[cwebster]

My new wheels arrived yesterday, just in time for the upcoming weekend! Below are some shots and notes from the install. Yes, they're 18x12 rims and 12" wide Mickeys.

Other threads and posts where I took measurements, sought help, and conducted research in choosing the wheels and tires:

03-14-2017, 11:27 AM Wheel sizes and offset values
03-21-2017, 01:20 PM 6th Gen ZL1 Drag Strip Wheel & Tire Options
03-21-2017, 01:51 PM Weld Tech and MT options
04-04-2017, 11:32 AM Drag Wheels & Tires - final purchase

Paul from PK Auto Design ordered the rims and held the tires and TPMS sensors I shipped to him. When the rims came in he inspected and assembled the wheels then shipped them to me.

Here we are in my driveway with wheels and tools all ready to go:
(not shown is a jack stand under rear support beam)



Wheels were well-protected from scratches. Came with a bubble-wrap envelope (not shown) containing custom wheel lugs and a snazzy, water-jet cut aluminum warranty card.



My pneumatic impact driver, ready with the 7/8" deep-well socket to remove the stock wheels.



Stock and Drag Wheels side-by-side



Drag Wheel Inboard View



Torque Drag Wheels - My Kobalt 50-250 ft lb torque wrench set to 140 ft lbs. OEM lugs will fit but socket will bind in the recess. Custom lugs are 3/4" (see inset).



Tight Fit - There's about 1/4" clearance on the inboard, front corner of the new tire. I put a strip of masking tape along the liner where it sits closest to the tire. This should show rub marks if I have clearance issues. So far no issues. During the test drive after the install I heard and felt no rubbing. More testing after rain dries up Thu/Fri before taking them to the track.



Protrusion Outside Fender - They do extend slightly beyond the fender well but the curved edge has more than 1" travel before it touches.



They don't stand out to bad, right?



Installed Close-up Shot




--Cal

[Fraxum]

Looks great! Looking forward to your times. Keep an eye on the connector on the front of the drivers side wheelwell. You do not want to start rubbing that with the tire. A forced tour mode launch with those big tires might lower the fender enough to rub. I moved my connector out of the well.

[cwebster]

Originally Posted by Fraxum

Looks great! Looking forward to your times. Keep an eye on the connector on the front of the drivers side wheelwell. You do not want to start rubbing that with the tire. A forced tour mode launch with those big tires might lower the fender enough to rub. I moved my connector out of the well.

Thanks for the warning. I spent some time on a creeper under there and didn't see anything except the liner that was closer than 1" to the wheel or tire. Is there a connector behind the liner or something? I'll be doing some highway-speed testing before I go to the track Friday. I'll be driving to the track with my OEM tires so I'll have another look when I go to swap them.

[Fraxum]

Originally Posted by cwebster

Thanks for the warning. I spent some time on a creeper under there and didn't see anything except the liner that was closer than 1" to the wheel or tire. Is there a connector behind the liner or something? I'll be doing some highway-speed testing before I go to the track Friday. I'll be driving to the track with my OEM tires so I'll have another look when I go to swap them.

Yes, connector under the liner unless the ZL1 design moved this. And at least one member has trashed this connector. My 20x305x35 NT555Rs rubbed so I wrapped the connector in plastic and moved the connector out of the way to under the car. There are several threads about this.

[cwebster]

Originally Posted by Fraxum

Yes, connector under the liner unless the ZL1 design moved this. And at least one member has trashed this connector. My 20x305x35 NT555Rs rubbed so I wrapped the connector in plastic and moved the connector out of the way to under the car. There are several threads about this.

I just got finished going on a 2nd test drive with the DRs (24 PSI), this time at highway speeds. I also did some more 1/8 mile accelerations through 3rd gear. Wasn't watching the speedo but I'm sure it was around 80 or 90 for a second. I even went over some railroad tracks to get some suspension movement.

I did another inspection with the wheels off and don't see any wiring or hydraulic lines anywhere near the tire or rim. There's the brake line to the calipers and ABS sensor cable but those are well secured and routed along the control arms and stabilizer, well clear of any moving parts.

There were some minor rub marks on the tape (photos below) but I think it was just from the edges coming loose and flapping around. I think I'll be okay with these. I'll put some fresh tape on when I change back to the DRs at the track then see if there was any rubbing at 1/4 mile trap speeds. If so, then I'll look behind the liner to see if there's anything critical back there.

