Topic: Twincharged Solstice = Turbocharger + Supercharger

[Steelmesh]

- On the way to dyno, noticed new vibration...under load seemed like it went with engine speed, so thought it was a misfire
- Rescheduled dyno pulls after arriving and explaining I had a problem
- Got home and found my prototype 3.73 torque arm diff swap was loose. Slept on it (monsoon rains)
- Next morning, clean everything up, red loctite and used a torque wrench this time 110 ftlbs. Head to work.
- Get home, get ready for a test drive to make sure its good (Wed is drag races)
- Vibration there, but sounds even worse, sketchy bad..but this time it is on coast down engine braking and not load
- Place my bets, on the drive back home mentally prepare myself: to AAA tow if it explodes, to find out how to get a transmission by the weekend, if diff I will swap the 3.91, and a driveshaft should be easy to come by on car-part.com
- Ripped it apart, the front CV joint of the driveshaft has major play and when I punch it, it makes that rattle noise. 
- 3 used shafts are available locally

I had a discussion in that other forum where I found the driveshaft rattled when I punched it lightly with my fist like the sound I was hearing on the road; so I replaced it and the rattle went away. 

2015 videos here of driveshaft noises:

https://youtu.be/Db3QDAGVTzY
*It's like this but worse, I can see lateral movement in the CV (1-2 mm?)

https://youtu.be/lqO_wYepzxU


I will totally make a customer driveshaft if I have to, cheapest from my understanding would be dual u-joints because driveshaft shops know them well unlike the newer CV joint style (I made several calls). I am not sure about vibration and the harmonics with dual u-joint or just 1 u-joint...where the final solution could be the guibo and a larger front CV joint like from V8 muscle cars. 

[Steelmesh]

I pulled the shaft and put a pry bar on the transmission output shaft and also felt up the rear end, everything feels tight so I still think it is this driveshaft but not yet confirmed.  I stopped by a jy in actual Detroit, it was making the that noise in the video above just barely, and they wouldn't sell it under their asking price $125 so I walked away.  I will try to rebuild the CV tomorrow with a kit I ordered and confirm if the car is fixed.


Solstice Driveshaft disassembled. Pop the cap, pull the snap ring and it all comes apart:





I rolled the balls on a glass table, they didn't roll far and changed direction, and stopped abruptly.  Finger nail check on the inner and outer races did not reveal any significance, just superficial wear marks.  The balls are about 0.748" in diameter, which is 19mm.

Root cause analysis and theory:

- The first time I replaced the driveshaft, I noticed all the CV grease ended up in the tunnel, creating a perfect spray pattern in line with the CV end cap
- The second driveshaft (this one I am dealing with now) once again left a dang spray pattern of this nasty grease in the tunnel.
- When I disassembled this second driveshaft, I noticed there is no gasket or gasket maker!  The seal is the metal outer race against a stamped metal cap, on both sides. 

I already ordered this kit will be here tomorrow: https://www.amazon.com/Dorman-932-108-Speed-Driveshaft-Joint/dp/B004WLXKAU/

Notice it comes with two gaskets.  Other kits come with gasket maker.  I think the problem I am experiencing is actual/literal wear that is accelerated by my lead foot; in addition to CV grease acting as a damper for that rattling noise.

[Steelmesh]

How to replace Driveshaft / Propshaft CV joint (Dorman 932-108):

http://www.kappaperformance.com/forum/index.php?topic=11725.msg194179#msg194179

[Steelmesh]

Getting ready to be competitive for the drag race on Wed, here is the latest news in chronological order.

Bad News 1:

- I ran out of injector at around 21-22 psi while max power tuning (for the boost controller "ludicrous boost" switch).  I need to program max power on the GFB unit so it will use the PID properly (gain and sensitivity).


Good News 1:

- I installed 80lb Siemens DEKA injectors without a boost referenced pressure regulator; worst that could happen would I'd go back to the 60s. In addition, I already acquired 90% of the fuel system upgrade last spring as shown; but for now just installed the DDM fuel rail. Now looking at installing a surge tank with a mega pump for the twincharger setup (the factory style pump constantly fills the surge tank and the big pump pulls from and returns to the surge tank).





- I continued pushing the car and at 23-24 psi I am at around 85% injector duty cycle, this is running a big jet of water methanol, around 65/35 mix heavy on the methanol.  In the screen capture below it starts off at about 26 psi at the beginning of the hit, then tapers down to 23-24 psi near 6,400 rpm.  Not sure about the taper yet, it could be a combo of PID tuning the boost controller to that 2.5" single catback exhaust. 


