Rattle??

[JustinD]

I have an 01 LB7 with an LB7 CP3 and an LBZ regulator, truck idles very smooth and quiet, runs great and makes good power. I have an II Silver Bullet (66mm) charger, I notice that it rattles a little bit before it lights the charger? I would really like to see if I can quiet it down especially on my daily driver tune, I don't mind the rattle with the bigger tune because I'll only run it to race or pull. I have my B1010 table re-worked to run that regulator, should I look at pilot injection? soon as the turbo lights it seems to go away? Or maybe I can't hear it over that charger??? :wallbash:

[THEFERMANATOR]

What are you running the timing at? I would try dropping it back to about 30% in the areas for spoolup and see what happens.

[LB72004]

i agree, check your timing.

with lots of fuel and timing at low RPMs, it will be hard on the engine. keep your timing conservative at the higher MM3 and lower RPM areas.

high MM3, low RPM, high Timing. pick two

Jason

[JustinD]

I just adjusted my shift points and used a D5196 table that Jeff Toman sent me and it seems to be alot better, I think my "rattle" was just the motor lugging and not spooling the charger as it should have, I will report back in a few days to make sure nothing changes. Can't wait to drive it more and let the trans adapt.

[LB72004]

i would still double check the timing to be safe. even when lugging the motor it should not rattle. with the higher shift points and the engine at a higher RPM it could make it hard to hear/mask the rattle. with the engine rattling you are already way beyond what is considered "safe" for the life of the engine. a great tool to check your timing with is the: timing calc v3.xls. 50% timing is generally considered a good starting point. personally i would drop that number a little in the low RPM/high MM3 areas.

[JustinD]

Here it is:

[LB72004]

well it doesn't look bad to me but hard to say with out knowing the related MM3 and MPa. higher fuel MPa will get the fuel in faster effectively increasing the timing. there are several other factors such as the timing compensators, pilot injection/timing & temperature that will play part in this. the best way would be to monitor the cylinder presser, but that is currently unpractical for the masses. the next best would be to log the actual main injection timing and see if it is close to your timing map.

if your tuner knows what he is doing and feels it is safe then go for it. remember each truck is different and you can't effectively mass produces tunes for them. each tune needs to be tailored to the engine it will be running in. what works good in one may blow a head gasket in another. if no one else finds any fault in it then have fun

jason

[JustinD]

I might not have explained the "rattle" before, it wasn't a hard hammering sound just I could hear more motor than charger.

[LB72004]

i hear you. sounds don't translate well to text.

there is the typical "rattle" that most relate to the classic sound of a diesel. then there is fuel knock, mechanical valve/piston/hard parts engine-has-problems-knock and what most are scared of: the timing rattle.

i have someone at work that thinks my engine is damaged or going to blow up because he is not used to the sound of a diesel and it drives him nuts, he is a "Gasser" all the way and hates diesels. my truck can whip his left and right and gets 5+ mpgs better and he is still not convinced of the benefits of a diesel... sorry i digress

Jason

[JustinD]

Haha true!! Thanks alot man.