5 lug options, I'm confused Options

[goose2]

OK, I'm trying to gather all the bits I'll need for a 5 lug/bigger brake conversion on my 6cyl.car. All the possible permutations and combinations have got me totally boggled. (IMG:http://www.914world.com/bbs2/html/emoticons/headbang.gif)
What I have:
I have a stock suspension/brakes car to upgrade...has nice Koni's all around. Also have a parts car with EARLY (small caliper/non-vented) complete 911 front end and 911 rear stubs/hubs/rotors/calipers. This front end had good Konis too. This front end is not what I want to use because of the small (3") calipers, non-vented rotors, and early style ball-joints and A-arms.

What I want to achieve:
I'd like to have 911 vented rotors/calipers and the heavier torsion bars up front with the good Koni shocks, all mounted up to a later style 911 assy. I believe I can use my 911 stubs/hubs/rotors in the back with my 914 calipers and retain the handbrake, right?

The Deal: I've found a '73 911T complete front end locally (no shipping) for $500. Calipers will need to be rebuilt but looks ok otherwise. Bad news is...shocks are toast.

Questions: Will my 914 Konis work with the later 911 front end? Will the Konis from the early 911 front end work with the later 911 front end? Will the hubs from the early front end work on the later front end? (I've been offered the late front end for $150 less w/o hubs). I need to do this as affordably as possible (don't we all?), and will sell the bits I don't use here or on ebay.

I know this stuff has been covered before, so please pardon my repeating it here. I just haven't been able to put together answers I trust from the archives. I just know some of you out there have the experience to answer this easily.

Thanks, group...your help for this newbie has been invaluable and I'm hoping you will come through again.

[ClayPerrine]

A 73 T front end won't gain you anything. It's a 3 inch bolt spacing for the caliper mount. You need a 74 to get the 3.5 inch bolt spacing on the caliper mount.

[goose2]

Thanks Clay....maybe I'm mistaken about the year but it does have vented rotors (I've looked at it). I assume, perhaps incorrectly, that vented rotors mean 3.5 bolt spacing.

[ArtechnikA]

QUOTE (goose2 @ Jun 1 2005, 12:38 PM)

I assume, perhaps incorrectly, that vented rotors mean 3.5 bolt spacing.

nope. 914.6's had vented rotors and 'M' calipers...
it is true that all 3.5" calipers are for vented disks, tho...

[airsix]

QUOTE

I believe I can use my 911 stubs/hubs/rotors in the back with my 914 calipers and retain the handbrake, right?

Somebody correct me if I'm wrong, but I don't think you can use those hubs and stubs in the 914 trailing arm. Even if you could I don't think the 914 CV will bolt to the 911 stub will it?

-Ben M.

[ArtechnikA]

QUOTE (airsix @ Jun 1 2005, 05:31 PM)

Somebody correct me if I'm wrong, but I don't think you can use those hubs and stubs in the 914 trailing arm. Even if you could I don't think the 914 CV will bolt to the 911 stub will it?

hubs, yes - 914.6 uses a 901 part number hub (i.e. - nothing special there...)

you can use the 911 stub axle if you use the halfshaft (911 CV).
IIRC, the early 911 inboard CV will attach to the 914 output flanges.

so the only issue is that the axle shaft itself is the wrong length.

and there may be an issue with the 914.6 rear disk being a little (0.2" or so) too big (diameter) for a 914/4 rear caliper - evidently - some fit fine, some hit.

i do not think you can just use a solid 911 rear disk - but i'm pretty fuzzy on that one, and i don't think it'd buy you much if you could, since 914.6 rear disks are still available.

[Eric_Shea]

Let's make it clear. Here's some answers to your questions:

QUOTE

Will my 914 Konis work with the later 911 front end?

Yes. But as mentioned you will still have the 3" mount spacing. I believe that front end is an upgrade however. Vented rotors up front and a slightly larger torsion bar.

QUOTE

Will the hubs from the early front end work on the later front end?

No. There was a discussion in one of xsboost's threads. Those early hubs space a "solid" rotor properly under the non-vented style caliper. You will need the hubs that come with that 73 front end.

QUOTE

I believe I can use my 911 stubs/hubs/rotors in the back with my 914 calipers and retain the handbrake, right?

