Sorry, I havn't been paying attention. I assume we are putting this FCD in line with the MAP sensor ?

If so how about a 'T' before the Dawes (Turbo side), then attach FCD to MAP.

If the MBC Dawes sticks, the FCD Dawes should hopefully open and allow fuel cut to activate.

Setting FCD Dawes higher will raise the fuel cut, but will still activate the fuel cut if this limit is exceeded.


[Edited by Scott.T - 2/1/2002 11:41:11 AM]

[Edited by Scott.T - 2/1/2002 11:44:32 AM]

 

The answer Buy an old WRX with a TD05, stick in an uprated fuel pump, crank the boost and wehey for a wee while anyway !

On a standard MY99/00 I would think you could raise the boost cut off to the same level as a PPP using a ball relief valve 'T'd into the MAP line (without a bleed) and not run into any trouble ?
Maybe ?

[Edited by Cosie Convert - 2/1/2002 1:19:47 PM]

 

Have been searching the net for alternative to the Dawes, both from tuning firms and pneumatic companies. It seems that many of the tuning firms are just re-badging standard pneumatic valves.

Whilst hunting around I returned to the Turbosmart site and had a look at the 'Gated Boost Control Valve' which sound like a Dawes in a better package.

Has anyone used these in the past who knows how they compare to a Dawes. Much the same I would think, just abut £15 more.

[Edited by Scott.T - 1/30/2002 8:04:50 AM]

 

Another option is the Turbo XS - available here :

http://www.impossible-performance.cw...xs_contect.htm

I'm considering the High Performance one which combines a ball & spring with a bleed valve but it is a tad expensive in comparison to a Dawes type device plus Bleed Valve.

Would be interested to hear how your own MBC project goes.

Would also be interested in any other suggestions so btt also.

Chris

 

Or Dual Ball MBC http://www.joepmbc.com/ at $50

 

I've also seen a site that showed you how to make one for a few quid from a ball /spring valve,will search my files to see if i saved it as i'm interested in this as well.

Paul

 

Scott,
Check this link out http://www.xmission.com/~dempsey/perform/grainger.htm

[Edited by paul w - 1/30/2002 9:02:59 PM]

 

I made my Dawes replica from a ball relief valve available from RS Components for £8.00 Not quite as user friendly to plumb in but it does exactly the same job and works great !

cc

Part Number available if interested ?

 

Nice one cc I've been searching for a valve,will take a look at rs and maplin.Please mail me the part no also.

Have you fitted it on cosie or scoob.

Thanks Paul

 

CC

Is this the valve 398-9142. http://rswww.com/images/C398914-01.jpg

Cheers Paul

 

Yes, that's the one paul The testing part is to get an air connection to fit in the discharge hole at the top, I bonded in a plastic hose tail to suit the original pipework but a better method may be to solder on a brass or copper pipe ?

In order to function the same as the Dawes you need to drill a 1.5mm bleed hole in the top part, beside the outlet hole.

I have also used one of these valves as a Fuel Cut Defender
My 96 WRX RA has fuel cut at approx 1.1 bar By connecting in line with a T piece the MAP only reads max 1 bar but the boost can be wound up further (Just like a superchip conversion)

I can only comment on my own results but fueling is still fine at 1.2 bar.....and it goes like stink

CC

 

Bugger, didn't think about looking at RS and have just order a grainger valve from the states.... prob works out the same price tho' as was $7.33 + postage and duty.

 

CC,

Good idea on the map sensor fool,is the small hole used as the bleed for boost raise if so i'll T piece my bleed valve or drill a hole in an inline brass joiner.

Cheers

 

Yes, it's just the bleed Paul. Your valve would do the same job or drill the hole anywhere between the ball valve and actuator.

cc

 

For the FCD could you use a second relief valve which opens at say 1.3 bar to just raise the fuel cut? However, trying to think this through if you connected it in parallel to the first valve it would never see 1.3 bar. Any ideas?

 

Sounds plausible. Of note turbo outlet pressure is higher than manifold pressure. Also would we have three relief valves in all - one Dawes MBC, and two to put a notch in the MAP signal.

 

I think we may be getting near levels of destruction if boost is increased about 18psi.

Collins engineering used to run an Escort Cosworth at 21psi, but major engine work was performed in order to achieve this level of boost reliably.

The fueling on a Scoob may be OK but the internals i.e Crank, head bolts and head gaskets probably won't be able to handle those sort of levels.

The TD04 may run out of puff too.

 

Hence why I run 18 PSI, but you cannot do this with a standard ECU without raising fuel cut. PPP runs 17 PSI on some cars.

 

Guys, is this not just a little dangerous? The PPP for MY99/00 has been remapped for the higher boost on a standard MY00, defeating the fuel cut on the same non-PPP MY would take the boost into un-mapped levels for fuel and ignition....or have I mis-read the other posts?

Harry

 

If the fuelling and timing are OK then what is the problem? Anyone doing this would obviously check them. It is only what superchips do. Myself I would only RAISE not abandon the fuel cut. I think the only reason superchips cars blow up is by taking the boost too high with faults or when people fiddle with the valve without knowledge or any idea of their turbo compressor map.

 

Or they havn't got a Boost Gauge and tinker, then think by ek' this is quick......BANG :-( Bloody Superchip......it's all their fault....NOT...it's yours for fiddling...

 

You can use the ball relief valve mentioned to raise the fuel cut off point instead of eliminate it

The ball valve has a discharge port which can be restricted by a needle valve. As the pressure behind the ball valve increases then so does the pressure in the signal line to the MAP, it just rises slower than the true manifold pressure.

Ideally you would increase the cut out only 2 - 3 psi, this would allow you to target your boost pressure right on the original cut off point.
This would permit a little leeway for boost spikes or changing ambients.
I assume the ECU is mapped correctly to this point