Variable vane turbo for 944

[wild man]

What do you have to say about this issue? With both bearings being located at the front of the unit, the mechanical stresses on them will be greater, due to the turbine wheel being located farther away from the nearest bearing. And that would cause the bearings to fail sooner, wouldn't it?

[No_Lag]

Originally Posted by thingo

Which of your turbos would you recommend for the 951?

I ran the numbers for the 951 engine for both stock boost and ~15psi:

Stock boost:
Compressor Pressure Ratio: 1.82
CFM: 324.2
Intercooler Efficiency: ~65% (stock)

15psi:
Compressor Pressure Ratio: 2.03
CFM: 324.2
Intercooler Efficiency: ~80% (aftermarket)

It looks like the 200/482 would be a great fit. Here is the compressor map:

[No_Lag]

Originally Posted by wild man

What do you have to say about this issue? With both bearings being located at the front of the unit, the mechanical stresses on them will be greater, due to the turbine wheel being located farther away from the nearest bearing. And that would cause the bearings to fail sooner, wouldn't it?

This is a common misconception which I have covered already in this thread on page one. Here is the post:

Originally Posted by No_Lag

The bearing assembly itself is not what is carrying the load which you are describing, but in fact the wheels themselves are. First of all the wheels are extremely well balanced. While the turbine wheel is being pushed one direction, the compressor wheel inherently wants to be pushed the opposite direction by the air it's trying to compress. This effectively balances the wheels together. Secondly the exhaust gases entering the turbine are not flowing directly at one position of the turbine wheel, but are flowing through the vanes first. By the time the exhaust gases get past the vanes, the gases have been distributed to 15 different areas of the turbine wheel. This not only aids in quick spool-ups, but eliminates the possibility of deflection.

I hope this answers your question.

[wild man]

That does sound somewhat plausible, but I would like to see real-world life-expectancy results. Obviously, it is far too early in the "game" for those results to be available.

What do you claim as the lowest engine rpm that will spool 15psi in a 951?

[333pg333]

^..and at what sort of costs?

[74goldtarga]

I am Mr. "I'll buy one" Maybe Vic can figure this out and package it with his new EMS and then "I'll buy one". I would like to buy his new EMS anyway but my beloved keeps spending my car money on new furniture. My day will come. I posted this originally after reading about turbocharging and electronic engine management, I am glad people are still thinking about this as I want to see GT3s in my rearview at some point.

No-Lag, send Pauerman a free tester if he is willing and maybe he can figure out if it can be done. Better yet, send me the turbo and a stand-alone ems, I'll pay for installation/fabrication and then I'll post the dyno results!

[No_Lag]

Originally Posted by wild man

That does sound somewhat plausible, but I would like to see real-world life-expectancy results. Obviously, it is far too early in the "game" for those results to be available.

What do you claim as the lowest engine rpm that will spool 15psi in a 951?

Our twin-turbo G8 has over 20k miles on it's turbo kit as well as many customers who have been running our turbos for years on various applications. The one thing that will limit the lifespan of our turbos is taking them past their limits which unfortunately is 20psi. Above that the bearings will start to show signs of wear form over speeding. Which may be the answer to your question 333pg333. Though 20psi is more than enough for most applications.

As for when boost will come in it is difficult to tell for sure. Our G8 is running 10psi and hits full boost before 2000rpm however the charge tube area on that car is very extensive because the tubes have to run from behind the motor to the front mounted intercooler, around the radiator, and back into the motor. Since the 951 is a bit more efficient in terms of charge tube area I would estimate that you could reach full boost at 2000rpm with 15psi, 2500rpm at the absolute latest but that is a stretch. The disadvantage with the 951 is the length of the header before the turbo, being that it has to wrap around the engine to the other side.

Where are most 951's hitting full boost with the stock turbo? What about common upgrade turbos, where are they hitting full boost?

Originally Posted by 74goldtarga

No-Lag, send Pauerman a free tester if he is willing and maybe he can figure out if it can be done. Better yet, send me the turbo and a stand-alone ems, I'll pay for installation/fabrication and then I'll post the dyno results!

Give us a call at 913.541.0200 and ask for Brad. He's the president. We don't usually just give turbos away unless we are developing a turbo kit in house while using a customer's vehicle. However I have sparked his interest in the 951 application so he may just do it if you give him a call.

[thedge]

Only 20PSI? Mmmmm

Also, what is the replacement interval and cost of the bearing oil? I assume it has a mileage limit?

[No_Lag]

Originally Posted by thedge

Only 20PSI? Mmmmm

Also, what is the replacement interval and cost of the bearing oil? I assume it has a mileage limit?

Typically we recommend adding oil once a year. It is a loss-oil system to achieve the lowest amount of drag on the bearings. So once a year you will need to fill the turbo which typically requires two small bottles of our oil. Each bottle is $9 but we are always happy to send out oil at no cost if you provide us pictures of your application and a brief statement about it for our website. We haven't always done this but we recently built a gallery section into our website and I'd like to expand it.

[2Tight]

I can't speak for the Aerocharger longevity but the Garrett VGT on my 03 Turbo Diesel has over 140K on it now without a single problem. It still boosts very early and hits 25-29 psi all the time while towing. I would think a VGT valve could be easily controlled through many of the available standalone systems. My only concern is the controller valve is your 'wastegate' and last line of defense from overboosting if the unison ring hangs up. Too bad mine is the size of Rhode Island and would take up some serious room in a cramped engine compartment.

[thedge]

Originally Posted by No_Lag

Typically we recommend adding oil once a year. It is a loss-oil system to achieve the lowest amount of drag on the bearings. So once a year you will need to fill the turbo which typically requires two small bottles of our oil. Each bottle is $9 but we are always happy to send out oil at no cost if you provide us pictures of your application and a brief statement about it for our website. We haven't always done this but we recently built a gallery section into our website and I'd like to expand it.

