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Engine Specific Info and Questions => IDI Engine => Topic started by: UnderPSI on July 12, 2010, 04:05:47 pm
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Why does everyone orgasm over a VNT?
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Same reason everyone did for disc brakes when they came out.
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Same reason everyone did for disc brakes when they came out.
and TDI
x2
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Same reason everyone did for disc brakes when they came out.
because they're both round? ???
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Why does everyone orgasm over a VNT?
Because in theory they should be the best of both worlds. Act like a small turbo at low speed and flow like a big one at high demand. Are they better? Yes, in part because the variable nozzle requires no wastegate so they have less back pressure that a wastegated fixed nozzle turbo. Are the the best thing since sliced bread? Probably not or everybody would be using one. Are they incrementally better? Without a doubt.
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How hard/realistic/beneficial is it to replace the stock turbo on a 1.6td with a vnt? other mods I have already done to my 1.6td are: ic, giles pump, 2.25" exhaust. been thinking about the vnt
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MKII requires a custom rear engine mount...all would require a stand alone computer to run them or something like what libbybapa did with his VNT vanagon to control vanes.
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Same reason they put it on the TDI.
It's better.
It's easy to install on a MK1.
Exhaust is even easier than the stock setup.
It hangs down so there's room for a better intake,.. no fancy, high dollar intake needed to improve flow, a cheap gasser intake will do.
Plenty of power down low, no more waiting for 2000 RPM, and it still slips the clutch in 4th & 5th when pushing over 18psi. That's with a 1.5D, stock 190mm clutch.
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Same reason they put it on the TDI.
It's better.
It's easy to install on a MK1.
Exhaust is even easier than the stock setup.
It hangs down so there's room for a better intake,.. no fancy, high dollar intake needed to improve flow, a cheap gasser intake will do.
Plenty of power down low, no more waiting for 2000 RPM, and it still slips the clutch in 4th & 5th when pushing over 18psi. That's with a 1.5D, stock 190mm clutch.
VNT LOVE!!!
im on my second VNT equipped engine, and i LOVE it. this one is a 1.6 n/a, just boosted. still even has a n/a pump on it. i honestly like the n/a pump better. spools the turbo faster it feels like..
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They are only better if they have the proper control on the vanes.
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Seems practically impossible to use a VNT to it's potential without computer control.
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Seems practically impossible to use a VNT to it's potential without computer control.
This has been gone over lots of other times.........use the search.
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Wasn't a question, was stating the obvious.
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Wasn't a question, was stating the obvious.
Ah, but if you search you'll find numerous threads describing mechanical control systems that do a very very fine job of VNT control, with no electronics required. ;)
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I have seen them, seems that to take full advantage of what a VNT can do, electronics would be needed.
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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.........
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Was it worth it?
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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.
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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?...
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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.
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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
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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 :o
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.
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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 :o
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.
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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.
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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..
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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
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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?
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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..
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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.
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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.
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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.
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vanes are restricting flow? the only way my turbo could be any more free flowing, is if the vanes were completely removed. my vanes are open. pointing directly at the middle of the turbine wheel.
if you have the vanes closed, the turbo SCREAMS and makes almost 40 psi. this is not good. i learned this the hard way.
its better to have them all the way open, than all the way closed. its gotta mane a TON of drive pressure to have them closed, but ive never checked..
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vanes are restricting flow? the only way my turbo could be any more free flowing, is if the vanes were completely removed.
Exactly. When functional they are a beneficial compromise because of how tremendiously they help increase response performance. Inoperable they impede flow by adding obstructions and odd angles to the exhaust stream and drastically increase surface area absorbing heat energy.
pointing directly at the middle of the turbine wheel.
Which is the worst option. That forces the exhaust to make a tight turn into an inefficient angle of the wheel instead of hitting the turbine at a 45* angle as with a normal non-VNT turbo.
if you have the vanes closed, the turbo SCREAMS and makes almost 40 psi.
Um, thats why people build a system to control it. ::)
its better to have them all the way open
Without something to control the vanes, its better to have a normal non-VNT turbo.
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ok, well whatever you have to say, it doesnt matter. theres a VNT 17 on my car.. its faster then your rabbit. oh yea, your a stuck up mercedes benz driver..
do you ever have anything to say that is positive? rather than just negative all the time? its pretty sad when you have ME saying something about it..
why not give out some suggestions/solutions? rather than just point out someones/somethings short comings?
im aware my turbo could function better if the variable vanes were hooked up. but, it functions fine for me right now. the vanes are all coked up and dont really move anymore. thats why its never been hooked up right.
and if i had the vanes closed 50% so they were at 45* angles to the turbine, it would over speed and make around 35 psi. thats not what im looking for.
look at it this way: i got the car for free, i got the turbo for free, i have fun driving it.. thats all that should matter.
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oh yea, your a stuck up mercedes benz driver.
