VNT on non-VNT car? (w/ pic)

[arro]

Can a VNT turbo be controlled mechanically like this:



I'm trying to illustrate what Gary D said here:

DDG- VNT fact sheet


He apparently used it on a non-computerized setup. I'm just trying to see if my diagram is on the right track.

[turbomini]

you know "Gary D" is on here! you could ask him. or you can email him his email is on his site

[90vntShadow]

Keep my posted on what you find out. My VNT is locked up right now and I was
debating if I should go to a non VNT with manual boost control. I already have a
replacement VNT and would love to figure out how to run manual vane/ boost
control. I would imagine you could run it off intake vacuum/pressure like you illistated.

[arro]

turbomini, he has this on his site:

"I'm currently taking a break due to high e-mail volume"

Mr. Gary Donovan, as he always has been, gets buried in emails. I don't even know what his username is on here, but I imagine it's the same situation. That's the problem with the old crew, all of them are doing other things or are just so far removed from the present public forums now that unless you know someone who can give them a personal heads up, you're not always going to get through. I was hoping some of the vets were occasionally browsing this section. But maybe they aren't

Well considering what you've said, I should let you in on what I'm planning.

I'm a former turbododge owner... I've owned a Daytona Pacifica, Daytona Shelby T2, and a Chrysler Laser turbo. I started on the SDML back when Gus was just barely breaking into the 13's with his minivan, and his grainger valves were all the rage. Before Dempsey built his stroker. Before Gary built the 10-second Reliant, back when FM was the only 10 second car in the platform. I logged in over 200 emails with Gus at the time about vacuum control (I think he gave my my first G-valve actually), but that was a long time ago, and since then, I've moved into other cars.

So recently I ended up with this 2000 Neon. And my plan now is to use a VNT25 on it. It has more than enough boost range for what I need. And then I have this crazy idea that the 2.4L DOHC in the SRT and GT Cruiser could do really well with a VNT-S60. So that's where I'm headed with this.

I didn't know Gary was still active on here. Lots of the original crew (except good ol' Gus, RIP) are signed up on here, but don't usually log in nowadays.

I'll seek him out, but in the meantime if any of you care to look at what he said on that link, and compare it to my diagram, I'd appreciate it.

So 90vntShadow, why did you sell off that VNT-S60 and head?

[arro]

here's a few other drawings I toyed around with, but didn't get very far.







The blue object is a standard two-position vac solenoid, with one barb at the bottom, and switchable barbs on the side.

[90vntShadow]

You must have me confused with 90shadowvnt, or somebody else. I have never sold
a Vnt-S60 and head. My car is all stock, and I have a stock rebuilt VNT to replace
the existing bad Vnt on the car.

[90vntShadow]

I found this link by searching through some old threads. Pretty interesting, this
guy ran a VNT on his buggy controlling boost manually, but not adjustable.
DDG- VNT fact sheet

[arro]

Ahh yeah I mistook you for 90DodgeVNT. he was selling a VNT-S60 here:

FS :VNT S60 and FM Stage II head

There's pics of it on the thread as well as specs. He had a lot of work done to it.

The link you posted... isn't that what I put up in the first post here?

"This guy" is an old guru for these cars (Gary Donovan), who prolly has a way to control the boost manually.. that's where I got the basis for the first diagram I posted in this thread. I'm trying to decipher what he says on that particular webpage, and put it up here as a diagram.

For anyone satisfied with 15 psi or less, I don't see why this is a bad thing. In fact, I think the VNT. I also think that it has potential for more power as a VNT-S60. Maybe not as much as a T3/T4, but close.

[90vntShadow]

You are right, I did not even notice your link. I was too busy looking at
you diagrams. I know what you mean, I was also trying to picture what exactly
he was talking about. You would still have to have some kind of overboost control
like he mentioned, it acted different under a load. He mentions using an external
wastegate. I would be all for trying your ideas if you figure something out.

