Just installed a Comptech SC on my 04. Upon moderate deceleration and between 2.5k to 4k rpm's, it makes a whining noise above and beyond what I expected would be a normal SC whine. Kinda sounds like a circular saw winding down; very metallic. It seems to get a little better when the SC belt is loosened just beyond the .5 to .625/inch spec, but it's always there. Tightening the belt to spec or tighter makes it pretty loud and longer in duration.

I've also got an occasional vibration somewhere in the middle of the dash or around the tranny tunnel, almost like the sound of exhaust heat shields when they begin to let go. Doesn't sound mechanical or serious. Everything's tight, the SC doesn't rub anywhere, and there doesn't seem to be drive train vibration. It usually occurs upon moderate acceleration and between 2.5k and 4k rpm's.

Anyone else had these noises? Is the buzz saw sound normal? Is it a break-in thing that goes away in time? Bad bearings? I've only got 200 miles on the SC. Thanks for the help!

 

Try revving the motor from the engine bay as you listen to the S/C. You may have a bad bearing that may have been aggravated by an overly tight belt. You will know in a short time if the belt is too tight as it will shred on you.
You might also have an imbalance in the turbine or an odd harmonic at those rpms - not normal. A S/C will to some degree cause the engine to transmit more vibration into the cabin, particularly through the shifter. This is normal, however, some owners have lucked out and do not feel this as badly as others.

 

Sounds like the usual noises to me. You should hear a lot of noise on deceleration (exactly what you described). When under WOT you should not hear the supercharger unless you have the top down and you are near jersey walls or buildings. You still might not hear it under those conditions.

 

Thanks for the feedback. When I rev the engine while parked it doesn't make the saw blade sound. It only happens while driving. Parked it just makes the expected minor whining noises. I just put another 200 miles on it, with the belt at .75/inch and it's not too bad. No slipping.

If it's a normal sound, I can live with it. I'm more concerned that it's not normal because now would be the time to address it. I'm going to line the hood with 1/2 inch accoustic material to help absorb some of it.

As for the vibration, yours truly didn't fully tighten one of the air box bolts. With it tight, the vibration's gone.

I think I can relax now and enjoy the new power. Along with 4.57 gears and VAFC it's a lot more fun to drive.

 

I have a buz saw from idle to about 2500 rpm then it gets quiet. Purrfect for cruzin the local spots, gets everyone turning around and looking at zero boost.

The "Boss" wants me to remove it because it's an "obnoxious noise." She want's to know what it does. If I show her, she will get upset with me for driving that way. I just say it adds power. And, I like the noise.

It is amazing how many people get down on the ground and bow to the car. I've seen it over a dozen times in the last 3 months.

Without having to resort to :

 

Sounds like everything's ok then. I did have a mechanic whose installed a few SC's check out my work and he says everythings seems fine.

I go for the sleeper effect, so noises can get to me. I don't even want to upgrade the exhaust for fear of droning and giving away the stock look. I think everyone's mods look and sound great and make a statement, but I get a kick out of suprising the unsuspecting.

And I'm still struggling with the noise of the 4.57 gears, but I'm told that will get better soon and with the change in lube type.

But the performance difference of the gears and the SC is very worth it. I just installed VAFC yesterday and dropped the VETC engagement to 5k (no fuel adjustments yet); great improvement. It gets tuned and dyno'd this week.

Stick to your guns with the boss. It's your car, right?

 

So how do you like the SC overall? How is the power boost?

I have a MY04 and am interested in the SC as well.

Can you describe what it feels like?

Thanks

 

Before dropping the vtec engagement, it was still great. Serious rush of power, mostly once the vtec kicked in. But dropping the vetc made the biggest difference because now the power comes on sooner. For some reason the SC seems to get the rpm's moving faster, and lowering the vtec to 5k gets things started sooner. The SC is worth every penny.

Note that below around 4.5k rpm's the car actually feels a little less snappy, maybe due to the extra weight of the SC and, I'm guessing, very little hp increase above stock up to this rpm. Maybe dyno tuning will help this area.

Also, the extra weight does affect handling a bit. I installed the titanium strut bar, which helps stiffen things up. But this is a minor issue.

I really think the 4.57 gears helped a lot too. Not only do you start a launch off on a higher rpm (less drop clutching), but it seems like mid to lower speed corners are now taken at the optimum gear and rpm within that gear. For example, while entering a corner, where 2nd was too low and 3rd too high, now 3rd can be used so that the right rpm is used. Makes corner entering and exiting a lot more precise. The gears went in first, so I can't say what the SC would be like without the gear change.

Another reason for a gear change may be to help strengthen the rear end. I believe the aftermarket gears are stronger than stock. I didn't go for the Comptech reinforced diff housing because I'd heard the 04's diff is a little stronger than earlier models, the gear change alone helps, and I don't plan on going much further with hp mods for awhile. But I'm no expert on the diff and gears.

Even before the tuning this week, I'm thoroughly happy with where my car's at right now.

 

I have recently encountered some chirping in my '03 during the first 30-45 seconds of driving my car now that I am SC'ed. This did not happen at first. Only after I had adjusted the boost hoses the last time to make sure everything was on tight. Anyone heard this? After a a minute of driving it's completely gone. I can only describe as a bird chirp sound but mechanical. Anyone?

 

I hear every noise imaginable on my car from the S/C to the rear end. I learned to ignore it and put it off as normal until something breaks. So far so good.

Except for a new groaning noise when cruising at a constant speed. Not sure what it is. Might be the tires. They are completly bald.