Quick question, already searched . Boost on my car goes to 26 then settles at 20psi and about 6k it goes to 15 psi. It is not the snorkel for I have the clips in the trunk. i built a boost tester with a gauge and tested the pipes from the ic to the upper pipe and it held 25 psi fine. If I hook up the Throttle body I can hear a very faint hiss in the motor somewhere. I don't know if that is normal or is it suppose to hold the psi? I move the butterfly and there is no change in the faint noise I hear. I give up

 

why are u running 26 pounds off boost,the higher it spikes the more it will taper.are u running meth i would also check the plugs maybe the gap blew out?

 

I could not tell you why it goes to 26. I remember it use to spike a 23 and go to 20. I did run a log and I am not knocking. I check the plugs and they are fine.

 

The hiss maybe from a valve not fully closed. i guess. but if I put 20 psi from the ic, it slowly goes back to 0.

 

Searched for what??

https://www.evolutionm.net/forums/sh...d.php?t=225744 - if it hisses from tb

otherwise set your motor to TDC. And if you're looking at boost gauge - those are not accurate to determine what psi you run.

 

Read that. Its not coming from the tb. So I did search. Can anyone tell me if you put pressure in the motor is it suppose to hold or does it leak out?

 

It cannot hold, but it shouldn't leak out quickly.

If you didn't know why your boost went from 23 to 26, then wouldn't you just turn it down?

 

I know they are not acurate but 20 and drop to 15 And i do feel the car is not to it's potential up top.

 

That is cool, but the fact that i have boost taper real bad now. How quick does the air come out when you put pressure in it. It will all come out at about 45sec if I put 20psi in. The funny think is that it use to only go to 23 and taper to 20 now intermittent it goes to 24-26 ish. Is it poss for a mbc to do that? i have a dna motorsports.

 

^ That is plenty long enough to hold. You will have valves open so it will not hold pressure too long. Sounds perfectly normal to me.

 

Sounds perfectly normal to me. You will have valves open so it won't hold too long.

Damned double post HAHAH.

 

lower your boost a little,lower it to 22 pounds and see what happens...

 

What is DNA motorsports? Never heard of that. Not sure why you'd have an MBC from them, but I can't tell you if it's the problem or not. 45 seconds is a LOT of time, but you may still have a leak and don't know it. You need to spray soapy water all around, and you need to make sure you're doing the test right. You mentioned hooking it up to the IC, but it should be connected to the turbo inlet.

I assume you have an aftermarket open air intake?

 

I sprayed the soapy water. I did not do it to the turbo because of the fitting i made. i will try tomorrow. But for the hell of it I will take of the mbc and run it stock and see. thanks guys.

 

well i was testing more for a boost leak from the turbo and had to remove the fan. I manage to put a pin size hole in the radiator After cursing evryword in the book, I found that my mbc starts to bleed the moment i put pressure to the system. Is this normal? i could not see any leaks other than the mbc And did go to 30 psi . I'm stuck now. And now i have to figure out what I'm going to do with this radiator. i got sticker shock when the dealer said a rad from them is $860 .
A friend of mine said to bring it to a rad shop and let them fix it. It is just a pinhole, or should I say small than a pin hole.