Ah, insults. The favorite fallback of people with nothing intelligent to say in a debate.
do you ever have anything to say that is positive?
Did you ever stop to think about what I reply to? If people do something bad or post something thats wrong, what else is there to say?
why not give out some suggestions/solutions?
As was done multiple times in all of my replies to you.
rather than just point out someones/somethings short comings?
Oh, so you won't have any opportunity to think for yourself or make your own decisions derived from the facts you learn?
the vanes are all coked up and dont really move anymore. thats why its never been hooked up right.
I recall an old saying, "If you're going to do something, do it right from the start".
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Moving on....
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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.
He'll only respond if we haven't proven him wrong.
When he can't back up what he says he leaves, with no reply.
So you think a VNT-15 will only push 20psi? There he's gone.
Or wait, here's one he couldn't back up last time.
All factory VNTs setups have the vanes closed when you are idleing. really?,.. now he's really gone
The car wasn't floored going 80, and the turbo wasn't pushed to it's limit.
Concidering that, does it now sound optimal during heavy acceleration?
He does make some good points, but you have to sort them from the pompous garbage.
ROR, sorry, I thought with boost like that the vanes would have to be closed some.
Sounds like a VNT-17 is too big for a 1.6 Rabbit.
When the vanes are pointed at the wheel, they are closed.
Open, they make a ring around the wheel.
So maybe when he says the vanes will restrict flow with them wide open, he is thinking you mean wide assed closed.
I used to mix them up, then just concidered the wording like a wastegated turbo.
Closed is more air, open is less.
I can't match the vague old sayings that readily applies to guys who tried to get everything right from the start,
but due to time constraints now have a stripped down project for sale,
while I drive my car. ;)
they'll never get it finished because everything has to be perfect from the start, ha.
I am messing with another controller, one that's not related to the accelerator lever.
I want a manual knob on my dash that will let me set it to a general area, then let the boost controller do the rest.
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VNT flows most when vanes are open. When vanes are closed, it will choke flow and raise EMP and boost. 17īs are not big when fueling is right. I had vnt20 from V6 TDI in my 1,6, I could not get boost below 30psi with max fuel.
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I'll only respond if I have something completely worthless to say.
When I can't think of anything intelligent to say I reply, frequently.
So you think a VNT-15 will only push 20psi?
RELIABLY. BAM, you've been proven wrong yet you're still here? Good.
All factory VNTs setups have the vanes closed when you are idleing.
Yes. All of them. Have you actually LOOKED at any VNT/VGT systems to see what they are doing? Do you have a computer that tells you the exact vane position in real time? Thought not.
Got anything that will give you this kind of data?
Time 51:38.3
EGR Valve Position (Percent Open) (Percent) 10
Engine Coolant Temperature (F) 189.4
Engine Oil Pressure (psi) 18.4
Engine Oil Temperature (F) 206.6
Engine Speed (RPM) 692
Exhaust Gas Pressure (InHg) 47.6
Exhaust Gas Temperature (Calculated) (F) 555
Intake Manifold Air Temperature (F) 102
Intake Manifold Pressure (InHg) 1.9
Percent Accelerator (Percent) 0
Percent Fuel (Percent) 28
Turbocharger Compressor Outlet Air Temperature (Calculated) (F) 71
Turbocharger Control Valve Command (Percent) 70
Turbocharger Speed (RPM) 25800
User Fueling State: Low Speed Governor State
Vehicle Speed (mph) 0
ROR, sorry, I thought with boost like that the vanes would have to be closed some.
It does. My GT22 is lucky to hit 12psi with the vanes open no matter how much black smoke my 3.0L engine pukes through it. No way a GT17 can do 20psi on a 1.6L.
When the vanes are pointed at the wheel, they are closed.
Wrong.
Open, they make a ring around the wheel.
Wrong.
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Howsabout everybody simmer down and remember that:
1) these are just cars and engines... nothing worth duelling to the pain over...
2) we're here to learn from each other and share information, not prove who's the smartest or best endowed
3) the forum guidelines call for respectful posts at *all* times.
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It does. My GT22 is lucky to hit 12psi with the vanes open no matter how much black smoke my 3.0L engine pukes through it. No way a GT17 can do 20psi on a 1.6L.
I've seen a VNT17 on a 1.6 make over 20 psi with the vanes wide open, no visible smoke and EGTs under 900 degrees.
i own a car that will put down 25 psi, no smoke.. WORN OUT VNT 17!
is that not proof enough? how is it not possible? if i own a car that will hit 20 psi at my any whim? what do you say about that? is it still impossible to get 20+ psi from a 17? i wish i knew EVERYTHING..
i still dont get how my car runs, and makes boost, but its impossible?
and how did i crack a block? not from too much boost and drive pressure surely..
piss off OM617.. you have nothing useful to add to this, or any other conversation..