New Caprice - Discussion forums

The worldwide owner-to-owner online support system for the Chevrolet Caprice PPV
It is currently Fri Dec 15, 2017 8:56 pm

All times are UTC [ DST ]




Post new topic Reply to topic  [ 36 posts ]  Go to page 1, 2, 3, 4  Next
Author Message
PostPosted: Mon Aug 28, 2017 10:38 pm 
Offline
Administration Staff

Joined: Tue Mar 19, 2013 11:30 pm
Posts: 1341
Location: Canton GA
Most will probably not go to the effort that this mod calls for. In addition to welding on new adapter brackets/plates on the cradle for the larger bar's clamps, the bar itself will not clear the stock PBR calipers on the PPV, so a Brembo brake setup is necessary for it to work. Other potential clearance issues remain to be identified, such as the stock muffler flanges, which don't exist on the SS sedan, leaving more room in the area where this bar runs--they appear to be pretty close to the bar.

This is a work in progress at the moment, but I wanted to get the thread started, and post some pictures--more to follow.

Attachment:
File comment: 16mm - new bar will be 25mm or larger
stock rear bar left.JPG
stock rear bar left.JPG [ 38.61 KiB | Viewed 888 times ]
Attachment:
File comment: smaller clamp is secured with one bolt, and is prone to separation, especially with a larger bar upgrade
bar clamp comparison1.JPG
bar clamp comparison1.JPG [ 33.09 KiB | Viewed 888 times ]
Attachment:
File comment: bolts are larger on 2-bolt clamp, and existing bolt hole & nut will be drilled & re-tapped to the larger size, most likely.
bar clamp comparison2.JPG
bar clamp comparison2.JPG [ 36.74 KiB | Viewed 888 times ]
Attachment:
File comment: Left & Right--remains to be seen which will go on which side, or if changes will be needed
prototype bar clamp adapter plates.JPG
prototype bar clamp adapter plates.JPG [ 36.72 KiB | Viewed 888 times ]
Attachment:
File comment: plates are mirror image
plates with clamp.JPG
plates with clamp.JPG [ 35.97 KiB | Viewed 888 times ]
Attachment:
plates with clamp2.JPG
plates with clamp2.JPG [ 38.24 KiB | Viewed 888 times ]
Attachment:
plates with clamp3.JPG
plates with clamp3.JPG [ 37.33 KiB | Viewed 888 times ]


Attachments:
File comment: adapter plate will overlay cradle pad and will be welded to it, then new bar clamp is secured to the plate
new bar clamp on existing cradle pad.JPG
new bar clamp on existing cradle pad.JPG [ 38.67 KiB | Viewed 888 times ]

_________________
Bill Harper
inov8r@windstream.net
Top
 Profile  
 
PostPosted: Tue Aug 29, 2017 12:32 am 
Offline

Joined: Sat Feb 14, 2015 2:12 am
Posts: 597
Location: SE PA
WOW sir groundbreaking effort!

Again seems to me you should be making/selling them, can't wait to hear how it affects the handling


Top
 Profile  
 
PostPosted: Tue Aug 29, 2017 1:21 pm 
Offline
Administration Staff

Joined: Tue Mar 19, 2013 11:30 pm
Posts: 1341
Location: Canton GA
Once I've validated this first effort, it will be possible to make more adapter plates.

Those with possible interest should post up in this thread.

If the effort in this instance is too much (changing control arms and brakes), the option does exist to use the 2014 SS 28mm rear bar, which mounts to the cradle in the same manner (2-bolt clamps) but connects to the lower arms further inboard-, in the same manner as stock PPV bar--and the only way to do that is with new plates like I'm doing, or a cradle swap.

It will also require a stronger link between bar and control arm, and reinforcement to the lower arms--use of the 2014 SS lower arms, the Camaro 1LE upgrade arms (a kit), or a link reinforcement kit offered by BMR, or a combination of these parts.

