Rokktech Crank Sensor Installed...

[Matt400]

Well dang... always on a learning curve thats for sure. I found some great info at Chevron here:

http://www.chevron.com/products/prodserv/fuels/bulletin/diesel/l2_5_4_rf.htm



Some time ago I remember reading about cetane and why its good to increase it for a more early ignition, should have remembered that. I just confused it with Octane since I still work in the Gas world, thanks for the refresher!

 

[Winston Wolf]

KBennett

If you're getting mileage like that, why mess with it?



My understanding (correct I hope) is that this product's best use is on 600/610 engines -- the theory being that retarding of the timing is a cause of the apparent MPG loss on the later engines. Speculation was that this tradeoff was made to meet tighter emissions.

 

[67guzzler]

You're probably right, WW. The only other thought I have is that this mod is so reasonably priced, easy to install and fairly mild that it might be worth a try on a 555 just to see if it helps at all...

 

[corprimo]

We've now put about 1200 miles on our rig with the timing mod. OR to MT - lots of hills, mileage up from our usual 8. 9 to 10. 3. Some tail winds there and 100 miles were driven without 5er attached.



MT to NE - some strong headwinds, mileage came in at 9. 5, all hand calculated.



We're about 18,000 lbs gross combined, and cruise under 65 to save a few bucks.



So far, I would say there is definately some improvement in our mileage. We'll be on the road all winter, so I'll post more later.



Dan Heynen

 

[Amish Elegance]

If you're getting mileage like that, why mess with it?



My understanding (correct I hope) is that this product's best use is on 600/610 engines -- the theory being that retarding of the timing is a cause of the apparent MPG loss on the later engines. Speculation was that this tradeoff was made to meet tighter emissions.

Partially right... third injection event is what most people point the finger at for MPG loss in 600's. It was an emissions thing.

 

[BIG BOB]

You guys that are using your overhead to compute mileage are not getting a true reading. You have to hand calculate to get an accurate mileage number.



I installed my sensor on Saturday. Today, Monday I drove 634. 40 miles at 70 MPH.



I stated at the Flying J in Post Falls, Idaho and drove to Cle Elum, WA. 220. 3 miles, filled up and hand calculated mileage, 15. 66 mpg. I then drove to Monroe, Wa. and back to the same fueling station in Cle Elum, WA. 194. 2 miles and got 13. 96 mpg. I then drove back to the Flying J and filled up. 219. 9 miles and got 14. 535 mpg. With this test, I see not improvement in mileage on my truck.



Now I do feel better low end power and if definately cools off faster before shut-down.



This is what I have experience so far.

 

[steved]

You guys that are using your overhead to compute mileage are not getting a true reading. You have to hand calculate to get an accurate mileage number.



I installed my sensor on Saturday. Today, Monday I drove 634. 40 miles at 70 MPH.



I stated at the Flying J in Post Falls, Idaho and drove to Cle Elum, WA. 220. 3 miles, filled up and hand calculated mileage, 15. 66 mpg. I then drove to Monroe, Wa. and back to the same fueling station in Cle Elum, WA. 194. 2 miles and got 13. 96 mpg. I then drove back to the Flying J and filled up. 219. 9 miles and got 14. 535 mpg. With this test, I see not improvement in mileage on my truck.



Now I do feel better low end power and if definately cools off faster before shut-down.



This is what I have experience so far.

I installed mine last night and experienced nothing other than a initial hard start... there might be a little increase off the bottom, might be a little smoother... but it might also be the fuel too.



I did notice that the truck only smokes when under med to hard acceleration now... it would smoke through every gear before the install. Also, during takeoff, I start in 1st at an idle, then accelerate... before, it would drag down some when releasing the clutch... now it just takes off. . no drop in RPMs.



I noticed that the majority of people who really "felt" something are running 3. 73 rears... mine with the 4. 10s might not really notice a small increase since the gears were making up for any "loss" before. I was also getting almost 20 mpg too driving mixed highway/city (about 30 miles interstate/20 miles "city" driving)... so we shall see.



Install was easy, after the initial hard start, it hasn't started any different than before. I'm going on a 1200 mile trip this weekend so we will see if there is any increase.



steved

 

[OHale]

Just out of curiosity, has anyone made a cold start (below freezing) using the new sensor?

