EJ1 wilcox

Okay, so I went to the track on Friday and wasn't satisfied with my times at the only 7psi I am running on my car...

So yesterday I went to a local shop and picked up a turbo xs manual boost controller so I can turn the boost up a bit!

I installed it according to the instructions that came with it. I ran a line from the compressor nipple to the side port on the MBC and then a line from the bottom port of the MBC to the wastegate nipple. I turned the adjusting screw all the way closed (clockwise until it won't turn any more) and then backed the screw off three turns like it says to do in the manual.

I went for a ride to see if it worked... I gave it a little gas in 2nd and the boost shot up to 11psi before I let off the gas... okay, so a little too much. I stopped and adjusted the screw all the way closed which should put me back to my wastegate psi (7). I went for another ride but again, the boost shot up to 11psi before I let off the gas.

So, is the turbo xs MBC not meant for low boost applications? I mean, I have it all the way closed and it still is set at more than 11psi, I didn't even hear my wastegate starting to open at 11, which means it's set higher than that.

I already emailed turbo XS but I figured I'd ask you guys first as I'm sure there are others on this board running the same boost controller.

Sorry this one was a little long!

*cliffs notes* ---> my Turbo XS MBC won't adjust down to 9psi like I want it to. What should I do?

Thanks!

b00sted4dr

bump for you.

simike

I have used a Turbo XS high performance MBC in the past and found it hard to get it to work at low boost levels. The lowest I could get it was 8-9psi which is what I wanted anyway. Bump for more info.

EJ1 wilcox

Here's how I have it installed...





I'm pretty sure I have it right...

I need to get this figured out this week in case I need to take it back and get something else...

Thanks for the help so far!

BoOsTeD C1

the top port of the wastegate should be used for boost controller
opps...you got a mbc


Modified by VTEC_pWrD_CiViC at 4:00 PM 5/23/2005

DIRep972

iTrader: (1)

What size ID is your vacum line? You might need something a bit smaller. Or it is possible you have a bad boost controller cause it should have no problems getting boost down to the wastegate spring.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VTEC_pWrD_CiViC &raquo;</TD></TR><TR><TD CLASS="quote">the top port of the wastegate should be used for boost controller</TD></TR></TABLE>

not w/ a manual controller.

rmcdaniels

It looks like it is installed correctly. If you turn it all the way CW, then it should just run your WG pressure.

T-RO

I would make the lines as short as possible. I think that will make a difference.
I am using the same MBC. Mine when all the way closed is at 10psi (what i want), even though my (internal) WG is liek 8psi.

Thurman Merman

ground zero or race dezign?

ive got the same MBC that i'll be isntalling on my car here soon.... if i were you, i'd try to run the vac line shorter or have a smaller ID line running to it like DIrep said.

crx4life2002

u need to drill out one end of the mbc. Ull notice one end has a really tiny vaccum passage, I drilled it out equal to the other end and it was fine

97BLACKCIVIC

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EJ1 wilcox &raquo;</TD></TR><TR><TD CLASS="quote">I went for a ride to see if it worked... I gave it a little gas in 2nd and the boost shot up to 11psi before I let off the gas... okay, so a little too much. I stopped and adjusted the screw all the way <U>closed</U> which should put me back to my wastegate psi (7). I went for another ride but again, the boost shot up to 11psi before I let off the gas.

Thanks! </TD></TR></TABLE>

Ok if im not mistake you said that after you boosted 11 psi u closed theboost controller which will make u boost more. you get what im sayin

If you need me to explain more let me know

EJ1 wilcox

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 97BLACKCIVIC &raquo;</TD></TR><TR><TD CLASS="quote">Ok if im not mistake you said that after you boosted 11 psi u closed theboost controller which will make u boost more. you get what im sayin

If you need me to explain more let me know</TD></TR></TABLE>

Yeah, I know what you are saying, but that is the way the TurboXs instruction manual says to adjust it... it says to turn it clockwise for less boost and counter-clockwise for more boost. But even when I have it all the way clockwise it still won't hold low boost.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crx4life2002 &raquo;</TD></TR><TR><TD CLASS="quote">u need to drill out one end of the mbc. Ull notice one end has a really tiny vaccum passage, I drilled it out equal to the other end and it was fine</TD></TR></TABLE>

I did notice that the one end that runs to the compressor has a really small hole on the inlet, that's what you are talking about right? Hmmm, that would make sense, maybe I'll try that before I do anything else.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Thurman Merman &raquo;</TD></TR><TR><TD CLASS="quote">ground zero or race dezign?

ive got the same MBC that i'll be isntalling on my car here soon.... if i were you, i'd try to run the vac line shorter or have a smaller ID line running to it like DIrep said.</TD></TR></TABLE>

I actually got it at Speed Concept. Ground Zero was out of MBCs and I forgot to call Race Design. Speed Concept had them in stock at a good price and I live pretty close to them anyways.