These links may not say specifically that these parts fit a PPV, but that's an internal BMR issue.
https://www.bmrsuspension.com/index.cfm ... ductid=987
https://www.bmrsuspension.com/index.cfm ... superpro=0

_________________
Bill Harper
inov8r@windstream.net


Top
 Profile  
 
PostPosted: Tue Aug 29, 2017 4:31 pm 
Offline
Administration Staff

Joined: Tue Mar 19, 2013 11:30 pm
Posts: 1341
Location: Canton GA
new photos - sway bar, clamp/plate, and link - each photo has additional remarks

Until fit check is performed, the plate position shown could be reversed (mounted left or right side)

The reason for the right angle edge/flange on one side of each plate is to add stiffness to the part, while still leaving the ability to position the plate with minimal modification, and to provide a welding seam on that side with no flange.

Once I've done the test-fit, I'll be drilling several additional holes through the plates for plug welding on the existing bracket for even more strength/stability.

Sorry about the shadows!


Attachments:
File comment: mock-up, plate front view
bar mount plate1.JPG
bar mount plate1.JPG [ 38.67 KiB | Viewed 858 times ]
File comment: mock-up, plate back view
bar mount plate2.JPG
bar mount plate2.JPG [ 40.59 KiB | Viewed 858 times ]
File comment: PN 22761221 - stabilizer link, complete assembly
bar down link.JPG
bar down link.JPG [ 41.3 KiB | Viewed 858 times ]
File comment: visibly wider SS bar - PPV bar arms turn forward just outboard of the bar bushings
bar clamp plate link.JPG
bar clamp plate link.JPG [ 29.99 KiB | Viewed 858 times ]

_________________
Bill Harper
inov8r@windstream.net
Top
 Profile  
 
PostPosted: Wed Aug 30, 2017 1:58 am 
Offline

Joined: Sat Feb 14, 2015 2:12 am
Posts: 597
Location: SE PA
I want a set


Top
 Profile  
 
PostPosted: Wed Aug 30, 2017 2:43 am 
Offline
Administration Staff

Joined: Tue Mar 19, 2013 11:30 pm
Posts: 1341
Location: Canton GA
what rear bar are you planning to use, out of curiosity?

_________________
Bill Harper
inov8r@windstream.net


Top
 Profile  
 
PostPosted: Thu Aug 31, 2017 1:13 am 
Offline

Joined: Sat Feb 14, 2015 2:12 am
Posts: 597
Location: SE PA
unsure still, I have the 1LE arms installed but have not done the brakes, would seem I could easily do the 14SS bar but maybe its not as good as a setup?


Top
 Profile  
 
PostPosted: Thu Aug 31, 2017 2:55 am 
Offline
Administration Staff

Joined: Tue Mar 19, 2013 11:30 pm
Posts: 1341
Location: Canton GA
The 2nd design rear bar originated with the Camaro 1LE. While I don't pretend to know exactly why it came to be, I'll take a guess.

The original design, as found on G8, PPV, early 5thGen Camaro, and 14 SS, evolved over time. The 14 SS represented the peak of that design--larger bar - 28mm vs 16mm on PPV, 18mm on G8, 20mm on GXP (and now on 14-17 PPV). On the 2014 SS, it included stronger control arm brackets for the sway bar, and new end links, with a double-shear connection to the arms, all changes which were intended to fix the separation problem many G8 owners experienced, and perhaps some early Camaros (I haven't looked into that).

The 1LE style bar requires Brembo calipers because there will be interference between the floating rear calipers and the bar, since the caliper moves inboard as the pads wear.

I am inclined to think that the reason the 2014 SS didn't get the 1LE-style rear bar in the first place was due to a supply issue with the Brembo rear brakes, so the bar waited for the brakes, which came along for 2015.

No matter how the SS rear cradle is different across the 4 years of SS production, the cradle bar/bushing mounting setup is a 2-bolt clamp design, where G8 & PPV are still using a single-bolt clamp, which has clearly shown weakness under hard use. There are at least 3 different PN's for cradles (actually, GM's name for it is CROSSMEMBER) from 2014 to 2017, but exactly what is different on each, and whether the sway bar bracket mounts are different, is not known at this point.

