Drag racing questions?????

[02duramaxfan]

Ok so I finally made a few passes on my new set up and wasn't happy about the results...i just bought the truck with a cracked piston and just got it put back together... i have

Built motor
Empire alt firing cam
S475
60% injectors
Dual pumps
So cal heads
Bid dipper trans 1055 converter
20x9 rims on 420s... I know there heavy
The truck does have 4.10 gears as well.. It use to be a pull truck with a rear locker
And so on....

But anyway wants everybody doing launching this thing I kept cutting shitty 60' all night.. Maybe to much air pressure it kept trying to push through the brakes with holding barely any boost???

It's tuned by Danville performance and in between shifts I noticed that it defuels... Should it not?? i mean i only trapped 95mph which i thought sucked for all it has done to it


I'm just trying to learn how to get the most out of this truck.... Any input would be greatly appreciated.. i would like to hit low 7s with it

 

[Evan@InglewoodTrans]

What's your 55 stalling to?

 

[02duramaxfan]

i believe like 2500 or 2600 rpm but its kind hard to tell i feel like i cant make more then like 10 to 15 psi before it just keeps pushing through...... before it cracked the piston in went 7.30 at 98..... with diffferent tunes on it and i went this past weekend and only trapped 95 maybe the tunes are not right on it.

 

[Burn Down]

Post your time slips so we can see your 60' and splits.

Lots of things can cause them to run poorly at the track

 

[02duramaxfan]

My best 60' was a 1.9 which I know is bad..... I will post a pic of it I get home
I only trapped 95mph and ran a 7.63

 

[02duramaxfan]

Well can't see to figure out how to upload my pictures...

 

[Harbin_22]

What are the specs on the 475? What's the truck weigh? Were you spinning when you left the line or what? What was your staging method? Did you build any heat in the turbo before you brought it up? The 4.10's really aren't helping any with staging. Might want to try a second gear start.

 

[Harbin_22]

Really need to log it to and see if it is actually defueling or the trans doing something wrong.

 

[2004LB7]

4.10s may be why you are pushing through the breaks real easy. And like mentioned earlier, try a 2nd gear start

 

[02duramaxfan]

It's a 83mm 1.10ar and they truck did jump and hop off the line I just feel like it would have trapped higher then that... The trans is fine before it the piston the cracked... It ran 7.30s at 98 at that time it had a 476 and different tunes I wouldn't have thought it would make the big of difference the truck has been data logged twice now...... And when I say defuel at shifts I mean it doesn't smoke a bit when it shifts I figured it would keep fueling non stop

 

[02duramaxfan]

I am just trying to learn everything that I can I haven't had a diesel in a few years

 

[Awenta]

You would need a tune that started you in 2nd. It's harder on the converter. The Allison needs to defuel.

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[02duramaxfan]

Ok thanks that makes sense the tcm is currently tuned.. By who though I have no clue

By the way it sounds would anybody be interested in my 4.10 with a Yukon locker or hell maybe even sell my front locker as well

 

[TheBac]

Whats your suspension setup like? Shocks, Tbars, etc?

What tires -- those 420s? What pressures?

 

[cat_dr.]

I'm having similar issues with mine. Can cut better than 1.9 60s and can't leave hard without it being all over the place


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[02duramaxfan]

I am lowered on a djm 3/5 drop and qa1 shocks all the way around... I was wondering if I had to to much pressure they were around 40 to 45 which is high

 

[Awenta]

Why is the tcm tuned now?

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[02duramaxfan]

It was already tuned when I got the truck.. I believe it is tuned by moonshine since that who's tunes were on it before

I mean the converter feels like it lock up really good

 

[DMAX497]

Are Tony's ( MOONSHINE ) ECM tunes in the truck right now as well?

His ECM/TCM tunes best shifting tunes I've ever had...

 

[02duramaxfan]

No there not I assume the tcm is still his tunes... Tune 1 through 5 all felt the same they all trapped 98-99 so after it broke I just decided to start fresh with it

Worst case I guess my mechanic still has those tunes I could always put them back in


I only changed three things to whole truck when I put back to together
1 I went with Danville tunes
2 it had SoCal 6480 standard can - I went with a empire stage 2 alt firing cam
3 it had a gt42 turbo that was shot- so I went with a s475