 

[steved]

Just out of curiosity, has anyone made a cold start (below freezing) using the new sensor?

I too am curious of this... it didn't start hard this am... it was about 50*... far from freezing (or even -20 that we see sometimes).



I figure if it happens, it isn't too hard to crawl under, loosen the screw, rotate the sensor back to "zero" and tighten the screw for the winter... it isn't like you need to change sensors... just rotate it back to "zero".



Anyone with a real "cold" start??



steved

 

[67guzzler]

By advancing the timing, colder starts should be easier. Getting the fuel in the cylinder earlier in the compression stroke will allow it to ignite earlier in that cycle. This can only result in either no change or slightly easier starting.



This is why cetane boosters are so helpful in cold weather. They make the fuel ignite at lower temperatures. But the negative to cetane boosters I've learned is that in warmer climates or when you otherwise advance the timing you can get some knock. BTU's make power. Cetane aids ignition.





[size=-2]

2005 Dodge Ram 2500 SLT QC SWB 4x4 G56 Patriot Blue / Silver

• Thunder Road • Roof Marker Lights • Light Group •[/size]

 

[jsimpson]

I installed mine today. It feels peppier at part throttle and at full throttle (purely subjective), but my overhead says I'm getting almost three more mpg unloaded. That's the bottom line for me.

 

[jwduke]

Well, majority rules. Guess I'm in for one.

 

[RMachida]

Agreed, most seem to notice an improvement so I just ordered one. The claim on their site is payback in 6 months.

 

[jsimpson]

Agreed, most seem to notice an improvement so I just ordered one. The claim on their site is payback in 6 months.

And that was BEFORE diesel jumped by eighty cents a gallon!

 

[CRUSH'EM]

It came in the mail last night, had it in in about 15 minutes, would have been quicker, cept' my fat fingers didn't have that much room to work, and I'd just shut the truck down hot from coming home from work! Noticed a lot let rattle this morning, which I usually notice when it's colder in the a. m. Was 86 when I put it in last nite, got up this mornin, and it was 46!!!!!!! I love the colder weather, but she seemed to idle way better, will have to see about the mileage, have 1/2 tank left, hopefully will see some increased #'s on the mileage.

 

[RHildreth]

I put one on my truck with about 200 miles on the tank. I filled up at 522 miles ($86 for 27. 3 gals. :--) ) The overhead read 17. 5 mpg when I installed the sensor and 18. 1 when I filled up. Hand calculated is 19. 1 mpg. That may be a little better than my average, but not much if any. I was hoping to get the magic 20 mpg, but I can't complain about 19. 1. My old Bronco only got about 12. 5. I would hate to be filling it up at these fuel prices.



I agree with everyone else about bottom end torque. Feels stronger at lower rpms, smoother through the gears, faster spool up. Actually has some diesel rattle you can hear now. I'm happy.

 

[steved]

I have nothing calculated... just noticed it isn't using as much fuel to get back and forth to work now... the gauge isn't falling as fast, or at least it appears that way.



Even if it get's me closer to a consistant 20mpg, I'll be happy.



steved

 

[Cattletrkr]

The overhead on dad's '03 has always read low, even with the Bank turned up all the way. He drove about 75miles today with the Banks off and the sensor in, first trip with sensor. Overhead showed 19. x. It's never even stayed at 17+ before. Time will tell if it's actually working.



Mine's (sensor) been in long enough to know that the truck will still start, but it hasn't moved yet.

 

[OHale]

Just a follow up. I had the bad sensor that threw crank codes and was hard starting. Paul at Rokktech immediately sent a replacement which arrived yesterday. I installed it this morning and had a normal start with no codes. I'm looking forward to field testing today.



It appears Rokktech received a bad sensor for modification. Anything made by man can fail or break. What I appreciate is the fast customer service from Rokktech.

 

[corprimo]

We're into the 2nd month of a 7 month RV trip. Sensor was installed 2 weeks ago. Mileage seems to have improved by at least 5%, although head winds and such make it very hard to pin down. Between Anchorage and Portland OR, we never got over 9 mpg, and between OR and MN we've gotten 9. 5 on a couple of tanks. 5700 miles and $1700 in fuel so far... ... .