Low/No Boost; Help
03-25-2008, 12:29 AM
#1
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Low/No Boost; Help Alright, My car is back together now but it has a problem. It wont boost unless the waste gate reference is completely disconnected. Then it makes about 8psi max. There is a 6 psi spring in the gate. Tune is super rich with really conservative timing to keep it safe untill the boost issue is figured out.
408 motor, rear mount tc76 (.96ar), TRT FMIC w/ BOV, car is an auto. The standard STS setup had no problems making boost. Turbo is brand new from FI.
What do you guys think?
408 motor, rear mount tc76 (.96ar), TRT FMIC w/ BOV, car is an auto. The standard STS setup had no problems making boost. Turbo is brand new from FI.
What do you guys think?
03-25-2008, 12:38 PM
#3
Sounds like the wastegate is not set up correctly, or the spring really isn't a 6.
For example, to make just 1-2 psi, having the reference line hooked up or not shouldn't make any difference at all. 1-2 psi shouldn't be able to push a 6 lb spring open.
If you are careful, you could test with a block-off plate in place of the wastegate and see if you get more than 8 psi. That would tell you if the wastegate isn't holding.
Another thought is if the BOV or some of the piping is leaking, or there is something in the piping obstructing the flow. Then a boost gauge at the front could read lower psi that what a reference line at the back is feeding the wastegate. You could move the boost gauge to read at the wastegate temporarily, to see.
For example, to make just 1-2 psi, having the reference line hooked up or not shouldn't make any difference at all. 1-2 psi shouldn't be able to push a 6 lb spring open.
If you are careful, you could test with a block-off plate in place of the wastegate and see if you get more than 8 psi. That would tell you if the wastegate isn't holding.
Another thought is if the BOV or some of the piping is leaking, or there is something in the piping obstructing the flow. Then a boost gauge at the front could read lower psi that what a reference line at the back is feeding the wastegate. You could move the boost gauge to read at the wastegate temporarily, to see.