LBZ: Built trans, upgraded turbo, wrong converter?

Lost_in_tx

New member
Oct 18, 2018
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06 lbz, stock fuel other than fass 150, some intake/exhaust upgrades, efi live with conservative tunes, Danville 3794 st1 turbo

I recently had my transmission built along with a few other things and I’m not satisfied with the trucks performance down low. Once it gets going, it runs strong. It literally has no low end torque and decent amount of smoke until the turbo spools up and then it’s ok. Turbo is a Danville 3794 st1 (maybe this is the problem?), tuning is by the same guy prior to the turbo which ran great before.

The builder used a DEFEO rebuild kit and suncoast 105x converter which I’m told is near stock stall.

Main question - is this a converter issue or is this turbo the wrong fit for my application? The tuner has messed with the truck a few times and it’s gotten a bit better but he is out of ideas. Local guy with good reputation.

I did try the “coasting at 30-35, hammer it but not enough to downshift, look for quick 500rpm jump and equal increase in speed” but I’m not confident in the result. Yes, a little money goes out the tailpipe but also the speed increases a bit. Just don’t think it’s the same.

Thoughts?




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clrussell

pro-procrastinator
Sep 23, 2013
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I’ve used that turbo multiple times. It’s never been Smokey on conservative tuning. I also use mark for tuning though.
 

Lost_in_tx

New member
Oct 18, 2018
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Mike - I was told it’s a 105x. I thought the x meant he wasn’t sure the last number but he said no, it’s a sun coast 105x.


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duramaxzak

Wanna be puller!
Nov 22, 2008
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Mike - I was told it’s a 105x. I thought the x meant he wasn’t sure the last number but he said no, it’s a sun coast 105x.


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You need to know what the last number is, it makes a huge difference in what converter you have.
 

04chase

Member
Mar 28, 2008
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i have nearly the same setup but with a stage 2 3794 from danville and mike l built my trans with a goerend converter. it is a little slower to spool then stock but is over run by the performance every where else. I have APT tuning on this truck and seems to run well with dsp5 switch. i do get some smoke on lvl 5 when lugged, but 3 and below is clean as can be.
 

Lost_in_tx

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Oct 18, 2018
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I would change the converter and leave the turbo alone.



At this point I’d prefer not to, but what do you recommend? It’s a daily driver, light towing every other month, not looking for big power.


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Mike L.

Got Sheep?
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Aug 12, 2006
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An engine should not be modified around a converter. Just the opposite. The 1800 stall 105x will not be fun on the street or even towing. IMHO
 

Lost_in_tx

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Oct 18, 2018
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An engine should not be modified around a converter. Just the opposite. The 1800 stall 105x will not be fun on the street or even towing. IMHO



Sorry, I meant what converter do you recommend.


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