Just a quick update... After removing the Amal valve, I fitted the boost controller without adjusting the actuator rod. It was hard to adjust the boost controller precisely. I found that small tweaks were necessary once I was in the vicinity of the boost pressure limiting cutout activating. I adjusted it so that the cutout was just operating, then backed it off until it doesn't activate at all under any circumstances. I understand that the cutout operates at 18psi and this is the maximum that I can safely run with the standard intercoolers anyway? I haven't got a proper boost gauge yet. It's in the post. I'm also relieved that the cutout is working!
I also fitted a VAG (Volkswagen Audi Group) type recirculating dump valve in place of the original. It was a straight swap. This has no effect on performance but just sounds different. Instead of a fluttering sound, I get a definite hiss (quiet) when I lift off. Does this mean that the original valve might not have been working?
The difference from removing the Amal valve is astonishing! Especially in 1st gear. I know that Amal valve doesn't limit the boost in 1st gear on the Quadra, but the difference in "go" is like night and day. The car now feels properly quick, whereas before it felt a little bit slower than it really should have been. The main difference is the throttle response. I can now pull away gently in first and then mash the throttle. The car takes off like a scalded cat! It's amazing! The other difference is that the boost isn't quite so well controlled. In fact, you can see the boost varying slightly under WOT. The gauge fluctuates slightly and you can feel the car surging slightly. I presume this is to be expected?
I've left the dampener in place.
When I originally fitted the boost controller, I fitted it backwards (D'oh - I only found the instructions in the packet afterwards) and it didn't limit the boost at all! In fact, I blew the lower intercooler apart. I'm not bothered as it was in shocking condition. I slightly bent it in the accident and all the fins were falling out of it, so it was already weakened. I temporarily fitted the cooler from my GT Turbo. The GT Turbo one fits but is too tall. The one I have is double capacity. It will do for now. Yet another excuse to fit a FMIC!
Very pleased with the change brought about by removing the Amal.
I also have nearly all the parts I need now for my garage to do the major work over the first part of January. I now need to find a friend to help me go and pick up the gearbox from my unit! Anyone got a friend I can borrow? (Only joking)
Andrew
p.s. I have added Dave's wise words on boost, etc. to the wiki, here:
http://turborenault.co.uk/mediawiki/Renault_21_Technical_Information