What's up??

[HellOnWheels]

I've installed a .63 Garrett turbine housing that's been modified to fit my "P" trim 63 turbo, I've also installed a BtsC electronic boost controller using 2 stock wastegate solenoids. As long as the BstC is turned on I've got a good handle on controlling the boost pressure. However, when I turn the BstC off the boost will go thru the roof!??. The wastegate arm is adjusted out as far as it will go, and the wastegate hole is opened up to 1". I've checked and double checked all the vacuum lines and all are in good condition so they can be eliminated as the cause, am I right in thinking the w/g hole need to be enlarged????
Anyone else have this problem????
TIA,

HOW

 

[scottyb]

Well, with 2 solenoids, you're gonna get double the "difference from base" that your chip commands. If you have a stock style actuator adjusted all the way down, you're at a base of ~ 10 lbs. If the chip commands a "difference" of 5 lbs to get 15, then use of 2 solenoids will yield 20.

With the BSTC off, the chip regains solenoid control and likely bleeds something close to the max that the BSTC would do when you have it cranked all the way up.

HTH

 

[scottyb]

Hey, you started another thread.

That's what I mean. The solenoids under max pulse can bleed enough to get 6 lbs of boost each. That's why you get 6 lbs of adjustment with one, and 12 lbs of adjustment with 2. When you turn off the BSTC, the chip will control the solenoids (and it thinks there is only 1). If the chip is aggressive, then it likely approaches max pulse. This would be similar to leaving the BSTC on and turning it almost all the way up.

I have 2 solenoids also, but I never turn off my BSTC becuse my boost would be too high.

 

[HellOnWheels]

Originally posted by scottyb
Hey, you started another thread.


Finger at work before engaging brain.....

That's what I mean. The solenoids under max pulse can bleed enough to get 6 lbs of boost each. That's why you get 6 lbs of adjustment with one, and 12 lbs of adjustment with 2. When you turn off the BSTC, the chip will control the solenoids (and it thinks there is only 1). If the chip is aggressive, then it likely approaches max pulse. This would be similar to leaving the BSTC on and turning it almost all the way up.

I have 2 solenoids also, but I never turn off my BSTC becuse my boost would be too high.

Welp, before I installed the .63 housing I was running a Precision .85 housing and I could adjust the boost down to 14-15 #'s when the adjustment rod was extended out to max-letting the chip control the boost, by the same token I could turn on the BstC and could control the boost up to 23-25 #'s of boost. HOWEVER, since the .63 housing was installed I can't adjust the boost DOWN enough to keep it below 23-25 #'s, that's letting the chip control the boost!!??

I want the adjustability of being able to set the stock/chip boost to 14-15 #'s just in case the BstC decided to go south and blow the hell outta the engine.

HOW

 

[HellOnWheels]

....anymore opinions as to what would cause the overboost with the BstC turned off????


HOW

 

[scottyb]

So with all else being equal, you're now getting overboost. You had 2 solenoids before, and all you changed was the housing?

What boost do you get with the controller turned all the way down? all the way up?

 

[HellOnWheels]

Originally posted by scottyb
So with all else being equal, you're now getting overboost. You had 2 solenoids before, and all you changed was the housing?


Yes.


What boost do you get with the controller turned all the way down?


~14-15


all the way up?

20#'s and up.

Gonna check wastegate actuator tomorrow and see if it's working okay.


HOW

 

[salvageV6]

Mines been on IGN power for 5 years now with no issues.

If the BSTC goes south it likely will cause low boost not an overboost but that is one failure mode I would suppose.

I'd email TurboBob or Mike L. at Full Throttle and ask if they have ever heard of full solenoid bleeding with a BSTC failure causing overboost.

I doubt it.

Much easier to just let the BSTC and 2 solenoids do 12 psi. of work and regulate your boost with the knob.

Just my .02.

 

[scottyb]

Originally posted by HellOnWheels
20#'s and up.

Gonna check wastegate actuator tomorrow and see if it's working okay.


HOW

That's a good thought.

With the BSTC on and turned all the way down, you should get ~10 lbs on a stock actuator. Now you prolly get over 25 with it all the way up and the chip control will do that as well. Matbe the actuator/arm/puck is binding or not lines up well with the new housing. Porting the WG hole certainly won't hurt.