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

[Racer]

its my recollection that the Maxlite 911R wheel is NOT an exact 911R replica. Maxlite is 47mm offset while the original 911R is 49mm offset.. and in this case, 2mm will matter!

We had a 74 911S (stock narrow rear fenders) and ran 911R wheels with 225/50-15 yokohama A008 (1980s here for reference). Despite fender lip rolling (like yours) previously on our 914/6 (to fit a 205/70-14 in period tire combo), that 911R combo just wouldn't fit on our /6 or on my /4. Both cars would require a slight pull of the fenders to work (but less pull than a 7x15 et23 wheel). fwiw, on our /6, the 205/70-14 was an extremely close fit, such that a 195/70 became the default tire in the 1970s on that car.

You also need to take into account tire flex / expansion and suspension movement etc under use.. and the harder the use, the greater the movements.

Another question, even if the trailing arm was made thinner, what is the relationship (plane) between the arm and the inner fender well? Does the arm protrude past the inner fender well or sit flush? ie, even if you thin the arm, will the tall tire still hit the inner fender?

[Andyrew]

My issue has always been rubbing the top of the chassis sheet metal. I've done it many times and have the half moon scars to prove it (IMG:style_emoticons/default/smile.gif)


Not once have I hit the trailing arm, and if the brake line got in the way then it was relocated.

If we didnt have increased camber as the tire went up then the trailing arm might be more of an issue.....

Also I have a fairly well sprung ride (225/275) so I dont have excess travel like a softer car.



I think your looking at the wrong issue here Pete. With the stock chassis 914 owners need to go outwards for larger tires. Not inwards.

(That being said... I have always wanted to build a tube chassis rear that can put a significant amount of tire more inward....)

[mepstein]

Pete - Just buy this.

[914forme]

The original Sheridan car had a custom set of rear arms with all the toe and camber settings out on the end of the arm.

Can be seen in the ultimate 914 racer Articles in European car circa 2013

[horizontally-opposed]

The original Sheridan car had a custom set of rear arms with all the toe and camber settings out on the end of the arm.

Can be seen in the ultimate 914 racer Articles in European car circa 2013

Ah, Roger's car. I wonder if that's the one Dave Darling was thinking about?

Looks like they're pretty trick—as is so much of that car—but that they push the ultra-wide wheels even further out, as one can with the Ultimate 914 bodywork.

[horizontally-opposed]

Thinking more down this road…though 914 unibody is obviously very different.

[sixnotfour]

Half way there..

[rick 918-S]

I totally get the look. 15's with vintage looking tires are so period 914. It really sucks that the tire selection is so limited. I really liked the Yokohama's mounted on my 15X8's with 225/60's and 215/60's vintage cool. I ended up going to 16X8 and 16X9's running 275/50's and 225/50's Yokohama tires until they discontinued the 275's I am down to one tire selection and that will eventually evaporate too.

Question: I don't have a car here at the new house I can examine. Is the trailing arm the first obstacle inboard or is the body sheet metal the first point of contact?

The trailing arms can be modified pretty easily really without going to a flat plate type arm if there is any benefit.

[horizontally-opposed]

Half way there..

Holy moly…

[horizontally-opposed]

I totally get the look. 15's with vintage looking tires are so period 914. It really sucks that the tire selection is so limited. I really liked the Yokohama's mounted on my 15X8's with 225/60's and 215/60's vintage cool. I ended up going to 16X8 and 16X9's running 275/50's and 225/50's Yokohama tires until they discontinued the 275's I am down to one tire selection and that will eventually evaporate too.

Your car looked fantastic on the 15s—I hope you kept them? I am hearing more and more good things about the Radial T/A, which appears to be available in 215/60 and 225/60. I wrote them off as Trans-Am tires but some Porsche guys are running them out here and say they feel good. They were cheap for a long time, then went up considerably (still much cheaper than Avons or a lot of other tires). My guess is that Michelin, which owns BFG, may have updated the technology behind them or at least the compounds. May be worth a shot, with black letters out?

And yes 16 choices are thin on the ground these days but better than they were a couple of years ago. Period P7s and a good Yokohama are out now, both of which would look great on a 914 with M471 flares, though they're 225/50 and 245/45. The fact that 15s went to near zero choices, sending many to 16s, suggests maybe the 16s will come around again too. I know people who buy and bag tires for old cars when they come available, as they're loathe to settle for all-seasons or worse, no tires at all—a big part of why I'm liking factory tire sizes. They not only look right, they're likely to be available in at least 1-2 sizes.

Question: I don't have a car here at the new house I can examine. Is the trailing arm the first obstacle inboard or is the body sheet metal the first point of contact?

The trailing arms can be modified pretty easily really without going to a flat plate type arm if there is any benefit.

First point of contact is brake line & trailing arm—there's room at the inner fender, to my surprise with a 215, though not enough for the tire to move around under load. So pulling the outer fender and adding more spacer will help the inner fender more than the brake line & arm. Right solution probably needs to address both.

Sounds like I might be shopping for a pair of good trailing arms…

[Montreal914]

A few years back, planning on my 5 lugs upgrade, I had a nice set of 15 x 6 Fuchs. After reading that the tire selection is greater with the 16", I sold them and got a set of 16 x 6. (IMG:style_emoticons/default/headbang.gif)

I am currently preparing my narrow body car for paint and will eventually reassemble it with the 5 lugs.

I am puzzled as to what summer tire selection there actually is in the 16" (IMG:style_emoticons/default/sad.gif) . It feels like the selection is greater in the 15", or am I missing something... (IMG:style_emoticons/default/confused24.gif)

Being in SoCal, I am looking at summer tires, but don't want too much of a modern look. I understand that by switching to 16, I walked away from the proper era look (IMG:style_emoticons/default/headbang.gif)

Sorry to jump in the OP's thread, but I know Pete is thoroughly investigating the tire file... I read one of your post talking about the Michelin Pilot Sport AS3 205/55/16. I am not sure if this model is still available though...

Interesting topic! (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/popcorn[1].gif)

[horizontally-opposed]

A few years back, planning on my 5 lugs upgrade, I had a nice set of 15 x 6 Fuchs. After reading that the tire selection is greater with the 16", I sold them and got a set of 16 x 6. (IMG:style_emoticons/default/headbang.gif)

I am currently preparing my narrow body car for paint and will eventually reassemble it with the 5 lugs.

I am puzzled as to what summer tire selection there actually is in the 16" (IMG:style_emoticons/default/sad.gif) . It feels like the selection is greater in the 15", or am I missing something... (IMG:style_emoticons/default/confused24.gif)

Being in SoCal, I am looking at summer tires, but don't want too much of a modern look. I understand that by switching to 16, I walked away from the proper era look (IMG:style_emoticons/default/headbang.gif)

Sorry to jump in the OP's thread, but I know Pete is thoroughly investigating the tire file... I read one of your post talking about the Michelin Pilot Sport AS3 205/55/16. I am not sure if this model is still available though...

Interesting topic! (IMG:style_emoticons/default/smile.gif) (IMG:style_emoticons/default/popcorn[1].gif)

16x6 allows for some GREAT tires—from (at last check) the Pilot Sport AS3, which has a simple sidewall and an "old enough" looking tread pattern and more than enough performance and feel for me on the street, to some pretty serious R-compound tires for autocross and track use. Last I checked, not only Toyo RA1 but also Michelin Cups and some others.

The good news with 205/55R16 is it was original fit for Porsches on 16-inch alloy wheels from 1975~ through 2004 (last of the 986s on 16s) as well as a ton of other performance cars built in big numbers, such as the Subaru WRX. The bad news is sneaking them into the rear fenders. I had no problems with 205/60R15 other than a bit of rubbing on the inside, so you might get them in. Some 914s seem to have less clearance than others.

You may also have a bit of interference up front depending on where your wheels sit in the fenders (I use spacers up there, and 185/70s can occasionally just barely catch my LE-style spoiler with the right amount of steering lock and suspension compression, such as on the way into a certain kind of driveway…though it's ultra rare and I've seen zero damage). But if you sort them, as many have, 205/55R16 is a wonderful size for a narrow body 914 and probably the ultimate performance setup without resorting to much in the way of trickery.

