piehole1983

iTrader: (7)

I'm gonna try to touch on this again as I've never really got to the bottom of a big boost spike and poor control on my 97 UK T2000.

Basically, I get big spikes in boost when I go to WOT in any gear. It lasts a little longer in the higher gears, 3rd, 4th etc. Sometimes it can trigger the fuel cut. After the spike, boost goes back to normal-ish, a little unstable.

Quick spec:
TD04 (standard)
Autobahn FMIC (already fitted when I bought the car)
ESL installed (by me)
Blitz Nur Spec R full system (already fitted)
Decat up and down pipes (done before I owned it)
Turbosmart BOV (again already fitted)

So, I've had lengthy conversations with Andy Stevens at ESL about the best way to control the boost and he has given me a stack of time and help (thanks Andy!) and still haven't really got sorted. In the map I've had to reduce WG max duty cycle waaaay down to around 55% to get target boost of 1.1bar which in itself is odd. That was using a 2 port BCS, which seems to be working and is clean. All my vac hoses are new, correctly routed and the restrictor pill place.

Recently I've fitted a 3 port BCS to see if that would help, boost levels dropped straight away by 0.2bar at the same WG duty cycle. It's piped correctly and pill moved to the correct location. Still have the big spike though, maybe even worse!

The only thing that I want to suggest is, would the restrictor pill be causing my issues? I say this because some time ago I was offered a Blitz dual solenoid boost controller for easy money and decided to buy it. I fitted it to the car and ran standard boost. With this, I've had the best boost control I've ever had on the car and it didn't have the restrictor pill in place.

What's your experience with removing or re-boring the restrictor pills and what outcomes have you all came to? Does a modified engine react differently to a standard boost control system?

piehole1983

iTrader: (7)

Bump

Gambit

iTrader: (6)

Have you tried backing off the preload on the actuator arm a turn or two

piehole1983

iTrader: (7)

I actually just set the preload up as it should be really, not backed it off as such. Wouldn't that cause boost creep?

I found a great explanation of what the restrictor pill does and it's effects and I think I might try removing it completely with a view to logging with it fitted and not fitted. That way I can compare logs and find a happy medium.

Gambit

iTrader: (6)

Was under impression If its overloaded itll cause spikes

rather than taking out pill just go get varying sizes of welding tips (place, weldpro. down beside hurst tyres in docks does them) and use them to see what difference they make, pretty certain std is 0.9mm so you want to go bigger but just in 0.1mm increments

piehole1983

iTrader: (7)

That could be the case indeed. I'll check the preload again. I also have a few welding tips here already and some tiny drill bits too. I'll drill an old tip out to 1mm and try that.

But check this out:

http://www.force8.demon.co.uk/impreza/bcontrol.htm

I found this last year before discovering ESL. This guy is switched on. The section on boost and restrictor has made me understand things much better.

piehole1983

iTrader: (7)

Thinking back to when I checked the WG preload, I actually tested it using nitrogen and a regulator to make sure it opened at 0.7bar which is standard spring pressure. I also drove the car with the compressor housing piped straight to the actuator and didn't experience any spikes, if anything the boost was slow to come on.

piehole1983

iTrader: (7)

So I went out for a run with the restrictor removed completely, boost spike still present. I'll go down the WG preload route now to see if that helps any. Could the WG actuator itself be faulty?

piehole1983

iTrader: (7)

I've now adjusted the preload on the WG actuator to about 1.5/2mm of the hole showing past flapper arm pin. From what I read that's about the right setting from the factory. To be fair the preload was a little high, maybe 3/4mm of the hole showing.

Went for a spin, still got the initial spike on WOT. How difficult should it be to push the actuator in and out? Mine is fairly hard to move by hand, and doesn't sound too healthy either. Sounds dry and squeaks a little, like a dry bearing. Is this a possible cause?

joz8968

iTrader: (13)

When I had a Forge T2 w/g actuator fitted at API, the mechanic recommended, and adjusted the arm, so that half the hole was showing - before prising the turn buckle over the flapper spindle.

Tight - but not stupidly so.