Took the cobra out for a ride last nite to try a lite 5th and 6th gear run. I went to 120 in 4th shifted to 5th took it to 130 then 6 to about 135 and then it made a loud vibe and kind of grinding sound. I put it in neutral and coasted to about 90 till it stoped. I can take it to 6500 rpm 1 thru 4 no issues. Did I over load the tranny or do I need a rebuild before I add more power? Its got pennzoil syncromesh in it. RP 75-140 in thr rear end, and all new wheel bearings and new rear end bearings all about 3 months ago. I still mant to LSR this car. I got a price on a new engine build and I may do it but want everthing esle up to par. Thank you all.
High speed vibe
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Take it back out and creep up to speed an see if she still does
It?
Have u had it to that speed before?
Ive been chasing a high speed vibe aswell
It seems for me baby steps
I haven found a single cure
Alot of little things have added up to almost gone
It?
Have u had it to that speed before?
Ive been chasing a high speed vibe aswell
It seems for me baby steps
I haven found a single cure
Alot of little things have added up to almost gone
I've had it to those speeds in 4th on the road and the dyno, no issues. It feels and sounds like its from the tranny. Maybe a new clutch or a tranny rebuild is in the works.
Replace the u joints and have the shaft rebalanced
I did that didn't work, but def a great place to start. I bought full tilt boogie racing front and rear differential support bushings and shim, set-up the pinion angle just like Bruce recommends and about 80% of the vibration is gone. I need new tire's so that should eliminate the rest of the vibration..
Yes i did a new DS and did the FTB kit and most is gone but over 100mph im feelin a vibe - resonance comin from the tunnel
Ive started clockin my DS and its been gettin better ( kickin in at higher speeds) i will continue to clock till its at the best spot
And from there i will start adding weight opposite point of most run out using a dial indicator
I dont remember which mag it was but i read an article about high speed vibe and supposedly they got rid of the vibe using washers as weight on the yoke bolt opposite point of max run out and as little as two grams made a difference
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I'm chasing vibe as well. Didn't have one for my other cobra but on this one I do. I already installed Bruce's kit with the lowering mount and no luck.
I fixed mine with the maximum motorsports irs diff mount. It lowers the rear of the diff and raises the front. The goal is to match the driveline angle and pinion angle. Before the install my engine was 3 degrees and the pinion was -2 degrees. I had bad vibration over 100. After install they are both at 3 degrees. The car is a track only car now and regularly goes to around 140 with no vibration at all.
I was able to get rid of a lot of the harsh vibrations by getting my tires road force balanced. It made the car drivable on the highway. I still get a very fine"high frequency" vibration on the highway, which seems more noticeable after I do a pull of any sort. I am going to try the FTBR lowering mount and front diff bushings next.
Have you guys tried a carbon fiber driveshaft?
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