What to call a thread about 2 stage boost controllers? :) - page 1 - IDI Engine - VWDiesel.net The IDI, TDI, and mTDI source.

• What to call a thread about 2 stage boost controllers? :) by Baxter on 06 Apr, 2006 09:07
• Heh, been reading around a bit and quite like the idea of a 2 stage boost controller for around town driving at more or less stock boost pressure and having a electropnumatic valve to bleed air when needed.
  Thing that concerns me, okay, as I understand it, it is pointless having more boost without the fuel to go with it.
  So, I fit a bleed valve and set the fuelling to suit the new boost pressure.
  If I then revert back to stock boost pressure and leave the fuelling alone will I end up with a uneconomical smoke monster?
  Again, not the most CI minded!
  Any thoughts welcome.
  
  System I was thinking of using was a t-piece from the wastegate actuator to a electropnumatic valve to a grainger valve.
  So, actuate switch, open valve, bleeds air.
  Sounds simple enough, just the fuelling part bothers me!
• #1 by RabbitJockey on 06 Apr, 2006 10:16
• i always thought the same as you,  it'd be easy to set it up to run at different boost levels, but the fueling just won't work right.
• #2 by BellCityDubber on 06 Apr, 2006 11:19
• Quote from: "Trev0rbr"

  i always thought the same as you,  it'd be easy to set it up to run at different boost levels, but the fueling just won't work right.

  
  
  okay, yeh.. well. I'm no dieselgeek but yeah, too much fuel and not enough air would most possibly make waaaaayy too much smoke if the A/F ratio's are off
  
  BUT
  
  this is what I've found on the vhortex
  http://forums.vwvortex.com/zerothread?id=2538407
  
  Go down to the very bottom of the thread.... looks to me like an automatically electronically actuated fueling screw adjustment
  
  I'm very VERY curious...
• #3 by malone on 06 Apr, 2006 15:25
• I concur with libbypapa's post.
  
  Here's another way, I drew this diagram a while ago:
  
  
  
  For the newbies; the LDA is generally the boost enrichment device on top of the fuel injection pump.
  
  Disregard the LDA on/off switch for your application.
  
  Leave the turbo's wastegate to open at max. possible boost. If I'm at low LDA and the turbo still manages to hit max. boost, then so be it. Naturally, the diesel's power is controlled by fueling.
  
  It might however be better for the turbo's longevity to not always hit max. boost in case acceptable performance and exhaust opacity can be retained with lower boost (for your "low" stage setting). That said, have two air pressure sensors/switches prepared for the turbo's wastegate. The illustrated LDA switch will also select the pressure sensor/switch to use.
  
  Get two Hobbs Pressure Switches at a local auto parts store; set one at medium boost, and the other at max. boost. For example, 15 PSI and 24 PSI respectively. Wire both switches to one solenoid/valve that passes air to the turbo's wastegate.
  
  This way you will have medium boost + medium fuel, or max. boost and max. fuel by a flick of a switch. It is quite inexpensive to put together. It's also very simple to adjust the fuel + boost level for each stage, perhaps easier than customising the various LDA parts.
• #4 by malone on 06 Apr, 2006 15:53
• Quote from: "BellCityDubber"

  this is what I've found on the vhortex
  http://forums.vwvortex.com/zerothread?id=2538407
  
  Go down to the very bottom of the thread.... looks to me like an automatically electronically actuated fueling screw adjustment
  
  I'm very VERY curious...

  
  
  I thought of something like that last year but didn't really have the drive. About time someone did it! Friggin' awesome. This may be the ideal solution to the high-idle problem if you already have the largest possible plunger (e.g. 11mm or 12mm) and perhaps large injectors, both of which I have yet to use.
  
  This is the way I'd like the electronically actuated fuel "screw" to perform: The fuel "screw" by default will be pushed in as far as the engine idle will allow (i.e. no more than 1,000 RPM warm). If the factory WOT switch trips, then the "screw" propels forward as far as possible for maximum fuel. There's easily enough fuel for 1% to 90% throttle applications so an electronically actuated fuel screw that gradually moves (based on certain inputs) isn't needed - it should just move in or out (in 2 places). This should make a reliable solenoid.
  