There was one thing that bothered me. A screw was loose on the left rear hub assembly (photo below). I'm not sure what it goes to - maybe the ABS sensor. The right side was still tight.

--Cal

Disturbing loose screw on left rear hub assembly. I didn't notice this yesterday when I first swapped the wheels.



Wide view of left rear wheel well - front face. No cables or lines near the wheel. Minor rub marks on tape.



Tape close-up, left side - minor rub marks, probably from edges of tape flapping around.



Right rear hub assembly - screw is tight.



Tape, right side - minor rub marks, probably from edges of tape flapping around.

[TheRealJA105]

That screw is just to hold your rotor on.

[Bow Tie Affair]

Originally Posted by cwebster

Thanks for the warning. I spent some time on a creeper under there and didn't see anything except the liner that was closer than 1" to the wheel or tire. Is there a connector behind the liner or something? I'll be doing some highway-speed testing before I go to the track Friday. I'll be driving to the track with my OEM tires so I'll have another look when I go to swap them.

How close was the liner to the wheel/tire?

[SGDM]

I would move the cable, easy to do and takes little time to ensure you don't have issues in the future. http://www.camaro6.com/forums/showth...467998&page=14

Rims and tires look great!

[laynlo15]

Now you need to get to the track and try those honeys out.

[cwebster]

Originally Posted by TheRealJA105

That screw is just to hold your rotor on.

Well it certainly wasn't doing a good job of that, was it. Seems like there should have been some lock-tite on there or something. Have you had these ZL1 hub assemblies and rotors apart?

Originally Posted by Bow Tie Affair

How close was the liner to the wheel/tire?

I estimated about 1/4" at the closest point. This was on the front, inboard corner of the tire on each side. The stock tires only leave about 3/4" clearance.

Originally Posted by SGDM

I would move the cable, easy to do and takes little time to ensure you don't have issues in the future. http://www.camaro6.com/forums/showth...467998&page=14

Rims and tires look great!

Thanks man! So that same harness is behind my liners on the ZL1? I'm assuming the photo shows its new, tied off location. Where is it beforehand? It's hard to tell from the photo where that would be positioned under the liner. The only place where it could be jeopardized on my setup is immediately behind the lower, front, inboard corner. Now you've got my curiosity roused so I'll have to rip that liner off to see, even though it hasn't rubbed at up to 125 MPH during 5 1/4 mile passes. When I swapped back to the OEM tires there was no indication of rubbing whatsoever. I've got to change the diff fluid again anyway so I'll do it while it's on the lift.

Originally Posted by laynlo15

Now you need to get to the track and try those honeys out.

I ran 5 passes on them Friday night. Almost zero wheel slip with or without a burnout. Problem is that now it's like a different car. I've got to learn to launch all over again. At least now the spinning is out of the equation. Each pass got better but now I'm bogging the motor. I need more torque (higher RPM) at launch to get the 60' time down. That 4K RPM launch limit is cramping my style. After watching the video footage, I need to work on my launch habits too. I'm working on it... it's just gonna take some more seat time to get fast again. My last (best) pass was 12.0942 ET @ 119.64 MPH. It was a little disappointing after doing 11.6 on the stock rubber but I'm not sorry to be rid of the slip-and-slide. I may run the the stock rubber again on a good day but for now I'm concentrating on learning how to get fast on these without massive clutch abuse.

I've been studying the video footage, time slips, and notes; and deciding how to proceed on the next trip. I'll post a thread when I'm done with links to the PDR, Helmet GoPro, and Spectator videos. I learn something new and/or gain some skill every time I go. Maybe posting my video, notes, and lessons will shorten someone else's learning curve or maybe someone will have a suggestion that'll bring me to the next level.

Anyway, that's for the feedback.

--Cal

[Fraxum]

Originally Posted by cwebster

That 4K RPM launch limit is cramping my style.
--Cal

The ZL1 limits the launch to 4K with everything off? What were your 60's?

[cwebster]

Originally Posted by Fraxum

The ZL1 limits the launch to 4K with everything off? What were your 60's?

Yes, every drive mode is limited to 4K idle RPM except track mode. Default track mode idle limit is 3600 RPM unless you go into custom launch controls and set it to max 4K RPM. That's what I do, then turn off all nannies before launch.

