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Idea About Manual Boost Control

Old 02-25-2005, 10:36 AM
  #1  
DUB
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1.0 Facts (that I found true with my car)



A. Wastegate opens early on (I can smell it)

B. Boost creeps with water injection

C. Turbo spools a lot quicker when I take the wastegate line off

D. umm...that's all I can think of that's revalent for now...



2.0 Goals



A. Quick solid boost control

B. Without electronics controlling it



Reason: I'm not sure. I like the idea of springs, a ball, and pressure controlling an air compressing/supply system that feeds a container than relies on the use of electronics.



2.1 Performance Goals



a. 15-17psi

b. Pump Gas



3.0 Equipment



A. Turbo

0.70 A/R compressor housing

Wheel: 60-1

1.00 A/R turbine housing

Wheel: P-trime

Wastegate: 40mm



B. Water Injection

ON: 5800rpm OR > 8psi

OFF: 5600rpm AND <6psi



Note: System is not mapped, used only to cool intake charge.



4.0 Random thought



Install a heavier spring in the wastegate (20-22psi) and install a charge relief valve to vent boost entering the motor (16psi).



This way the wastegate will stay completely closed longer and the charge side would relieve some of the boost also...probably still a balancing act, but in my head could solve a boost creep issue in any temperature weather.



Less air in = Less air out



http://www.turbocalculator.com/compr...s/t04-60-1.jpg

Doesn't look like this turbo will have any problems sitting around 20psi.



I wasn't aware if this type of system existed or not, care to share your thoughts or call me crazy? This wouldn't be anything expensive or impossible to test, I believe I can build this system using stock parts (and maybe the use of an ECU...that is already installed in my car. Is that cheating or considered not meeting my goals???)
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Old 02-25-2005, 03:00 PM
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any thoughts of why this wouldn't work or why this is a bad idea...somebody humor me.
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Old 02-25-2005, 03:06 PM
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I guess the trick would be to figure out how to bleed off the right amount of air, what's the right amount of air?? I mean, I don't exactly want a blow off valve size boost leak, do I???



...dayem, why didn't I pay more attention in differential equations???
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Old 02-26-2005, 02:53 AM
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seriously, nothing?
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Old 02-26-2005, 03:09 AM
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what boost controller are you using? and charge relief valves are commonly used.



oh yeah you can overspool the turbo and wear out the bearings and seals, cuz in reality, the turbo could be spooling to 40psi and your releif valve would do the job to hold the boost down to 20psi. when this happens your intake temps will skyrocket, because although you're releasing pressure, the air is still being compressed to 40psi (all numbers are made up).



your wastegate will never open since your relief valve will never let it reach 22 psi



so overworking the turbo and shortenning its life, and dangerous intake temps are the main concerns i think



















disclaimer: im neither experienced nor knowledgable in this matter. read at your own risk
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Old 02-26-2005, 10:30 AM
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ah, thanks for the thought...so charge relief valves are used to limit boost. Good point about the AITs, but water could compensate for some of the added heat. But yes, I would be shorting the life of the turbo...its rebuildable, haha what a mind set.



I'm using a Hallman's.



I think I could limit boost by showing the wastegate pressure from the charge pipe or compressor housing...and vent just before the TB.



Am I thinking about this wrong??? Would this be just like an open circuit?











this is starting to make my hangover worse.....yucky
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Old 02-26-2005, 12:54 PM
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we put a racing beat boost controller on cymfc3s's black t2, and i think it was just a ball and spring, but man it worked great! ive never seen a boost needle snap to attention like that.
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Old 02-26-2005, 02:58 PM
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starting to think I could need to just be normal and up the size of my wastegate...plumbing it back into the DP before the cat couldn't possibly be less restrictive
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Old 02-27-2005, 01:46 AM
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Originally Posted by j9fd3s' date='Feb 26 2005, 02:54 PM
we put a racing beat boost controller on cymfc3s's black t2, and i think it was just a ball and spring, but man it worked great! ive never seen a boost needle snap to attention like that.

I'm running emission's equipment, maybe thats the difference?!?! Can't imagine how two ball & spring MBC's would have too too different responses??? Glad to see people out there sticking with the roots, ha!



Okay but I've got another manual boost control (+stock parts) idea.



I have a Hallman's Boost Controller, which is a ball and spring; "Quick Spool" manual boost controller type. (maybe I'm bitter because, I've been having a creep issue, I have to set my controller to bleed boost early (and creep to max boost) and this kills my response, cough***laggy***)



I'm thinking of putting a stock seq. system solenoid valve in the output line of the boost controller...Keeping my wastegate completely closed until about one psi before max boost, instead of the 4-5psi before; that's when I start smelling it.



Since I have the ECU programmed to inject water based on load AND RPM, I was thinking of running this solenoid off this same function. So, at high rpm driving, the boost controller acts just like my (laggy...shh) ole MBC. However, low rpms and high load the solenoid will hold all air back from the WG and wait for max boost then show the wastegate enough air to open the WG all the way at once. It would act almost like an EBC (without the oscillation of a solenoid)...at least it would have the mad quick spool characteristics, yo.
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Old 02-27-2005, 03:52 PM
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Originally Posted by DUB' date='Feb 26 2005, 11:46 PM
I'm running emission's equipment, maybe thats the difference?!?! Can't imagine how two ball & spring MBC's would have too too different responses??? Glad to see people out there sticking with the roots, ha!



Okay but I've got another manual boost control (+stock parts) idea.



I have a Hallman's Boost Controller, which is a ball and spring; "Quick Spool" manual boost controller type. (maybe I'm bitter because, I've been having a creep issue, I have to set my controller to bleed boost early (and creep to max boost) and this kills my response, cough***laggy***)



I'm thinking of putting a stock seq. system solenoid valve in the output line of the boost controller...Keeping my wastegate completely closed until about one psi before max boost, instead of the 4-5psi before; that's when I start smelling it.



Since I have the ECU programmed to inject water based on load AND RPM, I was thinking of running this solenoid off this same function. So, at high rpm driving, the boost controller acts just like my (laggy...shh) ole MBC. However, low rpms and high load the solenoid will hold all air back from the WG and wait for max boost then show the wastegate enough air to open the WG all the way at once. It would act almost like an EBC (without the oscillation of a solenoid)...at least it would have the mad quick spool characteristics, yo.



that doesnt sound like a bad idea.



might want to email rb and see wtf they used for the boost controllers back in the day, i looked at it and it looks like a home depot kinda part
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