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 |
rick 918-S |
Jan 28 2021, 04:30 PM
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#2
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Hey nice rack! -Celette Group: Members Posts: 20,443 Joined: 30-December 02 From: Now in Superior WI Member No.: 43 Region Association: Northstar Region |
If I had my new shop set up I would build a gig and narrow a couple. One of you guys should take this on for Pete. Couldn't take but a couple days of messing around to make a couple.
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horizontally-opposed |
Jan 28 2021, 06:15 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 |
If I had my new shop set up I would build a gig and narrow a couple. One of you guys should take this on for Pete. Couldn't take but a couple days of messing around to make a couple. Thanks, Rick—but I am actually interested in something for more than me. Our 914s have always lived in the shadow of the 911 when it comes to suspension upgrades, being "lucky" to benefit from parts developed for the front of the 911 and even luckier if a matching rear damper/spring was available. I get the idea that there wasn't enough market to justify the developments we've seen for 911s in years past, especially when 914s were $5000-30,000 cars, but I have to wonder if there isn't now? How many people have made jigs to narrow two trailing arms (I've found several independent jobs in my research) and/or slice off the wheel carrier to weld up a 911 e-brake to gain access to better/lighter calipers? And you're still dealing with a 50yo arm that might need to be repainted, etc. And maybe reinforced, too—though there are two schools on that. How much does all that labor add up to? Might be cool nice to see something developed that addresses all that, takes any of the three available bushing types up front, accepts a 911 e-brake, can accept different calipers via adapters (914, 930, 986), and maybe offers some adjustment with 2-3 mounting points for the rear damper. Won't be cheap, but people are spending real money on 914s these days. I know of someone who might be willing to fund such a thing if it's done to a high level—and that would leave a cool product on the market. Or maybe we can figure out a group buy. I've been cooking through another idea that might drop serious weight off the back of the 914, and might not be insane in lieu of what some are spending or will eventually spend in this area of the car. I know an F1 contractor who might be cajoled into helping with the billet aluminum (or?) sections, but we also have some very smart cats here. Yes, I'm definitely thinking out loud—and taking some hits for it—but that's all good. (IMG:style_emoticons/default/beerchug.gif) 7.5"x16 ET38 wheels, minimal spacers different on each side. Normal trailing arms. Hoosier 205/45/16 which of course runs wider than numbers would suggest. Does not hit the brake line or arm. Fenders were yanked a bit and folded. Inner wheel well rubs first, before you would rub brake line or trailing arm. Thanks for this, and very cool to see. I've seen people sneak 16x7 Fuchs in (both 951 and maybe 911 too?), but not these—as they appear to have a bit of lip on them. 205/45R16 definitely seems to help, too. @sixnotfour is running custom 16x7.5 Fuchs also, I think, but they're flat-faced with the added width on the back iirc. Like a 16-inch 911R wheel. As you note, actual tire widths ≠ tire sizes. When I ran 205/60R15 A-008Rs, I had the same point of interference as you and no interference at the brake line/trailing arm. I went on to drop down to 205/55R15 BFGs and, later, Yokos, and had no issues. 185/70 and 195/65 have all been fine, but no surprise there. Test fit with the 215/60R15 Pirelli P6000 shows brake line clearance is a bigger problem than inner fender clearance—so pulling the fender and spacing the wheel further out will help the inner fender more than the brake line, and I'd love to minimize that fender pull… We could play with it if you want... Was hoping you might chime in, as one of very few logical vendors for trick 914 trailing arms. (IMG:style_emoticons/default/sunglasses.gif) Would be great to compare notes and do some thinking… |
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