12 Valve 2nd Gen Dodge Cummins 94-98 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps

Turbo spool trick... Fuel cut?

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Old 04-13-2011, 07:12 PM
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Default Turbo spool trick... Fuel cut?

I have been scouring the web for the past 30 mins of so and have come up dry in search of how to spool a turbo with a manual without slipping the clutch...

Ive seen sled pullers do it, but nothing is published... kinda hard to imagine in this vast space AKA the internet...


To describe it: it sounds like a solenoid is cutting fuel to the engine at high revs to assist the turbo spool. Is this whats going on? or is there something else happening...

here is the best video I could find of this trick at work.


dont even try searching for the video, the guy has some garbage tags that have nothing to do with the title.... I typically google "houston we have liftoff 150 psi"

thanks in advance!
 
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Old 04-13-2011, 08:20 PM
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Most drag or sled puller trucks use automatic transmissions with manual valve bodies, giving them all the benefits of an auto (quick shifts and keeping the turbo spooled the whole time vs having to re-spool the turbo in every gear with a manual transmission) while being able to shift gears at any desired RPM with the manual valve bodies.

Like in the video, I think the truck is using a Trans Brake to build spool and RPMs as the truck is stationary.

Here's a link to a Trans Brake manufactured by Sun Coast: Sun Coast Racing Products
 
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Old 04-13-2011, 09:35 PM
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Trans brakes are outlawed in pulling, and he's def slipping the clutch that boucing that sounds like a limiter is actually the injection pump causing the sound with the ag gov and quick rate cam in the pump along with oversized injector lines as well. But I assure you the clutch is weighted and def is slipping to build boost. But free reving the truck to 5 or 6k will build boost with no load as well.
 
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Old 04-13-2011, 09:45 PM
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hmm, I see... ag gov? agriculture governor?
 
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Old 04-13-2011, 09:46 PM
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correct and for sure 13mm pump as well
 
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Old 04-14-2011, 03:20 PM
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And no street toy for sure. Ag governors cant be used on the street.
 
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Old 04-14-2011, 07:19 PM
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Sled pullers don't spool the turbo up as they are bringing up RPM. Once you are at 4500RPM+ it is rather easy to get a turbo to start spooling when setup properly.

Most associations outlaw ag governors unless in the mod or open class. Majority of sled pullers DO NOT run automatics as clutches are far cheaper. And the guys making a lot of power are running Triple Disc clutches that are weighted and bring the clutch in at a certain rpm and shove the drivers foot right off the clutch pedal and provide max clamping pressure while running down the track.

The whining you hear while the truck is running down the track is the gear train and the turbo charges as the load o nthe engine is changing as the truck is "bouncing" down the track and more and less load is applied to the engine.

The chug chug chug you hear as the truck is running up rpm is do to the cam, compression, build of injection pump, and a few other factors that help the engine spin 5500+rpm and make a crap ton of power.
 
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Old 04-14-2011, 10:42 PM
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Originally Posted by 1SlowCTD
Sled pullers don't spool the turbo up as they are bringing up RPM. Once you are at 4500RPM+ it is rather easy to get a turbo to start spooling when setup properly.

Most associations outlaw ag governors unless in the mod or open class. Majority of sled pullers DO NOT run automatics as clutches are far cheaper. And the guys making a lot of power are running Triple Disc clutches that are weighted and bring the clutch in at a certain rpm and shove the drivers foot right off the clutch pedal and provide max clamping pressure while running down the track.

The whining you hear while the truck is running down the track is the gear train and the turbo charges as the load o nthe engine is changing as the truck is "bouncing" down the track and more and less load is applied to the engine.

The chug chug chug you hear as the truck is running up rpm is do to the cam, compression, build of injection pump, and a few other factors that help the engine spin 5500+rpm and make a crap ton of power.
Very In depth detail, learned a lot from this, thanks!
 
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Old 04-15-2011, 05:06 PM
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Originally Posted by 1SlowCTD
Sled pullers don't spool the turbo up as they are bringing up RPM. Once you are at 4500RPM+ it is rather easy to get a turbo to start spooling when setup properly.

Most associations outlaw ag governors unless in the mod or open class. Majority of sled pullers DO NOT run automatics as clutches are far cheaper. And the guys making a lot of power are running Triple Disc clutches that are weighted and bring the clutch in at a certain rpm and shove the drivers foot right off the clutch pedal and provide max clamping pressure while running down the track.

The whining you hear while the truck is running down the track is the gear train and the turbo charges as the load o nthe engine is changing as the truck is "bouncing" down the track and more and less load is applied to the engine.

The chug chug chug you hear as the truck is running up rpm is do to the cam, compression, build of injection pump, and a few other factors that help the engine spin 5500+rpm and make a crap ton of power.
I feel slighty dumber after reading that
 
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Old 04-15-2011, 05:09 PM
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Please correct me where I'm wrong. I don't know everything and I'd rather learn than be wrong a second time.
 

Last edited by 1SlowCTD; 04-15-2011 at 05:16 PM.
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