[Joey911]

Just wanna share this here, no one mentioned it:

The notchy and thud you when you shift into 1 at stationary, or shift to 2 from 1, are even worse with LSD, like so much worse, I hate it thudding every time i shift, with a diff lockdown, the thud can be felt/heard from 5 to 6 gear

[justpete]

Originally Posted by Joey911

Just wanna share this here, no one mentioned it:

The notchy and thud you when you shift into 1 at stationary, or shift to 2 from 1, are even worse with LSD, like so much worse, I hate it thudding every time i shift, with a diff lockdown, the thud can be felt/heard from 5 to 6 gear

No thud here shifting into first while stationary or downshifting from second to first with a Performance Gearing LSD. And that's with solid engine, trans, and diff mounts, a Clutchmasters 850 dual disc race clutch (stand type, solid friction disc hubs), and solid flywheel. What kind of diff are you running? Wondering what's happening there.

[Joey911]

Originally Posted by justpete

No thud here shifting into first while stationary or downshifting from second to first with a Performance Gearing LSD. And that's with solid engine, trans, and diff mounts, a Clutchmasters 850 dual disc race clutch (stand type, solid friction disc hubs), and solid flywheel. What kind of diff are you running? Wondering what's happening there.

The infamous wavetrac thump... Wondering could it be other component in the driveline getting old

[justpete]

Originally Posted by Joey911

The infamous wavetrac thump... Wondering could it be other component in the driveline getting old

Ah, OK, thanks. Does it feel like the car twists when it thumps?

[Joey911]

Originally Posted by justpete

Ah, OK, thanks. Does it feel like the car twists when it thumps?

Can't really feel the drivetrain twist, I want to put all the new rubber mounts in the driveline though.

What LSD do you have?

[justpete]

Originally Posted by Joey911

Can't really feel the drivetrain twist, I want to put all the new rubber mounts in the driveline though.

What LSD do you have?

Was thinking the subframe is getting torqued and worn subframe bushings might let the car twist enough to notice when the diff loads up, just a thought. Maybe the guibo, u-joints, CV joints in the axles, etc. Maybe more than just the diff?

Right now, no diff. Waiting on Jim to rebuild my Performance Gearing LSD to his sixth gen design, change the final to 3.91 from 3.73, and machine the cover to weld in bungs for the diff cooler and temp sensor. Will have 30/60 ramps and six clutches per axle instead of 45/45 ramps and four clutches per axle.

[Joey911]

Originally Posted by justpete

Was thinking the subframe is getting torqued and worn subframe bushings might let the car twist enough to notice when the diff loads up, just a thought. Maybe the guibo, u-joints, CV joints in the axles, etc. Maybe more than just the diff?

Right now, no diff. Waiting on Jim to rebuild my Performance Gearing LSD to his sixth gen design, change the final to 3.91 from 3.73, and machine the cover to weld in bungs for the diff cooler and temp sensor. Will have 30/60 ramps and six clutches per axle instead of 45/45 ramps and four clutches per axle.

Performance Gearing? Never heard of this. Wavetrac is gear LSD, and you have clutch type. Ive been thinking that clutch type is smoother?

Could be rear subframe bushings and diff mount, will have that changed when I put new suspensions on I guess.

[justpete]

Originally Posted by Joey911

Performance Gearing? Never heard of this. Wavetrac is gear LSD, and you have clutch type. Ive been thinking that clutch type is smoother?

Could be rear subframe bushings and diff mount, will have that changed when I put new suspensions on I guess.

Used in many Grand Am race cars, among others. Clutch type is more predictable and these progressive Salisbury diffs Jim makes are very smooth, pricey though.

[Joey911]

Originally Posted by justpete

Used in many Grand Am race cars, among others. Clutch type is more predictable and these progressive Salisbury diffs Jim makes are very smooth, pricey though.

I think the LSD unit contribute a lot of thump/clunk because of the backlash INSIDE the unit itself, they said space is needed in steel gears, cause steel heats up and expand.

They gave me a revised version and the thump/clunk is lessen. But still present...

I have a question related to the thread title here actually lol! When I'm stationary and shift into first gear, sometimes, quite often, it stuck halfway! I have to pull it back to neutral, release and re step on the clutch to push the shifter into first... Sometimes it won't go in the second time either

[justpete]

Originally Posted by Joey911

I think the LSD unit contribute a lot of thump/clunk because of the backlash INSIDE the unit itself, they said space is needed in steel gears, cause steel heats up and expand.

They gave me a revised version and the thump/clunk is lessen. But still present...

I have a question related to the thread title here actually lol! When I'm stationary and shift into first gear, sometimes, quite often, it stuck halfway! I have to pull it back to neutral, release and re step on the clutch to push the shifter into first... Sometimes it won't go in the second time either

Dunno, sorry. Somebody's gotta know, hopefully they'll post an answer.

[sparky_phantom]

Still haven't heard anything from Cobb yet, but 2nd gear is starting to do better since the PPK for some reason.

[shirtpants_]

I have trouble with revs staying up for a second, right after the clutch is pushed in as well. I thought there was something wrong with the car when I first got it. I even brought it up at the Dealership. I eventually just learned to drive around it. The revs hang if you try to shift before about 2500 or 2600 RPM in every gear except when going from 5th to 6th. I usually just shift between 2500 and 3000, and then there is no delay whatsoever.

I don't think this is something cobb is going to solve.
Maybe ProTuningFreaks would be able to provide an answer...

It might be that we all just need to reset the adaptations. I know there's a series of commands you have to do to reset them, I just haven't been bothered by it enough to try it out...

[sparky_phantom]

Originally Posted by shirtpants_

I have trouble with revs staying up for a second, right after the clutch is pushed in as well. I thought there was something wrong with the car when I first got it. I even brought it up at the Dealership. I eventually just learned to drive around it. The revs hang if you try to shift before about 2500 or 2600 RPM in every gear except when going from 5th to 6th. I usually just shift between 2500 and 3000, and then there is no delay whatsoever.

I don't think this is something cobb is going to solve.
Maybe ProTuningFreaks would be able to provide an answer...

It might be that we all just need to reset the adaptations. I know there's a series of commands you have to do to reset them, I just haven't been bothered by it enough to try it out...

So it seems to feel better for the shifts as long as shifting after 2.5k?

[shirtpants_]

Originally Posted by sparky_phantom

So it seems to feel better for the shifts as long as shifting after 2.5k?

Yep