About the VNT

[rabbitman]

I have seen them, seems that to take full advantage of what a VNT can do, electronics would be needed.

Why do you ask a question and then appear to know it all? It seems like you've already made up your mind.........

[UnderPSI]

Was it worth it?

[410]

After my first drive with my m-vnt setup I can say from firsthand experience that it is 100% worth it.  More power, better fuel economy in cruise conditions, virtually no lag and all without a computer. 

[punkvideo81]

so, I can setup a m-vnt on my 1.6td in my caddy and get similar results? what's the best source for a vnt? used/new?...

[fatmobile]

Someone said earlier that a VNT-15 isn't big enough for a 1.6.
 I'm not sure what you have planned for a 1.6D, VNT-15 but it is most certainly powerfull enough for most everyone.

I built one last summer.
 It got up and went like hell,
 surprised Andrew when he took it for a test drive.
 Didn't expect that to happen when he put it to the floor, freaked out the guy I built it for.

 What's obvious to one soul,
 is insanity to others.

I've been running the 1.5D, VNT-15 the vanes tied closed.
 Climbing a hill on the interstate, going 80, accelerating, EGTs 1100, boost around 20.
 Sounds pretty optimum, even without a mechanical controller.
VNT-15 tied closed and max fuel screw adjusted to the collar.

I want to put a knob on the dash so I can manually change the vanes, instead of having the accelerator lever change the position.

[punkvideo81]

hey fatmobile (or anyone with vnt/1.6td experience) , to answer your question as to what I have planned for my 1.6td, here is what I have done so far:
intercooler
2.25" tt downpipe/exhaust
giles modified ip (tweaked to be good to 18psi boost)

would the vnt fit well considering those mods? I want a quick daily driver, no drag racing etc. 
I am having the engine rebuilt right now. is the vnt 15 right or is there a better choice? any mods needed to make it fit right? thanks   

[fatmobile]

A VNT-15 will work great for that setup.
 Only the "MOER POWER", Tim Taylor guys will say different.

 18psi is a good goal for the VNT-15 even though it will go higher.

Right now I'm running one on a 1.5 and dreaming of the next 1.6 VNT.
 This turbo really shows where the power is on each engine.
 The 1.5 is missing torque/power when I take off, and comes on at midrange, I like reving it to the limit,.. the sound, ha.
Some of that could just be different pump tuning.

I believe it was ROR that mentioned using a non-turbo pump.
 That's what I use.
 It keeps the cost down.
The turbo pump doesn't get you more power,
9mm will pump; what 9mm can pump.
A turbo pump will help keep smoke down before boost comes up.
A VNT provides boost earlier, so there isn't as much need for that, there isn't 2000 RPM of no boost.
It will still leave a black cloud if you stomp on it.
Stomping on it at idle will leave pieces of soot floating in the air, inside the cloud.

 A stock turbo gives you no boost when revved out of gear.
 How much boost will a VNT-15 give you if you floor it out of gear?

2.25" fits great.
 More than that might get in the way of the nuts/studs that hold it to the turbo.

ROR points out that the KP39 (larger VNT from a later PD) is probably the cure for that.
He also mentions that the VNT will help quiet the exhaust,.. he had the vanes tied closed,..
 because if you ever heard one with the vanes tied open you'd think differently 
A 2.25" TT with borla sounded quiet (I think it had a resonator too),
 but my 2.5" TT, with muffler that has a couple 3" turndowns,.. no resonator, out is too loud with vanes open, even at idle.

[rabbitman]

Hey, I'm hearing two different things here. You all probably remember my discouraging attemped at running a VNT.

Well back then Andrew said on a quantum 1.6D, vanes wide opened and stock fueling did something like 20psi and was it 900F EGT?

Now Fatmobile says he runs with the vanes tied shut and is doing 20psi and 1100F. He also says ROR tied his vanes shut too.

I ran mine with the vanes opened and got 4psi, black smoke and 1350+ egt, after closing them partway it was 13psi, black smoke and 1350ish egt.

he had the vanes tied closed,..
 because if you ever heard one with the vanes tied open you'd think differently 
A 2.25" TT with borla sounded quiet (I think it had a resonator too),
 but my 2.5" TT, with muffler that has a couple 3" turndowns,.. no resonator, out is too loud with vanes open, even at idle.

