Gto ls2 in '86 Monte carlo ss
02-26-2017, 03:43 PM
#121
I dont think its got damaged, looks good. plus my other 3" steel drive shaft that I had built had the same problem.
My car is lowered so I might try putting the original springs back inthe rear and messing with the angles more. would 3.5* u joint working angles cause this?I know the target is 3* or less.
My car is lowered so I might try putting the original springs back inthe rear and messing with the angles more. would 3.5* u joint working angles cause this?I know the target is 3* or less.
02-26-2017, 05:15 PM
#122
its possible but unlikely a half a degree would do it. if you have 3.5 front and rear then it's not a phase issue. you could check by collapsing the rear suspension down a little to get 3 degrees in the back ---just some weight in the trunk would do it
with these things, never be afraid to re-check previous work. usually i make a list of stuff it could be (including things ive already done) and then organize it with easy n cheap at the top and hard or expensive at the bottom.
and then just work through it.
with these things, never be afraid to re-check previous work. usually i make a list of stuff it could be (including things ive already done) and then organize it with easy n cheap at the top and hard or expensive at the bottom.
and then just work through it.
02-28-2017, 12:10 PM
#124
TECH Senior Member
iTrader: (7)
What is weird is that the vibration is working its way through the steering wheel. In my experience, driveline vibrations are too high in frequency to do this...
Andrew
Andrew
02-28-2017, 02:40 PM
#125
It gets bad between 120-140 then after 140 it smooths out.
I'm hoping a lot of it is the fact I'm testing it on jack stands with no load.
You can feel it in the entire body of the car and it's pretty audible standing outside the car why running it on the jack stands. The only thing I can think of is it's in the rear end, but I don't know what. Everything in the rear axle is new except the axle bearings. Motive gears, true trac diff, moser axles and new pinion/carrier bearings. The gears are quiet, but with the provided shim kit I could only get the backlash to .010, if I swapped the smallest shim to the other side it was too tight.
My car is all new poly bushings, the only rubber is the motor mounts so that may be why the vibration is so pronounced in the body. I swapped the poly trans mount to a new oem one with no difference also.
I'm hoping a lot of it is the fact I'm testing it on jack stands with no load.
You can feel it in the entire body of the car and it's pretty audible standing outside the car why running it on the jack stands. The only thing I can think of is it's in the rear end, but I don't know what. Everything in the rear axle is new except the axle bearings. Motive gears, true trac diff, moser axles and new pinion/carrier bearings. The gears are quiet, but with the provided shim kit I could only get the backlash to .010, if I swapped the smallest shim to the other side it was too tight.
My car is all new poly bushings, the only rubber is the motor mounts so that may be why the vibration is so pronounced in the body. I swapped the poly trans mount to a new oem one with no difference also.
02-28-2017, 07:14 PM
#126
TECH Senior Member
iTrader: (7)
Show me a picture of the driveshaft installed in the transmission.
At 120mph you may very well be approaching the critical speed of the driveshaft. How long is it u-joint to u-joint centerlines? You can also be experiencing some sort of weird harmonic between 120 and 140...
**edit** went back and saw the critical speed discussion...
Slip yoke engagement is critical too....also keep in mind, slip yoke center themselves with load. If you are running on jack stands and there is no real load, that's doing funny things with the slip yoke.
Andrew
At 120mph you may very well be approaching the critical speed of the driveshaft. How long is it u-joint to u-joint centerlines? You can also be experiencing some sort of weird harmonic between 120 and 140...
**edit** went back and saw the critical speed discussion...
Slip yoke engagement is critical too....also keep in mind, slip yoke center themselves with load. If you are running on jack stands and there is no real load, that's doing funny things with the slip yoke.
Andrew
03-09-2017, 04:09 PM
#127
I replaced the axle bearings, they looked good still but there was noticeable slop them compared to the new ones. The roads were dry yesterday so I took the car down the road and got it up to around 90 in 6th gear and felt smooth with no vibrations knock on wood. Before fixing the loose 5-6 gear on the trans it would start vibrating in 5th and 6th around 70 and get worse the faster you went.
03-18-2017, 01:05 AM
#128
Bought and installed an lnc-2000. Just using it now for launch control and no lift shifts, but Probably use it in the future with nitrous/forced induction. Excited to be able to get the car out on the road/track to try it out.
Last edited by onebadbowtie86; 03-18-2017 at 01:13 AM.
03-18-2017, 08:13 PM
#131
The 2 step is on a micro switch on my clutch pedal, with a toggle switch to turn the entire setup on or off. When the systems on, any time you push the clutch in it activates the 2 step/cuts spark to the engine. Takes load off the trans so you can leave the accelerator to the floor and just use the clutch.
03-19-2017, 09:37 AM
#132
TECH Senior Member
iTrader: (7)
That doesn't really make much sense. When you press the clutch in, that already takes the load off the trans. Keep the throttle planted and grab next gear. Power shifting 101.
Andrew
Andrew
03-19-2017, 12:11 PM
#133
No lift shifting with a 2 step is about the same thing as letting off the throttle and shifting normal since you are cutting spark to the engine/reducing load. That's what I gather anyways, a lot of people do it this way. It has to at the least be easier on the clutch then power shifting. I got the 2 step mainly for launch control, but want to try the no lift shifting.
03-19-2017, 01:42 PM
#134
TECH Senior Member
iTrader: (7)
No lift shifting with a 2 step is about the same thing as letting off the throttle and shifting normal since you are cutting spark to the engine/reducing load. That's what I gather anyways, a lot of people do it this way. It has to at the least be easier on the clutch then power shifting. I got the 2 step mainly for launch control, but want to try the no lift shifting.
Now, if you had a dog-ring trans, and a load cell on the shifter, then "no-lift shifting" is done without using the clutch and staying at WOT. The ignition interrupt unloads the input shaft, which allows the trans to be pulled out of gear and into the next gear. So full throttle and no clutch actuation.
Andrew
04-22-2017, 09:31 PM
#140
Got the car to the opening test and tune, Still couldnt get the 60' down to where I wanted them, but the car was a lot easier to launch with the bias ply vs radial tires. I got a couple 7.50 passes and a bunch of 7.60's with a best 60' of 1.75, but mostly 1.8 60's.
My 2 best passes pretty much matched them selves:
60 ft: 1.75
1/8 e/t: 7.56
1/8 mph: 96.25
Unfortunately I didnt get the video of my better runs, heres video from one of my 7.70 runs with a 1.85 60'. Still pulled the Heavy torq thust wheel on one of my slowest runs, really wishing I would have recorded my faster pass's.
https://www.youtube.com/watch?v=9JmR...ature=youtu.be
My 2 best passes pretty much matched them selves:
60 ft: 1.75
1/8 e/t: 7.56
1/8 mph: 96.25
Unfortunately I didnt get the video of my better runs, heres video from one of my 7.70 runs with a 1.85 60'. Still pulled the Heavy torq thust wheel on one of my slowest runs, really wishing I would have recorded my faster pass's.
https://www.youtube.com/watch?v=9JmR...ature=youtu.be
