i ground my dowel hole completely out of the way.my ring is advanced till all the slack is taken up out of the 4 bolt holes that hold it on.from best i could measure,it advanced between 1.5 to 2 mm,closer to 2 mm it appeared...all i can tell is when letting out the clutch in second gear,without giving any throttle,the truck doesnt lug down and rattle like it used to.its smoother and thats it...as mikey was talking about earlier in the thread,with my quad tow box,the truck doesnt have that 2 stroke feel to it anymore.it doesnt have that 2krpm light off feel to it now.its just smooth across the entire rpm range now with no spikey spots in it.im not saying im corect on the amount of advance evrybody is geting,but i would like to be certain of the amount.....i would like for mikey or superduty to post back and see what they think about it..........bama...............after rechecking,,i had a burr preventing full advance,,it now has 5mm slack............

 

Okay. I ordered the sensor a couple weeks back. I have an 04.5.

first impression was not much change in noise at idle, does not really start any harder, and not much increase in power or low end that I could feel. truck feels almost the same to me.

Now the gas milage is up. I am trying to decide how much. I think somwhere between .75-1.25mpg. this last tank of gas had mixed driving. got 16.5 hand calculated. the only way I could get 16.5 in the past was highway driving only. the minute mixed driving was thrown in it would be 14.5-15.5

I can get over 500 miles on a tank now. I had never done that in the past.

my goal with this truck was to try to get 18MPG with the 37's. I felt that would be like getting 20mpg with a stock truck. I feel like I could be getting close 100% hwy to the 18mpg.

was it worth it? cost $70 If diesel stays at $3 a gallon will pay for itslef is say 6-8months in my case so I think it is worth it. even if prices drop it will still pay for itself inside 1 year.

now the tone ring mod is free I just wanted something where I could turn the truck back to 100% stock if a waranty issue came about.

 

Well my mileage dropped to 15.2 and I also have more turbo lag. So I pulled the mod'd sensor and put the stock one back in with the tone wheel clocked a little... we will see what happens with this tank/configuration...

 

Just installed modified sensor. Should have some MPG info this week.

No noticable noise or power increase.

 

after reading through the threads again,,i notice im not the only one that noticed this..post page 21-SoCal-305 measured and came up with what i found,,,for 2 degrees,you would have to advance ring 3.7mm,which is the 1.833 per degree i mentioned.is nobody else figuring on this?.........bama

 

using so-cal-305's numbers this is what I got. 660mm is the circumfrence.
devide that by 360 degrees equals 1.83333mm per degree.
devide this by the conversion # 0.03937 (converts mm to inches) comes to .07203 inches per degree
.14406 inches equals 2 degrees at the edge of the tone wheel.

This being calculated out I can see where the dowel pin would only need to be elongated 70 thousandths to get 2 degrees. This is because the dowel pin is located halfway to the edge of the tone wheel (educated guess till someone takes a measurment). The midpoint (dowel pin hole) would only have to move half the distance of the outer edge of the tone wheel. If this sounds confusing draw a picture real quick. It should make it clear.

 

thats the numbers i figured....but i wasnt really talking about how much to remove from dowel hole,i was talking about how much(distance)you can move the ring,measuring at the outer edge of it.completely opening my dowel hole out of the way,and taking up all slack of bolt holes(4 mounting bolts)i couldnt move mine but about .080 from center of slack....ill double check it this weekend to make sure though..................bama.............after rechecking,i had a burr preventing my wheel from advancing.it has 5mm slack from full back to forward........

 

With 80 thousandths slack at the bolts I believe that you got the full 2 degrees at the edge on the tone wheel.

 

Superduty did the math and even drew a little picture. Search his posts in this thread, it was a ways back. It confirms the 2deg.

 

Asher,
What pin hole did you open up? I installed the sensor and my mileage dropped! Did I miss something on the installation?
Odie

 

alright ,i took it all off and measured evrything today.....measuring at the edge of tonewheel,with dowel hole butchered completely out of way,all slack taken up to the bolts,the tone wheel has 5 mm travel from full retard to full advance...so,,if i was full retard position,the max degrees i could have gotten was 2.7 degrees.from what i could tell stock,i was about in the middle of slack.so,i should be at 2.6 advance from where i started.....driving a tank out now,taking it easy not going over 2k rpm to see what gain i can get...........as it turned out,,while checking it out,there was a burr i left on the dowel hole that was preventing much advance..now with it full forward 2.6 degrees,there is a difference.with my quad 65hp box on it,,it smokes a good bit.if you push on the go pedal,it starts smoking at about 1800,and doesnt stop.not a fog mind you,but alot more than a haze.(for comparison,it smokes like my 02 with dd3`s and a puck now)it has a really good pull to it now from 1800 on up.pretty impressed with it now that ive got it right.........bama

 

Just ordered my sensor today! So far I haven't heard any negative comments about it and might as well give it a go as my first minor BOMB!

