1.7K KB noises?
07-30-2009, 09:40 PM
#21
CMOC Rookie
Join Date: Dec 2006
Location: London
Posts: 25
Last fall I had a used 1.7L KB twinscrew intercooled kit with a 9-psi pulley installed on my 02 GT. The blower uses the flat-face design for the pulley, FWIW. After buying it, I'd turned the rotor by hand and with a power-drill and it seemed quiet and smooth. I was assured it was pretty low miles and nothing I saw on the kit indicated otherwise. Everything looked quite clean. Today, after a long winter of waiting, I finally picked the car up and drove it home (~200km) today and have some questions about noise I've noticed from the blower.
First, the power is great. But it seems that there are several places in the RPM range where I get a fairly "hollow resonance" sound from what I believe is the blower. The more throttle I give, the louder it seems to get. It occurs at off idle, ~1900RPM and ~2900RPM (I haven't heard it obviously above this but haven't really beaten on the car at all yet...) It only seems to last for a few hundred RPM around these points. Because it's linked to throttle angle, I was thinking perhaps thrust loads on the rotors is high under boost and perhaps the rotors are moving and contacting the case...? Thoughts?
Also, with the car idling, I hear hints of a dry-bearing-ish periodic "chirp" noise from the back of the blower, in the vicinity of the inlet. Sometimes I think I can hear this noise coming reflecting off curbs with the window down.
If I rev the engine under the hood I don't really hear anything unusual from the engine or blower. I just hear this resonance sound at a few points in the RPM band and the odd chirp.
The fluid level is right at the full mark. I'm running 20W50 synth in it right now and plan to suck it out and replace it with Redline 50W race oil in the coming days. The car has the factory air-inlet (right down to the paper filter in the OE airbox) though the rubber silencer has been removed.
I really don't want to have to take it off and send it in somewhere for rebuilding/reconditioning. I'll have to park it for a while if this is the case because funds are, uh, low right now. I'm hoping others with the same blower might chime in and tell me "Mine does that too"
or "Yeah, it's not supposed to do that. Mine's dead-silent..." 
Any recommendations, if the worst case scenario is the deal, on a GTA facility to rebuild/recondition a KB blower?
First, the power is great. But it seems that there are several places in the RPM range where I get a fairly "hollow resonance" sound from what I believe is the blower. The more throttle I give, the louder it seems to get. It occurs at off idle, ~1900RPM and ~2900RPM (I haven't heard it obviously above this but haven't really beaten on the car at all yet...) It only seems to last for a few hundred RPM around these points. Because it's linked to throttle angle, I was thinking perhaps thrust loads on the rotors is high under boost and perhaps the rotors are moving and contacting the case...? Thoughts?
Also, with the car idling, I hear hints of a dry-bearing-ish periodic "chirp" noise from the back of the blower, in the vicinity of the inlet. Sometimes I think I can hear this noise coming reflecting off curbs with the window down.
If I rev the engine under the hood I don't really hear anything unusual from the engine or blower. I just hear this resonance sound at a few points in the RPM band and the odd chirp.
The fluid level is right at the full mark. I'm running 20W50 synth in it right now and plan to suck it out and replace it with Redline 50W race oil in the coming days. The car has the factory air-inlet (right down to the paper filter in the OE airbox) though the rubber silencer has been removed.
I really don't want to have to take it off and send it in somewhere for rebuilding/reconditioning. I'll have to park it for a while if this is the case because funds are, uh, low right now. I'm hoping others with the same blower might chime in and tell me "Mine does that too"
or "Yeah, it's not supposed to do that. Mine's dead-silent..." Any recommendations, if the worst case scenario is the deal, on a GTA facility to rebuild/recondition a KB blower?
