Drag racing questions?????

Josh154

Well-known member
Sep 28, 2015
1,220
85
48
Sioux Falls SD
The truck was only holding 24.5-25.5k rail pressure. I have a lift pump race plug and ported drivers said rail fitting. Is that 1-1.5k in rail pressure killing me that much?
 

DMAXchris

It’s only temporary!
Apr 28, 2009
2,273
2
38
44
Natrona Heights PA
Well **** if I'm at 6800 then I'm only putting down like 500... I can launch 20psi on black top and it just hooks and makes me feel like my eyeballs are in the back of my head lol
Thats what youre looking for!
The truck was only holding 24.5-25.5k rail pressure. I have a lift pump race plug and ported drivers said rail fitting. Is that 1-1.5k in rail pressure killing me that much?

No. My truck ran 12.40s with just a lift pump & draining down to 23xxx
 

Josh154

Well-known member
Sep 28, 2015
1,220
85
48
Sioux Falls SD
Ok so if rail pressure is not my issue then wtf is lol. I sent Kory some logs and he said everything looked great. Boost is hitting 38 pretty late in the run. Vanes are only opening up 55% max
 

motoking_1990

Active member
May 9, 2011
1,957
5
38
Terre Haute, IN
Something definitely isn't right that's for sure.

Do you have trans tunes?

Also agree with Harbin on the lockup situation. You need to see if it's locking up. May want to try a lockup box. From the video it didn't look like you left hard at all. The tires squealed and the power was gone for for a second. Sort of like traction control.

Sent from my SM-G920V using Tapatalk
 

valleyduramax

Member
Jul 25, 2010
233
4
18
Ottawa ON Canada
Just a thought but your sig says you have the egde cts. They usually read the ambient pressure then add boost pressure on top of that from what i remember. Maybe your misreading the display wrong? Just a thought
 

Josh154

Well-known member
Sep 28, 2015
1,220
85
48
Sioux Falls SD
So the Lly turbo I had built and installed has all this done to it

-port And polish
-fingers high flow vanes
-10 blade turbine
-batmo tct compressor wheel

Under wide open my vanes are opening up 55% so my vpos shows 45%. I just don't understand the point in doing high flow vanes if your not going to open them up further wide open? I may be completely in the wrong mind set but it's being pushed as hard as my stock turbo. 35lbs most of the run and will hit 38 towards the end. This should be a bad ass little turbo.
 

bluessmax

Tabasco Injected!
Nov 4, 2010
1,143
6
38
Lake Charles, la
With trans tuning or a lockup controller - you will shave close to 2 10ths off your time.

Vane are 45-50% in the run and look to be playing around 36-38lbs boost.. plenty more than enough for stock fuel and that turbo.

Duration is 3150, but I allow duration to drop as rail psi drops as to not drop rail too low.. So 26k desires 3150uS but being at actual 24k its hitting 2900-3000uS and maintaining.

Timeslips do seem a little on the slower side, but lockup will help that out. If i had to guess - this truck is likely clean as a whistle with no smoke once on boost... With that said - time for more fuel. At the end of the day - making power is simply fuel and air.
 

Harbin_22

Active member
Dec 4, 2010
3,858
7
38
Southern Indiana
If you aren't pushing a modded VGT hard, the vanes don't need to be open all the way. It can actually hurt power and EGT's from lack of boost from too little drive pressure. Need a DP gauge if you really want to mess with vane tuning.
 

bluessmax

Tabasco Injected!
Nov 4, 2010
1,143
6
38
Lake Charles, la
If you aren't pushing a modded VGT hard, the vanes don't need to be open all the way. It can actually hurt power and EGT's from lack of boost from too little drive pressure. Need a DP gauge if you really want to mess with vane tuning.

On my dyno with the 3794 and stock fuel - I have seen peak power running the vanes a little tight between 45-55% WOT and with stock fuel peak power around 3200rpm.
 

Josh154

Well-known member
Sep 28, 2015
1,220
85
48
Sioux Falls SD
Thanks for explaining things a little further Kory! I will just need to send injectors off to be honed and get a bigger cp3 then we can push it harder.

I would really like a lock up box or trans tune if that will do the same job. Even in tow/haul my 58 isn't locking as soon as I like it too
 

02duramaxfan

New member
May 13, 2013
25
0
0
virginia
No I didn't change anything from the first time I went the truck still traps 95... But I did manage to cut a better 60'

I still want more out of it so I think I will just spray it here within the next month or so 7.4s isn't fast enough :thumb:

With that being said what's the best set up I should go with??