Hi Guys,

I have a stage 3 2WD sapphire, T34, Greens, Bayjoo Chip, 3 Bar, Pace RS500 Cooler, Mongoose exhaust.

I junked the amal years ago on the recommendation of the rolling road operater at that time and having been using the old faithful bleed valve ever since. I have recently been on the rollers due to a new turbo being fitted and now having a problem getting full boost.

I get a spike of 21 psi (which tails off to around 16psi) at 4250 rpm but boost will not increase any more further up the rev range. The bleed valve is fully open and I have a brand new .31 Actuator with the spring done up really tight in an attempt to get the wastegate to stay closed a little longer.

Should I go back to the amal valve or does anyone else have any ideas how to get round this, an after market boost controller maybe?

Thanks, Mike.

 

i'd go back to the amal valve personally, with the correct jetting and preload it will hold much more boost than you are seeing,my own holds nearly 2 bar

 

could be your wastegate penny no longer seating properly

take the wastegate off the actuator and fix it closed by other means. then carefully drive it and see if boost increases higher than it did before. i'm sure i don't need to tell you what could happen if you drive too hard with the wastegate fully closed

if it doesn't boost harder, you know it's a wastegate problem, not a control problem

 

Thanks for your replies,

The turbo is new and I checked it all out prior to fitting so I would not have thought it be a wastegate problem.

I will try a reworked amal valve like bud-weis suggested, anybody have any ideas how I go about re- jetting it?

CheeRS, Mike.

 

I dont know the condition of your engine, but it could also be high backpressure, causing the wg to open. High backpressure, because of an worn engine, bad rings, valves, headgasket etc.