Help me shave off a tenth

[DmaxHawk]

Went to the track Saturday and managed to get a best of 13.103 @ 101.17 out of 6 slips. Was a relatively good day for racing, temps were in the low 80s/high 70s. Track is around 4000 ft. Humidity was relatively high (an inch fell in 15 minutes at 5:15 that morning). And the track was hooking well. I have a feeling my tune needs refining. Out of the 6 runs, ALL my runs were at 101 and the times ranged from 13.10 to 13.5. Heres how they broke down.


10:53 am
60ft.-1.832
e.t.- 13.175
MPH- 101.35

11:26 am (lanched too hard and it bogged when the converter locked)
60ft.- 2.038
e.t.- 13.538
MPH- 101.18

11:55 am
60ft.-1.748
e.t.- 13.103
MPH- 101.17

12:33 pm
60ft.- 1.824
e.t. 13.251
MPH-101.28

12:51 pm
60ft.- 1.794
e.t.- 13.229
MPH- 101.13

1:40 pm
60ft.- 1.871
e.t.- 13.285
MPH- 101.35


Now for my setup:
Tailgate and spare tire removed. Running 4, 30X14X16LT M&H cheater slicks. Bars are dropped. Mirrors folded.

My tune:
Max uS: 3350
max pressure: 190 MPa
Max boost: called for 34 (gauge read about 32 max)
Max mm3: 120
Max timing: from 3000-3400 is 31 degrees.

I dont have a log for the runs, is there anything from what I've told you that I can change to get into the 12s? I'm thinking that running taller tires would help. :baby:

Thanks
-Sal

 

[wikdlmm]

take the seat out, and headlight and air cleaner off....

 

[paint94979]

3350 sure is alot of pulsewidth... i would def. bump it down. gmduramax(Anthony) dropped his PW and as he did the better his ET was

 

[Osubeaver]

How does the truck run before the converter locked? What was your RPM like? How'd it shift? Does it really bog when the converter locks, or does it just rev to all hell before, making it seem dramatic?

You can run a very high 12 @ 101. I ran a 12.997 @ 101 with a stock turbo on 33" mud tires and 7300 lbs. PPE tune. Took a while, but it happened.

60' = 1.810
1/8 = 8.198
mph = 83.13
1/4 = 12.997
mph = 101.49

 

[JoshH]

3350 sure is alot of pulsewidth... i would def. bump it down. gmduramax(Anthony) dropped his PW and as he did the better his ET was

That's probably because he was losing rail pressure with the higher pulse width. I doubt the OP is experiencing a drop in rail pressure with the dual CP3s.

 

[DmaxHawk]

take the seat out, and headlight and air cleaner off....

Headlight was out, having a new filter mightve helped though

3350 sure is alot of pulsewidth... i would def. bump it down. gmduramax(Anthony) dropped his PW and as he did the better his ET was

What about pressure? how much can I move it up?

How does the truck run before the converter locked? What was your RPM like? How'd it shift? Does it really bog when the converter locks, or does it just rev to all hell before, making it seem dramatic?

You can run a very high 12 @ 101. I ran a 12.997 @ 101 with a stock turbo on 33" mud tires and 7300 lbs. PPE tune. Took a while, but it happened.

60' = 1.810
1/8 = 8.198
mph = 83.13
1/4 = 12.997
mph = 101.49

My converter locks pretty much when I hit 2nd due to the co-pilot. It shifts fast, rpms were fine and normal, its just that when it hits second, combined with the converter locking, i guess it doesnt have enough boost to power over it?

What was your altitude?

 

[NWTDIESEL]

Injectors and turbo will do it

Should be able to cut 1.6s with slicks, that will do it too.

Are you coming to the meet at Abq, NM Dragway Oct 17th?

 

[JoshH]

What about pressure? how much can I move it up?

Unless you have found something, there's no way to make an LBZ command more than 180 MPa of rail pressure.

 

[Osubeaver]

What was your altitude?

basically sea level.

 

[paint94979]

That's probably because he was losing rail pressure with the higher pulse width. I doubt the OP is experiencing a drop in rail pressure with the dual CP3s.

isn't there also a point in which too much fuel can "put out the fire"?... Once again guys on stock turboed truck's with much lower than 3300 PW have ran in the 12's... not too sound repetative but on a 3000 PW Anthony ran a 12.56 stock turbo, full weight, stock tires... i would look into your tuning before hard parts are switched for sure

 

[rushingbc]

I dropped some of the fuel out down low on the tune I race with, and the turbo spooled better, less smoke, and an improved 60' time. I'm running cheater slicks too though. Hopefully I'll make it back to the track before long.

 

[NWTDIESEL]

I know he has Dual Cp3s but....

I too would lower it and would run 3100

Alot of it is our high elevation. If you went to AZ or sea level you would run a 12.8 or so IMO

 

[DmaxHawk]

Unless you have found something, there's no way to make an LBZ command more than 180 MPa of rail pressure.

I didn't know that. Thanks for the info.



I'll bring the pw down some, too much fuel on the launch might be bogging it down correct?

 

[RPM Motorsports]

TCM tune??? Shift points around 3400-3600? You have atleast .15-.2 sitting in your 60' times waiting to be found.

 

[DmaxHawk]

TCM tune??? Shift points around 3400-3600? You have atleast .15-.2 sitting in your 60' times waiting to be found.

Should I do that for all gears?

 

[RPM Motorsports]

I did! Raise the MPH by the same % you raise the RPM @ WOT.

 

[JoshH]

isn't there also a point in which too much fuel can "put out the fire"?... Once again guys on stock turboed truck's with much lower than 3300 PW have ran in the 12's... not too sound repetative but on a 3000 PW Anthony ran a 12.56 stock turbo, full weight, stock tires... i would look into your tuning before hard parts are switched for sure

I would be surprised if that is the case here. Perhaps he is overfueled early on, but once the turbo is at full boost, I see no reason to lower the max pulse unless rail pressure or EGTs are a concern. I don't have EFI on the computer I'm on, but there is a table that limits fuel or torque (I'm not sure which) by MPH. Perhaps you can use that to limit fuel when you are launching, but it will come up to full fuel by the time you get to 4th gear.

 

[seven3smoke]

Can you dump any additional weight? Seats, rear bumper and hitch, ect... Can you drop the front of the truck any to reduce airflow under the body?

Good Luck!

 

[DmaxHawk]

I would be surprised if that is the case here. Perhaps he is overfueled early on, but once the turbo is at full boost, I see no reason to lower the max pulse unless rail pressure or EGTs are a concern. I don't have EFI on the computer I'm on, but there is a table that limits fuel or torque (I'm not sure which) by MPH. Perhaps you can use that to limit fuel when you are launching, but it will come up to full fuel by the time you get to 4th gear.

Good idea with those tables, I'll try those out ad see how it does.

Can you dump any additional weight? Seats, rear bumper and hitch, ect... Can you drop the front of the truck any to reduce airflow under the body?

Good Luck!

I dont want to take out the seats or the bumper/hitch. Front of the truck has been droppped

 

[DmaxHawk]

Unless you have found something, there's no way to make an LBZ command more than 180 MPa of rail pressure.

New table B1058 (might only be for beta testers right now) shows "Maximum allowed fuel pressure."

Shows 180 MPa. Min is 0 max is 250 MPa. Would that make it go past 180? Or is that physically not possible?