Zero PSI turbo

[Bluevitz-rs]

Anyone ever though of setting up a 0 psi turbo like the ones used on aircraft. It would give the car a massive boost of torque without the problems that arise from going into boost and tuning. A small fast spooling unit could be used that would be up to speed by 1200-1500RPM.

[Bluevitz-rs]

Your waste gate will allow you to run whatever boost level you want provided you use the appropriate spring inside. Or run an external one with electronic controls.

As I said, airplanes use it to compensate for altitude, so don't say it can't be done.

[xixarchangelxix]

We're not flying our cars at 30000 feet in a thin atmosphere. As you said, they use it to compensate. They are meant to keep intake pressure regulated so that it is equal to sea level. They are "0 psi" because at altitude, the pressure that might be 10 psi (for example) at ground level becomes 0 psi at altitude. So unless you plan on strapping on wings to your yaris, it can't be done in the manner you're speaking of. Can you run a turbo at 0 psi at ground level? Yes. Will it do anything? No.

[Bluevitz-rs]

Ok, then tell me why my car had a massive boost in torque from 1500rpm at 0 psi when I had the turbo on my car?

[xixarchangelxix]

Massive boost? Can we see a dyno chart? And no, a picture of your butt won't suffice.

[Scubaru Steve]

you can, get the spring out of an aircraft. i know the added torque your talking about. it only give you low end and would probably rob power in the higher rpm range.

[Parmas]

Blue: You need to consider many things about this theory but I think I understand what you want to point out.

Let's say you are N/A and have a short intake pipe venting from the front and have constant high wind speed blowing directly into this pipe... then in my opinion that way you will see a good amount of engine reponse at all rpm loads.

But if you want a turbo at 0 psi to make the same effect you need to install the turbo discharge pipe short and straight into the throttle body.
Keep in mind turbos have a negative effect to exhaust flow since they are restrictive due to the small exhaust outlet into the turbine and that is enough to cost you some power loss due to back pressure.

Also to do this 0psi turbo setup you need to do a custom turbo setup that costs much so who with all that money spent will keep this damn thing at 0psi!

[Bluevitz-rs]

HAHAHAHA, ok

I'll do my best on explaining how a waste-gate vavle operates.

You normally have three different air forces at work inside the valve itself. Atmospheric, vacuum and a positive pressure. On the side with the rod, you have atmospheric pressure. (aprox 14.7 psi a) On the other side you have vacuum at idle 0 psi a (ideally) and normally, boosted pressure, so anything above 14.7 psi a. I'll use 4 psi g as our target boost pressure.

Also on the rod side you have a spring (6 psi) to hold the valve closed adding to the pressure of the atmosphere, adding up to 20.7 psi a. When the car is running, you have exhaust gas pressure building up on the other side of the vavle wanting to push it open, your "back pressure". Lets say that the pressure difference is only 2 psi g across the internal waste-gate valve. When you deduct that pressure from the total pressure on the valve, you're back down to 18.7 psi a or 4 psi g, <--your set wastegate pressure.

20.7 psi a - 2 psi g = 18.7 psi a

18.7 - 14.7 = 4

If you have a restrictive exhaust system beyond the turbo, it will affect the pressure drop across the turbo increasing your waste-gate set point. The freer flowing the rest of your system is, the lower the boosted pressure will be do to the greater pressure difference. The more pressure wanting to push the valve open, the sooner it will open.



So to make an atmospheric waste-gate work, you only need to use a spring stiff enough to overcome the pressure difference across the turbo and use vacuum pressure to keep the valve shut. As vacuum pressure approaches atmospheric pressure the valve looses to the pressure difference across the turbo and the valve is pushed open.

Now if you used an electronic vacuum valve you could control valve exactly when and how quickly it opens. Just like if you were boosted.

I'm pretty sure I have a grasp of how a simple spring loaded pressure valve works.

I can post up some thermodynamics problems from school if you want something complicated. :thumbsup:

[Bluevitz-rs]

Blue: You need to consider many things about this theory but I think I understand what you want to point out.

Let's say you are N/A and have a short intake pipe venting from the front and have constant high wind speed blowing directly into this pipe... then in my opinion that way you will see a good amount of engine reponse at all rpm loads.

But if you want a turbo at 0 psi to make the same effect you need to install the turbo discharge pipe short and straight into the throttle body.
Keep in mind turbos have a negative effect to exhaust flow since they are restrictive due to the small exhaust outlet into the turbine and that is enough to cost you some power loss due to back pressure.

Also to do this 0psi turbo setup you need to do a custom turbo setup that costs much so who with all that money spent will keep this damn thing at 0psi!

You'd simply need to modify the spring in your waste gate and use an electronic boost controller. That way you could run it with boost or without, kind of like a supercharger with an electronic clutch.

[Bluevitz-rs]

Blue: Just to let you know on a N/A motor as RPM goes up, vacuum goes down. So for all we know our car @ WOT has 0 vacuum (same as 0 psi). I cant do this test cause Im boosted. If you are not boosted, connect a gauge to you car & do the test.....

Have you ever taken a class in auto mechanics?

[cali yaris]

Let's see some real life examples of turbocharged CARS running 0 boost. If the theory is sound, someone has tried it and posted data.

I'd like to see that "massive boost of torque" demonstrated, since you are claiming that as fact in post #1.

I really am curious about it; never heard of it being done.

[Bluevitz-rs]

My ass told me so when my boost gauge read 0 and I was only at 2000 rpm. As soon as I took the turbo off, I didn't have nearly the same pull at 2000 rpm.

The whole point of it is to make a high flat torque curve from low rpms for efficiency.