You can use your hubs but rotors and stubs would be impractical. Yes... you can spend all sorts of time and effort trying to get an axle combo but... to better steer you in the proper direction, I believe "Mittlemotor" sells 914-6 stub axles all the time on eBay for $250.00. Shipping is $50.00. This makes them the best -6 stub axle buy on the market.

Your 914-4 caliper with the handbrake incorporated will need to be spaced to use that vented rotor.

So to make it a little more clear and practical:

73T Front end - Bolts on. Slight upgrade.
73T Hubs - Needed in the package.
Rear Hub - Yes, with a 914-6 stub axle.
Rear Rotor - Not without a "V-Caliper" (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) (standard rear 914-4 caliper needs to be spaced out for this vented rotor... you did say 73T right?)
911 Stub Axle - Not practical. Get the 914-6 stub axle.

With that system you would have a stock 914-6 system with the exception of the slightly larger rear caliper.

Now... questions for you; What horsepower do/will you have?

[Eric_Shea]

QUOTE

I don't think the 914 CV will bolt to the 911 stub will it?

No. You're correct. Hence the 914-6 stub axle.

Also... I noticed that Goose may be talking about his "early" 911 rear rotors. If you plan to use solid rotors you'll need to get the 914-6 rotors.

One more thing. THAT PRICE IS TOO DAMN HIGH FOR A 73T FRONT END. RUN AWAY. (IMG:http://www.914world.com/bbs2/html/emoticons/ohmy.gif)
You should be able to find one for 1/2 that... complete. There was one in the classifeds for $400.00 that had all new "everything" including new Koni's I believe. Couple pages back by now. Guy was from MN.

[goose2]

Thanks for the information all (IMG:http://www.914world.com/bbs2/html/emoticons/clap.gif) I think I'm clear on the front end now...and I'm grateful for the heads up on the pricing, Eric, I suspected his price was high. However, he's just down the street from me and he'll deliver (no shipping costs). And to further clarify...the front end he's selling is 911 with vented rotors, 3.5 calipers.

On the rear...I believe what I have (from a converted parts car) is: '67 911 hubs, rotors (solid), stub axles, and complete half shafts. This had all been fitted up to the car and appeared to work ok. I've torn it down and the CV's look ok but of course I wasted the wheel bearings getting it apart. If I read your replies correctly, I may be able to use this whole setup, right? I'd have to mount the 914 calipers though, if I want a handbrake, perhaps respacing them... and the 911 nonvented rotors MAY be too large in diameter. Is there any advantage to using the 911 half shafts if that's what I have? Stronger? More availabile if I break something? Whew!...this has turned in to quite a puzzle.

To answer your question Eric...motor is a 2.4 Euro spec...Zeniths and good headers...probably 150 HP and lots of torque. A Dan Root job. This is a street car and I only drive like a maniac occasionally. Power is addictive though, and I'm already wondering how a 3L would run.

Thanks again all for coming through with some answers,
Randy

[Oled]

Vented rotors on rear is an easy change. Just rebuild the 914/6 calipers and add M caliper spacers and longer bolts. SC vented rotors shoud fit just fine though some require a very small amount of machining of the perimeter to stop rubbing on the middle of the caliper.

[Eric_Shea]

OK... now we're getting somewhere.

Let's start here:

QUOTE

probably 150 HP and lots of torque

I think you would be on the edge of OK with an M-Caliper setup and your stock rears with solid rotors. But you mentioned:

QUOTE

the front end he's selling is 911 with vented rotors, 3.5 calipers

You also mentioned:

QUOTE

I've found a '73 911T complete front end locally (no shipping) for $500

Which is it? As Rich mentioned, vented rotors don't necessarily mean 3.5 caliper spacing (but 3.5 does mean vented rotors). 73T's came with 3" spacing and M-Calipers. So, if it's an early Koni or Bilstein (early 3.5) set-up it was either special ordered for that 73T (very rare indeed) or it was fitted aftermarket later. It might be worth $400 with the bad inserts if it is truely one of those two. If it's local go check it out. You will either have S-Calipers (aluminum) or A-Calipers (iron) if it's truely a 3.5" strut. Bad inserts = price reduction. Also, if it is one of those struts, your Koni's won't fit. More dough out of your pocket. With Boge strut's (3" spacing) your inserts will fit.

Now on to the rear.

QUOTE

Just rebuild the 914/6 calipers and add M caliper spacers and longer bolts.