All that is largely a matter of observation with some opinion thrown in--I don't think GM would be doing the 2nd design/1LE style if there wasn't value to doing so. The lever/arm (that part of the bar on the outboard side of the cradle bushings) is longer, so the action/reaction to input (wheel motion) is going to be more linear and gentler--the 1LE bar is about 25mm, but can generate as much resistance force, or more, than the 28mm bar at it's narrower connection position, so it's just as effective as far as what it's purpose is. The link design for the 1LE bar is much less problematic as far as possible separation issues, whether due to bar link or control arm bracket failure, even though the re-design for 2014 probably fixed the past tendencies for this to happen.

Either bar is a win-win over the PPV stock rear bar. Both will require the mounting plate mod to the cradle, and the Camaro 1LE lower control arms, which ARE stronger (and cheap) might work OK. Otherwise, the 2014 bar on PPV would call for either the 2014 SS arms and links, or a BMR control arm bracket reinforcement kit and some sort of HD end link setup, whether from BMR or other sources.

_________________
Bill Harper
inov8r@windstream.net


Top
 Profile  
 
PostPosted: Thu Aug 31, 2017 5:41 am 
Offline

Joined: Mon May 30, 2016 8:12 am
Posts: 286
Location: phx az
from road tests ive seen the 14 SS handled on track better than the 15-17's , and this was from the same PRO driver on the same track


Top
 Profile  
 
PostPosted: Thu Aug 31, 2017 12:26 pm 
Offline
Administration Staff

Joined: Tue Mar 19, 2013 11:30 pm
Posts: 1341
Location: Canton GA
I'm guessing Randy Pobst/Motor Trend?

Similarities/differences 2014 SS vs 2015-2017
Tires - same
Wheels - same size - heavier in 16-17 (increased unsprung weight)
Springs - different PN's 15-17 - rate changes unknown, but matched with MRC, most likely
Front bar - same
Rear bar - different design 15-17
Rear lower control arm - to accommodate rear bar change
Brakes - Brembo rear 15-17, more robust, rotor heavier (increased unsprung weight)

There are so many variables that would impact the subjective call about handling differences on otherwise "identical" vehicles, considering different day/different conditions--unless they were done in a side-by-side direct comparison, with instrumentation--not throwing the BS flag on Pobst or MT, just suggesting that as good as a driver may be, is it possible to make such a statement outside of some pretty strict controls, really only achievable if both vehicles were evaluated at the same time?

Not that I'm sticking up for Holden/GM as far as the changes made, but engineers, given a budget to work with, won't typically do things that intentionally degrade performance. The KISS factor (in favor of the 2014 version) may be in play, certainly, when a system like MRC is such a significant change....multiple changes, even minor, can have a stacking effect, and not always positive in nature. The unsprung weight difference is such an example--I don't know what the actual difference is, but the newer (15-17) cars are heavier, just not sure how much.

Just my opinion--the handling differences are likely most affected by the MRC "damper" system vs conventional gas pressure shocks in 2014. I recall something saying the spring changes took the softer approach, to make for a more comfortable ride in the least-aggressive MRC setting - Touring? If that is the case, the lower spring rate, regardless of damper settings, may contribute to Pobst's observations/SOTP feel difference.

Interesting parts lookup--as it may pertain to rear sway bar use: rear lower control arms for 2014-2017 SS & PPV (VF & WN) platform show complete cross-commonality. This means the sharing of these components could make it easier to fit your choice of sway bar to a 14-17 PPV, or scavenge those parts from a 14-17 "parts car" for that purpose.

There does not appear to be any commonality of the cradle/crossmember between SS & PPV, so the sway bar mounting for larger bars will be a matter of modifying/adding plates for the more robust 2-bolt clamp setup for either SS bar, or a swap-out of the cradle.

_________________
Bill Harper
inov8r@windstream.net


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 36 posts ]  Go to page 1, 2, 3, 4  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group