[90DodgeVNT]

I sold the turbo as I could get the setup to run correctly.

I had a ND/FWD/Rob Maxon hybrid VNT calibration set for 16 psi, *but*, when I went to a 3 inch exhaust, I lost complete control of the boost pressure and it was spiking (on the old VNT28) upwards of 23-25 psi.

Here was my old setup (major parts):

- +20 injectors
- VNT28 turbo
- 16 psi cal
- 3 inch exhaust
- ported intake/exhaust manifold
- ported head
- 3 bar map
- walbro
- Venoila shortblock

On the new Super60VNT, I tossed the +20 injectors in favor of the +40's, and all it did was bog. Part throttle was unreal and just a monster, but full throttle the car would crap out from too much fuel. I tossed the +40's and swapped to the +20's and I could not get it tuned right. It was still bucking/choking out, and it was finally traced to the calibration. I purchased a stock VNTchip (which I still have) from someone to swap out the 16 psi cal, and then use and MBC like Will Martin did, but by that point I had hit my limit as to farting around with the car, so I scrapped the project. I had too much invested and it seemed to go nowhere. In hindsight I probably could've worked through it, but I said the hell with it.

My final VNT setup was:

-VNT S60
-Custom intake
-TU header
-3 inch exhaust
-Cone filter
-Spearco FMIC
-Ported head

Right now I am rebuilding the car as a true Super60 setup and keeping my fingers crossed for a Tu VNT to S60 calibration. You can see some of the pics that I had on the "other" site as I never ported/posted them over on TD.com, just search my user name.

Later,

Mike

[arro]

the overboost control would be what I show in the last diagram, an external wastegate. You'd need a good external one with excellent flow to manage it. A TiAL or HKS should be able to handle it, maybe even a Turbonetics unit.

If I manage to figure this out, all the VNT guys worried about calibration would be able to handle it easier without cals. But I'm still not sure. I'm still not getting how a stock VNT regulates itself bosotwise.

[90vntShadow]

As far as I know when the computer senses max boost it opens the turbo blades to
bleed off boost. I read this somewhere, but I can't find it.

[arro]

So then we need something that uses manual control of that... like an adjustable pressure switch from NAPA:



per Gus Mahon:

You will note that there's a vacuum line barb on the switch. These switches DON'T LIKE vacuum! Use a pressure source that doesn't see vacuum. Use an intercooler tube; epoxy a small vacuum line barb on it.
...Or use the intake manifold for a source, but put in a one-way (check)valve so that it doesn't see vacuum. Then install a tiny pinhole vent to atmosphere between the check valve and the pressure switch (about .015"to .020")

The switch will work on higher boost when the adjustment screw is turned clockwise; it will work at lower boost when the screw is turned counter-clockwise.

SO, that could be used in some fashion with a vac solenoid... but how?

[90vntShadow]

I am going crazy now, trying to figure this out. Back to your link under The Garrett
Vnt25. It states that the vanes can open fully when boost is not needed, thus in your
vacuum drawing with a grainger/boost controller on the pressure line going to the
canister if you bled off pressure you would get a spike in boost with vanes closing,
you actually need a boost in pressure to open the vanes more and bleed off pressure.
Is this correct? Maybe a second vacuum line that is opened up by a solenoid that
send more pressure Teed into the 1st vacuum line going to the canister. In other words
a pressure boost that would open up the vanes to bleed off pressure.

[90vntShadow]

How about this idea, In one drawing you have the pressure line coming from the intake
and in another drawing you have the pressure line coming from the turbo pressure
side nipple. What if you tied these two together having one pressure line from turbo
nipple controlling vanes and one pressure line from intake with grainger valve. When
intake sees say 15lbs boost the adjustable grainger valve opens sending more
boost back to the canister, thus opening the vanes more bleeding off pressure.
See if you can illustrate that and I will tell you if that is what I mean? I need to
get my car going so I can experiment.