It may seem easy but, don't forget the custom pad pins (10mm longer in the center $75.00), the 911 rear M-Caliper spring kit for the pads ($45.00) and the custom machined rotor spacer to space the rotor out 5mm from the hub (splitting the difference of the 10mm spacer you just put in. $75.00) All told that's about $195.00 with of parts. And most important: He doesn't have -6 calipers... it's a conversion car. (IMG:http://www.914world.com/bbs2/html/emoticons/huh.gif)

QUOTE

If I read your replies correctly, I may be able to use this whole setup, right?

I don't think so but you can try. Rich mentioned:

QUOTE

so the only issue is that the axle shaft itself is the wrong length.

That's a pretty big "only issue" in my book. You could stretch them (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) They may fit up but I believe the strain on the CV's wouldn't make a long lasting solution. The 914-6 stub axle or simply selling it all and getting a set of 5-lug 914 hubs from "somebody" would be a more cost effective solution in the long run. Also, I doubt if the 911 rotors would fit under your calipers.

Let's find out what front end you have. I think a 73T front end with M-Calipers and really good pads (read: organic and good) would be OK for your HP. Mate that with a stock -4 caliper and a 914-6 rotor and you should be OK. If it were mine, I'd use a V-Caliper and go with a vented rotor. Here's a picture of the V-Caliper due out soon. It comes with longer pins and the rotor spacer BTW.

[ArtechnikA]

QUOTE (Eric_Shea @ Jun 2 2005, 01:02 PM)

So, if it's an early Koni or Bilstein (early 3.5) set-up it was either special ordered for that 73T (very rare indeed) or it was fitted aftermarket later.... You will either have S-Calipers (aluminum) or A-Calipers (iron)...if it is one of those struts, your Koni's won't fit. Rich mentioned: QUOTE so the only issue is that the axle shaft itself is the wrong length. That's a pretty big "only issue" in my book.

okay - for completeness - there IS a 3.5" brake Boge strut. i used them.

911.341.043.02 (.L.)
911.341.044.02 (.R.)

you will be able to run "aftermarket" inserts in those - i bought them when i did the S caliper change and got a killer deal on some externally-adjustable Koni inserts. they do use the newstyle (wedge-pin) ball joints. and the M18x1 spindle clamp bolt. both of which i had to discover the hard way.

i believe those were used on '69 T Sporto Targas. i have a pair that will be going on the 911 and no, they're not for sale...


should i have put "only" in quotes?
there *are* places that make custom axles.
now that all 914 CV's are NLA, i'd guess some enterprising (and better funded than myself) individual would contract Sway-A-Way (or someone) to build up a batch of axle shafts the right length so we could run 911 Turbo CV's with 914.6 or 914.4 stub axles.

the last time i saw numbers on custom axle shafts i was frankly surprised at how inexpensive they were, especially in comparison to all the other mods being done at the time to require them.

[goose2]

OK...all this input is great but I'm still confused. Lets forget about the front end for now. The local one I found is overpriced and not in great shape anyway. I'll keep looking for a vented rotor, 3.5 caliper setup and buy new inserts if necessary. What years/Models should I consider?

About the rears now, would the restudded 914 hubs with my stock 914 calipers be adequate? This seem like the simplest solution. If I understand correctly, if I want to use my 911 solid rotors with these, there will be spacing and rotor diameter issues. Using 914-6 rotors would eliminate this complication, right?

So what I'm considering is finding a front end complete with vented rotors and 3.5 calipers. $250-350 with good struts if I shop hard. Redrilled 914 hubs from Eric for $135 exchange. 914-6 rear rotors for $110. That's about 600 bucks on the high side. I can probably sell all the leftover and unused parts I have for a couple hundred. This sounds doable If I've got it right.

Sorry to sound so thick about all this.

Thanks again, randy

[ArtechnikA]

QUOTE (goose2 @ Jun 2 2005, 03:49 PM)

I'll keep looking for a vented rotor, 3.5 caliper setup and buy new inserts if necessary. What years/Models should I consider? About the rears now, would the restudded 914 hubs with my stock 914 calipers be adequate? This seem like the simplest solution. If I understand correctly, if I want to use my 911 solid rotors with these, there will be spacing and rotor diameter issues. Using 914-6 rotors would eliminate this complication, right?