Ahhh ok thats a cheap price then!

[Rogue_Ant]

Originally Posted by 2Tight

My only concern is the controller valve is your 'wastegate' and last line of defense from overboosting if the unison ring hangs up.

You could always keep a true wastegate in the system, and just set it a little above the AeroCharger. This way you have (yet another) over-boost protection...
I.E. AeroCharger is set to 15psi, real wastegate is set to 17psi.


-Rogue

[Rogue_Ant]

Collin,
Thanks for coming here and your time - it is great to have new options and vendors willing to communicate with this community.

A quick question, is the vane controller moveable? The 944turbo uses a fairly unique turbo mounting system, simply put - the turbo is bolted-to the drivers engine-mount, which is hollow, allowing oil to drain from the turbo. This puts the turbo in a tight spot between the engine mount, engine block, and intake manifold. We would most likely need the freedom to move the controller along the turbos axis in order to get it to fit.

Thanks!

[No_Lag]

Originally Posted by Rogue_Ant

A quick question, is the vane controller moveable?

Glad to help, and yes the controller is movable. We have mock-up turbos available for new applications like this. When somebody isn't quite sure about the orientation of their turbo they order a mock up (just an empty turbo) get it into the correct orientation, sent it back, and we built the turbo to match their mock up.

[2Tight]

Does the controller on the Aerocharger travel by oil pressure and electric solenoid or solenoid only? I'm just curious how other units work.

[No_Lag]

Originally Posted by 2Tight

Does the controller on the Aerocharger travel by oil pressure and electric solenoid or solenoid only? I'm just curious how other units work.

The controller is actually much simpler than you may be thinking. It's a common misunderstanding when people think variable-vane they think that there must be an elaborate, complex control device. However this is not exactly the case. In fact the controller is very similar to the wastegate actuator on an internal wastegate turbo.

The controller is made up of the following: A piston, diaphram, spring, shims, gasket, inlet fitting, jam nut, and a control rod which connects the main vane wheel and the controller itself.

How the controller works is it pulls an air sample from the charge tube area somewhere, typically we recommend just pulling directly form the compressor outlet to get the most accurate boost reading to the controller. The controller then responds and adjusts the vanes accordingly. The boost is controlled by the rate of the spring and fine tuned with the number of shims within the controller. The attitude of the vanes is controlled by the fitting/jam nut. With this you can adjust when the vanes come in and how quickly.

[2Tight]

Thanks. The mechanical method is so much simpler than what I envisioned. Ford sure made their VGT controller way too complicated in comparison.

[944obscene]

So, I've been reading this for the past couple days now. Pretty interested actually. I like doing things different, but not for the sake of nonconformity. I like innovation and design improvement. This turbo technology is both interesting, but leaves questions on the table; a number of which are being covered so far.

I'm not looking into doing a different turbocharger for a while. But when I do, this is really something that has my interest. If available, reasonable, and effective I'd drop the cash for one. A few of my questions though:

1: How much on the car will I have to alter mechanically, on the 951, to use this turbo? (as it no longer needs a conventional boost controller, or wastegate)
2: Is there any way to use this with a stock computer? Even maybe a piggy controller or signal converter if needed? I know the DME is finicky and touchy. This seems about as feasable as running MAP on a stock computer so...
3: My power goals, if switching to a larger turbo (and doing the modifications therein) are about 350whp, roughly 400 at the crank. Is there an aerocharger that I can fit, which can readily, and efficiently support this (without exceeding the 20psi limit), or would I be better off with other proven turbochargers?

I love exploring new things, but this does have the potential for quite a few headaches. I like the idea of running a wastegate set for just a little higher boost than the turbo will regulate, as a backup. That would be pretty darn cool. Although, I will say that I would miss the wastegate noise a bit. Dipping my foot into the throttle and hearing that thing open up is fun. Loud turbo Supra's... Oooohhhh. Yeah. Kinda like a defining aspect of turbo cars and half the coolness in the first place lol.

In all seriousness, people doing this would probably be altering their cars to the point that a stand-alone computer and an engine tear-down would probably accomodate an aerocharger (on a 951). I'm just wondering what the stipulations require, and what one could get away with on these cars. Things like the AFM, Bypass units and the function of the DME/KLR make modifications a bit of a pain sometimes. Not to mention tooling on the motors in the first place can be annoying occasionally (like adapting aftermarket turbos in the stock location).

The only thing that bugs me about your turbo design is the bearing assembly. It looks like you took something and addressed multiple issues all with a big makeover. Moving the bearing section to the intake side of the turbo, addressing lag issues with the Variable Vane Tech. I'm just trying to get around the funky bearing design. Love the work and idea, but it makes mounting and maintenance different and or difficult.

With the turbo having a lot going on up front; getting the unit mounted would be hard without custom mounting brackets and adapters. And the fact that your turbo/aerocharger is self contained would make maintenance kind of difficult for us 944 guys, no? The turbo resides under the intake manifold and if I have to fill that oil once a year, that means I'm gonna need to get a quick way to the turbo with a filler neck, or remove the manifold to get to it... Which means I'll need to get a new gasket when I do this. It's obviously a good idea to look things over at least once a year, but with most conventional turbo's, the only time you really need to get to one is if it malfunctions. Not really an annual thing. I wonder if there's a way around this issue. Maybe a modified manifold, making access easier? Then there's more money lol.

Wow, I'm curious though! I'd love to make a VV turbo 951. I have visions of minimal lag, coming out of "The *****" on Hallett, and tearing down the back straight in a car that feels like a big motor beast. *salivates*