Modern trailing arms for the 914?, 986 carriers/calipers/e-brake, more adjustability, more tire? Options

[sixnotfour]

well 7.5 x 16s ..No flares,, If you have flares 245/50 x15 on 9s

[rgalla9146]

well 7.5 x 16s ..No flares,, If you have flares 245/50 x15 on 9s

Mmmmmmmm....the Jon Lowe GT

[horizontally-opposed]

I agree that the market is very different today from what it was in the 80s and 90s. Back then, the only thing that mattered to most 914 owners was the price. If it wasn't cheap, they weren't buying it. Now, quite a few 914s are in the hands of people who are much more willing to spend money on them.

--DD

^ Fully agreed.

I don't know what kind of market there would be for aftermarket trailing arms, though. Might be an interesting project for someone, but I suspect that not enough people have run into problems with the 50-year-old steel parts to make that much of one, but my crystal ball doesn't work for crap! (I was absolutely certain that the Cayenne would never sell, for one thing.)

They would be neat, but they might wind up a one-off kind of thing.

--DD

I don't, either, and not sure anyone does.

But looking at my options—rebuild another set of 50yo steel trailing arms for $1000-2400 for a bunch of custom work that others have done, too—got me to thinking there must be a better way.

Carbon-fiber/titanium/Elephant Racing NASA spring plate/etc are overkill. Steel seems like a better idea, and Rennline's pair of height-adjust spring plates for the 911 for $250 (!) seem more down the right road. "Simply" lenghten, triangulate, and add way to mount 986 carrier with caliper ears & e-brake and it might be something pretty attractive—for any 914 owner who puts performance ahead of originality.

Goals:

• At least as strong as factory arms
• Sacrificial to protect the unibody in event of an impact?
• Option to replicate or exceed strength of reinforced arms?
• Two lower mounting points for dampers for lowered cars?
• Fine ride-height adjust for corner balancing?
• Fine adjust for toe and/or camber?
• Save weight if possible while keeping price below cost of rebuilt/modified arms
• Provide more room for 215 or 225 tire on 15x7R wheel or custom (or 951) 16x7s

Not sure steel arms would save much weight, but alloy 986 carriers and alloy calipers might. Engineering the arm is way above my pay grade. Needs someone who understands the 914 suspension geometry well, torsional loads, etc.

[horizontally-opposed]

The wheel /tire combo most sixes actually left the factory with. A rare sight now.

I wonder how many 914-6s are still running 110hp to preserve the 911's place in the lineup—or U.S. ride height and 165R15s, for that matter!

They've got to be few and far between.

well 7.5 x 16s ..No flares,, If you have flares 245/50 x15 on 9s

Love a narrow 914 with its fenders stuffed full of tire…and a GT/M471 car done right. Both of these sure qualify…

[Mueller]

Boxster carriers with 15x7 BBS wheels...they almost[i] fit. I am sure with 16" and larger no problem.



Clearance with my 23.3mm(?) offset BBS wheels with 205/55-15s
I had borrowed a fixture to with the intent to modify the trailing arm by moving the tire mounting face inboard 1". I am glad I did not perform this as now the inside of the wheel/tire would for sure hit the inboard trunk wall.

[horizontally-opposed]

Boxster carriers with 15x7 BBS wheels...they almost[i] fit. I am sure with 16" and larger no problem.



Clearance with my 23.3mm(?) offset BBS wheels with 205/55-15s
I had borrowed a fixture to with the intent to modify the trailing arm by moving the tire mounting face inboard 1". I am glad I did not perform this as now the inside of the wheel/tire would for sure hit the inboard trunk wall.

^ Thank you for this, Mike! (IMG:style_emoticons/default/beerchug.gif)

Real-world test fit just as I learned something I never knew: 15-inch wheels were actually considered as standard equipment for the cost-cutting 986 but finally ruled out because they looked way too small no matter how cheap they were.

From your pic, it looks like the caliper is an issue, and maybe the 986 "pinch" strut mount too? Was thinking the latter was going to have to be modified or removed, but interesting to see the rear caliper that tight to the wheel—as 986 2.5 calipers fit inside of a 15-inch Fuchs with various custom mounts out there. If the caliper is positioned as on a stock 914 or 986, the e-brake cable is going the right way and might even be set up to hook right up with a 914. "Steering" knuckle at the back could be used for mounting to a steel arm and/or for fine toe adjustment.

Will see if I can figure out how far I spaced the 15x7R Fuchs when I test-fit the 215/60, as that may help with clearance. It was a fair bit.

EDIT: Just noticed the 987 part number. If I remember right, PAG beefed up the Brembo castings for the 986 to incorporate larger rear wheel bearings around the same time or just after the 3.2-liter Boxster S came out (1999 for 2000 MY). I wonder if that would have had any effect on the castings' outer dimensions? In this case, it might matter…

[Chris914n6]

Too much bad weather last week but did score a Boxster susp yesterday (IMG:style_emoticons/default/piratenanner.gif)

I'll post up my findings as I get to play with it.

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1614200342.1.jpg)

[douglastic]

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1614200342.1.jpg)

Sweet.
Still rocking the 80s 2-door Pathfinder.