'69->'89 (the long-wheel-base cars.)

only SOME early cars (specifically, 911S) had 3.5" struts. later on, ('74? '75?) they all got 3.5" struts as the 'A' caliper became the base caliper. when you get into the "Carrera" caliper cars ('85?) they started using 24mm vented rotors instead of the original 20mm rotors. they're both fine but you'll need to know what you've got when you start buying other parts (like pads).

yes - drilled & studded rear hubs work fine. i can't see any real reason to use 911 solid rotors except maybe "they're paid for." the "early" hubs are preferred, if yo have a choice. if you can live with a solid rear rotor (not a lot of track events) this is a slam-dunk. if you want to move up to vented rears, you'll have to use 911 disks, and deal with the caliper (or handbrake) issues.

[Eric_Shea]

QUOTE

this input is great but I'm still confused

I don't blame you.

Rich, this wouldn't be some obscure referrence to a "Hydropneumatic" strut would it? If not, those are "new" to me... learn something new everyday. Seeing as how those are probably rarer than a picture of Slits with a woman (or "Z" with his pants "on"), I think relevancy is an issue here...

Goose, if you're looking for a 3.5" strut look for either Koni or Bilstein struts (or Rich's unobtainium Boge models) (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) If you find either of the more "common" Koni or Bilstein you'll have a 3.5" caliper mount. Look for a later (1970 for 911's I believe) style with the new wedge pin base.

QUOTE

would the restudded 914 hubs with my stock 914 calipers be adequate?

Probably but (with the calipers) up to a limit... meaning, what calipers have you decided to use up front? With the M-Calipers you should be fine.

QUOTE

if I want to use my 911 solid rotors with these, there will be spacing and rotor diameter issues. Using 914-6 rotors would eliminate this complication, right?

Well... I'll reserve comment but I think it's the "diameter" of the 911 rotor that would be the problem. They may be a different offset as well... why bother? Get the 914-6 rotor or go for a vented rotor in the rear.

QUOTE

So what I'm considering is finding a front end complete with vented rotors and 3.5 calipers. $250-350 with good struts if I shop hard. Redrilled 914 hubs from Eric for $135 exchange. 914-6 rear rotors for $110. That's about 600 bucks on the high side. I can probably sell all the leftover and unused parts I have for a couple hundred. This sounds doable If I've got it right.

You've got it. I think that's a good plan with "maybe" one exception, I think the 3" M-Caliper setup would be an OK match for your current HP and would be a better match for your stock rears with solid rotors. I do think you'll save a bunch by getting 5-lug 914-4 hubs (mine or elsewhere... although mine are better (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif) )

I'll make it simple and lay out two setups I would use with your HP and given the 3" vs. 3.5" model:

3" Front:
Early 911 M-System (struts, a-arms, t-bars, sway-bar, M-calipers etc.)

Rear:
Drilled Hubs
914-6 Rotors
Stock Calipers

3.5" Front:
Early 911 S-System (Koni or Bilstein or Bogeunobtainium struts, a-arms, t-bars, sway-bar, S or A-calipers etc.). I like this because of the early sway bar mounts but, later SC systems may be more prevalent and can be switched back to early style mounts.

Rear:
Drilled Hubs
911 Vented Rotors (70-84?)
T-Fitting
V-Caliper

The later system is really pushing the limits of your stock rear caliper. Anything beyond that (up front) and you'll have to start looking for different calipers out back (rear M-Calipers from a 70-84 911) and a new handbrake system.

For a good balance without dumping loads of cash, I would vote #1.

[ArtechnikA]

QUOTE (Eric_Shea @ Jun 2 2005, 04:27 PM)

Rich, this wouldn't be some obscure referrence to a "Hydropneumatic" strut would it? If not, those are "new" to me... learn something new everyday. Well... I'll reserve comment but I think it's the "diameter" of the 911 rotor that would be the problem. ... Get the 914-6 rotor or go for a vented rotor in the rear.

they are standard damper-insert (i.e. not hydropneumatic) struts.
donno how rare they really are in the field.
once i had the part numbers, i just ordered them through the dealer, but a search today on Stoddard's site didn't turn them up. (i think their 'new' site doesn't have all the parts catalogued yet...) they were a little expensive (then) but not breathtakingly so.

probably a call to EASY, PartsHeaven, or dC Automotive would turn up a pair if they're out there. rights are always harder to find than lefts.

i did mention the reference was "for completeness..."


it's been mentioned before that using /6 rear disks in /4 calipers "may" result in rubbing at the edges (bit too big diameter). just passing it on - i haven't seen anyone who's been able to state definitively what calipers have enough clearance and what don't - just production tolerances on calipers that only had to fit the disks for whch they were made is my guess.