Looks like the AS3s are available in H-rated or V-rated for $135-140ea, but may be on closeout? But whatever, I doubt availability or selection will be a problem with 205/55R16. 225/50R16 may be a bit more of an issue, and 245/45R16 has already been an issue (being down to track tires or Fuzion, take your pick) but there are some very good 245/45 options out there again.

[Montreal914]

Thank you for this very valuable information (IMG:style_emoticons/default/smilie_pokal.gif)
I will look for some AS3 (IMG:style_emoticons/default/thumb3d.gif) I do have an LE replica valence, and also have a set of thin spacers (6-7mm?) off of a 68 911 that I might use in the front to fill up. I will definitely keep in mind all of the clearance issues you have pointed out. I hope the rear wont be an issue. (IMG:style_emoticons/default/sad.gif) Didn't think it would be... You are now making me wonder if I should try the rear fit before having the car painted, but that would mean installing the new 5 lugs trailing arms and... Many things to think about, Thank you!!! (IMG:style_emoticons/default/smile.gif)

[horizontally-opposed]

^ You are welcome, but @sixnotfour is probably our resident king of sneaking 205/55R16s into stock or stock-ish rear fenders.

I just wanted to get a conversation about rethinking the 914's trailing arms going.

After some more thought, I wonder if I can't rope @Optimusglen in, as some of the thinking stems back to the dreamy "GT" build we commissioned him to render for 000 (below) and might even tie into something else he's working on.

If a North American wheel supplier can create custom billet 20x12-inch wheels that exactly match Porsche AG concept car wheels for $1250~/wheel, I have to suspect two pieces of billet aluminum to accept stock, poly, or needle bearings up front and a 911 e-brake, wheel bearing, and a caliper at the back connected by a "blade" or two of carbon fiber might not be so crazy? It would be interesting to compare prices for the above against making jigs to narrow 50yo steel arms, adapting 911 e-brakes, repainting, and rebushing a set of stock trailing arms—which would still be boat anchors. Lightweight arms might save 20-30~ pounds in unsprung weight. Pair that with a lightweight battery, and it could add up to half~ the weight gain of a six conversion in roughly the same part of the car. Not gonna be cheap, but look what folks spend on bodywork, paint, wheels, lightweighting (!), etc.

[mepstein]

Pete - Have you weighed a 914 trailing arm. They look heavy but really not that bad. I don't have one in front of me but I'm guessing a bare one at 12-15lbs.

[horizontally-opposed]

Pete - Have you weighed a 914 trailing arm. They look heavy but really not that bad. I don't have one in front of me but I'm guessing a bare one at 12-15lbs.

I've handled three pairs of them over the years, with and without other parts on them, and they seemed like a heavy, strong, and inexpensive part for a mass-produced car.

Kinda like early 911/912/911 steel crossmembers, before PAG moved to aluminum.

I'd be curious to know their weight without bearings, etc.—as that would be the relevant comparison. In the old days, I could head down to EASY and very likely weigh one. Those days are gone, sadly.

[ClayPerrine]

Just put this under the back of your 914. Better suspension design, already has a parking brake and big vented rotors.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i.ebayimg.com-1143-1611869758.1.jpg)

[horizontally-opposed]

Just put this under the back of your 914. Better suspension design, already has a parking brake and big vented rotors.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i.ebayimg.com-1143-1611869758.1.jpg)

^ Ha.

Guessing this requires cutting the 914's unibody up, isn't compatible with 914's track width, wouldn't fit under standard 914 fenders, and would ultimately be heavier and more expensive than custom trailing arms let alone a small run of lightweight arms…

[mepstein]

Pete - Have you weighed a 914 trailing arm. They look heavy but really not that bad. I don't have one in front of me but I'm guessing a bare one at 12-15lbs.

I've handled three pairs of them over the years, with and without other parts on them, and they seemed like a heavy, strong, and inexpensive part for a mass-produced car.

Kinda like early 911/912/911 steel crossmembers, before PAG moved to aluminum.

I'd be curious to know their weight without bearings, etc.—as that would be the relevant comparison. In the old days, I could head down to EASY and very likely weigh one. Those days are gone, sadly.

I'll do it tomorrow if nobody beats me to it.

[rick 918-S]

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.