ironcityboom

Truck is on the dyno and the tuner is having a hell of a time getting it to rev over 5k rpm. Last pull it took 3 seconds to get from 4400 to 5200 rpm. Its not missing or anything odd feeling, just wont rev. About 10 psi of boost as of now. Has an ATI Converter in it and I called them and they assured me it isn't an issue with the converter being too loose or tight. Pretty much just said put more boost to it but I'm wondering if there's something more obvious that were not thinking. Also no indications of valve float either, boost is sustained. Thanks guys!

Atomic

iTrader: (42)

How experienced is the dyno operator? Turbo vehicles are tricky on the dyno. He needs to lower the load to let it rev easier. I dont like full power runs longer than 5-6 seconds with high powered stuff, you adjust the dyno loading to whatever power the car makes to get to that. With a turbo youll want to load it up some down low before ramping out to give the turbo time to spool up and get ahead of the engine first.

MikeGyver

iTrader: (5)

That's kinda how my truck slammed the 1-2 shift on the street once. I guess the clutches are bad. It went through the rpm range too fast to 4400-ish and hung there until I let off.

Atomic

iTrader: (42)

Could also be the converter. If its "blowing through" and the stator vanes are bent the efficiency goes down the tank and you are basically just heating up the trans fluid. What does the TCC slip rpm look like compared to engine rpm? Trans temp?

Vortec350ss

iTrader: (20)

What plugs and what are they gapped at? Are you blowing out the spark? Does it sound like its making power and wont rev, or does it sound like something is bogging? Are the narrowbands hooked up?

ironcityboom

He’s experienced and highly recommended by others, he adjusted the Dyno load and it didn't seem to make a difference. I apologise im kind of a middle man here I wasn't able to make it up to the Dyno yesterday so I'm just going by what he's telling me. He still has the truck, and I haven't heard anything else yet. He wanted to mess around more wtith the boost controller. But it didn't seem to help


Truck has BR7's in it right now but yesterday he told me it almost sounded bogged down, it wasn't missing or anything odd feeling Just didn't want to rev. The last time I spoke with him he had been able to get it to 5700 and made 495 on 10lbs.

Vortec350ss

iTrader: (20)

Blowing the spark out will feel like you all the sudden released a chute that makes the truck stop pulling... i would NOT be surprised in the least if this is your issue. Tighten the gap on them and strap it back down. You didn't mention what the gap was? How much boost do you plan to run? I would target .024 as a starting point for your gap.

ironcityboom

Heres a video guys, if you listen close you can hear the rpms plateau then start to climb back up but it seem to take forever. Also, were only able to build 13lbs. I'm running an eBoost2 and tried every wastegate configuration they have with no changes, tested the solenoid and it works fine. The wastegate is a 60mm JGS with the big spring guessing it's 12-13lbs spring. Plug gap .020 right now. I'm trying to get the dyno graph..

smokeshow

iTrader: (16)

I'd be looking at IATs, back pressure, fuel consumption/BSFC, dyno load... Operators tend to overload eddy current dynos with turbo/auto vehicles because they're strain gauge dynos and always bias towards high torque and low power with an unlocked converter. First thing they do is increase load because 'it should be making more power'. See this torture test the dyno operator put my truck through on an old build of mine...

Atomic

iTrader: (42)

Easy test, go make a hit on the street and if everything is fine then its the dyno. You dont race a dyno anyway