over boosting

Redline · Post by **Redline** » Sun Apr 29, 2012 11:42 pm

Ok i been working the last little issues out with my car so i can tune for more boost. This issue has me stumbled

I am over boosting it never stops just keeps going. I have a off brand manual boost controller. I have a vacum line coming off the turbo to the bottom wastegate port. A t split half way with a boost controller ran to the top port. With my boost controller turned all the way down it will run off the spring 7psi but if i turn the controller 1 click or 20 clicks it just boost to the max. Any clues why this would happen.

Also i have another boost controller but it acts back wards if i turn boost up it goes down and it i turn down it goes up.

v-tecivic · Post by **v-tecivic** » Sun Apr 29, 2012 11:59 pm

With the manual boost controller, you only need to use the bottom port on the wastegate. It should go from turbo(or other boost source) to bottom nipple on the mbc, then from the mbc to the bottom wastegate port.

Redline · Post by **Redline** » Mon Apr 30, 2012 12:11 am

When i had it like that before i would hit my boost mark then creep back down as the rpms went up

5thgen · Post by **5thgen** » Mon Apr 30, 2012 12:13 am

v-tecivic;292962 wrote:With the manual boost controller, you only need to use the bottom port on the wastegate. It should go from turbo(or other boost source) to bottom nipple on the mbc, then from the mbc to the bottom wastegate port.

Exactly.

When you have it going to the top side you are actually helping push the valve/ diaphragm downward to close the valve....so no exhaust escapes, it just goes into the turbo making it spin more.

Redline · Post by **Redline** » Mon Apr 30, 2012 12:18 am

Ok thanks guys

Redline · Post by **Redline** » Mon Apr 30, 2012 12:42 am

Ok so what would make my boost creep back down after i peak at 5k rpm and still have 3k to go

rickles8099 · Post by **rickles8099** » Mon Apr 30, 2012 12:20 pm

Redline;292966 wrote:Ok so what would make my boost creep back down after i peak at 5k rpm and still have 3k to go

too small of a turbo, too big of a wastegate, or boost leak, or faulty wastegate.

Redline · Post by **Redline** » Mon Apr 30, 2012 5:06 pm

Its probley the turbo its the only cheap thing of my build its a ebay and i wasw running 16psi, it would hit it fast then creep back down to like 12 or 14

Boosted_da · Post by **Boosted_da** » Tue May 01, 2012 6:19 am

rickles8099;292998 wrote:too small of a turbo, too big of a wastegate, or boost leak, or faulty wastegate.

i would have to agree with rick you probably need a bigger turbo

crimsoncivic · Post by **crimsoncivic** » Tue May 01, 2012 12:53 pm

Boosted_da;293076 wrote: you probably need a bigger turbo

Lol isn't that always the answer :rock: