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DIY Manual Boost Controller

 
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Thu Aug 24, 2006 6:22 pm    Post subject: DIY Manual Boost Controller Reply with quote

Heres a very simple DIY boost controller, if anyone's interested

http://us.geocities.com/chmwatson/FAQs/mbc.html
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flosho  



Joined: 01 Jul 2004
Posts: 3153
Location: Eau Claire, Wisconsin

PostPosted: Fri Aug 25, 2006 3:19 am    Post subject: Reply with quote

That is a very well done tutorial. If you're hard up for a MBC, that day that would be a good one to follow.

Otherwise, its probably just easier to buy one for $7.

I'm using a $7 one.
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CBass  



Joined: 03 Nov 2002
Posts: 2807
Location: Vancouver, Canada

PostPosted: Sat Aug 26, 2006 8:19 am    Post subject: Reply with quote

I've seen an interesting device, it's a boost controller that has a valve in it that doesn't open until it's set boost level has been reached, so it won't let any pressure hit the wastegate actuator until you're running full boost.
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'81 931 in various states of assembly
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Sat Aug 26, 2006 8:27 am    Post subject: Reply with quote

Quote:
I've seen an interesting device, it's a boost controller that has a valve in it that doesn't open until it's set boost level has been reached, so it won't let any pressure hit the wastegate actuator until you're running full boost.


the one I posted does the same

The ball & spring stops any pressure going to the wastegate, until the pressure you set overcomes the ball and spring, and only then is pressure applied to the wastegate.

I made a semi manual version, that used a solenoid instead and wired it to my overboost fuel cut switch, so that only when the boost hits 1.2 bar does the wastgate get any air.

Was to spiky, I got peeks of 1.5 bar boost, was alot of fun though, apart from the detonation

Problem is,,,,, if you eliminate wastegate creep, by fitting a spring loaded cotroller, then you introduce boost spikes.

thats why you have 2 stage controllers, and all those electronic gizmos, they are trying to avoid the spike problem.

I would stay away from the electronic controllers, because they still spiky and fiddly, and unreliable...

The best is a heavy duty actuater or wastegate, and a proper closed loop ECU.

If you cant afford that then a 2 stage manual controller is best, stay away from those cheap and nasty electronic gizmo's.


Last edited by OutOfTheBox on Sat Aug 26, 2006 8:40 am; edited 1 time in total
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flosho  



Joined: 01 Jul 2004
Posts: 3153
Location: Eau Claire, Wisconsin

PostPosted: Sat Aug 26, 2006 8:27 am    Post subject: Reply with quote

Thats what all MBC(as far as I know anyways) do... Thats what allows the turbo to spool faster by just installing the boost controlers.
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OutOfTheBox  



Joined: 31 Mar 2006
Posts: 434

PostPosted: Sat Aug 26, 2006 8:53 am    Post subject: Reply with quote

Incidently the best NON cockpit adjustable boost control for the 931, is to drill the top of the wastegate out, and fit a bolt and lock nut.

When you screw the bolt in, it pushs down on the wastegate spring, and increases the force holding the wastgate valve down. This accurately allows you to set the boost higher.

This will give you A1 reliabilty, with smooth and accurate operation.

After all,why install another spring and valve, when you can just increase the force of the original wastegate spring. This way you dont get any boost spikes.
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