Sounds like my vibration at 3000-3200rpms. do you feel any vibration at 3600rpms? How about removing the clutch/pressure plate and transmission of course. Then start the car and rev it with just the flywheel. If the vibration is gone then you know it's the clutch/pressure plate.

I have no idea if you can start the car with no transmission connected, but it's an idea. You'll probably get the fail safe mode. Probably not the best idea seeing as how the clutch is hydraulic and you'll have to step on the pedal to start the car.

By the way, my vibration is almost not noticeable with the stock driveshaft, much worse with my 1 piece.

Now i'm not sure what clutch to buy. [:@]

 

Moosestang, do you feel your vibration with the car sitting still and in neutral? I am not sure if I feel the vibration at 3600rpms or not. Honestly since it started I have just been concentrating on the 1500-1900rpm range and checking out any part that seems like it could cause the vibration. Also, could the clutch and pressure plate be causing a vibration when the clutch is not engaged? According to Spec it can't.

 

Yes I can feel it when sitting in neutral. If the pressure plate is not balanced correctly it can cause a vibration. It's bolted to the flywheel, maybe spec doesn't know that.

 

Your question has prompted me to join this forum. I sympathise with your painstaking troubleshooting. I have an '07 Mustang GT 5-speed with about 6,000 miles with no performance mods yet. I have noticed from the first week that at about 1,700-1,800rpms there is a slight vibration whether I am on the highway or at idle. This is kind of annoying since that is about where I cruise at on the interstate. It is such a slight vibration that most people probably wouldn't notice. I really haven't worried about it since it has been there since I bought it, new. I am assuming that it is something engine related like a flywheel that was not balanced to lower the vibrations enough, or maybe turbulence from the throttle plates opening in the intake. I wanted to provide you with some input before you tear you car back to stock.

 

Thanks for the input Helo. Unfortunately I already put the car back to stock, and put her back together again...LOL. I had it down to where the only parts that were on the car that were not stock were the gears, driveshaft, and clutch. I had the shop that installed my clutch pull it down and they said everything looked good, and everything balanced out. So I put it all back to the way it was. The vibration is still there, so I have to assume that it is just a side affect(so to speak) of everything I have done. The car seems to run fine, it pulls good, has plenty of power, etc. it just has that annoying vibration from 1800 to about 2300. Which is especially noticeable in 3rd, 4th and 5th. So of course right where I always cruise also. But without the torque limiters on the car the vibration is tolerable. So I guess unless something comes apart there is nothing more I can do. I guess I will just keep adding power parts until it so fast I just don't care anymore.....LOL.