eastmentCTD600

Decided to perform the tone ring mod today. I made one slight modification to the process. I elongated the dowell pin hole such that the ring can rotate past where the 4-bolts stop it, then "cleaned up" the four bolt holes ever so slightly with a Dremmel.

End Result:

*Tone ring advanced by 2.5 degrees
*0 - 70 MPH time is down by 1/4 sec. consistently (average of 6 runs pre and post modification)
*Idle is up by ~ 25 RPM
*As for "feel", I don't notice much difference.
*No codes

So this begs the question... "how much advance is too much?" I thought someone said the ECM threw a code if the ring was advanced by 3+ degrees, can anyone speak to that?

FYI - by rough calcualtion, one tooth on the ring is approximately 6.14 degrees. I hope to see a mileage gain more than anything with this mod.

ptm600

I did it two weeks ago. Noticed a little low end gain, and fuel milage may be up a bit , but I'm not sure yet as I haven't put that many miles on. So far it appears as though I may have gained 1/2 mpg.

Superduty

If you widened the dowel hole so you are up against the crankshaft bolts then you advanced it more than 2.5 degrees. At least you would have on my crankshaft and tone ring.

Mark Hodowanec

I did this about 5000 miles ago. Noticed no change in performance or milage.

abc4yew

Mark, Is that no improvement in performance other than the faster 0 to 70 mph times? A 1/4 second is a good improvement in my books. I've heard that spooling seems better so that when you press the go pedal you go now versus a little later. I think the TR Mod adds maybe 10 to 15 hp in the very low rpms ....like before any of the boxes add timing or fuel and very little at highway speeds. Those that run around a lot in town seem to notice the biggest mileage gains. After having a little more hp for a while you wouldn't notice any difference unless you switch back to where it was. ks

Superduty

The tone ring mod isn't a "some is good, more is better" situation. If you advance it too far, engine efficiency goes down. I don't know where the optimum point is.

eastmentCTD600

I tried to be careful as possible marking and measruing. Here are the steps I took to get my measurements:

1. made a pointer from some copper wire, bolted to the motor and aimed it at a tooth which I painted (reference tooth). This was my reference before I proceeded in disassembly.
2. removed damper and tone ring
3. elongated dowell hole and just "touched-up" the bolt holes ever so lightly.
4. re-installed only tone ring with 4 crank bolts. I threaded the bolts in until they held ring flat against face of the crank snout but loose enough to be able to to rotate the ring by hand (snug fit).
5. aligned pointer and marked tooth which positioned the ring in its original position. BTW - the original position of my ring was alll the way counterclockwise against the dowell pin, thus the reference point was easy to maintain - all the was counterclockwise and I'm back to stock.
6. I used a square placed along front lip of oil pan and marked ring's original position, remember its indexed to the stock position at this time referenced by the pointer.
7. Without moving my head (to minmize parallax) or the square, I rotated the ring clockwise until it stopped, then marked it again with the square. Now I have a distance between marks of length L, which was approximately 0.175" +/- 0.005"

FYI - I made the marks on the portion of the ring where it is absent a few teeth.

After you know the diameter of the circle where you've plcaed your marks (approximately 7.9375") and the length between marks "L" (measured with calipers) its a bit of trig to get the degrees swept by the arc. 2.5 degrees by my calcualtions.

The question remains, does anyone know how much advance is too much? Has anyone tried more and with what result?

Thanks all!

midwestdually

wow, thanks for taking the time to write that all out

smokin05

dudes is this not the same dang thing as taken out the plastic crank sensor and grinding the shoulder off and stickin it back in? i did it months ago when some clown was tring to sell modified sensors? it took like ten min was good for about two degrees?

Superduty

There is a debate about how much advance one gains by grinding the crank sensor.

Tone ring is 210mm dia IIRC. 8.267 inches. Has a radius of 4.1338 inches.

If you advanced it 0.175 inches on the periphery, then...

cos(Adv) = opposite/adjacent = 0.175/4.1338 = 0.04233

Adv = acos(.042,333) = 2.426 degrees.

smokin05

lol i guess....i tell you what i did mine and could not tell a bit of difference hardly? but i do remember "them" sayin dont leave her idle to long...and i know why now,...its dont matter if its straight piped...but if u got the epa goodies still i bet it cloggs them up cause the one thing i did do was make the truck run cooler.....is that good or bad in a heat engine ...you tell me ?

goose2

I put the rokktech in mine. Advanced it all the way to the top. (2 deg) Mine felt like it had more bottom end but the milage went down. (if it is possible) So I backed down to 1 deg and the milage seems to be a small amount better than stock.

bigblock2stroke

I'm not sure of the exact number, but it the crankshaft sensor (uses tone wheel we are all modifying) and the camshaft sensor (reads 1/2 speed with tone wheel part of the camshaft) are different by more than X (whatever that is 3, maybe 4 degrees, but I would have thought it to be less) than you get a "rationality" error and a check engine light.

Hoss

What is a Tone Ring Mod??

eastmentCTD600

SD,... what is meant by "Tone ring is 210mm dia IIRC", specifically IIRC? Forgive my ignorance, what does IIRC mean?

I'm assuming we are measruing the diameter of the ring at two different places, thus we have a difference in degrees (albiet 2.527 - 2.426 = 0.101 degrees - essentially a moot point because measuring errors are probably larger than the difference).

Just for clarity, here is how/were I measured....

If you look at the tine ring there are two possible diameters where you can make a measurement.

One is the outermost diameter of the wheel (I'm assuming this is 210 mm as stated by SD), the other is the diameter described by the outermost diameter less the height of two of the teeth. This is what I used. I made my marks on the blank spot on the wheel (where it is missing teeth).

Thanks.