That's weird, mine sounded real good at idle with a 2.5" straight pipe and the vanes opened, shutting them made it even quieter.

[BlastIt]

I have a vnt15 on a 1.6. I started with a NA pump and now have a TD pump on it. The NA pump seemed to bring the turbo in much quicker but would level out mid to upper range. The Td pump brings the turbo in a little later but seems to keep pulling much longer. The Na pump had higher EGTs and a LOTS of smoke. The TD pump lower EGTs and very little smoke. The TD pump seems to work better in my daily driving conditions ( back roads ). I have a vain controller on my vnt15 the boost tops out around 15 to 16 psi. I would strongly recommend a vnt turbo to anyone.

[Rabbit on Roids]

why does everyone think my vanes are tied closed?

they are wide-ass-open, for the best flow. not to make it spool fast and make way too much boost.

i got no vane control, and see 20+ psi at the top of a shift. most of the reason i dont control the vanes is because they are soo stuck..

it doesnt matter on these turbos wither the vanes are closed or opened, these turbos are just really quiet. i am running nothing more than a down pipe, and its quieter than my gas GTI with a full exhaust. until you get into about 10 psi.. then it starts to make a little noise. but its really not that noisy at all..

[lord_verminaard]

I have a vnt15 on a 1.6. I started with a NA pump and now have a TD pump on it. The NA pump seemed to bring the turbo in much quicker but would level out mid to upper range. The Td pump brings the turbo in a little later but seems to keep pulling much longer. The Na pump had higher EGTs and a LOTS of smoke. The TD pump lower EGTs and very little smoke. The TD pump seems to work better in my daily driving conditions ( back roads ). I have a vain controller on my vnt15 the boost tops out around 15 to 16 psi. I would strongly recommend a vnt turbo to anyone.

What vane controller???

Brendan

[745 turbogreasel]

why does everyone think my vanes are tied closed?

they are wide-ass-open, for the best flow. not to make it spool fast and make way too much boost.

i got no vane control, and see 20+ psi at the top of a shift. most of the reason i dont control the vanes is because they are soo stuck..

it doesnt matter on these turbos wither the vanes are closed or opened, these turbos are just really quiet. i am running nothing more than a down pipe, and its quieter than my gas GTI with a full exhaust. until you get into about 10 psi.. then it starts to make a little noise. but its really not that noisy at all..

Are you sure they open all the way?

[Rabbit on Roids]

i had the turbo separated from the hot side when i set the vanes. there wide open. i checked. physically as open as possible on this particular turbo.. i promise..

[BlastIt]

I have a vnt15 on a 1.6. I started with a NA pump and now have a TD pump on it. The NA pump seemed to bring the turbo in much quicker but would level out mid to upper range. The Td pump brings the turbo in a little later but seems to keep pulling much longer. The Na pump had higher EGTs and a LOTS of smoke. The TD pump lower EGTs and very little smoke. The TD pump seems to work better in my daily driving conditions ( back roads ). I have a vain controller on my vnt15 the boost tops out around 15 to 16 psi. I would strongly recommend a vnt turbo to anyone.

What vane controller???

Brendan

It's close to libbybapa. I used hard lines were he used cables. It's been on there for about 2 months now seems to be working great. I'll try and snap some photos of it.

[OM617]

Are the the best thing since sliced bread? Probably not or everybody would be using one.

Cost is the only reason for diesels and exhaust heat for g@ssers.

They are only better if they have the proper control on the vanes.

Not really. A simple wastegate actuator can be used to control it, though not optimally for low-loads.

Seems practically impossible to use a VNT to it's potential without computer control.
...
Wasn't a question, was stating the obvious.

Oblivious is the correct term for you to use.

Was it worth it?

Without question. It will completely change the torque curve of any engine.

I've been running the 1.5D, VNT-15 the vanes tied closed.
 Climbing a hill on the interstate, going 80, accelerating, EGTs 1100, boost around 20.
 Sounds pretty optimum, even without a mechanical controller.
VNT-15 tied closed and max fuel screw adjusted to the collar.

That is an extremely poor choice. Boost is around 20psi because it cant flow any more air! All you're doing is overspeeding the turbo and putting your engine's life at risk.

they are wide-ass-open, for the best flow. not to make it spool fast and make way too much boost.

Then all you've got is a non-wastegated turbo. The VNT has a disadvantage in your case since the vanes are obstructing free flow.