Chattering sound above 3K

[Gene 64 2dr]

I finally got the car on the road and have a problem with a load “chatteringâ€￾ sound that appears to be coming from the clutch area staring around 2,900 rpm. It gets far to noisy to suit me above 3,200 so I have been shifting around 2,600 or so. Everything works great below 2,700.
I going to be tearing it down soon and I’m wondering if anyone has any ideas what to look for? I’m thinking maybe a bad throw out bearing or loose pivot arm.
Everything is new, resurfaced flywheel, clutch. Throw out bearing, and pressure plate.

My set up is: Ram street strip clutch connected to a T5 trans using a cable pull clutch pedal setup.

While I’m at it I have another question. I’m running an open 8â€￾ rear end with an impossible 2.9 ratio that I’m going to be changing it looks like sooner that later. Around town I can barely get it out of 3rd gear. 40 mph is around 2,000 rpm and if I go to 4th I back down to around 1,500 rpm and can barely keep it up to speed. Forget it on the highway. I have to be going over 70 to get it over 2,000.
I’m going to change the gears and I’m wondering what ratio I should be looking at. Yes it will be a limited slip rear.
It’s going to be headed to the drag strip as often as I can and I’m not looking at driving fast on to highway.
I’m thinking somewhere around 3.85 or 4.10’s


Thanks for any input
Gene

 

[PaulS]

You need to reduce your timing advance.
You can check for 34-36 degrees total (with vacuum advance disconnected) at 3000 rpm.

 

[Ronbo]

I would also suggest verifying its not your timing before ripping it apart. It just may sound like its coming from the clutch area. Ten minutes of time could save a whole bunch of work eh?


Ron

 

[Gene 64 2dr]

Well I found out where the noise was coming from. It was the radiator fan. It was slightly bent so when it got up to around 3K it started to wobble so bad it generated a great deal of noise and also managed to scrap the double harmonic balancer I put in.
It was so noisy in the car because of the interior being completely stripped. The noise was so load and you could not quite hear where it was coming from it appeared to be from the back of the engine. Finally while standing outside and looking in I noticed the fan trying to shake itself to pieces when it got around the 3k mark. When stopped it seemed nice and tight. I straighten the blade some and now I came now rev it up just fine above 4k with just the normal noise.

The fan is coming out and I’m going to replace it with an electric fan.

I think the noise you were talking about was engine knock with the timing set wrong. It's now quiet enough that I can actualy hear that now if it's a little off.

Gene

 

[Ronbo]

Glad to hear you didn't have to wrestle the tranny back out!

Ron

 

[170-3tree]

As far as those rear gears go you might wanna look into about 3.50. i wish i could get 2.9 in mine it would be so much easier on gas

 

[Rustang Racer]

For the rear gears, I would choose something that will put you near redline in 4th gear as you go through the traps with the car running as fast as you expect it ever will with that rear.

I have a 250 with a T5 and the fastest I could imagine my car ever running is low 14s. I picked 3.55s to try and keep the revs below about 5000. Its fine on the highway with the torque of the 250 (I think around 2000 at 65) but you would probably want at least 3.73 for a 200.