Experimenting with a Garrett GT3782 VNT

That spinning thing that makes all of the cool noises. OE and Aftermarket.

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93forestpearl
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Experimenting with a Garrett GT3782 VNT

Post by 93forestpearl » Tue May 12, 2009 4:06 am

My buddy is starting to get to the point where he can play with the vanes on his Powerstroke turbo. The little bit of experimentation is quite impressive. 3000 rpm at half throttle was producing 10 psi at 80% duty cycle on the vanes. Basically, this thing will produce insane amounts of boost at a ridiculously low rpm for a large framed Garrett that has the compressor wheel of a GT4082.


Last edited by 93forestpearl on Tue May 12, 2009 4:16 am, edited 1 time in total.
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ericem
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Post by ericem » Tue May 12, 2009 4:10 am

Holy Moly!! I was starring at that temp gauge not even really paying attention to the boost and RPM's going crazy!! Then I realized your put a bubble staying it was broken. Wow, that was scary lol.

Make a thread "Heart Stopping SS boost vid"
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93forestpearl
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Post by 93forestpearl » Tue May 12, 2009 4:15 am

He just started playing with the vanes. With the vanes fully open it hits at 5k, but stays spooled when his built (rigoli style) auto shifts to 4500.


I'm just really excited to see how this plays out. He needs to fully tune the car (Hydra) with the vanes open, and slowly close them down at lower rpm's, and tune for it.

If this works out, I'll be converting next winter...
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93forestpearl
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Post by 93forestpearl » Tue May 12, 2009 4:46 am

It's funny how the exhaust gets MUCH quieter when the vanes close. With the vanes open the car is very loud, since there is only two resonators and no muffler.
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93forestpearl
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Post by 93forestpearl » Tue May 12, 2009 7:13 am

Image
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BXSS
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Post by BXSS » Tue May 12, 2009 1:02 pm

Nice turbo!
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Post by douglas vincent » Tue May 12, 2009 7:42 pm

I have a Garrett VNT that is the equivilent of a gt28 which is run off of vacumn... Not sure exactly how its gonna work, but we are going to run it with E85 to keep the exhaust cool.
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Post by Mattheww044 » Wed May 13, 2009 1:54 am

that looks fun!! :D gotta love turbos lol. plans for a 5mt?
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93forestpearl
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Post by 93forestpearl » Wed May 13, 2009 1:57 am

Vacuum? I could see it referencing boost and opening the vanes as the boost comes on. Interesting though.

I think the Holset variable geometry turbo for diesels is electronic. A stepper motor or something like that.
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douglas vincent
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Post by douglas vincent » Wed May 13, 2009 2:58 am

Yeah, vacuum. I had no idea it was VNT till I opened it up. Its the turbo on the diesal jeeps.....

Vacuum its closed, boost opens it up.... (or vice versa)...
Reddevil, Awaiting new heart, will it ever happen?
1990 wagon, EJ25 12.3 @ 116.5 FAST Family wagon getting new motor soon
1992 wagon, wifes daily, high compression
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Post by WhiteLegacyGuy » Wed May 13, 2009 3:02 am

Hi all
I am the owner of this car in the video clip above.

Them smaller VNT's use a vacuum system with a vac pump and a solenoid that is independent of the boost pressure. it uses sensors and ecu to control boost. On the dodge/mercedes sprinter vans the ecu can de-spool the turbo just before the transmission shifts. its kind of funny hearing that happen while your driving it

But u can use a normal wastegate actuator and boost controller to move the vanes.

the gt3782 vnt uses oil pressure and a little hydraulic cylinder and a solenoid to move the vanes

there is also a larger gt42 size vnt on series 60 detroit diesels that uses pressure from the air brake system to move the vanes.
93 Legacy Sport Sedan, Eagle/Wiesco EJ22T DOHC, GT3782vnt turbo at 28psi, Hydra Nemisis 2.6, RC1200cc injectors,
Built 4EAT. AP-racing Sure-trac R160. Brembo GT BBK. JDM Legacy B4 Bilstein struts w/ground control coilovers.

VNT FTW

93forestpearl
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Post by 93forestpearl » Wed May 13, 2009 8:08 am

You actually made a post, hooray!