[Eric_Shea]

QUOTE

it's been mentioned before that using /6 rear disks in /4 calipers "may" result in rubbing at the edges (bit too big diameter). just passing it on - i haven't seen anyone who's been able to state definitively what calipers have enough clearance and what don't - just production tolerances on calipers that only had to fit the disks for whch they were made is my guess.

Tis true... about 95% seem to bolt on. There's a link to a thread on it in my 5-lug conversion resource thread. Dan (xsboost) had a question about it. We couldn't really determine which years worked and which didn't.

[goose2]

OK...I'm making progress with all your help. I need to clarify some terminology in my own head now. Can you define "M" caliper or "M system"...."A" caliper or system...and "S" and "V". I need to know what to look for and what to ask for while shopping for parts. I'm going for Eric's suggested configuration number 2 in his earlier post. That way if I acquire more power in the future, I can just upgrade the rears and I be stoppen good as I be goin. So Eric...I am ready to order the rear hubs...I'll also need a set of bearings. How to proceed? PM me so we don't pollute this fine thread with crass commercialism.
Thanks a bunch for all the help, guys....this group is awesome! (IMG:http://www.914world.com/bbs2/html/emoticons/beerchug.gif)
Randy

[ArtechnikA]

QUOTE (goose2 @ Jun 3 2005, 02:19 PM)

OK...I'm making progress with all your help. I need to clarify some terminology in my own head now. Can you define "M" caliper or "M system"...."A" caliper or system...and "S" and "V".

the 'M' (for, i believe, "Mitte" - Medium) caliper was the stock, iron caliper on 914.6 and most contemporary 911T.

the 'S' (for 'Schwer' - or Heavy(-Duty)) is a larger, all-aluminum one-piece casting that was used on the 911S (but that's not where the 'S' comes from...) and 911E. and some others.

later, as cars got heavier and they all inherited ventilated disks, Porsche had Ate (AH-tay -- Alfred Teves Company...) cast the 'S' caliper in cast iron. uses the same pads, heavier but more rigid.

'V' - i donno - that's a new one that slipped by me.

there's also a neverending supply of other kinds of calipers in use from all manner of other cars, and some of them work, and well. there's less support for those, tho and most involve a bit of modification to the caliper, the strut, or both.

HTH ...

[Eric_Shea]

Here Goes:

M-System - Basically a system (Boge struts, a-arms, hubs, calipers) that utilize the Porsche "M-Caliper".

M-Caliper - The most common "early" 911 caliper. It started as a narrow caliper in 64 and went wider with 7mm spacers with the introduction of the vented rotors. The 911 rear caliper is also called an M-caliper but it's a bit different with a nose made to clear the tall hat on the rear rotor. It has 42mm pistons up front and the rears have 38mm pistons (same size as the 914-6 rear caliper). M-Calipers came stock on the front of 914-6's.

S-Caliper - This was the first Ate caliper for a production Porsche to fit on the 3.5" mounting ears. They are aluminum and came out in 1969 on the "S" models (hence S-Caliper errrrr corrected once again by the Richmeister) and were used through 1975 when the A-Caliper came to replace it on standard cars. They were still used on 930's through 1976 and some SC's showed up with them through 78. S-Calipers have 48mm pistons.

A-Caliper - The A-Caliper was a more standard caliper that Ate was making. I'm currently doing two sets of Mercedes calipers now that are... Ate A-Calipers. They made them for Alfa as well. The A-Caliper has the same pad area but was a bit narrower than the S-Caliper. Pistons were 48mm.

V-Caliper - It's a name some clown (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) on the 914club board is using to describe his new caliper that allows the use of "Vented" rotors on the rear of a 914 and still keep the stock handbrake functional. It works well with everything up to an A or S-Caliper size. If going larger than a 914 front caliper I'd recommend swapping the P-valve for a T-fitting. The V-Caliper is made from standard 914-4 cores, bead blasted to bare metal and replated using silver (clear) zinc. 10mm spacers are fitted and a special set of pad pins and a custom rotor spacer are used to keep everything in line.

Here's an S-Caliper and Koni struts on my car. I have them on both my cars with raised spindles. PM to follow.

Hope that helps! (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)