Won't make more than 4lbs
#1
Won't make more than 4lbs
I have a 03 with ms3 from braineack. I have had a tuner come out to the car 4 times now. Every time he came we only got so far because I had to fix certain issues before we tried again... 1. Bad wideband o2 2. Downpipe was too short 3. Fuel injectors 4. Boost leaks. After fixing every little leak possible, it holds 25psi with no leaks at all. There are no exhaust/wastegate leaks either. Its externally gated. No leaks there. Wastegate was bench tested and opens at 7 ish lbs. That being said... it has never even opened. The cars runs good. AFRs are good at idle and at cruise. Under throttle it is fine as well but under "full" throttle it will shoot for 13-14.7 AFRs. It's like the car is N/A 😥. No matter what RPM it's at it pegs at 4psi and stays there. Would AFRs too "lean" under throttle (13-14.7) be a cause of no more than 4psi?
Last edited by 1stgen<3; 04-05-2017 at 12:38 PM. Reason: Spelling
#4
The wastegate is hooked up directly to the end of the compressor housing. No boost controller just spring pressure. I even disconnected it completely to see if it would budge over 4. Nothing still. I'll post a log when I get home. It's 57trim w/ .63a/r. The tuner has a good reputation in the community knows a lot about megasquirt.
#13
Boost Czar
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here's another thought, are you using a water jack port and not a boost port?
exhaust pressure can overload the spring pressure and push it open and divert turbine. if you plumb boost to top, that boost pressure will exhort extra force and hold the spring closed -- and major boost will ensue.
exhaust pressure can overload the spring pressure and push it open and divert turbine. if you plumb boost to top, that boost pressure will exhort extra force and hold the spring closed -- and major boost will ensue.
#14
Ya I'll try that when I get back. I will say though I can't even push it open with my hand. Not sure how strong mani pressure is but... ill send the boost to the top to hold it shut and see. Another side note... when I look in the dump tube there is absolutely 0 sign of any exhaust ever running through it
#17
SADFab Destructive Testing Engineer
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You are probably running out of fuel. That could be why it goes lean, and that could be why it wont build boost.
Who is your tuner? I'd like to know so I know who to never let tune my car....
Who is your tuner? I'd like to know so I know who to never let tune my car....
#20
It's counter productive to get defensive and cocky when asking for help, especially on a forum where we can't see all the mistakes or issues with your car and taking your word for mechanical soundness of the work.
*edit: richen it up and at least eliminate that variable.
Last edited by 18psi; 04-05-2017 at 04:39 PM.