Have you seen the video of the turbo being controled by a simple spring the spring pulls the vains closed against a stop and as throttle is aplied exhaust pressure builds forcing the vains open supper simple but efective
[This message has been edited by engine man (edited 01-07-2012).]
Have you seen the video of the turbo being controled by a simple spring the spring pulls the vains closed against a stop and as throttle is aplied exhaust pressure builds forcing the vains open supper simple but efective
I saw this video a while back....I had.planned on using the wastegate method as DH has used but might give the spring method a try.
I don't see the spring method working good at all. When i'm at full boost I want that thing as open and free flowing as possible.
After posting I went back and watched it again...I agree as it seems like it may not open the rack fast enough but then again the ra k doesnt have far to move. I have a bid on a 7 PSI WG right now so that is probally the method I will take...
Do u think a BBV off the M90 would work to open rack?
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03:09 AM
engine man Member
Posts: 5364 From: Morriston FL Registered: Mar 2006
An even better and more precise method of controlling it is to run a code mask that uses a solenoid controlled wastegate which has programmable duty cycle in the code like code59 and Turbo Grand Prix 8F as well as others for example. This will allow you to set the openning rate based on boost level as well as the vehicle speed at which the actuator is pemitted to sense boost and respond by openning at an incremented rate based on the duty cycle you enter. You will need to run a separate/external wastegate to limit the boost level independent of that but at least you'll have variable control over the solenoid instead of a consistent scaled response.
This is characteristic of boost creep in a wastegate, to get the full advantage of VGT you don't want the vains to open any more than necessary so that you get the most out of every rpm. If your traction can handle the vains being fully closed at 3500 rpm you don't want them creeping open and slowing the turbine at 2800 rpm, likewise in a wastegate. That's where the solenoid comes in and allows you to register higher boost pressures earlier in the rpm range than you could without it due to unregulated wastegate openning before the desired boost level is reached.
Fact 1. You will never "slow" the spool by opening the vanes too quickly.
Fact 2. Trying to use some crazy ass reverse boost controller would be a ton more work than it would ever be worth. The fact that you still have a cracking pressure via a wastegate spring you would have to run something with basically no spring pressure in it.. which would never hold it closed during spool... aka it would be a giant mess of engineering for as mentioned no positive real world results.
Using boost pressure is a very "organic" way to handle this, and the process benefits from the organic / exponential nature of boost pressure.
Fact 1. You will never "slow" the spool by opening the vanes too quickly.
Fact 2. Trying to use some crazy ass reverse boost controller would be a ton more work than it would ever be worth. The fact that you still have a cracking pressure via a wastegate spring you would have to run something with basically no spring pressure in it.. which would never hold it closed during spool... aka it would be a giant mess of engineering for as mentioned no positive real world results.
Using boost pressure is a very "organic" way to handle this, and the process benefits from the organic / exponential nature of boost pressure.
Typical response from you. It's an idea and although only part of what you're saying is correct, trying to reason with the unreasonable makes no sense, so I will not bother. Not sure what you have against tact, but for your own benefit it would be good to get over it.
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07:32 PM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
Typical response from you. It's an idea and although only part of what you're saying is correct, trying to reason with the unreasonable makes no sense, so I will not bother. Not sure what you have against tact, but for your own benefit it would be good to get over it.
You are just so clueless when it comes to automotive related conversation I figure I would just skip the tact and go straight for the obvious.
An even better and more precise method of controlling it is to run a code mask that uses a solenoid controlled wastegate which has programmable duty cycle in the code like code59 and Turbo Grand Prix 8F as well as others for example. This will allow you to set the openning rate based on boost level as well as the vehicle speed at which the actuator is pemitted to sense boost and respond by openning at an incremented rate based on the duty cycle you enter. You will need to run a separate/external wastegate to limit the boost level independent of that but at least you'll have variable control over the solenoid instead of a consistent scaled response.
to my understanding most solenoid controlled wastegates simply manage manifold pressure that reaches the wastegate via pulse width modulation. That is how I would design a system, it cuts electromechanical hardware, so that the solenoid only has to overcome manifold pressure and not dynamic exhaust pressures and spring seat pressure, and allows for a shorter system response. And still using the manifold reference wastgate method as the base, a programable boost controller can provide the same features regardless of the engine control implemented, where the OEM controller codes are handy is in failure modes and the ability to leave the "wastgate wide open" when conditions that can instigate engine failure present themselves. How that can apply to a veriable geometry turbocharger is an intresting quesiton, when does anyone want spool to be delayed?
Fact 2. Trying to use some crazy ass reverse boost controller would be a ton more work than it would ever be worth. The fact that you still have a cracking pressure via a wastegate spring you would have to run something with basically no spring pressure in it.. which would never hold it closed during spool... aka it would be a giant mess of engineering for as mentioned no positive real world results.
Using boost pressure is a very "organic" way to handle this, and the process benefits from the organic / exponential nature of boost pressure.
My above qoute applies to your comment too, your shade tree system still works, but provides a level of tuning that is more flexible and adjustable "on-the-fly" than orifi and spring sytems alone. finding a boost controller that allows full range table modification would be a priority here, where SOME OEM code allows map-vs-speed tables as well, so you can have a non feedback straction control situation.
or we can use a bigger hammer...
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01:59 PM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
http://www.msdignition.com/...oost_Controller.aspx this is something along the lines of a powerfull tool one could use to contol the vanes. I wonder if there are any units that are designed to independantly control a sequential twin turbo system, so that one can control but the VGT "wastegate" and a true wastegate.
There is a reason my fast fiero has a manual boost controller on it... The mess that is electric boost controllers is not worth my time on my car.
Your approach to performance is confusing to me, your wanting to push the envelope in performance, embrace modern torbocharger advances, run modern fuels, with a late model engine, but as not mess with " messy" electronics? it wouldnt control boost, it would control spool time. you still need a standard wastegate on gas engines. Its like using points becuase hall effects sensor can fail suddenly...
it's pretty much a done deal DIS is better, more reliable, performs better...
Im not trying to insult you, just trying to understand.
Im sure your method has met your expectations, and perfomance goals. But its not as though it cant be improved upon.
Im not trying to insult you, just trying to understand.
Understand that sometimes the added complication is not worth the time when there is no obvious light at the end of the tunnel. There are TONS of things that are obvious issues on my cars that need attention well before "fiddling" with an electronic spool controller would be a wise project.
I also explained why a manual control was "better" in terms of spring pressure holding it closed, and the "opening" being organic enough to not cause spikes.
EBC's that control boost come with their own set of problems as well... They are unreliable without specific tuning, and trying to tune one on a car like mine is nearly impossible anywhere but a race track, and also can be quite dangerous if I was to create a boost spike situation. Manual boost controllers are very easy to adjust, and are dead nuts reliable time after time in any temperature. Predictable boost changes can be made with just a turn of a knob vs the adjustment of 3 values in a EBC...
I also use manual boost controllers because of their tendancy to crack the wastegate open just a tad until I make full boost, which significantly helps me pedal launching.
