently with an all-time high reading of 1,371 degrees! The only thing I can think of is that my piston crown was coated by Bore-Tech's ceramic coating. This is supposed to keep the heat away from the piston and in the exhaust gases, right? Is this a good reason as to why the temps are so high? What is everyone else getting as a high reading for EGT?

Well, I think I've bored everyone enough. If you do have a Digatron and do respond to this thread, please note your Pilot modifications. This will help (I hope) to shed some light on how certain mods affect certain temperature areas.

Thank you all in advance for your time and efforts!

Water Temp - yes, that's about normal for a Pilot.  Do you have a rad relo?  That will drop the temp down to 160ish.  Under race conditions, the old 500 ran about 190 - 195, but under trail/play conditions I usually saw 160 - 180 depending on ambient air temp and such.  The 400's were pretty much the same.

8870??  WOW!!!  Do you have a new belt installed?  A worn will make the revs go up.  What size tires?  Smaller are going to tax the drive train less than taller tires.

How many washers in the clutch?  Adding a couple will make it upshift sooner, but also bring down top RPM limits.

1371...  Aluminum melts at 1425.  Neil and Jay always say that 1300 to 1350 is good, but it scares the snot out of me.  I prefer to keep my engines in the 1200 - 1300 range, where 1300 is topped out, screaming across the desert for a few miles and it still scares me...

Up a jet size and see what that does.

It's amazing what info you can get from a well set up EGT computer.  I've been running the Exhaust Gas Technologies Advenger III for a while now and it will let you set all sorts of limits, alarms, do mph, odometer, show the actual gear ratio between the engine and tranny, blah, blah, blah.  Great tools!

Did you get any compression numbers by chance???

[PilotSniper]

Water Temperature (H2O): My H20 readings never exceeded the 178 degree point. I attribute this to the over-sized, major-heat-dissipating design of the K-fab head (awesome job Skeeter!!!). What is everyone else getting as a high reading for H2O?

Tachometer (RPM): My RPM readings were excessive, in my opinion. I have a modified CDI, but I hit a maximum of 8,870!!! What is everyone else getting as a high reading for RPM?

Exhaust Gas Temperature (EGT): My EGT readings were off the charts, in my opinion. I was hovering above the 1,300 degree mark quite frequently with an all-time high reading of 1,371 degrees! The only thing I can think of is that my piston crown was coated by Bore-Tech's ceramic coating. This is supposed to keep the heat away from the piston and in the exhaust gases, right? Is this a good reason as to why the temps are so high? What is everyone else getting as a high reading for EGT?

Well, I think I've bored everyone enough. If you do have a Digatron and do respond to this thread, please note your Pilot modifications. This will help (I hope) to shed some light on how certain mods affect certain temperature areas.

Thank you all in advance for your time and efforts!

Water Temp - yes, that's about normal for a Pilot.  Do you have a rad relo?  That will drop the temp down to 160ish.  Under race conditions, the old 500 ran about 190 - 195, but under trail/play conditions I usually saw 160 - 180 depending on ambient air temp and such.  The 400's were pretty much the same.

8870??  WOW!!!  Do you have a new belt installed?  A worn will make the revs go up.  What size tires?  Smaller are going to tax the drive train less than taller tires.

How many washers in the clutch?  Adding a couple will make it upshift sooner, but also bring down top RPM limits.

1371...  Aluminum melts at 1425.  Neil and Jay always say that 1300 to 1350 is good, but it scares the snot out of me.  I prefer to keep my engines in the 1200 - 1300 range, where 1300 is topped out, screaming across the desert for a few miles and it still scares me...

Up a jet size and see what that does.

It's amazing what info you can get from a well set up EGT computer.  I've been running the Exhaust Gas Technologies Advenger III for a while now and it will let you set all sorts of limits, alarms, do mph, odometer, show the actual gear ratio between the engine and tranny, blah, blah, blah.  Great tools!

Did you get any compression numbers by chance???

Skeeter,

No rad relo. It's OEM. It looks like we're good there since the temps are normal.

As for the RPM's, I do have a brand spankin' new belt from Marv at 4x4Tuff, so I'm good there too. I am running 22" ITP's in the rear, so they are definitely smaller than average. That would explain the higher rev's.

Regarding the PowerBloc clutch, I started out with 9 washers in each puck. I'm engaging at 3,900-4,000 rpm with this setup. I might need to try a couple more, based upon your recommendation.

I agree on the EGT temps. If Ludedude maxed out at 1300, there's a reason for it. I don't want a meltdown, so I'm going to have to start playing with jetting. Wow! I absolutely LOVE jetting!!! Let the fun begin!!!  :cry:

Ditto on the computer. I don't know how I managed before having it!

Finally, compression is still at 160lbs with the shallower of the two interchangeable domes. I was running 93 octane AMOCO Ultimate with a 32:1 ratio using Yamalube R. So far, so good...

[PilotHawK]

EGT temps can be greatly affected by the probe placement in the "cone of fire" coming out of the combustion chamber. An EGT is merely a tool. You have to tune it to what your spark plug is telling you. Once you get it to where your plug chops are where you want them, refer to the EGT as your reference point. A 1" change in either direction from the face of the piston CAN create a huge difference in EGT temps. Go by the plug...then the EGT.

