TOO MUCH BOOST bleeding off (STS)
Then please explain it to me... ?
BTW
This is not true as like I said mine is referenced from the compressor and my boost control is perfect.
BTW
Originally Posted by Blackbird
if you want it to work right you need to run the reference from up front.
simple as that.
simple as that.
If you do reference it from the front you can put the MBC anywhere.
Just for the record I'm not saying referencing it from the front will not fix you problem... it most likely will... but you can leave it in the back with a restrictor as well and it will do the same thing.
Just for the record I'm not saying referencing it from the front will not fix you problem... it most likely will... but you can leave it in the back with a restrictor as well and it will do the same thing.
The MBC I'm using right now looks like it has a restriction built in. The 1/4" inlet has only a pin hole sized opening. I've been told by other supra owners that this bleed type MBC is 
this is the one recommended
The RX kit has a ceramic ball instead of the 316 stainless ball that comes in the Hallman Pro and Hallman ES valves. The ceramic ball weighs a fraction of what the stainless steel ***** weighs. This weight difference allows the ceramic ball to act very quickly as it is constantly changing directions during operation. This helps to minimize spiking, particularly when used with applications that produce lower boost.
The RX kit also includes a light spring. The light spring allows for very fine adjustment of boost up to 4 to 5 pounds of boost over "stock". Boost can be adjusted in as little as half pound (.5 PSI) increments very consistently with this valve.
The combination of the ceramic ball and the light spring make the Hallman Pro RX kit very well suited for the turbo enthusiast that wants to add a few psi of boost over stock, and have a great amount of control over those few pounds.
this is the one recommendedThe RX kit has a ceramic ball instead of the 316 stainless ball that comes in the Hallman Pro and Hallman ES valves. The ceramic ball weighs a fraction of what the stainless steel ***** weighs. This weight difference allows the ceramic ball to act very quickly as it is constantly changing directions during operation. This helps to minimize spiking, particularly when used with applications that produce lower boost.
The RX kit also includes a light spring. The light spring allows for very fine adjustment of boost up to 4 to 5 pounds of boost over "stock". Boost can be adjusted in as little as half pound (.5 PSI) increments very consistently with this valve.
The combination of the ceramic ball and the light spring make the Hallman Pro RX kit very well suited for the turbo enthusiast that wants to add a few psi of boost over stock, and have a great amount of control over those few pounds.
I borrowed my buddys hallman rx boost controller, and man this thing is great compared to the bleed style, The boost comes on sooooo much sooner, 
but alas the same drop in boost 
. So there it is, its confirmed, you do need to reference off the front of the car. Sorry for being such a hard ***, but I need to test stuff out myself, for me to believe it. I will be running an 1/4" aluminum line from near my brake booster down to the charge pipe and into the wastegate.
but alas the same drop in boost . So there it is, its confirmed, you do need to reference off the front of the car. Sorry for being such a hard ***, but I need to test stuff out myself, for me to believe it. I will be running an 1/4" aluminum line from near my brake booster down to the charge pipe and into the wastegate. 
TECH Addict
Joined: Nov 2001
Posts: 2,659
Likes: 1
From: Bellevue, Wa
it's good that your not just a blind sheep following the herd. you tested, you learned, now you can fix.
let us know how it turns out after the change, the top end should feel sooooo much better.
let us know how it turns out after the change, the top end should feel sooooo much better.
Originally Posted by HydroStream6
Then please explain it to me... ?
BTW
This is not true as like I said mine is referenced from the compressor and my boost control is perfect.
BTW
This is not true as like I said mine is referenced from the compressor and my boost control is perfect.
for those of us that want to run off the wastegate, or CAN't turn the **** up any more
and nothing is going to catch the line from under the car.... there are the other fuel lines and other lines right up there to the left of the driveshaft... i don't think a small hose run along with those is going to get caught on anything.
now if you go mudding... or drive in the woods... have fun ripping everything out from under your car.
also, you are measuring pressure, you want X pressure on the intake side going into your motor... place your reference at your intake..and you will see X pressure there. Now, if you have no intercooler or anything cept' STS's piping, you can just run off the gate
this is my 0.02 cents
On The Tree
Joined: May 2004
Posts: 100
Likes: 0
From: Breese, IL
There's 3 points of pressure talked about here...
A) compressor housing
B) after intercooler
C) intake manifold
Pressure measured at each location under boost will be different: A > B > C
The more piping and the more inefficient the intercooler, the bigger difference there will be between A and B. The more restriction between B and C (throttle body blades half closed as an example), the bigger the difference between B and C.
