Alignment

[AC2024]

Does anyone know the relative contributions for front camber form the top hat adjustment listed in the owners manual vs. adjustment of the camber bolts on the wheel carrier? I am looking to like adjust to ~-2 deg front and ~-1.5 deg rear to give a nice set up for street driving and I am not sure if I can just make one adjustment or the other to get there.

On a related topic, anyone have a good recommendation on an alignment shop north/west of Boston?

 

[vblkwng]

On my CT5-V Blackwing we (3 different shops) couldn't get it to -1.5 on rears without excessive toe. However, with the ZL1 adjustable toe link that issue has been resolved.

 

[Mbar]

No need to touch the 'top hats'. You just need to adjust the camber bolts by loosening the lower nut slightly and removing the top nut and banging out the bolt.
Now....here's the problem....there is NO freaking way to know how much is -2.0
If you max the camber it will be -2.5 , if you go the other way it will be 0.0
There is no way to know how to reach -2.0 except trial and error. But every time you try you need to remove the wheels, adjust the bolts , replace the wheels, roll the car back and forth and check the camber and pray you got to -2.0
Just been through that this past weekend (my front right camber moved from -2.0 to -2.7), took me 3 trials. I did it this time at home and after I got the correct camber, I'm taking it to a shop to dial the front toe, rear toe and rear camber.
I wish GM would have added adjustable camber bolts in the front, like we got in the rear. I don't like the feel of -2.5 on the street as the steering wonders too much and the shock absorbing feels harsher.

5BW has a hole on top of the strut where you can thread an additional bolt for micro adjustment. I used it with my 6Gen Camaro, there it was 10M bolt, if I remember correctly (see Camaro pic below with hex bolt). 4BW does not have that option.

@poor-sha created this great video that will help you.

 

[poor-sha]

I haven’t tried this, but if you remove the bug bolt, insert the adjuster bolt, and then lower the car, you should be able to set the alignment with the adjuster bolt. Once you get that right, just lift the car, remove the wheel, and tighten the big bolt. Or you can use hub stands which is what I do now.

 

[Neebs]

Reviving this thread. Any aftermarket solutions (camber plates, bolts, etc.) to get more than -2.5 in front on ct4bw? I would like to get closer to -3. Outside edges just don't last on track when pushing and trying to do 25-30 min sessions.

 

[AC2024]

Do you drive the car on the street? I think any additional solution will absolutely kill Street drivability.

Therefore, honestly, I think you’re cheapest in the long run solution is dedicated track car.

That said, not trying to be a jerk, but if you are chewing shoulders with the track alignment, is it possible that you’re over driving the car? I run -2 deg up front and haven't noticed a shoulder wear issue- that said i generally lap 8/10 or 9/10 save the occasional limit lap.

 

[Neebs]

I primarily drive on street, but my driving is so little and shared with another car, that I am ok sacrificing some more driveability for better tire longevity on track. I feel car is better on street with -2.5 than on stock alignment.

Considering other car options that can be optimized more for track but have rear seats to put little kids back there in a bind. If 1-2 suspension parts can solve issue 4BW, than that’s easiest way.

I can take constructive criticism . Part of the issue is definitely overdriving and bringing in habits from a very different platform (911). Other issue is I try to drive near my 9/10-10/10 (not necessarily cars) likely leading to overdriving and don’t enjoy holding back. My home track is MSR Houston which has very abrasive track surface so that probably doesn’t help. Finally I am running advance group / pace. I have only done a couple of days in BW primarily because i can’t get my fronts to last more than 1.5 track day and its annoying.

May be need an instructor to help iron out bad habits vs suspension mods

 

[AC2024]

Ok, this making a bit more sense. There’s alot happening here.

If you try to drive a front engine car like a rear engine car, you’re gonna struggle. While I love 4S tire for dual duty, its going to struggle at 10/10 for 25 mins on an abrasive track and high temps. Lastly, the 4BW is still 3800 lbs and physics are physics.

Id suggest slow down a bit for a little while and get used to optimal lines for the front engine and feeling out the rotation of the car. Thats said, if you wanna go 10/10 in a 3800lb car on street tires…. Budget more for tires

 

[Neebs]

All correct. I am running kumho v730s (200 tw tire) which is a track tire.

My biggest issue is I am relying more on trail breaking into turns that I should which is probably not great for tires on a front engined 3800lb car (but a necessity on a rear engined car).

So going back to earlier question - is there a aftermarket way to get more camber than what the oem parts allow?

 

[AC2024]

Short answer is no. Not aware of any aftermarket camber plates that give more adjustability or adjustable control arms/hubs.

I guess you could try stiffer springs like swifts? The lowering will add a hair a camber due to mcpherson strut design and stiffen the roll moment

 

[Neebs]

Bit of a bummer personally. I guess joys of owning a low volume enthusiast car.

 

[LastGas]

@Neebs it's a great question, you aren't alone with the overall issue even if 1.5 days is maybe a bit to do with driving style. I think anyone is going to wear out the outside shoulder first at the stock max camber and not get great tire life. The fast Camaro and atsv drivers are running camber plates and 3° or more. Probably time to pick up the phone and call Vorschlag. Maybe we will get lucky and the atsv product fits the ct4.

 

[Neebs]

Reached out to Vorshlag. Seems like ATSV camber plates work with longer bolts. Here is their full response:

The Camaro parts absolutely do not fit.
The ATS parts do work with the new cars. We have not test fit them ourselves, but we have customers that have reported that they fit.
The only issue they came across was that they needed longer bolts to accommodate the thicker strut tower brace on the Blackwing that the ATS didn't get.
Vorshlag Cadillac ATS Camber Plates & All Perches

 

[LastGas]

Thanks @Neebs ! That's good news.

 

[VR_IRL]

Agree - great news and something I'll be considering as well as i get more comfortable with the car (currently on GM's track alignment).

Someone with a 5 upthread mentioned excessive toe when adjusting rear camber which was fixed with the ZL1 toe links. Since I'm a bit of a suspension noob, does anyone with more experience know whether this is an issue and solution with the 4?

 

[LastGas]

I don't think it is an issue with the 4, I was able to get the track spec rear camber and toe without any problem.

 

[VR_IRL]

I don't think it is an issue with the 4, I was able to get the track spec rear camber and toe without any problem.

Thanks. I was able to as well, just wasn't sure whether this would arise if I attempted to gain more camber in the rear in the future.

 

[Neebs]

Noob question but would these camber bolts provide incremental 1.75 degree of camber? Or a total of 1.75 degree camber ie less than what oem bolts allow (-2.5).

If incremental, it seems to be a way cheaper solution than camber plates.

https://www.spcalignment.com/component/spc/?task=part_description&pid=81280