  How about a plug n' play version; you screw in what looks like a heli coil, a hollow screw, and a metal rod runs through the centre of the coil, which slides in or out (solenoid) for fuel control. If you need to change the default fuel level (while the solenoid's off), simply screw in or out the heli coil just as if you were to adjust the stock fuel screw.
• #5 by hillfolk'r on 06 Apr, 2006 16:30
• i just set my fuel for "kill",,and most of the time i do run it closed wastegate,,but it gets nice and loud,with wastegate open,,,,i found some "air switches" on  a big truck,,,i did a little post about them somewhere,,,looks just like a normal electric switch,but has air fittings on the rear,and air goes thru it,,theyuse them for  moving the 5th  wheel,and locking axles and stuff,,,,try one of those,,i would just "series" it with your other boost controller(ie;iuse a shop air regulator),,,im never in it  for too long  anyways to worry about smoke/egt,,,,yea it smokes more on open wastegate,,but  the afc is mostly turned up all the way anyways,,more conservitave,would probably be less smoky,,,you could use the air regulator set for whatever lets say 18 psi,,then whenyou need it,when you are init,,wack the switch to closed ,and see it go30+ psi,and fly             http://www.vwdiesel.net/phpBB/viewtopic.php?t=3227
• #6 by Baxter on 07 Apr, 2006 13:51
• This is all I was thinking...
  
  
  
  Anyone see any problems with that?
  
  All it is basically is like one of these
  
  http://cgi.ebay.co.uk/Turbo-Bleed-Valve-Motorsport-Version_W0QQitemZ8054518388QQcategoryZ43120QQrdZ1QQcmdZViewItem
  
  But electrically controlled.
  
  Infact, you could use one of those, and the exit to atmosphere could go to the electro-pnumatic switch to turn it on and off.
• #7 by Baxter on 07 Apr, 2006 14:33
• Quote from: "malone"

  I concur with libbypapa's post.
  
  Here's another way, I drew this diagram a while ago:
  
  
  
  For the newbies; the LDA is generally the boost enrichment device on top of the fuel injection pump.
  
  Disregard the LDA on/off switch for your application.
  
  Leave the turbo's wastegate to open at max. possible boost. If I'm at low LDA and the turbo still manages to hit max. boost, then so be it. Naturally, the diesel's power is controlled by fueling.
  
  It might however be better for the turbo's longevity to not always hit max. boost in case acceptable performance and exhaust opacity can be retained with lower boost (for your "low" stage setting). That said, have two air pressure sensors/switches prepared for the turbo's wastegate. The illustrated LDA switch will also select the pressure sensor/switch to use.
  
  Get two Hobbs Pressure Switches at a local auto parts store; set one at medium boost, and the other at max. boost. For example, 15 PSI and 24 PSI respectively. Wire both switches to one solenoid/valve that passes air to the turbo's wastegate.
  
  This way you will have medium boost + medium fuel, or max. boost and max. fuel by a flick of a switch. It is quite inexpensive to put together. It's also very simple to adjust the fuel + boost level for each stage, perhaps easier than customising the various LDA parts.

  
  
  What is the purpose of the restrictor?
• #8 by jtanguay on 07 Apr, 2006 15:33
• Quote from: "Mr Brick-Yard"

  Quote from: "malone"

  I concur with libbypapa's post.
  
  Here's another way, I drew this diagram a while ago:
  
  
  
  For the newbies; the LDA is generally the boost enrichment device on top of the fuel injection pump.
  
  Disregard the LDA on/off switch for your application.
  
  Leave the turbo's wastegate to open at max. possible boost. If I'm at low LDA and the turbo still manages to hit max. boost, then so be it. Naturally, the diesel's power is controlled by fueling.
  
  It might however be better for the turbo's longevity to not always hit max. boost in case acceptable performance and exhaust opacity can be retained with lower boost (for your "low" stage setting). That said, have two air pressure sensors/switches prepared for the turbo's wastegate. The illustrated LDA switch will also select the pressure sensor/switch to use.
  
  Get two Hobbs Pressure Switches at a local auto parts store; set one at medium boost, and the other at max. boost. For example, 15 PSI and 24 PSI respectively. Wire both switches to one solenoid/valve that passes air to the turbo's wastegate.
  
  This way you will have medium boost + medium fuel, or max. boost and max. fuel by a flick of a switch. It is quite inexpensive to put together. It's also very simple to adjust the fuel + boost level for each stage, perhaps easier than customising the various LDA parts.

  
  
  What is the purpose of the restrictor?

