vacuum leak on nick williams 102 tb
03-09-2013, 09:28 PM
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vacuum leak on nick williams 102 tb I have been hunting down vacuum leaks forever now it seems and finally decided to do a turbo test a friend of mine did on his mazda speed.
So I took a 3" pvc cap and put a tire schrader valve through the top of it so I could pressurize the intake and look for leaks. I found at 3 psi (using a vacuum/pressure gauge to watch the pressure) the throttle blade was leaking out the side.
I can't imagine that this is how its supposed to be because that would be un-metered air getting sucked in during vacuum situations.
My hope is that someone else has seen this and can confirm one way or another.
So I took a 3" pvc cap and put a tire schrader valve through the top of it so I could pressurize the intake and look for leaks. I found at 3 psi (using a vacuum/pressure gauge to watch the pressure) the throttle blade was leaking out the side.
I can't imagine that this is how its supposed to be because that would be un-metered air getting sucked in during vacuum situations.
My hope is that someone else has seen this and can confirm one way or another.
03-10-2013, 10:52 AM
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Going to get a video posted of the problem area sometime tonight. Is this an acceptable leak and that is why no one is replying? I wouldn't think that any unmetered air would be acceptable but wouldn't be the first nor last time I am wrong 
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03-11-2013, 01:53 PM
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It is actually a very small leak. There is less than .0005" clearance around the bearing and shaft. What you are seeing is coming from that and what air can get past the seals on the bearing.
I can assure you that this isn't the cause of any issue you may be having.
Nick
I can assure you that this isn't the cause of any issue you may be having.
Nick
03-11-2013, 02:21 PM
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It is actually a very small leak. There is less than .0005" clearance around the bearing and shaft. What you are seeing is coming from that and what air can get past the seals on the bearing.
I can assure you that this isn't the cause of any issue you may be having.
Nick
I can assure you that this isn't the cause of any issue you may be having.
Nick
I have less than 1000 miles use on this throttle body (just wanted to throw this in because I have had it for 2 years, car doesn't get driven much). You may be right and there may be more to the puzzle but I would like to solve this one if I can.
If you think its at all possible that I have a defective unit I would at least like to try to work something out where I could get it functioning without leaks.
03-12-2013, 03:59 AM
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ive got a NW 92MM and it does the same thing leaks at the throttle shaft on the outside i think its unacceptable IMO the stock one dosent leak i had a EVAP smoke machine to test mine out
03-12-2013, 08:54 AM
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Very useful info, thank you for that. I was wondering if anyone had the smoke test performed. I am going to try out the fast 92 big mouth and compare.
Last edited by gokussx4; 03-12-2013 at 08:55 AM. Reason: Misread the post
03-12-2013, 10:05 PM
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This is 3psi of air, about half of a common supercharger setup. So the equivalent in vacuum may be off here but the point is that it started leaking with +-1 psi. I just took it to 3 so I could watch it leak down.
03-13-2013, 05:53 AM
#19
if you are FI go ahead and tell us how many hundred CFM your charger pushes and take the reciprocal snd that will be the percentage of a "leak" you have ther. That assumies its about 0.01cfm leak rate.
My point is youre overestimating the leak if NA or youre worried about a meaningless ~0.2% leak if FI. Its like being pissed at the charcoal canister for wasting your fuel.
03-14-2013, 02:53 PM
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I assumed you were na. Point is the pressure difference. The sign of that pressure difference is irrelevant unless we are talking about something like a check valve.
if you are FI go ahead and tell us how many hundred CFM your charger pushes and take the reciprocal snd that will be the percentage of a "leak" you have ther. That assumies its about 0.01cfm leak rate.
My point is youre overestimating the leak if NA or youre worried about a meaningless ~0.2% leak if FI. Its like being pissed at the charcoal canister for wasting your fuel.
if you are FI go ahead and tell us how many hundred CFM your charger pushes and take the reciprocal snd that will be the percentage of a "leak" you have ther. That assumies its about 0.01cfm leak rate.
My point is youre overestimating the leak if NA or youre worried about a meaningless ~0.2% leak if FI. Its like being pissed at the charcoal canister for wasting your fuel.
How can you say the leak is that much? If the test method I have used does not provide conclusive results (soap bubbling) then you can't assume a certain amount of leak. How do you know that the problem isn't a busted seal in the bearings? I would imagine that since there is a o-ring seal in the assembly of the shaft and bearings that the point of the o-ring is to seal it up.