The Alchemist

iTrader: (19)

Well, I just tested my and I have 2 pretty bad leaks, at least I think they are bad. One is at my iat sensor and the other is at the proflo valve. I wanted to change both anyways, so I'll kill two birds with one stone. My IAT is slow as dirt to respond. It doesn't even react to methanol being sprayed on it.

Anyway, here's my video. I set the pressure to 17-18psi and it's pretty loud the leaks. I'm wondering how much boost I'm losing between the two leaks.

Blackbirdws6

iTrader: (7)

How much pressure did you run through the system? If you ran a lot, the leaks will be more noticeable for sure. They sound significant.

The Alchemist

iTrader: (19)

That was only 15-18psi, which is what I would expect to see at higher rpms. I think they are significant. Well, after tonight, I'll have the stuff ordered to replace them.

11SECSS

iTrader: (199)

yeah that's crazy the IAT is leaking like that ,maybe the proflo isn't closed all the way ?

98Camarod

iTrader: (43)

The threaded IAT is from a cyclone, mine doesn't leak

Blackbirdws6

iTrader: (7)

Yea at that pressure you have some significant leaks. As to how much you are losing, we could both do some fancy engineering calcs to figure it out but in the, you will just fix the leaks and log the results . I asked the question to make sure you weren't pushing 50+ psi through everything.

The Alchemist

iTrader: (19)

One way to figure out how much is leaking is to leave the regulator as it sits, the cap off the leaks and see how much the pressure rises. I'm more interested in just fixing the leaks.
I started with the regulator completely closed, then slowly started opening the regulator till I hit just a tad over 15 psi, and not yet 20psi. It's one of those that goes up to 200psi, so at 15-20psi, it's not entirely accurate.

So is this a fast responding iat sensor?

http://www.summitracing.com/parts/dfp-ts10077/overview/

qqwqeqwrqwqtq

Did you have a line tee'd off of your pressure source to the reference line on the bypass valve?

The Alchemist

iTrader: (19)

No, but yes. I left the intake tract connected through the motor, so technically the manifold was seeing 15psi as well, and the bypass valve line comes from the manifold.

One thing I'll do today is turn on the ignition to get a reading from the map sensor to see how much boost the manifold is seeing. I'll also investigate the proflo to make sure it's closing completely. I thought there was an adjustment on it. Maybe it's not closing all the way.

RONSBLACK1998TA

Iam just guessing but wont there be a leak at the open valve on any given cylinder through the intake manifold? No way every valve can be closed on every cylinder unless the camshaft isnt in the car. This car isnt taken apart so the cam must be in the car. Maybe iam missing something.

The Alchemist

iTrader: (19)

As long as one valve is closed, then you have a closed system. If the intake valve is open, then most likely the exhaust valve is closed, and vice-verse.
You're right, in theory... that at the specific point of valve overlap, you will have an open intake valve and exhaust valve, so you could lose air there. Remember though, that lifters are hydraulic, and bleed down over time, so there's a good chance that the little bit of overlap will actually bleed down and the valves will close. Maybe not 100% but that's ok. I'm still hearing and feeling a massive leak from the IAT sensor and the proflo valve, both of which need to be replaced, so it's not a huge concern.

qqwqeqwrqwqtq

I would guess manifold pressure was close to zero (assuming the throttle blade was closed during the test). That would explain the bypass valve leak but let me know what you find.

The Alchemist

iTrader: (19)

The manifold was definitely pressurized, I tried it again yesterday and confirmed via hptuners that it was at 208kpa, or 16psi. I opened and closed the throttle body and the manifold was charged with plenty of pressure.

I manually checked the proflo and there was air being pushed past the butterfly valve. I was able to manually open and close the valve and the pressure was closing the valve, its just blowing air past the valve. I pulled the valve out and checked it, and its just leaking. I think at 10 to 12 psi its fine, it just can't hold 15+ psi of boost, so its being replaced with a TiAL. I'm alos replacing the iat sensor with a bung and screw in sensor.

I don't know how much air was leaking, but it was a fair amount.

stevieturbo

Is the seat on the valve damaged or something ? Or any obvious signs as to why it was leaking ?

The Alchemist

iTrader: (19)

Its a butterfly valve, and air is just pushing past it. I guess its why Procharger recommends it for systems less than 600hp.

The Alchemist

iTrader: (19)

Just for clarification, this is the bypass valve that I'm talking about:

http://procharger.com/store/index.ph...d&productId=20



It's a butterfly valve just like a throttle body, and with it fully closed, air gets by. Too much for my liking.

stealth355tpi

I know you don't want to do this with your fast intake, but I have my iat threaded into the back of my ls6. That way I can tell how hot the air is in the back cylinders. I'll have to check which sensor I'm using but it is a threaded one and changes as soon as the meth comes on. I'm curious to hear how the tial sounds compared to my race valve.

Preston99WS6

iTrader: (7)

Alchemist

This is what you need, This screws in and seals/works well, and its plug and play.
http://shop.advanceautoparts.com/web...GRPSENSAMS____

stevieturbo

Ahh right, thought it was a proper valve style. Cant imagine a throttle style would ever seal properly ?

Cam72aro

iTrader: (28)

You motivated me to do a pressure test on my car now. I went to homedepot and got an air fitting and PVC pipe plug. Cost a total of $6. Put it all together and have several leaks. Throttle body gasket, iat bung, etc. now time to go down the line and fix them.