THOR Racing Posted January 21, 2003 Share Posted January 21, 2003 I'm looking for a cheap, small sized electronically controllable bleed valve. Tall order I know...but.... I've looked into using solenoid valves and pulsing them on and off to obtain an average constriction of flow but they are bulky. I cannot find any equivalent to the Apexi solenoid valve on the market. If someone knows phneumatics then maybe you can help. Ideally I'd like a valve that would act as a complete 100% pass through, when not in use, and when under control of a microcontroller (with either stepper motor or pulse width modulation of a on/off valve) to obtain 0->100% variable/proportional flow control. I can make an electronic boost controller but it's always the solenoid valve I fall over at. Nothing I've found would be acceptable by a DIY car tuner. Just to industrial looking. I've attached a picture of the sort of thing I'm after. It stuck me that just having a stepper motor attached to a screw thread would be all that was needed. Rotate the screw into the valve and constrict the flow. Any ideas anyone??? I know I've asked this a year or so ago but I still haven't come across anything as neat as the Apexi valve or as simple as the manual bleed valve. Regards Pete Quote Link to comment Share on other sites More sharing options...
Digsy Posted January 22, 2003 Share Posted January 22, 2003 Pete, The boost control valve used on the V8 Esprit is an off the shelf part (made by AC Delco I think). It measures about 30mm square and is a variable bleeder "T" with hose connections for pressure in and pressure out. It has an integral bleed off to atmosphere. It is controlled by a variable frequency signal from the ECU. I can get more info including a part number if it sounds like what you want. Quote Link to comment Share on other sites More sharing options...
Nathan Posted January 22, 2003 Share Posted January 22, 2003 Hi Pete, What sort of maximum cost would you be prepared to pay to make it worth your while........? As an aside, there ARE plenty of OE solonoids from Scoobies to EVO's to allsorts but many of them won't react fast enough for any real meaningful boost control. Most OE boost control systems are crude at best, failing miserably at worst, especially at heightened boost levels. Not sure on the Lotus one though Darren. Might be worth a go. Cheers, Nathan TDI PLC Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted January 22, 2003 Author Share Posted January 22, 2003 Thank guys... --------------------------- Darren, I can get more info including a part number if it sounds like what you want. Yes. Please. If it can be controlled fast enough this would be O.K. I'm thinking update 25time a second (25Hz) Sounds like it'll be either frequency based (as you suggest) or duty cycle (pulse width modultaion) based. I like the idea of proportional control rather than just pulsing a solenoid on and off at a desired rate. --------------------------- Nathan, What sort of maximum cost would you be prepared to pay to make it worth your while........? Well. Normal solenoid valves capable of 25Hz pulsed operation (which in my opinion are a little bulky but never the less perform) are circa £35-40. They are mainly bulky due to the large coil needed to push the actuator to move the valve fast enough. The Apexi solenoid valve replacements are about £100 (Which someone is taking the p*ss as it's way over the top) So something in the £30->£80 mark. Depending on performance and size. But ordering say 50->100 off so quantity discounts. What do you have in mind? As an aside, there ARE plenty of OE solonoids from Scoobies to EVO's to allsorts but many of them won't react fast enough for any real meaningful boost control. Agreed. The Supra VSV for instance is just an ON/OFF static device, never intended to be operated in a fast switching mode. Most OE boost control systems are crude at best, failing miserably at worst, especially at heightened boost levels. Agreed. This is why it's so hard finding something that fits the job perfectly. I can control any motor or pulse any valve but if the mechanical performance isn't up to it you might as well forget any decent control over boost. Regards Pete Quote Link to comment Share on other sites More sharing options...
Nathan Posted January 22, 2003 Share Posted January 22, 2003 Originally posted by TRL Performance Thank guys... --------------------------- The Apexi solenoid valve replacements are about £100 (Which someone is taking the p*ss as it's way over the top) And the fact that it's crap and looks like it came from an RS catalogue (Seddon Atkinson section).... So something in the £30->£80 mark. Depending on performance and size. But ordering say 50->100 off so quantity discounts. What do you have in mind? Regards Pete Well............ I do know of a really nice stepper motor (not crappy solonoid) that is robust, looks lovely and is compact....... I think you do too...... The problem is price. Leave it with me. I'll PM you if I get any good news. Cheers, Nathan. TDI PLC Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted January 30, 2003 Author Share Posted January 30, 2003 Just an update. I've found with the help of a Darren a Lotus solenoid valve. Still switched and powered in the conventional way like the Apexi valves are (pulse width modulated @12Hz (or something like that)) Here's a picture of it. I'm going to try it as a replacement valve for my Apexi boost controller to see if it performs as well. I've also found replacement Apexi valves as well. Actually sold by Autronic but are expensive at £65+VAT Regards Pete Quote Link to comment Share on other sites More sharing options...
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