08-13-2007, 10:37 AM #1
Hard to find boost leak ... Help?
Gotta admit I am frustrated ... I have two superchargers, 06 shaft kits, A Kit impellers, brand new metal washers, brand new spring washers, run-in, shimmed, slip double checked, built by Jerry, etc, etc. I have been running 7700 - 7900 rpms many days this summer, no matter what SC I run. I did have one good weekend two weeks ago, cut the grab handle and ran 8000 rpm all day long. This past weekend, rpms down and varying again, 7700 - 7950 and boost showing 5 lbs only ... I pulled the IC pipes, ran the IC/TB pipe disconnected to check for water leaks, no water leaks, put the IC tubing back on, still only showing 5 lbs of boost. Sprayed soapy water all over everything, no foam or bubbles, except up front on the intake where the temp sensor screws into the plastic intake itself ... did get a little foam around that.
Soo, I am looking for input ... have any of you had the stock plastic intake break/crack underneath, or had a boost leak at the temp sensor, or elsewhere that was hard to find??? Other than the low boost/lower rpms the ski starts and runs great, still having fun with it, just want to get the boost leak fixed and try to run some better numbers again ... Help??
08-13-2007, 10:41 AM #2
Have you removed the intake manifold to inspect it for cracks?
08-13-2007, 11:06 AM #3
i have a friend that is having the same issue vern
i put all the parts on and the most rpm we have seen is 7900
have you checked your i/c to see if it might be leaking water into the intake track
08-13-2007, 01:47 PM #4
Diggs, I did pull the IC to TB IC tube and ran the ski hard a few minutes ... nothing, dry as a bone. I honestly thought that was my problem, then again, maybe I need to run it longer? I ran it WOT for 3-4 minutes ...
08-13-2007, 02:03 PM #5
I haven't heard of anyone with cracks in the manifold, but it looks like you have checked everything else. Just remove the manifold and carefully examine it. It's easy to remove.
08-13-2007, 07:31 PM #6
- Join Date
- May 2005
- Fredericksburg, VA
Siliconeintakes.com leak tester is the best way I have found to find leaks. I found several huge leaks, the bov was leaking like crazy and one of the hoses was leaking so bad I don't know how it didn't pop off. The bad news is that with a rude sc running 11lbs I gained no boost or rpm by fixing all the leaks. I am guessing that the volume of air it is moving is so great that it didn't miss what was leaking.
08-13-2007, 11:02 PM #7
- Join Date
- Dec 2006
How To Check For Boost Leaks Correctly
Try this way as this is what we do for our Race Engines and you would be suprised how many leaks you get!
On the Air suction side of the Supercharger clamp a silicone hose and make a blockoff plate with a fitting to recieve air from an Air compressor.
Remove the J-Pipe and clamp a silcone hose onto the flange coming off the Exhaust Manifold and clamp a block off plate in the other end of the silicone hose.
Now you should have a sealed system that is sealed 100%
Put 14lbs of air from the Aircompressor into the Block off plate that you put on the Supercharger Inlet.
Now check for leakes using your ear and soapy water......
Let me know how you go!
08-13-2007, 11:35 PM #8
- Join Date
- Apr 2005
You could also spary some WD-40 all over your intake manifold while engine is running and see if you get any change in RPMS.DO THIS IN A WELL VENTED AREA ONLY.
08-13-2007, 11:49 PM #9
- Join Date
- Jan 2006
- Rydal, Georgia U S A
I know of several... INCLUDING MINE. 280 bucks a month ago.
Get a wb blockoff off a gtx?... drill a hole in it and put a valve stem in it. Then remove the hose off the SC and clamp it on and air it up NOT TOO MUCH!!!!!!!!!!! It's usually real obvious.
ALSO check to see if you SC's are sealed properly.
Last edited by jawz; 08-13-2007 at 11:52 PM. Reason: Addition
08-14-2007, 08:38 AM #10
I have the blockoff plate with a/c nozzle and have found some leaks a couple weeks ago using 15 lbs of air and soapy water. I think I have more leaks, in areas I did not check since I am still only seeing 5 lbs boost. I have wondered if the SC housing itself is leaking, or the intake ... I will mix up a big batch of soapy water, plug the exhaust and go at it again.
Jawz, $280 for an intake is cheap ... it looked more like almost $500 online ... do you have a better source? I hope I don't need one, but ...
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