[Chris914n6]

Ignore this... wrong axle (IMG:style_emoticons/default/slap.gif)

15s won't fit the stock Boxster assm. I tried Cookies and Fuchs
1. the caliper protrudes past the hub face
2. caliper hits the wheel where it narrows in the middle
3. adding thick spacers won't fix #2 and allow an improved susp
4. 16" fuchs will need spacers near 1" thus see #3 part 2
5. Boxster spec wheels will fix all the above

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1614201357.1.jpg)

[horizontally-opposed]

15s won't fit the stock Boxster assm. I tried Cookies and Fuchs
1. the caliper protrudes past the hub face
2. caliper hits the wheel where it narrows in the middle
3. adding thick spacers won't fix #2 and allow an improved susp
4. 16" fuchs will need spacers near 1" thus see #3 part 2
5. Boxster spec wheels will fix all the above

(IMG:http://www.914world.com/bbs2/uploads_offsite/live.staticflickr.com-431-1614201357.1.jpg)

Ah, thanks for reporting back! (IMG:style_emoticons/default/beerchug.gif)

Hopes dashed with #3 for those who want to stick with 15s, as a fairly thick spacer is a given with 911R (or similar) rear wheels. So what allows use of 986 calipers with 15s on a 914 trailing arm? Smaller rotor diameter/closer mounting? as a fairly thick spacer is a given with 911R (or similar) rear wheels.

[mepstein]

I’ve put lots of 15’s on cars with Boxster calipers. SirAndy has Boxster calipers f&r with 15x7 cookies.

They have to be regular Boxster calipers and not Boxster S calipers.

[eeyore]

Custom 15s do fit on the 5 speed 2.7 986s and earlier. Carl V down in San Diego ran them back in the 'Oughties.

(Wasn't a custom wheel part of the plan?)

[horizontally-opposed]

914-6 brakes

DISC SIZE FRONT 11.12 in/282 mm
DISC SIZE REAR 11.26 in/286 mm

986 brakes

DISC SIZE FRONT 11.73 in/298 mm x 0.94 in/24 mm (vented)
DISC SIZE REAR 11.50 in/292 mm x .79 in/20 mm (vented)

A quarter inch can be a pesky thing…

[horizontally-opposed]

Custom 15s do fit on the 5 speed 2.7 986s and earlier. Carl V down in San Diego ran them back in the 'Oughties.

(Wasn't a custom wheel part of the plan?)

Yeah, potentially—but a custom wheel being:

> 15x7R (factory 911R wheel but $$$$)
> Weidman 15x7R (modified deep 6, attainable)
> Group 4 15x7R ($550 new)

Question is how much spacer, and even then if it would work. Guessing what is a tight fit with a 911/914-sized rotor and may be a no-go with a 986 rotor.

[mepstein]

You use Carrera rotors for the Boxster caliper conversions.

[horizontally-opposed]

You use Carrera rotors for the Boxster caliper conversions.

^ Yes, and now looking at the 986 rotor sizes I can see why VCI (and others) question 986 caliper upgrades for not dealing with the heat-sink element in the way a 930 setup does—though a 930 setup is a very expensive proposition these days and I suspect 986 calipers are hard to beat for weight, stiffness, cost, and pad pressure spread across four pistons instead of two.

[SirAndy]

I’ve put lots of 15’s on cars with Boxster calipers. SirAndy has Boxster calipers f&r with 15x7 cookies.

They have to be regular Boxster calipers and not Boxster S calipers.

(IMG:style_emoticons/default/agree.gif)

[SirAndy]

You use Carrera rotors for the Boxster caliper conversions.

^ Yes, and now looking at the 986 rotor sizes I can see why VCI (and others) question 986 caliper upgrades for not dealing with the heat-sink element in the way a 930 setup does—though a 930 setup is a very expensive proposition these days and I suspect 986 calipers are hard to beat for weight, stiffness, cost, and pad pressure spread across four pistons instead of two.

I ran 930 brakes before i switched to the Boxster calipers. The 930 brakes never worked as well as they should, the Boxster brakes are *much* better.

Btw. i had to machine the RJ adapters slightly to use the vented rotors i had, which are slightly wider and the calipers otherwise would not be centered over the rotors.
(IMG:style_emoticons/default/shades.gif)

PS: I still have the 930 calipers in a box somewhere, if anyone wants a set

[mlmgm]

Tuthill has some interesting calipers and probably could advise on adaptation to a 914 trailing arm.


https://www.tuthillporsche.com/product/tuth...ke-caliper-set/

[mepstein]

You use Carrera rotors for the Boxster caliper conversions.

^ Yes, and now looking at the 986 rotor sizes I can see why VCI (and others) question 986 caliper upgrades for not dealing with the heat-sink element in the way a 930 setup does—though a 930 setup is a very expensive proposition these days and I suspect 986 calipers are hard to beat for weight, stiffness, cost, and pad pressure spread across four pistons instead of two.

The 930 is a heavy car. I think they are really close to 3K so I could see the need for big brakes at the track. The Boxster brakes and Carrera rotors are total overkill for our cars. Not that I have a problem with it.

Porsche put S front and M rear calipers on the early turbos.