Bad MBC connection physics...what happened? (Everything okay now)

Shpyder · #1 07-28-2004, 11:58 PM

Ok guys, here is the update. I need some technical advice about what happened.

I had a joeP MBC installed by a shop. I ran my car like normal for a few stop and go runs..about 60 miles. The BOV had stopped making that whistle pop at throttle release the second the MBC had been installed. Instead it made a huge flapping noise. And my car seemed slower than before

The MBC had been installed WRONG. At home, this is what I saw: the MBC had one tube going into the BOV, and one tube going into the surge/boost tank (right after the T-connector for the boost gauge). I removed the MBC and replaced the BOV to surge tank conenction with the stock 3/16" ID (inside diameter) hose. Again, a test run still yielded a huge pfffssshhttt sound at after 5psi indicating a major loss of power (boost leak was obvious). Nothing had changed.

After 1 hour, I took it for a test run, and everything was PERFECT. The BOV made its wihtling and sharp psstt noise at soft setting and the car ran fast. No power loss. Everything good.

Questions:
1. what effect did the wrong tubing of the MBC have on the car in terms of airflow and boost?

2. why did my replacing the MBC with stock tubing not solve the problem immediatly, and took 1 hour?

Thanks. Just trying to get to know more about how things work (or don't work, hahaha).

JoeWagon · #2 07-29-2004, 12:20 AM

I don't know what you're talking about, exactly. What is a surge/boost tank?

No permanent damage.

Oh yeah, you've read the RKO post on all this, right?
http://racingknowledge.org/topic.asp?TOPIC_ID=117

Shpyder · #3 07-29-2004, 12:31 AM

oh...well...okay...you know the T-conector you need for a boost gauge hook-up right? you feed one line back into the BOV right? thats what I mean (i got the surge tank idea from a defi boost gauge instruction manual). From the T-connector nipple that is supposed to go into the BOV...that went into the MBC instead, and the MBC's other tube went into the BOV.

Shpyder · #4 07-29-2004, 12:32 AM

OK that website helped a lot! thanks.

kjewer1 · #5 07-30-2004, 01:23 AM

Must have had the MBC controlling pressure to the BOV rather than the WG. HArd to guess from your descrpition though.

Shpyder · #6 07-30-2004, 03:32 AM

Hey man...was it your cideos where you have a GSX whipping a vette? If so, whats the link again? All my budz want to see that sht.

JoeWagon · #7 07-30-2004, 08:32 PM

His website is conveniently located in his sig, but I don't recall a run with a corvette.

kjewer1 · #8 07-31-2004, 12:03 AM

I did add it for that tool that was telling us all to buy Impalas or something. Its Mike Rs 1g tearin it up. Doesnt show the whole run, but it was an 11.6. 2 tenths faster than my car.

But tonight he just ran a new best of 11.2 using sheps wheels/tires as I mentioned in another thread. Its on the videos tab on top of my page.

Shpyder · #9 07-31-2004, 12:11 AM

His website is conveniently located in his sig, but I don't recall a run with a corvette.--->LOL sorry i didnt notice his sig, hahah.

kjewer1 · #10 07-31-2004, 11:37 AM

He had previously been stuck in an 11.3 rut. To already have gone faster before really getting used to the way it launches shows whats possible. I think we'll see tens out of that car this year.

Damn, finally found his website and it seems to be down.. Oh well. Anyone going to the Shootout will see the car I'm sure

Here's the RKO post on it:

http://racingknowledge.org/topic.asp?TOPIC_ID=5822

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