The bleeder hole in a good ball and spring MBC is for relieving the pressure after the ball re-seats itself. Otherwise, you will have a build up of pressure when the ball vibrates (open) and when the ball seats back (below set boost) there will be that pressure still there in the wastegate actuator.

You're only losing air through that hole when you're using your actuator to keep the boost down. If you were so close to maxing out the compressor where you would need every fraction of the flow, then the MBC would be screwed tight and no air would be going through to the bleeder hole. Also you would be losing pressure so the MBC would seal up on it's own even before you would have to screw it in so tight.

. . . Of course the bleeder style MBC is totally different. Which I do not like. Ball and spring MBCs can be built so affordably, I just don't inderstand why one would use a bleeder style piece.

Here's a picture of my M.B.C. . Notice the relief hole. It could be that air is leaking around the ball in my M.B.C causing it to leak pressure way to early. Because when i boost leak test my car i notice the M.B.C. starts blowing air out the relief hole around 10 psi when i have it set to 20 psi . I never thought that this maybe abnormal. Is it?

I know you guys are all looking for a cheap and economical way to increase the boost on a internally gated turbo, but I was having the same issue with my pte dual bb 60-1 internally gated. I couldnt get boost to hold steady at anything close to 24psi and i had spiking issues. The lowest boost i could run was 12psi so i know there is a weak spring inside the wastegate. I was using a manual boost controller that i purchased from AMS. I then found a used greddy profec b electronic boost controller for $150. I have since been able to run a steady 28psi(max boost capable 30psi) and eliminate all chances of spike at any boost level. I am also able to adjust when the solenoid starts to bleed air threw and was able to significantly increase spool up time(about 200rpms). Another plus is I dont have to get out of the car to adjust boost when tunning. I dont know if my results are due to the manual boost controller bleeding air threw to early or the spring inside it just not being strong enough, but either way it worked for me. As with anything im sure what worked for me might for others but not everyone. I know the profec controllers are pricey and you guys are looking for a cheap fix but i am very pleased with the route I went and it was much easier then going to a external gate. I just thought I would share my experience with a large internally gated turbo and how I resolved my issue.

kicknurass4fun said:

I then found a used greddy profec b electronic boost controller for $150. I have since been able to run a steady 28psi(max boost capable 30psi) and eliminate all chances of spike at any boost level.

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I don't see how an electronic controller is making the spring tension of your actuator stronger. I had a weak actuator on my buddy's Frank 5 20G for a while...he was only able to run 17psi with the wastegate line completely disconnected from the actuator head.

There are some electronic controllers that use boost to help hold the actuator closed until the desired boost level is achieved....for this you'd need a dual-port actuator:

Wow thats cool, I've never seen one of those before.

In all honesty it doesnt really make sense to me either its just how i solved my issue. I also tried a different boost controller off of a buddies car and i still had the same problems. I didnt purchase the profec b with hopes of being able to hold more boost. I more wanted the ease of adjusting boost between different tunes for pump gas, meth injection, and race gas. I was just fortunate that it for some reason allowed the car to hold more boost. If I wanted to run higher boost then I am currently I would try to rig up the hx40 wastegate actuator just as you guys are doing. Im confident with an hx40 actuator and the greddy profec b it would be the cheapest(meaning cost of hx40 actuator) and best boost control possible for an internally gated turbo.

I've got a stock hx-35 actuator if anyone wants it. It's probably pretty rusty though. (The turbo looked like it was fished out of the bottom of the ocean when I bought it .)

I hear sponge bob lives in a pineapple under the sea. He must also drive turbo cars.

There's no way your electronic boost controller allowed your actuator to hold more boost. Something wasnt connected properly before. There's no possibility that a controller helps spring rate. It's is more likely that you did things wrong in the first place repeatedly than defying the laws of physics

dsm-onster said:

There's no way your electronic boost controller allowed your actuator to hold more boost. Something wasnt connected properly before. There's no possibility that a controller helps spring rate. It's is more likely that you did things wrong in the first place repeatedly than defying the laws of physics

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Im sorry but i dont know... Im not arguing the theory behind it cause by the laws of physics your correct. Maybe i should have purchased a better manual boost controller? It just always seemed like my boost would spike then fall down to 24psi or so. Maybe the boost controller had a weak spring or it had a hard time resealing after opening? Im sorry i must have not put enough thought into it and misinterpreted my results by giving credit to the electronic boost controller when instead i should have blamed the manual boost controller that was on my car and the cheap one my friend had. I in no way had intentions of spreading false information I hope everyone understands that Sorry

Now that does makes some sense It's possible a botched MBC was the whole problem with your setup in the first place. I've had that happen. Especially with a weak spring. The MBC i use is a "gillis boost valve". BEst basick ball and spring boost controller you can get. They have the spring rates perfect for the levels you choose.

