boost figures

[boosted_diesel_84]

ok, so i got my ebay boost controller installed on my kkk, cut the line and teed it in, as for the wastegate threaded rod, i wasnt sure what to do with it, so i left it alone  at about 3/4 the way screwed in, it made 15 psi, no matter how i adjusted the controller, i could hear air going thru it and feel it coming out the other end, so i completly removed the wastegate rod, only made 9 psi, then no matter how i adjusted the controller, so i tried to thread in the rod all the way, or what i think is all the way, only a few threads stick out past the nut, and it didnt want to go in any further w/o forcing it, drove it, still  15 psi, no matter how i adjust the controller, but i can hear the wastegate open when i shift, does that mean i need to thread it in further? or what? please help, oh and the bov is shut what i think is all the way, but i will recheck to be forsure

[RabbitJockey]

ok, so i got my ebay boost controller installed on my kkk, cut the line and teed it in, as for the wastegate threaded rod, i wasnt sure what to do with it, so i left it alone  at about 3/4 the way screwed in, it made 15 psi, no matter how i adjusted the controller, i could hear air going thru it and feel it coming out the other end, so i completly removed the wastegate rod, only made 9 psi, then no matter how i adjusted the controller, so i tried to thread in the rod all the way, or what i think is all the way, only a few threads stick out past the nut, and it didnt want to go in any further w/o forcing it, drove it, still  15 psi, no matter how i adjust the controller, but i can hear the wastegate open when i shift, does that mean i need to thread it in further? or what? please help, oh and the bov is shut what i think is all the way, but i will recheck to be forsure

the wastegate doesn't open when you shift.  it opens when you reach the max pressure you have your car set for.  15 psi is about the normal boost for stock fueling on a completely close wastegate... i'm guessing you just have your waste gate closed the whole, play with the boost controller more and see if you can get it to have a max psi of some where between 9-15 that way you know its working.  9 is also about the minimum amount of boost you can run.  if you want more than 15 psi you'll probably have to icnrease fueling.  also to make sure your bov won't open, you need to remove the spring and put something solid in, don't just screw it down.

[mtnsammy]

Cap off the BOV or plug it completely. They leak even with the screw all the way in.

[boosted_diesel_84]

the spring is romoved from the bov, and i have something in there to keep constant pressure on it, so im pretty sure its not opening, because if it was, wouldnt it stop my boost at 11-12, not 15? also, i turned the controller to both extremes, and no difference, but it is dumping a lot of air out the open end, and i tried hooking it up on both ends, no difference either.

[Vincent Waldon]

If by ebay boost controller you're talking about an aquarium valve then what you are doing is adding a small leak to the pressure the wastegate sees... since it's not letting out a known pressure like expensive valves do the interaction will be a bit wonky since it depend on flow.... pretty much all or nothing actually.

Assuming you've disabled your BOV (which you probably have, since you saw 15 psi) chances are 15psi is all your turbo will spool with your existing fuel settings... as a next step I'd try adding more fuel (1/4 turn at a time)... hopefully monitoring EGTs ??

[boosted_diesel_84]

the controller is a Voodo POS from ebay like $10 or something, fuel is at all stock settings for the time, they were turned up, before the controller, it also made 15 psi, but since i dont have a egt YET i got scared, and turned it back down to stock, but still shouldnt the controller if i turn it down, decrease my boost any?

[boosted_diesel_84]

9 is also about the minimum amount of boost you can run.[/quote]

why is there a minimum? and why 9? is there a problem with running less boost?

[Vincent Waldon]

If it was an actual pressure regulator you could set it to "waste" 2 psi, the wastegate would see exactly 2psi less and would tell the turbo  to produce exactly 2psi more than the 9-10psi the wastegate is set for.

Because it's just a needle valve it's nowhere near this presise... the wastegate is somewhat fooled by whatever is wasted by the needle valve, but what is wasted by the needle valve depends on other variables... mostly flow.

In my view, the cheap boost controllers are really just an on-off switch... if you tweak them really carefully you might be able to dial the boost a bit, but it will be twitchy at best.   Generally:  closed= stock boost (9-10 psi) and open=max boost, which sounds like 15psi in your case with your current fueling.  Note that there's no way with a boost controller inline with the wastegate sensor line to dial in *less* than the stock boost... you'd do that by playing with the actual wastegate controller arm, and it's fairly limited as well.

Me: a solenoid on the boost line to the wastegate so that I can control electronically if it's open or blocked.  If it's open the turbo behaves itself to 10 psi and it's safe for my wife to drive.  Flip a switch, the solenoid closes, and the wastegate is effectively not there.  Boost is then regulated with my foot, on concert with my eyes which are watching boost, EGT, and oil temperature gauges.

[jimfoo]

On my k-14, max boost was about 21 psi. My Wal-Mart aquarium valve was actually able to control the boost quite well. If yours makes no difference, then something is wrong with it or the way it is hooked up. If you only get 15 psi, try unhooking the wastegate and see what the max boost you can get is.
If it is more than 15 psi, then either your tube to the controller or the controller itself are restricting flow.

[RabbitJockey]

9 is also about the minimum amount of boost you can run.

why is there a minimum? and why 9? is there a problem with running less boost?[/quote]

cause thats the rate of the sping in the k24 wastegate.  thats why when you have the screw backed out the whole way it won't go any lower than 9psi