TAC Tech => Tires, Brakes & Suspension => Topic started by: Wallington on March 01, 2025, 06:19:08 AM
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Just for the hell of it, figured I'd compare the different chassis brace bars of the Firebird and Camaro models.
These both appeared on the 78-81 models, holes exist for either since the chassis was the same for either. These can be fitted to earlier models but require holes to be drilled. Some 77 models may also have holes due to the brace bars used on the V6 models that year, although may have been added to specific vehicles as don't appear in any regular 1977 chassis rail shots I have. The crossmember holes and the control arm mount holes already exist, not sure how early they started.
Camaro Z-28 78-81 braces. While this diagram says 76-79, it's general only, it doesn't appear these bars existed until 78, and the later diagrams feature both types on same page with options alongside each, showing the Firebird WS6 bar version for 80-81. Other parts books and diagrams don't list these as used on Camaro, rather been a combined 80-81 diagram for F-bodies. Camaro continued to use the long angle bars to 81.
(https://live.staticflickr.com/65535/54357915463_2ac14d4a59_c.jpg) (https://flic.kr/p/2qPqwt2)Chassis braces Camaro Z28 angle type LH 470799 & RH 470800 (https://flic.kr/p/2qPqwt2) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
#470799 and #470800 Camaro brace bars
(https://live.staticflickr.com/65535/54357902493_1d281c1ca8_b.jpg) (https://flic.kr/p/2qPqsBp)Camaro 78-81 Z-28 chassis braces 470799 LH 470800 RH (1) (https://flic.kr/p/2qPqsBp) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
Compared to the 78-81 Firebird WS6 brace bar #10005519. One must wonder if the larger bars that picked out 3 locations were more sturdy and had less deflection than the shorter bars, but had even further clearance issues for non-stock exhaust systems.
(https://live.staticflickr.com/65535/54358085290_21f5b1a6a4_b.jpg) (https://flic.kr/p/2qProX5)Camaro Z-28 vs Firebird WS6 chassis brace bars (1) (https://flic.kr/p/2qProX5) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
(https://live.staticflickr.com/65535/54357902458_e43b4a4c4b_b.jpg) (https://flic.kr/p/2qPqsAN)Camaro Z-28 vs Firebird WS6 chassis brace bars (2) (https://flic.kr/p/2qPqsAN) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
Low-mile 1978 Camaro Z-28 showing the angle chassis brace bars installed at 3-points.
https://www.classicmotorsforsale.com/home/components/com_autostand/files/img_cars/full_image_148181_66bfe547b9c12.jpg
https://www.classicmotorsforsale.com/home/components/com_autostand/files/img_cars/full_image_148181_66bfe5471941c.jpg
This one is a classic backyard hack.....81 Z-28. Fits headers, cut braces rather than unbolt!
https://cdn.dealeraccelerate.com/ab/1/1802/103930/1920x1440/w/1981-chevrolet-camaro-z28
This is my 78 Firebird with WS6 brace bars fitted, holes are already there, simple bolt up. Normally, the bolt faces towards the engine with nut in sight. I think I had these turned for cleaned look and exhaust clearance way back. The diagrams call for the other orientation. It may simply be to avoid using wrong bolt by mistake and tightening against bush.
(https://live.staticflickr.com/65535/54356801662_392aa51dac_b.jpg) (https://flic.kr/p/2qPjPny)Firebird RH WS6 chassis brace bar 1-3-25 (1) (https://flic.kr/p/2qPjPny) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
And same with long Camaro bar in place, bolted in 2 places, normally the front crossmember would also be bolted from within. Lots of clearance with everything, factory-style Olds exhaust with manifolds, downpipe angles back.
(https://live.staticflickr.com/65535/54356801642_cb3a1be6f8_b.jpg) (https://flic.kr/p/2qPjPnd)Firebird with Camaro Z-28 chassis brace bar test fit RH 470800 3-25 (2) (https://flic.kr/p/2qPjPnd) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
LH side on Firebird with 403 and exhaust manifolds, in the case Thorntons, but the downpipe fouls where the long Camaro bars install due to the different angle of exhaust to RH side, coming straight down instead. Short WS6 bar is fine, as shown.
(https://live.staticflickr.com/65535/54356801652_fabbb25474_z.jpg) (https://flic.kr/p/2qPjPno)Firebird LH WS6 chassis brace bar exhaust downpipe 3-25 (https://flic.kr/p/2qPjPno) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
For some reason the 1977 V6 Firebird featured engine crossmember to chassis rail bracing bars, these were hollow tube with pressed ends. These were not seen on later year V6 or other models. This vehicle also had a GM towing-pack option, yes, with a V6. Note that the nut access holes in the chassis rail on the diagram doesn't exist in the photos. I had another diagram somewhere that mentioned it was V6-specific, but can't find it. Lost 2000 to Photobucket's greed.
