Doug: tranny question on race file?

[01 250]

I used the race file and all I can say is WOW! This thing has power like I never thought. When I dump the throttle it shifts smooth, but if I drive the truck normal its very jerky through the gears as the tranny shifts itself. Almost like its a double shift and the truck learches. It definetly dont like and load with the race file. I pulled a 2 place snowmobile trailer yesterday with 2 sleds, maybe 1000 lbs total and it was really weird under load. Is there any way too keep the power band as it is but make the tranny a bit smoother shifting? I tried the street tune and the tranny still has a slight bit of jerking if I don't drive it hard, but not as much. Thanks.

[TANK'S 250]

if that tune is good for playing,....keep it....and get another one for daily driving

[Carssuck]

All of the tuners have issues like this with their full blown race files. Some tuners just give you a version of their street file and call it their race file because they know it will be used as a daily driven file.
The more radical the tune, the quirkier they become on the street.
It's called a race file for a reason, 1/4 mile times. IMHO

I can only imagine what goes through the tuner's mind when a customer says "I run your race file as a daily driver and the truck acts weird when I......".:D

If the race file delivers a good 1/4 mile time and shifts well at WOT it's doing what it was made to do. IMHO

[PSDPlayer]

The issue is that the converter locks up as soon as the gear changes. So you feel like the truck is shifting twice. The jerking is the driveline winding up. I can add some delay to the converter lockup.

[01 250]

whatever you think Doug, your the expert. I dont know anything about coverter locking up?? I don't do any 1/4 mile time trials or go to the drag strip. I want to be able to smoke a corvette on Genesee street if I feel like it or drive to work. Thanks doug!

[mattsn]

Doug, do you think that this is what is going on with my Tow tune in the shifts i talked to you about? The converter locking up right after those shifts. his description of the double shifting really hard sounds a bit like mine. I thought maybe mine was a small flare. but mine does it when under 40% or more power. and if so why only those last two gears?

[COTTS4x4]

After a while you will get familiar with the way it feels and learn how to drive with it. Put some miles on it and you wont notice it anymore. I have about 12K on my race file.

[mattsn]

i just want to make sure that what im talking about isnt an issue with the trans. it just feels weird. specially since the first shifts are firm but very smooth

[01 250]

can someone explain what you mean "the converter locks up" Can this cause premature wear? I just feels jerky.

[PSDPlayer]

The torque converter transmits and multiplies torque. The torque converter is a device which includes four elements:

The impeller assembly
The turbine assembly
The reactor assembly
The clutch and damper assemblyThe standard torque converter components operate as follows:

Rotation of the converter housing and impeller set the fluid in motion.
The turbine reacts to the fluid motion from the impeller, transferring rotation to the geartrain through the input shaft.
The reactor redirects fluid going back into the impeller, providing for torque multiplication.
The clutch and damper assembly dampens powertrain torsional vibration and provides a direct mechanical connection for improved efficiency.
Power is transmitted from the torque converter to the planetary gearsets and other components through the input shaft.
http://www.gogodiesel.com/forum/filestorage/shopmanual/trans/Torqueconverter.gif

<TABLE cellSpacing=0 cellPadding=3 width="70%" border=1><TBODY><TR><TH vAlign=bottom>Item</TH><TH vAlign=bottom>Part Number</TH><TH vAlign=bottom>Description</TH><TR vAlign=top><TD>1 </TD><TD>— </TD><TD>Converter clutch and damper (part of 7902)</TD></TR><TR vAlign=top><TD>2 </TD><TD>— </TD><TD>Reactor (part of 7902)</TD></TR><TR vAlign=top><TD>3 </TD><TD>— </TD><TD>Turbine (part of 7902)</TD></TR><TR vAlign=top><TD>4 </TD><TD>— </TD><TD>Impeller (part of 7902)</TD></TR><TR vAlign=top><TD>5 </TD><TD>— </TD><TD>Fluid motion</TD></TR><TR vAlign=top><TD>6 </TD><TD>— </TD><TD>Transmission input rotation</TD></TR><TR vAlign=top><TD>7 </TD><TD>— </TD><TD>Input shaft</TD></TR><TR vAlign=top><TD>8 </TD><TD>— </TD><TD>Engine rotation</TD></TR></TBODY></TABLE>

The converter cluctch acts just like the clutch in a manual transmission vehicle. If you lock the clutch on a gear change you lock the engine to the transmission with no slip between the two. So when 8000lbs shifts into the next gear the entire driveline winds up. The driveshaft loads the leaf springs and the leafsprings snap back and bring the motor down.

