john banks

You may want to consider a Knocklink as well and/or a full remap for better results? Will be more expensive, but undoubtedly safer on our lower octane fuel than your car is mapped for - even before you improved the breathing and up the boost.

Consider also if you bleed off the MAP or similar and a hose between pressure and the wastegate acutator comes off and you are too late coming off the throttle you will go bang. One of my hoses came off, and I caught it on the throttle, but made me happy I had not disabled fuel cut!

[Edited by john banks - 12/2/2001 9:45:12 PM]

Cosie Convert

Hi there

I'm trying to work out where they are and what they do and I'm a bit stuck with the MAP sensor. I think I've located it OK beside the wastegate control valve on the RH inner wing. However there appears to be two bits to it. Hose comes from intake manifold to orange&black 'thing' with a 2 wire plug on it then on to what looks like the actual sensor (shiny black). Whats the orange & black bit ?
Also what is the item on the top of the intake manifold just after the throttle butterfly with a rigid pipe leading to it and an electrical plug ?

thanks

CC

Scott.T

iTrader: (2)

Yep, you've found the MAP sensor it's the black thing that appears to be mounted upside down on the strut top.

The Orange thing is just a valve that I beleive opens when you carnk the engine. Something to do with helping starting, I think.

john banks

http://www.mrtrally.com.au/performance/docs/WRX-V5.pdf

This is the manual for the Link ECU, but the wiring diagram and sensor location applies also to std or PPP MY99/00 UK spec vehicles. I think the bit you are describing is the pressure sources solenoid control valve - helps the MAP sensor, but check out the diagrams.

Also gives you the ECU pin outs and you can tap into some of the data there if it means anything to you and you know what you're doing. I have tapped into lambda and MAP with some success using a DVM. Shame we don't have OBD-II compliant cars as you can get a scanner that gives you most of the things that a Select monitor would for under £100 - see http://www.i-club.com/forums see factory forced induction and you will see plots off various sensors.

Would advise caution if you are thinking of altering the MAP signal to get more boost.

Cosie Convert

Thanks John that's helpful. Yes I did have plans to tamper with MAP signals, however I plan a few safety mods first.
My car is a 95 WRX RA, one of the first RAs on which the first STi's were based. It shares the same chassis No with the STi but only has some STi bits (Ally suspension & bonnet,CR box, water spray & STi exh system ) so I'm not quite sure what it is.

Anyway the plan is to fit a water injection system i used to use on my circuit race cosworth, this is triggered by a pressure switch (Renault 5 turbo overboost switch 13 psi) and when filled with a 50/50 mix of H2O and Methanol acts as an effective anti detonant and mixture enrichment.(on the Cosworth it reduced the charge temp by 25 deg C and allowed more ign advance)
With this in place I intended fitting an air relief valve on the signal line to the MAP, this valve would 'CAP' the signal just below fuel cut-off point (15psi ?)
The boost would then be raised by means of an adjustable restrictor valve in the wastegate control valve supply line.
The engine is currently standard although I'm fitting a Scoobysport downpipe and cat bypass.
I am lead to believe that the primary control parameter for fueling is the Air Flow sensor therefore I intend using 17 - 18 psi
whilst monitoring AF ratio and EGT. (only runs 12 psi standard)
I would welcome any comments on this set up as, all in, it's cost me less than $500.00 (inc $250 exhaust) ($ = pounds)

CC