This tubular version would likely have cleared the LH downpipe on my 403 Firebird, but of course doesn't pick up the control-arm mount either. If the threaded holes existed in the chassis rails you could easily make a giant WS6 bar set in addition to the existing bars and simply bolt on for whatever extra rigidity they'd bring.
(https://live.staticflickr.com/65535/54358158000_9f85dbbc13_c.jpg) (https://flic.kr/p/2qPrLyG)Chassis braces Firebird V6 1977 type (https://flic.kr/p/2qPrLyG) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
(https://live.staticflickr.com/65535/54357755481_802cb4ccea_c.jpg) (https://flic.kr/p/2qPpGUH)77 Firebird V6 unusual long frame braces2 (https://flic.kr/p/2qPpGUH) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
(https://live.staticflickr.com/65535/54356873692_3f1fb6e056_c.jpg) (https://flic.kr/p/2qPkbMs)77 Firebird V6 unusual long frame braces1 (https://flic.kr/p/2qPkbMs) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
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http://www.transamcountry.com/community/index.php?topic=83836.msg5333#msg5333
So, they won't work with Thornton's :-(
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I often wondered how much a difference those braces even made. The larger ones, I can almost see it.
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Ben, you are a wealth of knowledge, I was unaware of the Chevy version. They both look like they should help, the longer Camaro style more so. I would love to hear if anybody did some actual seat of the pants testing both long and short braces and comparing to nothing at all.
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Just trivial stuff. Had a similar post before the forum crash. Couldn't even find the saved pics on google image search to at least copy the information again.
One of those early Herb Adams and Supertuning your F body articles mentioned them too. Back then they were new so a simple task to pick up a set at the dealer. I don't recall any particular tests or advice other than 'liking' the idea of them.
As always, it comes down to the exhaust, pro-touring guys probably decided it's a compromise worth ignoring. Difficult area to even customise, except to suit different set-ups.
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The original fasteners used.
#473078 Bolts 3/8-16 x 1" and #1361640 3/8-16 flange nut.
A trivial detail is that in on of the original Camaro diagrams, the bolts used were 3/4" long not 1". Would still work, but I can imagine if the brackets had the slightest tweak in them, it may be hard to get the nut started and pull them in.
(https://live.staticflickr.com/65535/54360101508_1f9a5079ec_b.jpg) (https://flic.kr/p/2qPBJis)Firebird WS6 brace bar bolts 473078 flange nut 1361640 (1) (https://flic.kr/p/2qPBJis) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
I actually spun the bolt direction around on both sides, I though they didn't fit but was probably more to do with exhaust clearance and looking neater. RH-side.
(https://live.staticflickr.com/65535/54360101503_9ea3803c5b_z.jpg) (https://flic.kr/p/2qPBJin)Firebird WS6 bar RH with corrected bolt 3-25 (https://flic.kr/p/2qPBJin) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
Another angle of the LH-side. This is my 403 with custom exhaust from Thornton manifolds. You can see they come straight down then bend back. No room for the Camaro type on this side.
(https://live.staticflickr.com/65535/54360103438_7952658482_z.jpg) (https://flic.kr/p/2qPBJSJ)Firebird WS6 bar LH side exhaust 3-25 (2) (https://flic.kr/p/2qPBJSJ) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
And a saved pic I had from the older PTFB pages showing the standard WS6 bar and the small welded gusset on one of the cars. For the bolt-on guys they could have offered a right-angle plate that takes up one of those bolt locations and uses the control arm mounting hole to locate the other end with a longer bolt. Might be limited in improvement, but the sort of things that would still sell, just because.
(https://live.staticflickr.com/65535/54360093374_b36c7c509d_b.jpg) (https://flic.kr/p/2qPBFTd)PTFB WS6 bar brace vs welded gusset (https://flic.kr/p/2qPBFTd) by Ben (https://www.flickr.com/photos/196419001@N03/), on Flickr
NotaTA John, whom we lost a few years back, was working the custom braces on his car, including extending G-Braces and continuing from the Upper Control Arms to chassis rail, no doubt had similar mods to the Lower Control Arm area.
https://static1.pt-content.com/images/pt/2016/02/010_zpsnih6odon-1.jpg
https://static1.pt-content.com/images/pt/2016/02/007_zpsqojkvh2v-1.jpg
https://static1.pt-content.com/images/pt/2016/02/012_zps0ropnunl-1.jpg