The measure of boost available to the cylinders is C, which is why your boost gauge is referenced there.
Using A as your reference for opening the wastegate doesn't take into account the pressure drop between A and C. If you're using A as the wastegate reference point and dropping pressure measured at C, it's likely that the difference from A to C is growing due to a pressure drop across the intercooler.
There's 9psi at A, causing the gate to open, and 6psi at C, showing on your boost gauge, which accounts for a 3psi drop across the intake path between the compressor housing and the intake. Most of this is probably a pressure drop across the intercooler. Pressure drop across an intercooler is not constant and increases dramatically as you approach its maximum flow.
A) compressor housing
B) after intercooler
C) intake manifold
Pressure measured at each location under boost will be different: A > B > C
The more piping and the more inefficient the intercooler, the bigger difference there will be between A and B. The more restriction between B and C (throttle body blades half closed as an example), the bigger the difference between B and C.
The measure of boost available to the cylinders is C, which is why your boost gauge is referenced there.
Using A as your reference for opening the wastegate doesn't take into account the pressure drop between A and C. If you're using A as the wastegate reference point and dropping pressure measured at C, it's likely that the difference from A to C is growing due to a pressure drop across the intercooler.
There's 9psi at A, causing the gate to open, and 6psi at C, showing on your boost gauge, which accounts for a 3psi drop across the intake path between the compressor housing and the intake. Most of this is probably a pressure drop across the intercooler. Pressure drop across an intercooler is not constant and increases dramatically as you approach its maximum flow.
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Teching In
Joined: Jan 2007
Posts: 12
Likes: 0
From: Minnesota
Good explanation.
I would still get a ball and spring type MBC though. As you noticed the difference can be dramatic. Most of that is from the WG starting to crack open when boost starts to come up. The ball and spring MBC keeps it closed till you’re at the set boost pressure. Turbo XS does make a ball and spring type that also has a bleeder. I have used these to control boost from 8-33 PSI (turbos wouldn’t make anymore), they work very good. I should note that those were two different cars, MBC’s typically are able to bump boost up ~15-20PSI above the WG setting if everything else can handle it. The down side is they are kind of spendy, ~$175 IIRC
Last edited by LittleV6; Jan 26, 2007 at 12:00 PM.
Originally Posted by Blackbird
guys, go do a search, this has come up many many times before this.
take the signal after the FMIC and the problem will go away.
take the signal after the FMIC and the problem will go away.
Blackbird is correct, boost source to gate after the FMIC will fix the issue. I had the same problem.
I ran the hard line now and it seems to be working perfect. I'm glad I turned down the boost controller to "0" thought. Forgot I had a .5bar spring in there, now it hits a steady 7psi in fourth gear. So I'm gonna turn it up 1 psi unless some one wants to trade for a slightly smaller spring?
I had the turbo xcess mbc but I have up graded to eboost2 and love it. The prob I had was the same as yours I was told that the inputs where way to small. I referance from the intake and break boost line and have a steady 5 psi now in every gear.
Originally Posted by ZL1Killa
becuase you simply turn the **** up.
for those of us that want to run off the wastegate, or CAN't turn the **** up any more
for those of us that want to run off the wastegate, or CAN't turn the **** up any more
He was running a MBC, not off the WG spring. Why can no one else understand this? If he would have put in a restrictor and left the reference at the rear it would have been fine.
Glad you got it fixed either way, should feel much better now.
I guess my setup just defys physics
Bringing back the dead. Well this post atleast. So I thought everything was okay but the otherday I had a lead foot and now have some new Q's. In 3rd, 4th, and 5th I hit 8psi and it holds 8psi all the way. 1st gear I his 6psi and drop to 4 by red line and in second I his 8psi and still drop to 5 by redline WTF. Is there just not enough load?
Originally Posted by 2002ws-6
Bringing back the dead. Well this post atleast. So I thought everything was okay but the otherday I had a lead foot and now have some new Q's. In 3rd, 4th, and 5th I hit 8psi and it holds 8psi all the way. 1st gear I his 6psi and drop to 4 by red line and in second I his 8psi and still drop to 5 by redline WTF. Is there just not enough load?
This is a little off topic, I plan on getting a turbo set up down the road but I am new to FI so I am learning as I go. Why would you lose boost if there is no load? If your rpms are still up there I would imagine it would be the same.