[01 250]

so is this better or worse for wear on the torque converter? I heard stories of these things not being able to handle the power and crapping out?

[PSDPlayer]

The converter clutch is constantly being applied and releasing with the factory converter clutch strategy. It works just like the rest of the clutches inside the transmission. So it wears just like 1st 2nd 3rd 4th 5th and the coast clutch does.

[PSDPlayer]

so is this better or worse for wear on the torque converter? I heard stories of these things not being able to handle the power and crapping out?


Was the story about nitrous and meth passes at the drag strip on a 5r110? Or the old 4r100 that would destroy a converter while towing a camper?

[01 250]

No I have a friend that works at a transmission shop, and said they get powerstrokes in all the time with blown torque coverters. Can you send me the race file with less jerk in the tranny that I can run as an everyday tune? I want the power of the race file when I hit the flipper, but smooth shifts for when I am driving normal.

[PSDPlayer]

Tom check your email.

[01 250]

Doug, you are good! Thank you very much for getting that so quick. I loaded it this morning for my ride to work. Its is a perfect combo for everyday driving. It seems like a 1/2 way point for power between the full race tune and the street tune but smooth shifting somewhat between the street tune and the stock tune for everyday driving. I still laid a patch at the redlight. I see why you lock out the converter, its a night and day difference with it locked out. If I run to impress any nondiesel beleivers I will load the full race tune. I need an Honest answer: Will running the race tune either converter locked out or converter stock cause any tranny issues? I want safety first, and you seem like god when it comes to these diesels. Thanks again!!!!!!!!

[Carssuck]

Doug, you are good! you seem like god when it comes to these diesels. Thanks again!!!!!!!!

Awww man, I wish you wouldn't have said that! Now his head will get even bigger! LOL

01 250,
I am glad to hear you found a good compromise that works well for you and Doug is always willing to tweak the files to his customers personal preferences.

When it comes down to it, having the converter locked is 100% personal preference. Some guys love it, some hate it.

[01 250]

Whatever dont tear it apart. It seemed to have more power locked.

[PSDPlayer]

Whatever dont tear it apart. It seemed to have more power locked.


Of course it has more power locked. More power goes to the wheels when you lock the engine to the transmission. As an example. Would you drive around with your foot half on the clutch in a stick shift car?

[mattsn]

Doug are you ever going to answer me about my question? what you thought that shift issue was going from 3rd to fourth? and why it was only that gear? I know your a busy man but damn. lol

[01 250]

that makes sense, thanks doug.

[Abrannan19]

his head is soooo big right now Matt..he doesnt have time to answer any more questions! lmao

[mattsn]

LOL well hes been avoiding answering my question for a while now. Even on IM, he keeps running away as soon as i bring it up. :mad: Im begining to think he doesnt know the answer. Just kidding doug.

[PSDPlayer]

The converter lockup delay was set to no delay on the last 2 gear changes. I reset it to the facotory delay and put the lockup strategy back to stock on the last 2 gears. The "jerky" was it upshifting and locking the converter immediately. Like if you dump the clutch to quick in a manual transmission car.

[mattsn]

ok, so when it felt like it shifted twice real quick it was first the shift, then the converter locking up right after that? so now i have two more questions. ( sorry doug just learning ) so why was it more noticable on 3-4 than 4-5 and Im assuming that it is not damaging at all to the trans????? I havent had a chance to load and test the new file yet. I dont drive the truck much during the week. thanks

[PSDPlayer]

Its more noticable on the 3-4 cause the truck drop off in the rpm range is more from 3-4 than it is on 4-5.

[mattsn]

oooohhhh, ok makes sense. so then definetly not damaging to the trans then. Thanks Doug. see was that so hard. :D