Was at the track and the boost was dodgy in 3. and 4. Went up to 17 PSI and fell to 10, variable. 2. was pretty much fine. Does the ACT sensor cut the ignition or lower the boost?

 

the act sensor sends a signal to the ecu when acts goes higher than 68 degress C, the ecu should then send a signal to the amal valve (if u run a amal valve) and should cut back the boost, some can cut the ignition aswell mate

 

So it was probably too high ACT that caused the cut back in boost. It was 19-20 degrees that day. Had no problem last weekend, the temperature was a couple degees lower but I used the air filter box, I decided to try open filter for this weekend. I'm sticking to the box from now on. Using standard IC. Had no problems two days in a row last weekend, and this weekend the open filter fucked it all up. Correction, the boost peaks at 16 PSI not, 17 psi. Holds 14,5 PSI.

 

the act sensor will definately retard the ignition when the temp gets to 60 degrees,!! didnt think it reduced the boost though but not 100% on that one.

 

I was seriously down on power and the boost was variable. It made good power two hole days last weekend and the changes for this weekend was new plugs (Denso K24PR-ZU to NGK BCR8ES, but I changed back, no difference), five degrees higher ambient and open air filter from air filter box last weekend.

 

do u run the amal valve?

 

Yes.

 

take it off, install a bleed valve, a brass one,not one of those cheap ones,

amal valves play up to much and gives variable boost levels

 

a 3-way lockable bleed valve is what you need to replace the amal valve with
can adjust boost with the valve (sensibly) instead of just on the actuator

have you also considered the actuator may be worn?

 

What you might also want to consider is that the standard PLASTIC ended intercooler on the S2 will explode if running more than 1 bar boost over a prolonged period of time, my old standard alloy one on my S1 was very blown when i took it off and i was only running 13psi!!!
Your boost fluctuation may be a leak in your intercooler under extreme load, and IMO if an amal valve and actuator are set-up right it is far superior to a bleed valve, especially if you are prone to a spot of fettling

 

Scott, if it's a lockable one then nothing will go wrong, lock it up and be done with it

You've just got to be sensible when it comes to these things

 

so you have never been tempted to up your boost??

I know i have, and have been very lucky not to damage the engine, its too much temptation to have one fitted, at least with just the actuator you are less likely to change the settings as its a pain in the arse to get under the car and change it.
Once its set on my car now, generally i leave it alone except the odd occasion when i 'may' give it half a turn

 

Scott, always want too, but I know what'll happen - BANG!!

 

i always sweared by my amal valve, even brought a new one from ford!, but as soon as i took my car to APT they ripped it straight off, and installed a lockable,brass one,

Amal valve is now chucked in the bottom of my toolbox, havent had any problems since, as James said, Gary locked my bleed valve up, reisiting the tempatation of turning it up,

I think nowadays people who just chuck bleed valves on and whack the boost up, are just asking for trouble,

People who generally care for the cars, will leave their cars as setup by the experts, if not might aswell not bother with paying tuners to setup their cars.

After 16 psi, my amal valve just started making funny noises and playing up!

 

It was the ACT sensor. Boost was dodgy at the track today, unplugged it and boost was stable and power was strong. But my ACTs is dangerously high.

 

My friend has wrapped his manifold and turbo exhausthousing in heatwrap and fitted a plate that shields the crossover pipe from the manifold and turbo. I had no problem touching his pipe after we hade done some laps at the track, but mine was blazing hot. Huge difference in temperature.

 

Using a standard intercooler at 17psi, that is your problem. Standard intercooler is only just good enough for standard boost, let alone over double that. I bet by the time you got to 4th gear your charge temps would have been way over 70degrees...

 

can you still run a 2 stage boost switch with a bleed valve inplace of the amal valve?

 

It's more like 15-16 PSI, but I know. There was amazing difference in temperature of the charge pipe on my friends car. The charge pipe get extremely hot and should be shielded for best charge temperatures. A heat shield is easy to make and use the holes in the head where the bolts for the cover go to fasten it.

 

No, a bigger intercooler should be fitted for best charge temps lol

Using a standard cooler for anything over 7 psi is just crazy imo. I must admit though, after you said about a shield, it got me thinking about doing something on mine again, but still retaining the standardish look, hmmmmmmmmm.... Gonna be tricky....

 

I'm getting rid of the amal and fitting one of these.

http://www.dawesdevices.com/basic.html

One of the functions of the amal is to increase drivability by letting the boost come on softly. Even av high RPM's the boost is slow to build up. I noticed this on the track yesterday.