Tuner Rattle

[50+]

How Much is too much? or is there such a thing. I'm talking about the extra diesel rattle I get on a cold engine when running my Bully Dog. I expect theres got to be some because of the fueling going on. It does quiet down as engine temp comes up. I know from reading here that some tuners wont alow more fueling until temps are up. Curious if it will hurt anything. Thanks.

[Mark Rinker]

If its noticeable enough (over stock) for you to ask, I would be concerned.

Questions:

1) Are you seeing smoke at the exhaust during warm-up? After warm-up?
2) Is there any way quick way to enable/disable the system for warm-ups?
3) What are your boost levels and EGTs when towing?

[Kennedy]

Some timing rattle is a fact of life with a HP tune or MPG tune. Bully Dog seems to get a lot of negative press for theirs being excessive. I haven't actually "seen" the root cause of this, but I must say it seems typical of their tuning style. As it warms up the timing backs off a bit.

[50+]

Answers to your questions Mark.

I see no smoke before or after warm up at idle. It will put out more black smoke going down the road, only if I lean on it. Its a Bully Dog Power Pup and theres no way to disable it before warm up unless, one was to warm up the engine before downloading the tune, and then return to stock after shutdown, which isnt a bad idea the more I think about it. I have only used it on the 50hp tune, and dont plan to use it to tow with, as I am still running stock exhaust and intake, and no gauges. The extra rattle is only on a cold engine when I apply some throttle, dont hear it at idle. After temp comes up it sounds like stock. Havent used it enough to know if its going to increase fuel mileage.

JK.......your comment about timing does put it into perspective.

[Mark Rinker]

So JK, why is my 2002 with your tune as quiet or maybe quieter than my 2001 with stock tune at cold idle?

Not that I am complaining... :)

[Kennedy]

Any number of factors can influence timing rattle:

Ambient conditions:
Temperature (ECT IAT etc)
Humidity
Barometric pressure

Vehicle differences:
Fuel quality (cetane etc)
Exhaust (seems open exhaust sometimes is louder?)
Compression
Injector condition


Perception:
Some people hear things differently and some not at all at certain frequencies

Tuning differences:
I've spent a great deal of time refining my tuning. Much more than most any other. This accounts partially for what Mark is hearing (or not) from his tune. I tune the performance on the dyno and then refine the manners on the street. Occasionally you'll find a quirk here or there that needs to be fixed, but usually I'll find them first and remove before shipping. My style of tuning is much more involved than most. Most stick to minor changes in a relatively broad area to play it safe. This creates less side effects, but results in a lesser tune. I change a lot more and make more drastic chnages, therefore I have a lot more little fires (side effects) to put out, but once complete, the end result is well worth it...