  
  
  one switch turns LDA on/off the restrictor allows a lot of pressure to go through to the LDA or a little, hence Lo/Hi
• #9 by Baxter on 07 Apr, 2006 15:42
• Why restrict it and not bleed it?
  How do you vary the restriction?
  
  Sorry, it may seem really simple to you but it's really confusiing me!
• #10 by RabbitJockey on 07 Apr, 2006 16:21
• i think if you get too far into it,  you're going to be better off to use a tdi electronic pump...
  
  

  Quote from: "malone"

  Quote from: "BellCityDubber"

  this is what I've found on the vhortex
  http://forums.vwvortex.com/zerothread?id=2538407
  
  Go down to the very bottom of the thread.... looks to me like an automatically electronically actuated fueling screw adjustment
  
  I'm very VERY curious...

  
  
  I thought of something like that last year but didn't really have the drive. About time someone did it! Friggin' awesome. This may be the ideal solution to the high-idle problem if you already have the largest possible plunger (e.g. 11mm or 12mm) and perhaps large injectors, both of which I have yet to use.
  
  This is the way I'd like the electronically actuated fuel "screw" to perform: The fuel "screw" by default will be pushed in as far as the engine idle will allow (i.e. no more than 1,000 RPM warm). If the factory WOT switch trips, then the "screw" propels forward as far as possible for maximum fuel. There's easily enough fuel for 1% to 90% throttle applications so an electronically actuated fuel screw that gradually moves (based on certain inputs) isn't needed - it should just move in or out (in 2 places). This should make a reliable solenoid.
  
  How about a plug n' play version; you screw in what looks like a heli coil, a hollow screw, and a metal rod runs through the centre of the coil, which slides in or out (solenoid) for fuel control. If you need to change the default fuel level (while the solenoid's off), simply screw in or out the heli coil just as if you were to adjust the stock fuel screw.
• #11 by RabbitJockey on 07 Apr, 2006 16:27
• and also another thought, which may make it easier to tune ur car into a good level,  like stated previously, use a normal boost controller like in the ebay link, and then turn your lda up above where you would need it,  put an air valve or just another boost controller in between the mainfold pressure and the lda.  and if you run all the controls to the inside of your car you could tune it from inside.  but i suppose that would just be a simpler design as some of the above ones, but it would make drive more fun, turn down the boost and open up the lda and let the smoke pour.
• #12 by RabbitJockey on 07 Apr, 2006 16:29
• and another thought, if someone wanted to be able to control the max fueling screw from inside the cabin they could attach something like a speedometer cable to it and then run the line inside the car and put a knob on it.  just ideas, who knows how well they'd work...
• #13 by jtanguay on 07 Apr, 2006 16:52
• Quote from: "Mr Brick-Yard"

  Why restrict it and not bleed it?
  How do you vary the restriction?
  
  Sorry, it may seem really simple to you but it's really confusiing me!

  
  
  restricting is good because it keeps 'precious' boost air in.  bleeding would be good for parts that require cooling such as the wastegate valve.
  
  i'm sure the two stage lda controller wouldn't be too hard to make, just require lots of connections/parts $$.  A solenoid could be used to switch between the Lo setting and the Hi setting.
  
  Think of it this way.  LDA - Off/Low/High
  
  speaking of the electronic fuel actuator, I think its a great idea!  On the highway I would want the least amount of fuel, as well as the LDA off, unless I came up on a hill.  As said before our cars only need a certain amount of HP for a set speed.  Considering our engines make around 54.2hp(stock) at around 3000 rpm (which is around 100km/h approx), power could be greatly reduced and still keep up on the highway.
  
  

  Quote

  45 mph: Too small to be replicable on the dyno
  60 mph: 6.2hp!
  70 mph: 12.8hp
  80 mph: 29.2hp

  
  above thanks to moTthediesel
  
  Now I'm not sure if we could lower our engines power to 6.2hp @ 3000 rpm, but wouldn't that be sweet?  It would have absolutely NO juice to pass, and hill climbing would ultimately suck, but being that it would be adjustable, you could flick a switch to increase fueling in stages, or using some sort of dial.
  
  From a graph I'm looking at on the VAG manual, it shows that our engines consume 270g/kWh @ approx 3000 rpm.  I'm not sure how to convert that to litres or what...
• #14 by RabbitJockey on 07 Apr, 2006 17:01
• i think someone should try doing this set up and make a faq, i am very interested.... but my car has no turbo atm, so i cannot raise my hand and volunteer :^(