FAO Bren (How original!)

[Billy]

Bren mate, how much are MAP sensors roughly?

I'm planning a home built leccy boost controller, so mega-accuracy isn't critical, just repeatability.

In fact an adjustable switch would suffice if they're cheaper (and available!).

[Billy]

Have I upset you or something? :confused:

Or am I on your ignore list...:(

[bren]

Originally posted by Billy
Have I upset you or something? :confused:

Or am I on your ignore list...:(

LOL, dont be silly mate, I just didnt see your post. Cant see the forest for the trees etc :)

Im not sure what youre after. When you say map sensor are you after any map sensor? Like a Cossy item? If so a 3 bar sensor is £50.

By an adjustable switch do you mean just an on off pressure switch?

[Papa Lazarou]

How about a pressure sensor from a 'leccy boost gauge? I'm sure you should be able to buy spares seperately.

[Billy]

Yeah, anything would do.

£50 is a bit much for what will be in effect, just a pressure switch! Are there any cheaper options, since I doubt anyone will run 2bar boost. (I assume the 3bar is it's range from vacuum to approx 2bar boost?)

An on/off switch would be perfect as long as it's adjustable. It would mean I don't need the electronics either, just a relay. It'll lose the in-dash adjustment, but hey, it's a prototype!

Cheers. :)

(I think I've caught Jibber's paranoia!) :D:D:D

[bren]

Its a 3 bar positive pressure monitor but atmospheric pressure is 1 bar so in effect it can read up to 2 bar of boost.

Im not sure what youre trying to achieve, how can you build a boost controller with an on off setting? Or are you going to set the system up so that when you turn it on you include the switch in the circuit and when the boost reaches a certain level the switch will cut a power feed to an electronic bleed device?

If thats what you are trying to achieve then there are easier, cheaper and more reliable ways of doing the same thing!!

[Billy]

Well that would be telling!

No, seriously, I intend putting a solenoid valve in the actuator signal pipe and switching it at the preset boost pressure.
Just like an electronic boost control, really. Only cheaper. I hope.

Avoids the wastegate leaking that happens from about 6psi or whatever the cracking pressure is, so boost builds quicker.

[bren]

So youre wanting to get the boost to build more quickly or run a two stage boost control system?

If you want to get the boost building mopre quickly then as you say youll need a boost switch. Im not sure who will do a switch that will be happy contantly switching on and off as whenever your on full boost the system will be fluctuating in an attempt to keep the boost stable.

You can get an adjustable boost switch off a Mk1 Uno Turbo in a scrappy, itll cost you just a couple of quid and its located on the right hand end of the plenum. They arent designed to be operated continuosly though.

[Billy]

Haven't all the Mk1 Uno's turned to dust yet? :)

If it works, I'll have an infinitely adjustable boost range, not just two levels.

Yeah, I'd thought about the switching problem too, but as I say, it's just a prototype to see if it's worth the effort.

Papa's idea of a gauge sender sounds good. I suppose it doesn't have to be a boost gauge. Fuel would do, or oil .
Are they available separately? Must be cheaper than a MAP sensor, since you can buy a whole gauge for £50.

There's a thought. Can you get electronic boost gauges? I know about the Defi one and the like, but can you get a mechanical meter with an electric sender, that doesn't cost silly money?

Come to think of it, Otter control systems are just around the corner from my wife's works, and they make all that kind of switchy, thermostaty type stuff for cars, so may be worth a peek.

[bren]

I cant see how you will get an infininetly adjustable boost controller using an onn/off switch but I wont press for details ;)

An oil pressure sendor would cost you £15.

Or a used standard Cossy 2 bar sensor would only be around £20 :)

[Billy]

The adjustable bit needs the electronic version. The switch is just a cheap try out option.

The oil pressure sender sounds OK pricewise. I presume it will be a screw in jobbie.

Would a fuel pressure sender have hose fittings? Might make life easier.

Hee hee hee! Bet you wish you'd carried on ignoring me now? Sorry....:( :D

[bren]

Im not sure how they connect. They are available from Racetech on 01491 822000 :)

[Kev]

Billy, u should get the fecker running properly first mefinks!!:rolleyes: :D

I take it u would be sending a signal to a relay and then from the relay to a solenoid?
If thats the case, then u could enter a variable resistor in between the relay and the solenoid and this would effectively give u boost control, obviously u would wire the variable resistor to beside the switch in the cockpit.

Or do i also not understand what u mean?

Kev