manual boost controllers

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Nov 17, 2006
I'm about to install a CT26 on my 3B, the last piece to the puzzle is a boost controller...I'd like to be able to control the boost at my dash, so I've found two styles, one where the valve is located at the turbo and runs a cable to your dash, around $180, another that mounts in your dash, and you run the hoses from the turbo...$99
I assume the cable one is more responsive, as you don't have to pressurize the entire line, but once pressurized, the two types should react similarly shouldn't they?

If anyone has any experience or comments I'd love to hear them this is new to me, and I'd like to get it right the first time, any comments would be appreciated...
I've got a CT 26, with no idea what the waste gate actuator came out of, it fits a CT26, but could be set for anything...what I might do, is run it, and see just what happens...and go from there...

I have no idea on the history of my 3B, I don't want to run too high...
okay, run the boost gauge and see first but unless you turn up the fuel you will get roughly 6-8 lbs.

remember, even if you set the boost at 14psi you will still cruise down the highway (depending on fuel setting) at 4-6 lbs. once you hit a hill then it MIGHT go up to 12 lbs. i can make the PZ hit 16 lbs on a hill with full throttle but i have not cranked the fuel up much yet.

on the net there is simple instruction for making a boost controller for about $6 and works the same as the more $$$ ones. the extra hose will make no difference on the boost reaction.
I bought a manual boost controller off of Ebay for less than $20. It's very similar in design to the Home Depot special controller that Wayne posted about (and I copied and built for my previous BJ74) years ago. This one already has the proper spring and everything is put together nicely...and at less than $20 USD, it wasn't worth the effort for me to build my own.
I saw that one, but didn't know if it was feasable to mount inside the cab...I guess with long enough hose, it can be....
you have to remember that playing with the boost without adjusting the fuel will do little
except, if you leave the fuel cranked up for 14 lbs of boost and drop the boost down to 8 lbs for a max from inside the cab, the EGTs will skyrocket under full throttle. if you set the fuel for 8 lbs of boost and shove 14 lbs down its throat then you will have excessive intake temps eliminating the positive effects of the extra boost.
to do this properly you will need a full adjustment in the cab as well....
I read an online article (so it might be complete horse-puckey) that says that having a long line between the turbo and the wastegate actuator might actually improve performance.

the idea is that there is "wastegate creep" to deal with-- the wastegate isn't OPEN or CLOSED, but it opens up as boost increases. We don't really need/want the wastegate to open at all when boosting 6lbs. Right?

The fellow in question added a 2 meter line between the intake manifold and the wastegate in order to slow the wastegate's response time a little. Under full-throttle, he built boost faster, but it still topped out at the same max number. In essence, it didn't give him more boost, it just increased the low-end boost while boost was building, which made him happy.

My point is that the long line to the cab and back shouldn't hurt anything and it might actually make the boost come up a little (very little) bit quicker for better throttle response under heavy loads.

The article is: Killing Wastegate Creep

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"on the fly" adjusters are usually for racing applications. on a DD, you might as well set it to where it works best and leave it be.
I thought I might run a higher boost when in 5th and towing, and a lower boost when on the trail....
I thought I might run a higher boost when in 5th and towing, and a lower boost when on the trail....

I can't imagine why you'd ever want to do that. There is no benefit at all.

As for wastegate creep, it's only a problem for those running very low boost as it requires a wastegate actuator with a very weak spring. That graph shows 50kPa which is 7.5psi boost.
Instead of using a boost controller, cut and thread the actuator arm. This makes it infinitely adjustable and gives more preload at higher boost which stops wastegate creep.
I like the threaded arm idea
If I ever get around to my intercooler (and thus want some more boost) I'll take a look at that idea.
Thanks, Dougal.
Simpler? mine went on in about 15 minutes. Unless you're drag racing a Grand National or a Skyline GTR, I think the noticeability of wastegate creep would be pretty small.
yank the waste gate vacumm line off completely, you will only see 14-16 lbs max anyway...
as for trail vs highway, like i said, the boost is only there when the engine requires it. on the trail you will be lucky to see any boost unless you are giving it up a nasty slippery long hill and reving the s*** out of it. .
My 2 cents worth
I own a 1985 BJ70 with a 3B, I purchased a Turbo Glide kit from Australia. It came with a boost controller set at 7lbs, I installed a boost gauge and EGT pre turbo and adjusted my fuel to give me an EGT no higher then 1250F degrees under full load. I made a home made boost controller and finally purchased a very nice controller. I set my boost to go no higher than 13 psi and adjusted my fuel to stay below 1250.
Do Not just pull off your boost controller tube as this leaves the port open and you will blow air from it, if you must plug the port or put a steel ball in the tube. I would not recommend letting your turbo spool uncontrolled as you can get an over boost if you decelerate quickly the turbo will lag behind the engine RPM and can spike the intake pressure causing way to much pressure, the waste gate prevents this not just how high your boost goes.
I would think hard about what you want from your engine as to much boost fuel combo will shorten the life of your engine. The most common problem is your precombustion chambers will crack from the added heat and the heads of the 3B are prone to cracking. Both of these have happened to my engine and I am now installing a 13BT which was designed to work with a turbo, no precups, lower compression ratio,direct inject, and a fuel system designed to handle variable boost, non of which exist in the 3B. Higher boost/fuel equals shorter engine life.
When I plugged my line and let the turbo spool uncontrolled the boost would hit 19PSI which I believe is to high.
Like I said my 2 cents for what ever it is worth.
of course you plug the tube.
the CT26 will open the waste gate at 14 lbs anyway so over boosting is unlikely.
i have yet to see the decelleration statement, i will try it this weekend. i want to see how high i can make the boost go.

of course once you crank the fuel then the boost will go higher but the wastegate will still open, it just isn;t as controlled.

for the $6 to make a controller it really doesn't make sense to not have control ...
I thought I might run a higher boost when in 5th and towing, and a lower boost when on the trail....

Are you running the turbo yet? if not, wait until you do. You will need a intercooler way before a boost controller at least when pulling a trailer.

I went on the dyno today with my truck. (see my turbo thread). After doing the 4x4 run and 2x4 run i raise the fuel a full turn, to my suprise i lost 2hp. I then turn the fuel back where it was, then a other half turn lowering the fuel and this time lost 10hp. So i was pretty much on the sweet spot. It was fine temperature wise without pulling the m101, before the intercooler. But when i was pulling and going uphill the water temp would go high very fast. More boost would have not help me without a intercooler, IMO.

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