This man knows his stuff.....
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WhiteLegacyGuy
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Post by WhiteLegacyGuy » Tue May 19, 2009 4:09 am

I uploaded another video

I was doing some more testing and shot a quick video of me brake torqueing it. I think i need a lower stall converter.

http://www.youtube.com/watch?v=zKV-kDFNl4c

Keep in mind that this turbo is a bit larger than a 35R. they spool at around 4600 Rpm give or take.

later
93 Legacy Sport Sedan, Eagle/Wiesco EJ22T DOHC, GT3782vnt turbo at 28psi, Hydra Nemisis 2.6, RC1200cc injectors,
Built 4EAT. AP-racing Sure-trac R160. Brembo GT BBK. JDM Legacy B4 Bilstein struts w/ground control coilovers.

VNT FTW

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Post by 555BCTurbo » Tue May 19, 2009 5:39 am

Well...I think I now know what my Audi will be getting...


How much was that sucker? And I assume it's off of a 6 liter?
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93forestpearl
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Post by 93forestpearl » Tue May 19, 2009 5:47 am

I see them for $400-500 or so used. And you are correct in that they are off the 6 liter.


The trick is being able to control the vanes. You can get by with a very nice electronic boost controller to run the Ford solenoid, but a standalone with a general purpose 3D PWM output is better. A 4D map would be tits, so you could also reference load.
→Dan

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Post by AWD_addict » Tue May 19, 2009 8:01 am

Good stuff. Can you take a video comparing fully open vanes to controlled vanes building boost?
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93forestpearl
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Post by 93forestpearl » Tue May 19, 2009 5:58 pm

We might do some tuning tonight, and can take some video. With the vanes fully open, it makes about 20psi at 5k rpm.
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WhiteLegacyGuy
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Post by WhiteLegacyGuy » Wed May 20, 2009 2:08 am

We did do a little tuning tonight and here are the results

http://www.youtube.com/watch?v=7GdY55GfGus a nice little 2nd and 3rd gear pull. the tcc was locked in 2nd gear untill i shifted

http://www.youtube.com/watch?v=yvCQoaMttmM a full brake torque launch


There are more spoolup gains to be had with more tweeking.

Later
93 Legacy Sport Sedan, Eagle/Wiesco EJ22T DOHC, GT3782vnt turbo at 28psi, Hydra Nemisis 2.6, RC1200cc injectors,
Built 4EAT. AP-racing Sure-trac R160. Brembo GT BBK. JDM Legacy B4 Bilstein struts w/ground control coilovers.

VNT FTW

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Post by Legacy777 » Wed May 20, 2009 2:59 am

Nice!
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Post by AWD_addict » Wed May 20, 2009 4:55 am

Looks like fun!

What's the noise before the 1-2 shift? Torque converter?
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93forestpearl
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Post by 93forestpearl » Wed May 20, 2009 5:30 am

Derek was shifting it manually. He's using a SVX TCU since you can hold the gear as long as you want, and the SS TCU shifts at 6500 no matter what. The SVX TCU requires a "normal" TPS though, so it won't work with an SS ECU.

We think the torque converter clutch started to slip as well. It didn't like that much early boost in third gear with a hot tranny.


What was really interesting is how sensitive the motor was to moving the vanes. A matter of 5% duty cycle means the difference between not spooling that turbo quickly and choking the motor. We have a lot more work to do. This looks really promising though. I might have to take the plunge next winter. I'll need a twin disk clutch though :( With an hour and a half of work, this thing is spooling faster than my GT2871R 56T. That hurts.


Now for some LSD's, lol. Dunlop Z1 Star Specs shouldn't roast that long....
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Post by 555BCTurbo » Wed May 20, 2009 4:22 pm

93forestpearl wrote: but a standalone with a general purpose 3D PWM output is better.

Oh good...my standalone has that :D
Nick

1987 Audi 4000CS quattro...soon to be 20VT
1994 Dodge Ram 2500 4x4 CTD, #11 plate, 30 psi, Scotty II intake, 4" exhaust

93forestpearl
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Post by 93forestpearl » Wed May 20, 2009 4:51 pm

Apparently the Ford solenoid on the turbo is problematic, and might be why it was so sensative. Today the output transistor on the Hydra cooked and is shorted.

Hopefully just a new transistor will fix it, and a new solenoid.
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