My RokkTech sensor arrived tonight, so of course I had to immediately install it. Took all of ten minutes, and half of that was my doing it twice to make sure I had it down smooth in that tight space before I used Locktite on the screw. Then I went out for a spin. Initial observations....

The power band has shifted up and smoothed out. Used to be that when I hit about 2K RPM, there was a noticeable hesitation in power unless I then added more accelerator. Now the engine spools up starting around 1200 and goes right up to ~2800 or so. 3K is easy to hit, which didn't used to be the case; I really had to push it HARD to get to 3K and the engine acted like I was mistreating it. Now it loves the higher RPM's.

The engine is quieter at idle. Just purrs like a kitten.

The engine is louder during acceleration, with what sounds like more knocking. RokkTech warns that if this continues you should back off the advance a bit. I'm going to wait and see. Since this is my first diesel (other that the Case), I don't have much basis for comparison. The sound I'm hearing may be perfectly normal. I can still easily hear the turbo over it, so it's not really THAT loud - I just "think" it's louder that before.

There's a noticeable increase in overall power and acceleration. Putting my foot into it, even a little, puts me over the speed limit really fast. Climbing my hill is much more "comfortable" in the sense that the engine seems happier. Noisier, but happier.

Starting seems to spin the engine faster before it catches and starts. This is hard to describe; it's like the starter is spinning the engine faster than it was before. RokkTech warns it may take a bit longer to start when cold, but two warm starts both sounded like faster RPM's to me.

Overall, from a performance standpoint I really like it. We'll have to see how it handles dead-cold starts and how that increased knocking sound works out over time.

Anyone experience any of these changes when you installed yours?

 

I basically found all the same conclusions as you. Mine has been in for six months now at full advance. The only negative is, I don't use power service because the increased cetane causes knocking. When it gets below 40F on a cold engine, the first 10-20 seconds accelerating she knocks and then quiets down. I watched my pyro and when it reaches 650f the knocking stops and never comes back. Had a little fun with a dmax tonight on the highway. Doing the speed limit and he rolls up, nose in the air and hammers it. What the heck it's two in the morning, empty road, I slowly pin the go pedal. Just found out my truck max, 108mph and 3100 rpm. The bowtie driver was surprised to see me beside him and staying with him!

 

N.Johnson, what can you say about fuel mileage on your 03 after installing rokktech? Better or worse in town or highway? thanks

Eli

 

The knock (or rattle) is normal. With the advance timing the combustion starts earlier. The rattle goes away when the engine starts warming up (at least for me). A big benefit with the advance timing is a drop in EGTs. Before the sensor I was able to hit 1250 degrees with no load, with the Rokktech 1100 degrees with no load. Since adding the Edge EZ and set at level 2 the EGTs is backup to 1200 degrees. I'm very impressed with the performance using this combo.
Also have a gain in fuel economy, picked up 1 mpg for around town and 2 mpg towing. No change for non towing highway mileage.
Note, I just added the EZ so no mileage data yet for this combo.

MikeyB

 

Best you could do was "stay with him"? I'm surprised you weren't able to blow his doors off....

 

Duramax are fast, even stock. Hmmm, is 'Duramax' the plural of Duramax, or is it Duramaxes...or Durami

''Look at that herd of Durami o're yonder!''

Oh man am I bored this afternoon...

 

First I've heard that Duramaxen (???) are "fast". Is that to imply that they are "faster" than CTD's or PSD's? Is this commonly known? Is it due to the engine, the transmission, or...???

 

Stock V stock, the Allison tranny in the d-max puts the power to the ground the best of the big 3, from what I've heard. The bottom line is overall weight of the vehicle, the available power and the ability to put that power to the tires. My truck is probably putting 200/500 to the ground and I pulled my cousins stock d-max from a 50mph roll-on. I stayed in 5th he has the allison. BUT, he has a dump body and probably grosses 1500 pounds more than me.

 

I don't drive for mileage anymore as all it did for my rig was to carbon up the injector tips and reduce mpg! Maybe others found different, I can't say. I always use additive and it still happened. The rokktech improved mileage .5-1.0 around town and no difference hwy,same. Right now on winter blend I'm getting 18.2 mpg last fill and driving it like my mid life sports car

 

It was a brand new 06 and I'm stock so at higher rpm range the dmax makes it tough. Now from a stop it's another story

 

I just ordered my Rokktech today. I am only getting 15mpg hand calculated. Should I be getting near 18 mpg? Even if the new sensor gets me to 16 MPG I will be happy.

 

did you happen to notice about a 50 - 75 rpm drop in idle??? seeeeeems like mine did this, but yes a lot smoother idle, and it definately changed my exhaust note, took away some of the " angry sound" not sure I like that aspect...... but I got this to try to get a bit better mpg, so if it does that for me I will be happy, who knows, with this I may be able to hit 400 on one tank. power seems there, kinda hard to play around here, truck gets to speed quick as it is and once ya crack over 80 mph you really stand out....... not enough "bear free" zones near me.

 

No drop in idle. In fact, if I coast toward a stop light and put in the clutch, I swear it idles a little higher... just below 800 instead of 750, until I come to a complete stop. Then the idle drops to 750.

Some or all of this may be illusion, who knows. Many of the effects seem pretty subtle. However, the improved power band is REAL. The engine is MUCH happier above 2K than it's been before. Even if I get zero MPG improvement it's worth it just for that, and the performance I'm getting while driving now.

 

hmmmmmm directions say to rotate the sensor clockwise on the 5 mm allen head bolt, pretty sure thats what I did, sure doesn't look much different htan stock, o well I will be filling the tank today and resetting the trip meter. I just picked up 3 bottles of ps grey bottle, no added knock from the sensor install I wonder if I should give the tank a 1/3 bottle treatment? the nasty fuel they sell around here is 40, 42 cetane tops.......

 

I'm running Power Service Diesel Klean in every tank. Yes, it does rattle a little bit more but it doesn't bother me. Starting to sound like a real 24v.

MikeyB