Modern trailing arms for the 914?, 986 carriers/calipers/e-brake, more adjustability, more tire? |
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Modern trailing arms for the 914?, 986 carriers/calipers/e-brake, more adjustability, more tire? |
horizontally-opposed |
Jan 26 2021, 12:21 PM
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#1
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Advanced Member Group: Members Posts: 3,431 Joined: 12-May 04 From: San Francisco Member No.: 2,058 Region Association: None |
I've been reviewing past discussions on these (links below) off and on, having test fit a 215/60R15 Pirelli P6000 on a 911R wheel into both rear fenders of my narrow-body 914. It seems doable, but it's going to take some massaging on the outer fender, custom spacers, and—maybe—narrowed trailing arms. Which got me to thinking about the current state of the 914 trailing arm, which is the same it's been since 1970.
Basically, those heavy, non-adjustable steel trailing arms are one of the very few things on the 914 that hasn't been addressed or evolved by the aftermarket. I'm running PMB-rebuilt trailing arms with PMB-rebuilt calipers, and can redo them again with reinforcements and/or some reshaping, but I wonder how hard would it be to do blade-type trailing arms of similar strength with less weight and/or more adjustment. Could a 911 spring plate, or a triangulated or otherwise reinforced version of it, be adapted? Looking at the basic design of the 914 arm, it doesn't look all that complicated, but I'm no engineer. EDIT: Possible use of a machined 986 wheel carrier, an aluminum casting by Brembo that incorporates the 986 e-brake and 986 four-piston caliper mounts, comes up later—a very interesting idea from @Chris914n6, particularly as the castings are available for $100-200ea used or new from Porsche. Bolting that carrier to a new steel trailing arm with a lower damper mount seems viable to me, but here to learn. The custom work to narrow factory 914 trailing arms looks extensive, but has been done by both @914timo and @sixnotfour as well as, it looks like, Rich Johnson. I could see doing it in the process of moving to 911 e-brakes and 986 2.5 brakes, maybe, but I wonder if a group buy might attract a 914 vendor we all want to support? Relevant threads: http://www.914world.com/bbs2/index.php?sho...p;#entry1247827 http://www.914world.com/bbs2/index.php?sho...ailing&st=0 http://www.914world.com/bbs2/index.php?sho...238144&st=0 http://www.914world.com/bbs2/index.php?sho...234391&st=0 |
gms |
Jan 26 2021, 04:34 PM
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#2
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Advanced Member Group: Members Posts: 2,694 Joined: 12-March 04 From: Chicagoland Member No.: 1,785 Region Association: Upper MidWest |
I have always thought it would be great if someone made trailing arms out of cast aluminum like the later 911s
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horizontally-opposed |
Jan 26 2021, 04:45 PM
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#3
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Advanced Member Group: Members Posts: 3,431 Joined: 12-May 04 From: San Francisco Member No.: 2,058 Region Association: None |
I have always thought it would be great if someone made trailing arms out of cast aluminum like the later 911s This. Or carbon fiber if it makes sense, at this point. I have a 225/50-16 stuffed in the rear. I ran out of room between the sheet metal way before the arm could be an issue. 2nd thing... why would I ever want an oversized 215/60-15 with huge sidewall bulge? On factory 16x7s, right? I have seen it done a few times. I'm more interested in getting the tire inboard on a 911R-style wheel, as I want to stay with 15s and the "narrow body" look. 185/70R15 or 195/65R15 front and 215/60R15 are the correct spec with the right overall diameter for a lot of Porsches—from the 1973 911 Carrera RS through Carrera 3.2s and 944s of the late 1980s. Good setup, several performance tires available, and period correct looks. There's a lot to like about factory tire sizes—and now there are some good wheel choices as well, ready to mount for similar or less money than "normal" Fuchs that need to be restored and a lot less than previously unobtanium 911R wheels. https://tremotorsports.com/exterior/fuch-st...deep-6-7-wheels |
Chris914n6 |
Jan 26 2021, 09:37 PM
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#4
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Jackstands are my life. Group: Members Posts: 3,316 Joined: 14-March 03 From: Las Vegas, NV Member No.: 431 Region Association: Southwest Region |
QUOTE I have a 225/50-16 stuffed in the rear. I ran out of room between the sheet metal way before the arm could be an issue. 2nd thing... why would I ever want an oversized 215/60-15 with huge sidewall bulge? On factory 16x7s, right? I have seen it done a few times. I'm more interested in getting the tire inboard on a 911R-style wheel, as I want to stay with 15s and the "narrow body" look. 185/70R15 or 195/65R15 front and 215/60R15 are the correct spec with the right overall diameter for a lot of Porsches—from the 1973 911 Carrera RS through Carrera 3.2s and 944s of the late 1980s. Good setup, several performance tires available, and period correct looks. There's a lot to like about factory tire sizes—and now there are some good wheel choices as well, ready to mount for similar or less money than "normal" Fuchs that need to be restored and a lot less than previously unobtanium 911R wheels. https://tremotorsports.com/exterior/fuch-st...deep-6-7-wheels Stock wheels & tires, for a Boxster (IMG:style_emoticons/default/biggrin.gif) With spacers I think I ended up at Fuchs 911 offset and a bit of camber and rolled the fender. I think I test fit a 215/60 on a 7x15 cookie from the 944 set I bought. Billowing sidewalls. Might as well call them pillow tires for a sleepy drive (IMG:style_emoticons/default/laugh.gif) Found it. Silver cookie is a 6". I recall the 7" rubbed or was otherwise not worth using for donuts. (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1611718641.1.jpg) (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1611718642.2.jpg) (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1611718642.3.jpg) (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1611718642.4.jpg) (IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1611718642.5.jpg) For comparison wide 205/55 on a 7x16 911 Fuch spec. Basically the same as my Boxsters. |
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