Quick question but how long approx was it from ordering to actually recieving?

 

"This being calculated out I can see where the dowel pin would only need to be elongated 70 thousandths to get 2 degrees."

See the diagram in my photo gallery. 36 thou of movement on the dowel pin yeilds a bit over 2 degrees of advance.

"Superduty did the math and even drew a little picture. Search his posts in this thread, it was a ways back. It confirms the 2deg."

I confirmed that adding 36 thou to the slot width of the tone wheel on my truck advances the timing by 2.22 degrees. Nothing more. I have no idea how much the timing advances with some of the other methods, ie

- sensor geometry changes
- measuring advance on the periphery of the tone wheel
- using the tone wheel bolts as guides

While I am at it... the timing specs on the mechanical pumps on earlier engines are NOT comparable to the timing advance we are doing with the tone wheel. On the P7100s, for example, there is no timing advance on them and what you measure statically is what you'll get when the engine runs.

The electronic injection control on the 3rd gens is a little different. The tone wheel is advanced from TDC already and the ECM generates the timing by waiting for a present amount of time after it receives the tone wheel TDC signal. All we are doing is advancing the reference point on the tone wheel. So when someone says that their 12V needs 12 degrees of advance, we have to remember that the ECM is already giving our engine 10 degrees. (Fictitious number, I made it up.)

Another thing. I don't believe the allowable timing advance number that a member has mentioned on this topic. That much advance might be good at one particular point in the fuel curve, but everywhere on that curve.

The tone ring mod has increased my fuel economy at lower RPMs and at higher loads. I can see that by looking at my fuel economy records. However, the fuel economy of my truck appears to have gone down under low load/higher RPM conditions, like when cruising empty on the highway. If you think about it, Cummins only has to retard the timing under circumstances of high NOx production. That would be times of high fuel delivery to the cylinder (high torque) and long exposure time of air to high temps (low RPMs). Maybe under higher RPM/light load conditions the timing was already optimal and now I've got too much advance ?

The above comment is preliminary. I haven't driving my truck empty on the highway enough yet to know for sure.

One more thing. I was surprised at how sloppy the tone wheel was held onto the damper. The pilot bore isn't precise, the dowel pin isn't precise, etc. I am wondering how sensitive the timing sensor is to the air gap between the sensor and the wheel as well as what effect moving the sensor off center from the tone wheel has. When I replaced my tone wheel, I tried to get it as centered as I could on the pilot shaft.

Because of the geometry of the Rokktech sensor and its movement away from the center line of the tone wheel, I am unsure exactly how much advance is being achieved with those units.

Other than some uncertainty about empty highway cruising fuel economy, my Cummins runs excellent.

 

this is how mine gets run 99% of the time ,, empty on the hwy..
ive noticed that a little advance helped overall, a little more did slightly decreese my no load high rpm economy, but i continued to see an increse at lwer rpms, or under load. i had drilled the hole out w/ a 9/32 bit rather than fileing, and i keep mine now fully adavaced and am still averaging over 21mpg in daily driving.... stop and go comute in I5 traffic.... does not seem to improve much if any at constant 70 mph, but if i reset my overhead while back roading, i see as high as a 32mpg average...(overhead has only been off by .1mpg over the last 10 tanks) now if only i could find a rout to work that allowed me to maintain a constant 45mph w/o alot of hills...

 

robert,,the dowel hole is nowhere near halfway to edge,it sits really close to the center of ring...look at superdutys picture for reference in his gallery......i went ahead and filled up from over half a tank yesterday,and got a 1 mpg increase with mine...superduty,do you think you are close to having all the slack taken up to the boltholes on yours?is it correct to say then,with your 32 taken at dowel,you moved your perimeter 4.02mm?you would have to be close to the boltholes on that...........bama