*I need a different adapter to pick up fuel pressure so it was not measured


Bad News 2:

- The car eats driveshafts, I will need to figure something out for the twincharger build this is getting out of hand.  There is a drivetrain noise again (high cycle vibration, business a usual with a wearing driveshaft) and I took the backbone off and confirmed there is some play in the CV, rotating the shaft direction.  I guess I will rebuild another shaft with the backup CV joint for Wed and begin looking for the final solution for the twincharger.


Good News 2:

- I am proficient at swapping driveshafts now.

[Sly Bob]

Is there a chance that the Dorman CV joint isn't as robust as an OEM one would be?  Can you even buy one from GM without buying the whole prop shaft?

[Sol Asylum]

How much of the vibration is normal but the aluminum diff bushing is now transmitting into the body?  There is a reason GM uses rubber bushings.

[Sly Bob]

Wonder if this is the issue...

Many years ago I worked at a company that is still around that made, among other things, universal joints. They made them for most of the OEMs and had to hold very tight tolerances and most of them would go on drive shafts that we also built.
One day I had a job to pack a skid of maybe 1000 u-joints in boxes for a national retailer. The boxes had the brand of the retailer on the box and their part number. I dutifully packed up the joints, wrapped in a corrosion resistant paper and inserted them in the boxes.
Trouble was that the u-joints were scrap, didn't meet the manufacturers specifications so we couldn't ship them there but the national chain was happy to take them at what I'm sure was a steep discount. If you bought one of these and compared it to an OEM part they would look identical with the same markings but they were NOT the same.
They were the scrap that they couldn't sell to the OEMs.

Might be the issue you are seeing Steelmesh?

[Steelmesh]

Will have to compare the dorman bits to OEM and see how they wore/deformed differently. 

I certainly have the poly rear diff bushing, along with a poly filled trans mount and very stiff engine mounts.  Not sure if those could be contributing to the premature wear. 

[Steelmesh]

Wonder if this is the issue...

Many years ago I worked at a company that is still around that made, among other things, universal joints. They made them for most of the OEMs and had to hold very tight tolerances and most of them would go on drive shafts that we also built.
One day I had a job to pack a skid of maybe 1000 u-joints in boxes for a national retailer. The boxes had the brand of the retailer on the box and their part number. I dutifully packed up the joints, wrapped in a corrosion resistant paper and inserted them in the boxes.
Trouble was that the u-joints were scrap, didn't meet the manufacturers specifications so we couldn't ship them there but the national chain was happy to take them at what I'm sure was a steep discount. If you bought one of these and compared it to an OEM part they would look identical with the same markings but they were NOT the same.
They were the scrap that they couldn't sell to the OEMs.

Might be the issue you are seeing Steelmesh?

Certainly feasible this could be the case.  For the new propshaft assemblies I think it is less likely since they are contracted to build service parts, so some manufacturers look ahead and overrun normal production to profit more on the service part production later.

At the beginning, the dorman CV felt pretty stiff all around, no loose spots...something changed quick inside of it.  I was doing max power pulls, can't be helping hehe

[elff]

You have prevented your engine, trans and diff from moving.
I think that is sending all the energy at your driveshaft

[Steelmesh]

You have prevented your engine, trans and diff from moving.
I think that is sending all the energy at your driveshaft

Yup, changing the natural freq/harmonics of the whole system has been know to take out many strong-on-paper things.

I wonder if philly had an issue, just came across this post you'll remember:

http://www.kappaperformance.com/forum/index.php/topic,10832.25.html

His wicked launches on 555R drag radials, you'd think torque shocks would do a number, if not maybe it's my car uniquely: https://www.youtube.com/watch?v=kigG8dTJpGU

[elff]

No idea,
He disappeared and as we all thought, he never made his 1/4 mile claim.   I wonder if he blew his engine up.

[Steelmesh]

No idea,
He disappeared and as we all thought, he never made his 1/4 mile claim.   I wonder if he blew his engine up.