[PilotSniper]

EGT temps can be greatly affected by the probe placement in the "cone of fire" coming out of the combustion chamber. An EGT is merely a tool. You have to tune it to what your spark plug is telling you. Once you get it to where your plug chops are where you want them, refer to the EGT as your reference point. A 1" change in either direction from the face of the piston CAN create a huge difference in EGT temps. Go by the plug...then the EGT.

Hawk, that's an excellent point and one that I've considered. I mounted my probe just outside of the weld for the area of the exhaust pipe that mounts over the exhaust manifold. If I were to guess, I'd say it's roughly 4 inches from the piston. I looked at the plug after the ride yesterday and it was a little on the rich side, which is just where I like it to be. This is exactly what prompted all of the questions. One would think that excessive EGT readings would indicate a lean condition, which in turn would show up as a lean condition on the plug reading. Since this is not the case, I'm trying to determine a baseline comparison so that I know where I need to be (more or less). I understand that this is just like jetting (where everyone's jets and screw turns are different), but I don't want to have a reading that's completely out of whack, either.

[ludedude]

I think you're closer than me on the probe placement, I think I'm 6" from the piston face. So that may explain why my readings are different.

Clear the memory of the Digi....go do a plug chop..if you're where you want to be....hold the EGT button to see the max. Then you can set the limit a bit higher if you're reading a rich plug. If the plug is tan I'd set the limit very close to what you read as the max.

8870 on the rpm!!! Do you have the calibration set to 1 for single cylinder? I'm pretty sure I'm running 9 washers too...(notes are in the garage) I set my limit to 8400 I think. I think 8000-8200 translates to maximum recommended linear piston speed for the Pilot's stroke....I'd limit that down some bro! That scares me.

Glad you're up and running.

[betel]

Note to Ludedude:
I may want to get one of the Digatron gauges for my Pilot.  Do you have one available and how much is it.

[PilotSniper]

Note to Ludedude:
I may want to get one of the Digatron gauges for my Pilot.  Do you have one available and how much is it.

Don't leave home without it!!!

http://www.p-o-ps.com/store/view_product.php?product=DT-53K%20TMEWV

[MassOdy]

I'm using mine on a FL350. I didn't implement the relay rev. limiter option.

I'm really pleased with the one I got and all its features.

I like the ability to graph the data after the ride. I still need to sit down and learn how to get it into Excel.

I'm worried about my EGT as well. Chops look good but call for a jet change for comparison.

Water temps are 190 to 205 riding it. and 150 at hot idle before leaving.
          I want to get a pump in place for 1" hose. Livewire WCH, Gold
         Wing Rad.

EGT is hitting the full warning LED Indicator and upto 1340 to 1350.

RPMs are like up to 7800,7900 RPM Max

Will be making a jet change see how I fair. It its similar then I'll leakdown and see if I'm drawing air and leaning out on WOT.

Well worth the purchase in my book.

[PilotSniper]

I'm worried about my EGT as well. Chops look good but call for a jet change for comparison.

EGT is hitting the full warning LED Indicator and upto 1340 to 1350.

I'm glad to see I'm not the only one experiencing this.  :?

Mass, please report back on your findings after the jet change. I'm interested in seeing the results.

[MassOdy]

OK will do.

[MassOdy]

Well I went to a 145 Jet from a 142 in the stock 350 Carb. The outside temp. was in the 30s F.

The machine had great power and responsiveness.

I was still running hot on the EGT at WOT. High 1300s and into 1400s. :x

I backed off a while and drove to control the temp.. Later on in the day
I just drove and ignored the readings. And was OK.

I suspect my sensors might be touching the far edge of my pipe.
I have the Dig and a Analog as a secodnary. they both confirm each
other on these values.

I will move the jet one more size and try again.

I'll download the data and see how bad I was.

[PilotSniper]

I was still running hot on the EGT at WOT. High 1300s and into 1400s. :x .

WOW!!!

Bobster, can you say M-E-L-T-D-O-W-N???  :shock:

I went out to Homestead with Odykid again this weekend and ran the snot out of the Pilot. I continually got readings in the 1370's at WOT. The plug reading shows it as being a little on the rich side (where I like it), so I'm convinced that this is where I should be. I'm going to use this number as my high point. I don't see why I shouldn't, since she runs strong with no signs of a lean condition. I don't know what to tell you, bud, but watch that 1400 threshold!!!

Please post your findings after the next drop in jet size. I'm anxious to see the results.

Best of luck!!!

[ludedude]

what does your plug look like Bob?

[Moskito]

continually got readings in the 1370's at WOT. The plug reading shows it as being a little on the rich side (where I like it), so I'm convinced that this is where I should be. I'm going to use this number as my high point. I don't see why I shouldn't, since she runs strong with no signs of a lean condition. I don't know what to tell you, bud, but watch that 1400 threshold!!!

Actually, you're right in the range that Neil and Jay always said was good. (and scares me too) :shock:

Aluminum melts about 1425 - 1450 depending on what the properties are and you can spike 1400 for a couple seconds w/o damage.

If the plug says all is good, then rely on that and accept the numbers your Digitron says as good.