Best 60' on Fri with the DRs was 2.0341 on my last pass. There was a momentary wheel spin at 2200 RPM before it hooked and dropped to 1200 RPM (bogged). Passes 1 thru 4 had no wheel spin but bogged even worse, keeping the 60's above 2.0.

Best 60' on the stock tires was 1.9570 on my 2nd pass of the 20170409 trip. That launch also had slight, intermittent wheel spin; RPM never lower than 2500 and hooked at 2900.

From what I've been seeing this year at the drag strip, either the clutch or wheels have to be in a controlled slip at launch in order to apply the most usable force to the pavement. For street tires, the key seems to be to keep it close to 3K RPM (max tq avail) while engaging the clutch just enough to control wheel slip. For sticky DRs, I need to start at a much higher RPM and release the clutch more slowly. I think ideal launch idle RPM would be 5000-5500 on DRs. That would make it easier to keep RPM above 3000 as the clutch is released to keep from bogging. ECM limits my idle launch RPM to 4K so I've been trying to idle at 3900. I'm afraid If I apply more throttle before launch, automated launch control will be triggered at 4K and may pull timing (even with TC/SC disabled).

The DRs stick really well and I'm not used to that. Reviewing the PDR footage, I was hooking between 600-1200 RPM so I couldn't put enough torque to the wheels. I don't mind abusing the clutch a little but my "muscle memory" (from launching with OEM tires) takes over at launch and I let the clutch out to quickly. I was getting better by the 5th pass but, unable to stage above 4K RPM, it takes a lot more effort to find that balance between throttle and clutch.

I'll be writing up my analysis of this track day this afternoon and organizing everything in a new thread. Just finished annotating and uploading the PDR and GoPro footage to YouTube [Playlist: 20170526 Coastal Plains Dragway (DRs)]. Last pass of the day (07 of 07) was the best.

--Cal

[ULTRAZLS1]

The screw adds to nothing with the rims bolted to it.

It's to keep the rotor on for ease of installing brakes, wheels tires, to hold it on the assembly line. After the rims are on it does nothing

[SGDM]

Originally Posted by cwebster

Well it certainly wasn't doing a good job of that, was it. Seems like there should have been some lock-tite on there or something. Have you had these ZL1 hub assemblies and rotors apart?



I estimated about 1/4" at the closest point. This was on the front, inboard corner of the tire on each side. The stock tires only leave about 3/4" clearance.



Thanks man! So that same harness is behind my liners on the ZL1? I'm assuming the photo shows its new, tied off location. Where is it beforehand? It's hard to tell from the photo where that would be positioned under the liner. The only place where it could be jeopardized on my setup is immediately behind the lower, front, inboard corner. Now you've got my curiosity roused so I'll have to rip that liner off to see, even though it hasn't rubbed at up to 125 MPH during 5 1/4 mile passes. When I swapped back to the OEM tires there was no indication of rubbing whatsoever. I've got to change the diff fluid again anyway so I'll do it while it's on the lift.



I ran 5 passes on them Friday night. Almost zero wheel slip with or without a burnout. Problem is that now it's like a different car. I've got to learn to launch all over again. At least now the spinning is out of the equation. Each pass got better but now I'm bogging the motor. I need more torque (higher RPM) at launch to get the 60' time down. That 4K RPM launch limit is cramping my style. After watching the video footage, I need to work on my launch habits too. I'm working on it... it's just gonna take some more seat time to get fast again. My last (best) pass was 12.0942 ET @ 119.64 MPH. It was a little disappointing after doing 11.6 on the stock rubber but I'm not sorry to be rid of the slip-and-slide. I may run the the stock rubber again on a good day but for now I'm concentrating on learning how to get fast on these without massive clutch abuse.

I've been studying the video footage, time slips, and notes; and deciding how to proceed on the next trip. I'll post a thread when I'm done with links to the PDR, Helmet GoPro, and Spectator videos. I learn something new and/or gain some skill every time I go. Maybe posting my video, notes, and lessons will shorten someone else's learning curve or maybe someone will have a suggestion that'll bring me to the next level.

Anyway, that's for the feedback.

--Cal

The cable runs right down the middle of the wheel well. If it's not rubbing you should be good to go bro.