Edit: Ok, the point I'm trying to make is that an N/A engine is only sucking in as much air as it can due to volumetric efficiencies. As RPMs go up air inside the air inside the intake track speeds up compounding the effect and power is increased. With the turbo, you have a constant rate of air being pushed by the turbo eliminating the need for high RPMs to achieve the desired torque.

Holy crap, sorry for thinking outside the box.

[Bluevitz-rs]

No Im self taught. I rely on Practice vs Theory. In other words Im street smart not book smart.

well, i've got both behind me. I've worked at Toyota Canada, and taken it in school.

[Bluevitz-rs]

Ok, but when you make a post stating that it can't be done, yet it's used on internal combustion engines, what am I supposed to think.

Then you post that you don't know if an NA engine reads 0 psi g at WOT. Maybe it's best you don't post about thing you only have street smarts in. Just because YOU've never done it doesn't mean it can't be done.

[Bluevitz-rs]

Whatever man, sorry I even started this thread. I obviously have NO clue about how an internal combustion engine works, or turbo, or pressure valves, or physics for that matter.

Peace. I'm done with this thread.

[cali yaris]

I like it when people think outside the box. Always stimulating to mentally stretch and think about new things. Got no problem with that.

Just don't claim it as a fact:

It would give the car a massive boost of torque without the problems

Is there agreement that there are no real-life examples, used on cars, of the set up you describe, with data to back it up? If there are, I'd like to see them. That would be a great starting point for how to implement it on the Yaris.

[cali yaris]

oh man, I just read #23. :frown:

[Yoda]

You can set the psi to be 0 and yes there is a difference in tq over stock. Not by much tho. Is it worth the time? No. Why have a turbo to run 0 psi?

[Yoda]

Really? How exactly? How can you set the psi to be 0?

My turbo is internally gated. I control my boost lvl via a counter spring. I can set it as low as I want actually or as high.

[turboecho2005]

You can disconnect your wastegate acuator rod... Result is 0psi...

[Parmas]

Whatever man, sorry I even started this thread. I obviously have NO clue about how an internal combustion engine works, or turbo, or pressure valves, or physics for that matter.

Peace. I'm done with this thread.

Jamie you don't have to be sorry for this thread ! You opened this thread surely to get opinions from us and it always happens that people do not fully agree with our theories.

I cannot say how this 0 psi turbo setup could be and I am curious if this can be done infact with positive results although it's a shame putting a considerable amount of money and having no boost at all!

Although I am sure this can be done and with correct calculations you can gain something from it for sure. The only problem is Money wasted vs Power/Torque gains

[Bluevitz-rs]

Jamie you don't have to be sorry for this thread ! You opened this thread surely to get opinions from us and it always happens that people do not fully agree with our theories.

I cannot say how this 0 psi turbo setup could be and I am curious if this can be done infact with positive results although it's a shame putting a considerable amount of money and having no boost at all!

Although I am sure this can be done and with correct calculations you can gain something from it for sure. The only problem is Money wasted vs Power/Torque gains

All you'd have to do is take an existing system, like the zage kit sold at Micro Image, modify the spring in the waste-gate and add an electronic boost controller. It doesn't mean you're locked into not using boost.

I just thought up the idea from guys using the supercharger that can run with the clutch turned off to save gas. It's just that a turbo is more efficient on a small displacement engine.

[cali yaris]

Is anyone going to answer post 25?

[johnny_vitz]

All you'd have to do is take an existing system, like the zage kit sold at Micro Image, modify the spring in the waste-gate and add an electronic boost controller. It doesn't mean you're locked into not using boost.


How do you make more power or torque without any boost though?
To attempt to answer cali's Q - I've never heard or seen any automotive application with this set-up, they all make boost

Although, with that set-up, you could use your controller to only run say 3 pounds and be safe for your engine

[Yoda]

How do you make more power or torque without any boost though?
To attempt to answer cali's Q - I've never heard or seen any automotive application with this set-up, they all make boost

Although, with that set-up, you could use your controller to only run say 3 pounds and be safe for your engine

Your car is still in vacuum @wot so 0 psi is more than what the engine would under normal conditions. Only way to bring you n/a car close to it is to free up all the restrictions in the intake system.

[johnny_vitz]

Ok, i've never measured myself, but isn't it supposed to be only 1 or 2 in. vac (very close to 0) @WOT? I could see picking up a tiny bit, but nothing worth the money you would pay for a turbo kit.
We need a guinea pig...:biggrin:

[Focus_Sh1ft]

You can disconnect your wastegate acuator rod... Result is 0psi...

cdydjded, you answered it yourself... This method would work perfectly if there is enough flow.

It's a cool idea but definitely not worth the hassle or cost.

[turboecho2005]

cdydjded, you answered it yourself... This method would work perfectly if there is enough flow.

It's a cool idea but definitely not worth the hassle or cost.

If your wastegate is accessible it shouldnt take more then 5 minutes to pull the pin holding the arm.

[rob323]

Blue vitz, it is possible to do as you have suggested, I can think of numerous ways to do it. Restrictors on the inlet to limit air flow and boost, soft wastegate springs as you have suggested, pressure activated solenoids to bleed excess boost (may cause emissions problems though). All though have down sides and require more thought so that you could obtain a very low boost turbo setup with minimal losses at high revs.

[Viperoni]

Your car is still in vacuum @wot so 0 psi is more than what the engine would under normal conditions. Only way to bring you n/a car close to it is to free up all the restrictions in the intake system.

ding ding ding

I like the idea Blue, but there's no way I, personally, could keep a car at 0 psi boost when it could do more :D

[KCALB SIRAY]

...I like Ovaltine