Amal valve jetting....
like you knew if you did youd have posted so dont go glory hunting 
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29-03-2006, 09:40 AM
#8
Phil, you are indeed correct, if i knew much about Amal valves i would have indeed posted to help you, but as you should realise by now i dont ever post if im not sure, and im not one to regurgitate info that i dont have first hand experience of either in case its not correct, so a copy and paste job isnt my style at all.
Wasnt "glory hunting" was taking the piss, and even you have to admit it was pretty funny
Wasnt "glory hunting" was taking the piss, and even you have to admit it was pretty funny
29-03-2006, 09:48 AM
#9
First set the wastegate preload to 9 psi by temporarily connecting the compressor outlet to the actuator using a short piece of tube.
This should be about half a hole of preload if using a -31 (as in when you place the actuator rod over the wastegate shaft, you can see half a hole showing).
Then reconnect all the amal valve piping back to normal.
The restrictor in the amal union that normally goes to the airbox needs enlarging slightly. Change this to around around a 1.5mm increase using a suitable sized drill bit (it might be worth going up in 0.5mm steps, as you can always make it bigger, but you can't make it smaller!).
With this done the boost should be holding about 15-20psi.
If want more than the above results you will need to enlarge the restrictor in the other amal union, but like the above, go up in 0.5mm increments for the same reason.
Once you get NEAR what you want, THEN use the actuator to fine tine the boost limit. But DON'T slacken it to reduce boost (in case the restrictor was opened out too much) otherwise the wastegate will rattle. Also don't wind it in more than a holes worth - open the restrictor a bit more instead to get the required bleed off.
Hope this helps?
This should be about half a hole of preload if using a -31 (as in when you place the actuator rod over the wastegate shaft, you can see half a hole showing).
Then reconnect all the amal valve piping back to normal.
The restrictor in the amal union that normally goes to the airbox needs enlarging slightly. Change this to around around a 1.5mm increase using a suitable sized drill bit (it might be worth going up in 0.5mm steps, as you can always make it bigger, but you can't make it smaller!).
With this done the boost should be holding about 15-20psi.
If want more than the above results you will need to enlarge the restrictor in the other amal union, but like the above, go up in 0.5mm increments for the same reason.
Once you get NEAR what you want, THEN use the actuator to fine tine the boost limit. But DON'T slacken it to reduce boost (in case the restrictor was opened out too much) otherwise the wastegate will rattle. Also don't wind it in more than a holes worth - open the restrictor a bit more instead to get the required bleed off.
Hope this helps?
29-03-2006, 11:06 AM
#10
Mike are we making the hole bigger or smaller to get more boost in the amal to actuator one?...Also bigger or small to get more boost in the airbox one?
The problem at the mo using the bleed valve and amal is that you get a spike which i dont want...i want 30psi flat but to hold 30psi at the mo i have a 35psi spike
How does one jet it to have a flat curve?
The problem at the mo using the bleed valve and amal is that you get a spike which i dont want...i want 30psi flat but to hold 30psi at the mo i have a 35psi spike
How does one jet it to have a flat curve?
29-03-2006, 11:09 AM
#11
Originally Posted by Bosch-Man
Mike are we making the hole bigger or smaller to get more boost in the amal to actuator one?...Also bigger or small to get more boost in the airbox one?
The problem at the mo using the bleed valve and amal is that you get a spike which i dont want...i want 30psi flat but to hold 30psi at the mo i have a 35psi spike
How does one jet it to have a flat curve?
The problem at the mo using the bleed valve and amal is that you get a spike which i dont want...i want 30psi flat but to hold 30psi at the mo i have a 35psi spike
How does one jet it to have a flat curve?
Pipe length effects how much of a "spike" you get, you want it as close as possible to the amal valve.
29-03-2006, 11:12 AM
#12
Bigger on both 
, but be CAREFUL, as I said make it bigger in small increments and then test each time, as you can always make it bigger next time, but go too far and you can't make it small and you can't lose the boost on the actuator, as it will make the wastegate loose and it will rattle. Don't forget that a T4 will gain 1-2psi extra when it is hot!
, but be CAREFUL, as I said make it bigger in small increments and then test each time, as you can always make it bigger next time, but go too far and you can't make it small and you can't lose the boost on the actuator, as it will make the wastegate loose and it will rattle. Don't forget that a T4 will gain 1-2psi extra when it is hot!
29-03-2006, 11:15 AM
#13
PS
Phil, if what you want is a 30psi fixed value, have you considered a basic boost controller, like the bottom of the range apexi ones, they are very good at this sort of thing, and will automatically compensate for when the turbo is hot too
Phil, if what you want is a 30psi fixed value, have you considered a basic boost controller, like the bottom of the range apexi ones, they are very good at this sort of thing, and will automatically compensate for when the turbo is hot too
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