What am I missing

[6.4 Stroker]

Need to log the truck and see the whole picture. Trying to diagnose based off of two different runs on two different days is a crapshoot.

MPH will tell you if you're making the right power. ET is up to you as the driver.

This is based on a dozen runs. I was just using those two as an examples.
I understand what your saying about ET and Trap. I think mph is still low.
I've logged boost, ebp, frp, all seem great. That's why I'm pulling my hair out.

 

[6.4 Stroker]

Kindof thinking its the off the line launch. Tires breaking loose badly? How about suspension? I know they are heavy trucks but still suspension does play a role in this..

60' definitely could be better. 1.7-1.8s I didn't drop tire pressure though. I feel my trap should be a little more comparing to simular setups.

 

[6.4 Stroker]

Bump! Did a few runs data logging converter slip and it's showing anywhere from 200-300rpm slip under full lock. Is that enough to make a difference?

 

[SpartanDieselTech]

Truck definitely feels stronger at half throttle, than WOT.
Figured I would have gained SOMETHING from diching 500lbs.

If you are still holding 25-26k rail pressure, add .1 or .2 ms to your pulsewidth.

 

[SpartanDieselTech]

Bump! Did a few runs data logging converter slip and it's showing anywhere from 200-300rpm slip under full lock. Is that enough to make a difference?

Oh yes. New converter would probably help immensely. Hence why the truck feels peppier at part throttle (not enough torque to cause the slippage).

 

[6.4 Stroker]

Oh yes. New converter would probably help immensely. Hence why the truck feels peppier at part throttle (not enough torque to cause the slippage).

Okay, thanks for the reply.
It's an Old RCD converter that doesn't owe me anything so I'm not too upset about it.

 

[6.4 Stroker]

If you are still holding 25-26k rail pressure, add .1 or .2 ms to your pulsewidth.

I gave 2.0 and 2.2 ms a try, but trap speed and et times were pretty close.

 

[madman1234509]

It may not even be the converter, it could be your overdrive clutches. Others have seems "slip" on the gauge, when the converter is brand new, ends up being the clutches slipping.

 

[6.4 Stroker]

It may not even be the converter, it could be your overdrive clutches. Others have seems "slip" on the gauge, when the converter is brand new, ends up being the clutches slipping.

I could definitely see how that would happen. Good info!
It shows the slippage WOT from 2nd and 3rd gear. It holds fine 4th and 5th

 

[bigrpowr]

I could definitely see how that would happen. Good info!
It shows the slippage WOT from 2nd and 3rd gear. It holds fine 4th and 5th

could be either. i know my extra cab weighed 7900 with me in it , made 750 and ran 7.50 @ 91 . check the trans fluid, to start , see if its got the shiny stuff in it .

 

[6.4 Stroker]

Little update,
I sent the converter off to be refeshed and have the stall raised to 2000 from 1800. I've always felt 1800 was a tad low IMO.
Took it to the 1/8thile track again last night. Had a best time of 8.0 @ 86.48 mph. Meanwhile another 6.4 with a drop in 71 was running 7.9s
Any ideas where to go from here?

 

[6.4 Stroker]

Bump, lots of knowledgeable people on here.

Just to refresh, full build list includes:
completely rebuilt shortblock with balanced rotating assembly, .020 over delipped OEM pistons,
New heads, RCD Pushrods, 120 valve springs, A1 studs
Industrial injection 58/71 turbos, no limit intake,
dual K16s, 60% Midwest diesel nozzels.
Trans is an Elite Diesel stage 3 with a RCD converter.
Currently running Ge$rhead tunes.
Truck has made 750-800 on a few different dynos.
Track times put it around 625hp.
I'm not gonna give up on this thing.
Just don't know where look or data log.
Thanks.

 

[6.4 Stroker]

I think my next move is to pull the turbos and take a look at the turbines of both turbos.
Maybe the VGT turbine melted a bit. I know that was pretty common in the 6.0 world.

 

[tbsimmons]

In the calculator your using are you using ET to find HP or MPH?
If you 60' is not good then I can see many trucks running quicker with less power.
When I was racing, .1 in 60' was over .2 in ET in the quarter. MPH being the same.
Since you sent the TC off, did the slipping go away?