I continued reading the whole thing and it wasn't getting better lol

[Steelmesh]

I might have slightly over-reacted with the Dorman, it wasn't vibrating the car just making a noise; and it didn't have side-to-side movement, so I took it to the strip as is.  I was launching at maybe 13 psi and go 24 psi after hooking in 2nd. Street tires here, Ventus V12s

First run: 13.2

Second run: 13.3

Third and best run against a Mustang: 13.0 @ 111.9 mph:
https://i.imgur.com/o4hbONm.jpg

Almost hit 12's when I launched with full boost (you can see in 330ft) then did a 3-2 shift, that knocked the driveshaft out of balance. Compression looks good, I think it survived max 10,000 spike if it made it that high.  I theorize the mega reverse torque bent some metal in that CV joint, since it immediately had the vibration after this event. I did not expect to shift the car into 4th asI was not expecting 111 mph passes.  I think the 3.23 will bode well if I want lower 1/4 mile times consider 122 mph = 7500 rpm with 3.23 with 26.6" tires in 3rd gear.

Here is that run I nearly grenaded something, you can see a better 1/8 mile time and speed so I was destined for 12.X, but next time...I drove it to a hoist to confirm the driveshaft and drove home 55 miles no issues.
https://i.imgur.com/smmlNQX.jpg

[elff]

What do you mean by 3-2 shift?

Is that a typo and should be 3-4?

Those are nice times on street tires

[Steelmesh]

What do you mean by 3-2 shift?

Is that a typo and should be 3-4?

Those are nice times on street tires

I downshifted, 3rd gear to 2nd gear going ~100mph...I hope I didn't spin any bearings have good oil pressure still.  A major flaw I identified at the track last night is the thing between the seat and steering wheel.  It was suggested to flip my wrist around for 4th gear, so back of hand on left side.


Here is my best run 13.0 second, racing that Mustang:
https://www.youtube.com/watch?v=_GeaoH4mWNU

[Sol Asylum]

I continued reading the whole thing and it wasn't getting better lol

I don't know, I kind of liked the humor at the end.

[Steelmesh]

I don't know, I kind of liked the humor at the end.

In that sense yes, but as far as the topic derailment 

[MattM]

First....your car is definitely stout and should be we'll into the 12s.  Id recommend the n2mb wot and use the 2step which should really help!

With regard to the CV joint vids you posted....My car makes that same sound only when I'm in a parking lot and turn the wheel hard to the right..I wonder if I have a CV joint issue?

[Steelmesh]

First....your car is definitely stout and should be we'll into the 12s.  Id recommend the n2mb wot and use the 2step which should really help!

With regard to the CV joint vids you posted....My car makes that same sound only when I'm in a parking lot and turn the wheel hard to the right..I wonder if I have a CV joint issue?

I was looking at the wot box, not sure yet because I'd really like a standalone in the end (haltech elite) which would have these features available.

CV noises: if you haven't already lift it up and shake down the half-shafts, if those are tight you may want to drop the backbone and feel the propshaft.  On my setup I can pull the backbone alone, with a custom exhaust and ddm brace there is room to do it so it isn't a big job if yours is like that.  Like those above mentioned, I have stiffened up the driveline considerably; with that, do you have any bushing upgrades?

[Uranium-238]

110-111 ET's mean you should easily be in the 12's. Course I say that, and I never made a 12 second pass when my Camaro was trapping at those ETs...

[MattM]

I don't think there are any performance upgrades on any bushings.

I was thinking when I turned the wheel that hard to the right I was possibly getting something rattling on the exhaust....Hmmmm

[LatinVenom]

What I find fascinating is on this very forum someone posted 1/4 slip with a 12.9 using either a Trifecta tune or HPT tune and MT radials. I also believe it was an auto but could be wrong.
Joe the owner of this forum knows the member that did it, maybe some will remember the posting. It has been probably a couple of years ago when it was accomplished.

[elff]

I downshifted, 3rd gear to 2nd gear going ~100mph...

OUCH
I wasn't sure if your really meant that.
Transmissions don't like that.

My car literally shrieks if you do that.  Blocks the shift, but screams like WTF DUDE!! Right fingers are Upshift.
 

[Uranium-238]

What I find fascinating is on this very forum someone posted 1/4 slip with a 12.9 using either a Trifecta tune or HPT tune and MT radials. I also believe it was an auto but could be wrong.
Joe the owner of this forum knows the member that did it, maybe some will remember the posting. It has been probably a couple of years ago when it was accomplished.

I've met him as well. FWIW, he holds the stock 5th gen ZL1 Camaro record as well. He's one of those guys that is just that good. (And doesn't feel compelled to bloviate on forums either.)

And FWIW, MIR is a really low elevation track...on a cool fall day with good track temps, it's normal for records to be broken there.

https://www.camaro5.com/forums/showthread.php?t=21013
(Under the "ZL1 Bone Stock" category)