another MBC problem?

[4drboost]

Ok, I did search, no real luck. I installed a Turbo XS boost controller, the directions said to first turn the adjuster screw fully closed, than turn three times, causing the boost to rise 1 to 2 pounds. Well, with my boost controller fully closed, with 75% throttle my car was spiking 10 to 11 pounds. I did search and found installation instructions, and followed them. So I hope I didnt install it wrong. What do you think it could be? Im just a little freaked out, you know, spiking ten pounds on a practicaly stock MSP that I still owe money on (yea I know, my stupidity) I just want I to work thats all. Any help would be great

thanks,
Ian

[low_psi]

Did you use the stock vaccum lines or did you replace them? Is the turbo making boost as quickly as it was before installation of the MBC?

[BOOSTR]

Not sure which TXS you have, but you won't need to turn as much as they say to increase the boost a bit. With it locked down, your boost should be at your stock level. Mine is a dual stage TXS and stage 1 is off and registers 6.9 psi of boost. I turn the second stage 4-6 times depending on the weather and race fuel availability.

TXS has an excellent customer service feature on their website. You can send them an email and they will help you fix the problem. It does seem like you have something improperly installed or perhaps a defective unit. I have two TXS boost controllers and have never had a problem with them. Between the two of them, I have logged over 100,000 miles on them without any issues.

[4drboost]

No, I did replace the vacum lines. The one coming off of the wastegate, was crap, it was hard and brittle. And I have just the standard XS boost controller. It was weird, coming home, I was in third, and gave it about 75& throttle, and it stuck at about 5 or 6 psi. It was fully closed, so I figured, ok, its working. Than slowing down, I went into second, and at about half throttle, it went back up to ten again, and It feels like I could just keep going, thats why I was scared to go full throttle the entire night. Well, thanks for the help

Ian

[4drboost]

Ok, I think I figured it out. This morning, I tightened it till it couldnt turn anymore, I mean, it got tight at like 70% turned, but I still had a little more to go. Anyways, that gave me about stock boost, it was about six pounds. But this thing is sensitive, Turbo XS says, one full turn is one pound, well, like three little clicks brings me from 5 to 10. I dont know if this is normal. Also, I am spiking like 2 pounds. Now, it spikes like 12 than goes down to about 9 or 10. Well, if anyone has anymore ideas let me know

thanks guys
Ian

p.s. 10 pounds is fun!!

[jeffmsp]

your motor wont last long at 12psi without sufficient supportings mods. To give you an idea, I have a 12-13psi spike to 10psi@redline with the mods listed in my cardomain. I would definately stay away from 10+psi or your taking the motors life into your own hands lol Boost will vary depending on what gear you are in, try to keep it around 8-9lbs if you do not have many mods.

[jeffmsp]

btw when you are playing with your mbx adjusting it, take out the IAT sensor in your airbox and try to play it as close as possible to your rad fan or other hot areas so that timing will be retarded while you tune the mbc making it a bit safer for you. also you really should look into higher than 91octance if you have access to it, or a set of colder copper plugs and 91 octane should be ok up to 9psi ish, then I would look into higher than 91 in every tank or look into a methenol injection system as well as supporting mods like SMIC or FMIC and turboback exhaust if you wanna go 10+psi.

[4drboost]

Yea, your probebly right. Now, I only spiked it like five times doing testing, but I let off right away, so hopefully I didnt do any damage.

[jeffmsp]

Yea, your probebly right. Now, I only spiked it like five times doing testing, but I let off right away, so hopefully I didnt do any damage.


yeah its happend to me alot of times,since you are not going wot there isnt as much load on the motor so you should be ok. What I would reccomend is picking up a compression tester. They are not very expensive, and give you a great idea of how your motor is holding up. If you are worried about the spike you could pull the spark plugs and inspect them and the top of the pistons to see if anything bad happend.

[4drboost]

Yea, I actually had one, I used it alot on my Probe when I ran nitrous. And I ordered plugs a few days ago. What should good compression on a MSP be? 180 or so?

[4drboost]

Ok, Im not sure about this thing. Does everyone with a MBC spike all the time? Is that just how it is? I have been playing with this thing for two days, Its soooo damn sensative. Today it spikes like 11 pounds, than falls to about six. I want it to just be set at about 8. but that means, everytime I get on it, im going to be spiking what, like 14? Am I doing something wrong? Did I install it wrong? I mean, when its closed I get about 6 pounds. Than, I open it ever so slightly, it seems like it could go to 20! I cant find a medium. Sorry, im just a little stressed cause of this. well, any help is great!! Thanks

Ian

[BOOSTR]

It still sounds like you either have a defective MBC or installed it wrong. Sometimes a 1/4 or 1/2 turn is enough to affect the boost. Given your location and extreme winter temps, I suggest that you keep your controller off!

[4drboost]

Yea, I know, I have it all the way down for now. I figure once spring comes, along with my DP, ill mess with it then. Well, heres what I did for install. There is a T next to the BPV. The bottom of the T has a hose going to the wastegate, I removed that hose, and connected it to the bottom of the MBC. Than, I attatched the given hose from the MBC, and attatched that to the T, than to the side of the MBC. I hope that makes sense. I got the instructions (with pics) for the Joe MBC or whatever. So do you think its installation error, or should I bring the MBC back?