 

[Powerstroke Man 6.4]

Whats the pulse width and mass fuel desired commanded in the tune? whats rail pressure at WOT? is there alot of smoke or is it clean? hows the egts? whats the weight of the truck?
are you using tow/haul? are the tunes modified for the mods that's done to the truck?

are you 4WD launching and what psi of boost/RPM?

PSI in the tires?, if you are using a 1/4 to 1/8th calculator, what calculator are you using to convert the MPH/ET to 1/4?

I entered your stats posted above (8.0 @ 86.48 MPH) into this Wallace Racing 1/8th to 1/4 calculator.

http://www.wallaceracing.com/8th-quarter.php

it returned these numbers.

"Your 1/4 Mile ET is 12.55 seconds computed from your vehicle 1/8th ET of 8.0 seconds.

Your 1/4 Mile MPH is 107.24 MPH computed from your vehicle 1/8th MPH of 86.48 MPH."

enter these numbers and rough estimated of weight into our HP calculator up top and see what you get.

 

[Powerstroke Man 6.4]

Also what the max boost/EBP you see running down the track at WOT? do you know what your base fuel pressure is at idle and WOT? stock LPFP or aftermarket? is it shifting fine? when is the TC locking? is the transmission slipping? does it spool up fast from a strand still/boosted launch or is it laggy? did you monitor VGT DC% and see what its doing?

 

[6.4 Stroker]

In the calculator your using are you using ET to find HP or MPH?
If you 60' is not good then I can see many trucks running quicker with less power.
When I was racing, .1 in 60' was over .2 in ET in the quarter. MPH being the same.
Since you sent the TC off, did the slipping go away?

I was using the MPH/weight method.
The slippage I was previously seeing was in a window of .5 seconds when the converter calls for lockup in second gear. Which from my understanding, is normal tuning to avoid harsh lockup and breakage.

 

[6.4 Stroker]

Whats the pulse width and mass fuel desired commanded in the tune? whats rail pressure at WOT? is there alot of smoke or is it clean? hows the egts? whats the weight of the truck?
are you using tow/haul? are the tunes modified for the mods that's done to the truck?

are you 4WD launching and what psi of boost/RPM?

PSI in the tires?, if you are using a 1/4 to 1/8th calculator, what calculator are you using to convert the MPH/ET to 1/4?

I entered your stats posted above (8.0 @ 86.48 MPH) into this Wallace Racing 1/8th to 1/4 calculator.

http://www.wallaceracing.com/8th-quarter.php

it returned these numbers.

"Your 1/4 Mile ET is 12.55 seconds computed from your vehicle 1/8th ET of 8.0 seconds.

Your 1/4 Mile MPH is 107.24 MPH computed from your vehicle 1/8th MPH of 86.48 MPH."

enter these numbers and rough estimated of weight into our HP calculator up top and see what you get.

The tune calls for 2.2 PW. I've tried 2.0, 1.8 and 1 6 all yield slightly slower MPH'S and ETs.
Commanded rail pressure is 25.5 which it holds pressure great.
EGTS I'll have to get back to you on.
Smoke doesn't even try to clear up.
https://youtu.be/hp-gan1i1oQ
I don't use tow haul when racing.
I launch in 4x4 around 2000 rpm's with 40 psi on the front and 35 in the rear.

 

[6.4 Stroker]

Looks like it's just north of 650 calculating 7900lbs and 107

 

[tbsimmons]

When your comparing your dyno numbers to the track are you using corrected numbers that most dynos produce.
You have think weight is not everything. If you are comparing to a stock truck as in height wheels and tires can cause time also. Skinny tires on my car were a few tenths compared to the normal wheel and tires. Not worth it for me so I didn't run them because the car squirmed at the big end. For me 1/8 mile is hard to tell HP problems because you don't the the time and MPH difference between 1/8 and 1/4. But both having a 71 big turbo shouldn't that mean the HP is about the same. Seems like you have a lot of fuel for those chargers.


Sent from the bat phone near a drilling rig.