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Radix Installed

Old Aug 5, 2005 | 02:11 PM
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Default Radix Installed

Just completed the Radix install and have some questions:

I noticed that there is a knock, knock, knock sound from the unit when the engine first starts up. Sometimes just a single knock. Sometimes 3 or 4 knocks. Is this a normal condition? Could it be a misfire? No codes are set.

Fuel presure holds steady at 61 while running and 52 after shutdown. Vacuum is about 18 at idle.

Also noticed pinging on acceleration today and yesterday afternoon. Tank has been completely drained and is filled with 91 octane. Outside air temp was 77 degrees. Took it for a ride last night and had no pinging and it seemed to run a lot stronger?? Outside air temp was 68. Will check A/F as soon as I get the wideband hooked up.

10% ethanol blend(I believe they rate it at 94 octane) is also available and soon legislation will require all gas sold here to be blended. Is this OK to use with my setup and the provided Magnuson tune?

I also noticed a single knock/clunk from the supercharger when the engine is shut down. Is this normal?
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Old Aug 5, 2005 | 03:05 PM
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Finally got through to Magnuson. Apparently the knock is part of the normal operation of the internal mechanism of the Radix.
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Old Aug 5, 2005 | 05:14 PM
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Ya i believe mine did it too
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Old Aug 5, 2005 | 05:24 PM
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The internal mechanism the rep was referring to is some type of tensioner and he said that their show vehicles also make the noise. It only occurs when the Radix first starts to spin. He said this would also account for the clunk/knock at shutdown. The startup noise seems to eminate from the rear of the unit. It is not hugely loud. About the same as if you rapped your knuckles against the housing.

Drove around town a little and pinging seems to have improved but I think power is down as well. Perhaps the PCM has adapted to some bad gas.

Last edited by DrX; Aug 5, 2005 at 09:58 PM.
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Old Aug 5, 2005 | 07:30 PM
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I had an audible knock and found out it was my tensioner from Magna. Seems that the bushings / berrings went in the pulley. I only heard it at idle and it did not cause any KR. Just some additional info.
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Old Aug 6, 2005 | 12:54 AM
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Same knock here, mainly during cold starts. The lope from my cam made the knock worse. I went with a really tight fitting belt and most of the noise went away.

Hey Kev, good to see you on this site. I trust the Radix is treating you well?
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Old Aug 6, 2005 | 01:16 AM
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That noise is normal on start up and shut down. Mine does it too, with the tight tolerance of the rotors it is expected! If you are experiancing pinging that is another problem........
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Old Aug 6, 2005 | 10:14 AM
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Originally Posted by BlownChevy
That noise is normal on start up and shut down. Mine does it too, with the tight tolerance of the rotors it is expected! If you are experiancing pinging that is another problem........
Not concerned about the startup knock anymore. Ping has improved but still rattles it if I step on it. Obviously I am not getting the full potential of the Radix and won't be stomping on it until this is resolved. Seems to run very smooth otherwise. Just put 100 miles on driving out to the lake. Still no codes.
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Old Aug 6, 2005 | 12:02 PM
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must be the gas - try getting a hold of some higher octane and see if it cures the pinging - how many miles on the truck? Fuel filter may need replacing as well...
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Old Aug 6, 2005 | 02:13 PM
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Just went for another drive. Not much more power than stock. Tires won't even break loose. Still some ping. Seemed to run strong the other night before I filled it up. Only gas around here with more than 91 octane is the 10% ethanol blend. I'm told that premium fuel sits in the tanks for a long time. About 15000 miles on the truck. Filter is part of the tank module. Fuel pressure looks OK (61 and steady).

Sounds like a squeak from the belt tensioner or idler now.

The crud from the filter turned out to be dhpro's problem.

Will check things out and try some different fuel when I get back to the city.

Last edited by DrX; Aug 6, 2005 at 02:19 PM.
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