The vacuum line I am using should be fine, its the perfect side to fit over the wastegate barb, I took the barb in and got emissions hose that fit over it perfectly, it's also the same hose I am using for my blow off valve and the same stuff I was using for my wastegate line before as well... I don't thing that is the problem but I can try some smaller stuff out if nothing else works. I just don't know if I can get smaller tubing to fit, I have a hard enough time getting the hose over the barbs at this size, it's tight enough that I have to cut the hose off the barb on my wastegate, it's too tight to pull off.

Thanks for the help so far.

fjt

I have a different MBC(turbosmart) and when i installed it it boosted 2PSI more than what i had it set before adding it..Even with the MBC closed all the way it boosted 2 PSI more..

Thurman Merman

damnit, i was going to say tony @ speed concept

yeah, now that i thought about it over night, your hose size should be fine, but the other guy did bring up a valid point about drilling one of the fittings to make it equal in size to the other..... more than likely if i have this problem, you'll be getting a PM from me too

dustin

I've got a .25 bar WG spring if you want it... hehe.

EJ1 wilcox

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dustin &raquo;</TD></TR><TR><TD CLASS="quote">I've got a .25 bar WG spring if you want it... hehe.</TD></TR></TABLE>

If you were local and willing to give it to me than I might consider. Thanks anyways!

I just don't want to spend more money just because the product is not working correctly. If I can't get it to work within a few days I will just take it back and try the TurboSmart MBC.

Unsivil_audio

Right now your trying it as a restrictor valve, I'm not 100% on this but all the MBC's I've used; I used like a bleeder valve (i.e. put a "T" between the wastegate and compressor, run that line to the inlet on the MBC and leave the other end open, to bleed off pressure into the atmosphere). I think that will work much better for your application.

DIRep972

iTrader: (1)

Another you could try is changing your pressure source from your compressor housing to your intake manifold.

Boostfed

Yes I meant to reply to this last night. Make the lines as short as possible and closest to the wastegate and boos source as possible. Check your diameter on hoses and as Chris said try getting the boost source from teh intake manifold THAT will actually have you boosting more though

crx4life2002

Like I said, drill that bitch out and you will be mint. Correct me if im wrong but the idea behind a mbc is to block vaccum to the wastegate? Doing this will inevitably increase your boost. What I figured was that the smaller vaccum port was blocking to much air thus spiking the boost.

turboteg2nv

^^ Seems to make sense. Hmmm...need to do some research! I was also thinking about getting one for low boost, we'll see how this thread turns out.

EJ1 wilcox

I will drill the hole out tonight after work and we will see if that works!

99lspwr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EJ1 wilcox &raquo;</TD></TR><TR><TD CLASS="quote">I will drill the hole out tonight after work and we will see if that works!
</TD></TR></TABLE>

I did this exact same thing with mine because I was having some spiking issues, and turbo xs suggested to drill out the fitting as well...Well the spiking issue was fixed, but it would not boost over 7 psi no matter how you had the screw adjusted..

*Boostwerks*

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crx4life2002 &raquo;</TD></TR><TR><TD CLASS="quote">Like I said, drill that bitch out and you will be mint. Correct me if im wrong but the idea behind a mbc is to block vaccum to the wastegate? Doing this will inevitably increase your boost. What I figured was that the smaller vaccum port was blocking to much air thus spiking the boost.</TD></TR></TABLE>

Umm no. When your in boost, you don't have vaccum

Most MBCs hold boost pressure from the side port of the wg (which opens the valve) by using a ball and spring. The boost pressure must overcome the spring pressure of the MBC before it can escape into the WG and thus opening the valve. This increases boost pressure, as well as spool up time.

The reason that your turboXS controller won't let you go less than 9psi, is because even though you backed out the adjustment ****, the ball and spring are still slightly preloaded (just a tiny amount). This just holds off the boost from the WG just for a fraction of a second and increases the boost. If you shorten the line, the less boost you will have, but I don't know if that would even make a noticable difference

EJ1 wilcox

This evening I drilled out the side port on the MBC. Before I drilled out the fitting I took it apart so I didn't get any shavings inside and was able to get a good look at the way the boost controller works...

The TurboXS MBC that I have is NOT a ball and spring type controller but rather a simple bleeder valve.

There is no spring, and no ball. When the valve is all the way closed (clockwise) then the signal simply travels through the boost controller as if it weren't there. But, when you turn the valve counterclockwise, the valve opens little by little and allows some of the boost pressure to bleed off, thus increasing the amount of boost needed to open the wastegate.

Okay, so now that I figured that out and have a pretty good idea of how it works I am sure that by drilling out the fitting I will improve it's low boost performance.

I didn't get a chance to take it for a spin (because I had to get my son to bed), but I will give it a rip in the morning on the way to work and see what happens. I opened up the hole from very very tiny, to the same size as the other port, which was 1/8".

Anyways, I'll let you know if it works in the morning. Just wanted to clear up any questions about whether this is a ball and spring type valve or bleeder valve. I am glad it is a bleeder valve because there are really no parts that can wear out over time.