Why am I going SLOWER?!?!?!?!

[n0useforaname]

Maybe I'm missing something, but when I had my tranny built, I was told to do away with de-fueling....by multiple people....and in the truck I even asked George if it was ok to shut of de-fueling and he said it doesn't matter, go for it. Am I missing something?

 

[DIESELMAFIAPER.LB7]

Its easier on the trans with it on but I like the shifts with it off an I drive it like a grampa 90% of the time so I dont think its to hard on it but many frown on it so..I lost like 6-10 lbs of boost with it back on for sled pulls turned it back off yesterday an got some boost back an runs much faster

 

[MMLMM]

Density Altitude - Is an adjustment to the altitude when you factor in temperature and humidity. A 4,000 ft above seal level atmosphere can act like a 6,500 ft above sea level atmosphere when the temp and humidity are higher...

Basically the air density is less, making it seem like running at higher altitude.


I suggest try running little less pressure in the spinning axle and setup the suspension a little better for launching. This could help your 60' and a tiny bit of help in the first 60' (I say 60' because its a measured number you can compare) is going to effect your 1/4 mile ET significantly...

Maybe even try leaving a touch softer too.

 

[DetailsUnlimited]

Density Altitude - Is an adjustment to the altitude when you factor in temperature and humidity. A 4,000 ft above seal level atmosphere can act like a 6,500 ft above sea level atmosphere when the temp and humidity are higher...

Basically the air density is less, making it seem like running at higher altitude.


I suggest try running little less pressure in the spinning axle and setup the suspension a little better for launching. This could help your 60' and a tiny bit of help in the first 60' (I say 60' because its a measured number you can compare) is going to effect your 1/4 mile ET significantly...

Maybe even try leaving a touch softer too.

The temp saturday night was 85-90 and the humidity was 60-70%. Its bad here!
I'm leaving the line at 2100 - 2200 rpm's. Running 30 frt and 25-27 rear. I have a tru trac in the rear which hooks really well. And I did lower my rear 2 inches so I might go back to factory shackles. Front shafts are completely level. So run a little less pressure in the spinning tire up front. hmmm make sence! Should I tighten either one of the bars in the rear?

 

[x MadMAX DIESEL]

Have you been racing at the same track?

 

[DetailsUnlimited]

Maybe I'm missing something, but when I had my tranny built, I was told to do away with de-fueling....by multiple people....and in the truck I even asked George if it was ok to shut of de-fueling and he said it doesn't matter, go for it. Am I missing something?

Its easier on the trans with it on but I like the shifts with it off an I drive it like a grampa 90% of the time so I dont think its to hard on it but many frown on it so..I lost like 6-10 lbs of boost with it back on for sled pulls turned it back off yesterday an got some boost back an runs much faster

I like how my truck drives with it off. Smoother shifts I think. I tow a trailer in town 99% of the time so picks up a little better. I think it quicker also..

 

[DetailsUnlimited]

Have you been racing at the same track?

Yep, same track. Its and 1 1/2 away but only 1000ft.
Here's my launch with old set up and 10.3 run 1000ft.
http://www.youtube.com/watch?v=8s1_nAHOoNw

 

[DetailsUnlimited]

How tight are the cal trac's supposed to be? To where the bottom spring touches the rest of the spring pack or about an in of clearence?
New this year video- watch my bounce taking off....
http://www.youtube.com/watch?v=M8SJMma-WwU

 

[ripmf666]

Maybe I'm missing something, but when I had my tranny built, I was told to do away with de-fueling....by multiple people....and in the truck I even asked George if it was ok to shut of de-fueling and he said it doesn't matter, go for it. Am I missing something?

You might want to call George and ask hm about that again. I think hectold me to leave mine the hell alone lol.

 

[GMC_2002_Dmax]

There is a big difference between defueling a tune properly in the way it's written in the ecm or removing the tq/reduction request in th etcm tune.

LB7/LLY trucks use a different de-fuel then the LBZ/LMM do as far as ecm setup.

If you disable TCM table D5197 you are asking for serious transmission problems.

 

[DIESELMAFIAPER.LB7]

Mine works good have had converter issues before no defuel had no defuel for o 10k miles 35 k with it on runs fine still just need a better converter mines surges when it engages at cruzin speeds but clutches are fine still. Just like the shifts to be smooth an crisp

 

[DetailsUnlimited]

Well I'm going to try the supension stuff next time out. Take the drop shackles off and tighten the trac bars a little more take some air out of the frt left tire and add spring clamps....maybe
Hopefully have my ram air hood back on with Rick new EGR delete so the hood fits!!!! Cant have enough outside air

 

[Noreaster]

you can figure out the DA at the time of your runs http://www.dragtimes.com/da-density-altitude-calculator.php

 

[DetailsUnlimited]

Density Altitude: 2050 feet
Relative Density: 94.14 %
so Centerville Ar is 344 ft above sea level. How does this effect my runs?
at 10:53 ran
1.71 60ft
5.18 330
8.13 1/8 @ 85.76
10.50 1000ft @ 94.98

 

[GMC_2002_Dmax]

Just as a comparison,

I have a 2007/LBZ-Regular Cab
SC-IV, ADII-165, 4" exhaust, stock intake. My tuning not dyno'd so I have no idea what it makes.

Went to the track on 5/24/10 and ran consistent 12.6X-12.7X over 15 runs.

Scaled the truck at a CAT certified scale and it weighs 6900 lbs with me in it, that is 1/2 tank of fuel ( 17 gallons +/- ) and only the gate and tire removed.

Best run was

1.758/60 ft
8.025/ 1/8th at 84.98 mph
12.683/ 1/4 mile at 104.99

Your times are close to mine until the 1/8th and then it would appear to me after the 1/8th mile something is falling off causing you to lose mph/ET on the last 1/2 of the run.

 

[n0useforaname]

Ok...just a follow up on my previous statements...

1. I had a Banks box that had de-fueling......like tuning de-fueling that you could REALLY notice....George told me I could shut that off.... So before anyone thinks I'm getting bad info.....I'm honestly just an idiot and don't know enough yet

2. Nicks tuning DOES de-fuel....all his tunes do.....I just got off the phone with him and he gave me some good info. on how tuning works, and the difference between TCM tuning and ECM tuning...so again.....my bad

I don't want to be posting stuff that gives them bad names due to me being a Jack-A....so again, sorry, and I now have a better understanding of De-fueling!

 

[JoshH]

I'd like to see a log or screen shot of a log from an LBZ that has no defuel.

 

[GMC_2002_Dmax]

I'd like to see a log or screen shot of a log from an LBZ that has no defuel.

At part throttle or WOT ???

 

[JoshH]

At part throttle or WOT ???

Both if you have it. If you can show a screen shot I would really like to see the Engine Torque Reference PID too.

 

[TheBac]

IMO, you've just overpowered your old setup. Done that myself. Ive found that everything on these trucks has to work together to get good times. Very rarely does someone just "throw something together" and get low times.

What shocks are you using, both front and back? What other traction aids are you using?

How do you launch your truck? What RPM? Boost?

All that plays a part, and you still have about track prep to think about.