Figured I'd post my results with the "Jus" 20 psi holset internal wastegate. With my HKS EVC electronic boost controller turned up on high, I was seeing about 19 psi of boost at 7000 rpms on the "stock" Mitsu 16g wastegate actuator shimmed out about .120". With the stiffer "Jus" internal wastegate and the same amount of preload "shimming", on the same EVC boost setting, I was seeing about 25 psi at 7000 rpm on an 80*F day. Turning my boost almost ALL the way down, I'm seeing about 20 psi at redline. The trick is I have to put up with a massive midrange spike to get the 25 psi at redline if I crank the boost up, but I also have the wastegate fairly well preloaded and that might not be helping things.

Overall, an oustanding mod that will take some dialing in to get everything working happily together. Its going to be one of those mods I won't be able to take advantage of until I get some high octane racing gas that can keep my timing up at mega boost levels.

THANKS Jus

I installed 3 5lb springs on a 17lb buick GN actuator. I get the same results as those with the 20lb holset actuator. Around 20psi minimum, spike to around 35 and settle to 25psi by 6k. So either the spring pressure is still not enough or the flapper blowing open is not the real issue here. I even removed one of the springs and the boost did not change.

I will say the added throw of the buick actuator eliminated any spiking until the 22+psi level. Boost will jump directly to 20psi and hold.







Seems to me like this would be the best deal out there. You would install your controller between the 2 ports and manually bleed in the desired amount of pressure needed to hold the WG closed. Just like an external gate. It's an adjustable spring that gets stronger as boost increases. What could be better? If it wasn't for the $80-150 price tag I'd give this route a try.

For people on e85 or racegas wanting to get the absolute highest boost possible on a mitsu turbo, without going external, or evenb modding the stock wastegate. T it into the brake booster, after the check valve. You now have vacuum in the actuator holding it shut.

so whats the general consensus on this wastegate mod? Im looking to run around 25psi on my big 16g with e-85 but am considering just wireing the wg flapper shut since my motor is built and i have all the supporting mods to max out the 16g. I may just try it anyway because im pretty sure i can get a holset actuator pretty cheap and i have a few mitsu actuators laying around.

The general consensus claims it's a success. The most recent I built was used on a Big 16G with an Evo III turbine housing and 34mm flapper (hence the need for a stronger actuator) which netted 384whp at 25-26psi.

Not that some people don’t do this, but I’m told it makes a ton of back pressure and causes poor performance. A holset or modded actuator will get the closest. Porting your 02 pipe to creep is very helpful. Basically the total opposite of how everyone ports them. IMO if you have a decent flowing head and anyaftermarket cam setup you’ll need to spike the turbo to 30+ to hold 25psi 6500 or so.

forcefed86 said:

Not that some people don’t do this, but I’m told it makes a ton of back pressure and causes poor performance. A holset or modded actuator will get the closest. Porting your 02 pipe to creep is very helpful. Basically the total opposite of how everyone ports them. IMO if you have a decent flowing head and anyaftermarket cam setup you’ll need to spike the turbo to 30+ to hold 25psi 6500 or so.

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My turbo is completely unported and I spike 30 and hold 25.

On pumpgas with WEAK timing, good enough for 352awhp.

@jusmx141,
you still making these?

got any compenents laying around that you might be able to throw together?

I have plenty of Holset actuators if you're willing to supply a junk / spare MHI actuator.

I got like 3 or 4 MHI actuators sitting around if you're interested. You pay shipping

So far the actuator is running great. My electronic boost controller is set at about 50% and I can still still hold some pretty crazy boost levels. Kind of a mod where everything else that allows you to hold more boost needs to be in place though. Right now, I'm limited by my fuel pump more than anything else. On a speed density setup I see no problems for a well setup 16g to pull +25-26 psi to redline on a nice cool day.

I was looking at these 17 psi and 22 psi wastegates on ebay has anyone had any succsess with them?

Turbo Actuator DSM 1G EVO 1~3 VR-4 TD05H 14B 16G 17 psi | eBay


Turbo Actuator DSM 1G EVO 1~3 VR-4 TD05H 14B 16G 22 psi | eBay

My boost jumps to 23 24 and by third gear 6000 rpm i am only pushin 15psi!
Will this help me?

has anyone tried the ebay stiffer ones yet?

Not that I know of. They appear to be fine in the ad but they're not adjustable compared to the ones I build....plus Holset actuators last years and hundreds of thousands of miles on their OEM applications- not too sure about those aftermarket eBay specials.