5 lug conversion

[F1BADUDE]

I'm reading the 5 lug conversion tech article and am planning on drilling front rotors. Article shows drilling our 4 lug rotors. From what I can tell, a 914/6 rotor is vented where the 914/4 is not. PP also only has crossdrilled rotors for 914/6 and I would like crossdrilled at least on the front.
Has anyone drilled out a 914/6 rotor to fit 914/4 hub?
Is the rotor the same diameter?

Also, do you think I should find older rear hubs with bosses as my car is a 75.

Thanks,

[mike95125]

For indepth explanations, do a search. But, the short is that you can drill the rears on your car and should have no problem even though they lack the extra bosses (I have this, no problems). Drilling the front, I don't know. On the 914club.com web site Mike Mueller has fabricated a five lug front hub that fits on to the stock /4 front spindles.

HTH

[Acox914]

cant use vented rotors with stock 914 front calipers. (vented vs nonvented)

[F1BADUDE]

Was planning on converting to 320i calipers. Do you know if vented will work with BMW?

[Acox914]

thats a negative.. bmw work with non vented

[Scott S]

The hub assembly is vastly different from a 4 bolt to a 5 bolt. You can have someone like troutman drill and stud virgin front rotors to a five bolt pattern. Aslo, it seems to be the consensus that drilling front rotors for "venting" does nothing but give you less braking surface and cause cracking the holes.

There are tons of discussions on both topics.

[cruiksdr]

It's probably easier and cheaper and definately safer to upgrade to 911 struts/hubs/rotors/calipers. They are out there for fairly little $$ and are direct bolt ins. This gives you a stronger front end, vented rotors, and slightly larger braking surface without sacrificing strength. I don't know about you, but I don't my front end blowing apart at 90mph! I got a complete front and rear set of brakes struts from a 73 911 T for $400. Very easy conversion (including the 911 ebrake). I then got the larger BMW front calipers for another $200 w/new high performance pads. It's a great set up. Plus, when it's time to replace rotors, there's no modification needed. Just get the 911s and you're good to go. Think about it.

[F1BADUDE]

Will the 911 trailing arms bolt up to 914 as well?
What year range of 911 parts should I be looking for?

Thanks,

Originally posted by cruiksdr
It's probably easier and cheaper and definately safer to upgrade to 911 struts/hubs/rotors/calipers. They are out there for fairly little $$ and are direct bolt ins. This gives you a stronger front end, vented rotors, and slightly larger braking surface without sacrificing strength. I don't know about you, but I don't my front end blowing apart at 90mph! I got a complete front and rear set of brakes struts from a 73 911 T for $400. Very easy conversion (including the 911 ebrake). I then got the larger BMW front calipers for another $200 w/new high performance pads. It's a great set up. Plus, when it's time to replace rotors, there's no modification needed. Just get the 911s and you're good to go. Think about it.

[Acox914]

no. you use 914 rear arms, 914 parts; the hub redrilled for 5 lug or 911 (69 - 73) hubs and stub axles inside a 914 rear arm.

do a search here and on 914club.com and there is lots of info :0

[silver2.0]

Stupid question- Why does everyone convert to a 5 lug? I can understand if you want to use special wheels for monster brakes, but if you are just using 320i brakes like me, on a 4 stud, what's the big deal? Is it so you can run better quality wheels? I know you can put more power to a 5 lug, but there is no way on earth you will shear 4 lugs with less than 250 lb ft of torque. (from my experience). Thanks for humoring my newbie question.

[cruiksdr]

Originally posted by Acox914
no. you use 914 rear arms, 914 parts; the hub redrilled for 5 lug or 911 (69 - 73) hubs and stub axles inside a 914 rear arm.

do a search here and on 914club.com and there is lots of info :0

Yes, definately the 914 trailing arms. Most use redrilled 914 hubs, but 914/6 hubs are stronger. I'm not sure about the 911 rear hub/stub axle. the 911 hub will not work with a 914 stub axle (different splines). I had a 911 hub/stub axle set from a 73 911T, and the stub axle was too large to fit in the rear trailing arm. I don't know about earlier 911s but 73 and up will definately not work. I ended up redrilling my rear hubs, and that seemed to work fine.

From what I understand, for the front end, you can use struts, etc. from a 911 right up to at least 1986 or so. It's a straight bolt up opperation. You keep your A arms and just swap out the struts/brakes. It's pretty easy. What year/model you choose depends more on how much you want to spend and how much brake you want. The front end from an 80s 911 carerra will give you awsome brakes but will cost a bit more than earlier. For the rear end, as mentioned, keep the 914 stuff, drill the hubs, and if you want vented rears, get 911 rotors and M callipers. This is how I set up the 911 e brake since the 911 caliper does not have that built in like the 914. If you don't want/need vented rears, keep the 914 calipers and use 911 rotors

[F1BADUDE]

Originally posted by silver2.0
Stupid question- Why does everyone convert to a 5 lug? I can understand if you want to use special wheels for monster brakes, but if you are just using 320i brakes like me, on a 4 stud, what's the big deal? Is it so you can run better quality wheels? I know you can put more power to a 5 lug, but there is no way on earth you will shear 4 lugs with less than 250 lb ft of torque. (from my experience). Thanks for humoring my newbie question.

In my case ,originally, I wanted larger DIA & width 911 Fuchs to fill out my GT flares.
I later decided to do race build though and now. So as well as more braking surface, I would also need the extra beef

Here's my GT-5S plans:
16 X 8 5 lug Fuchs (new repros) 225/50 Yokohama A032R FRT
16 X 9 5 lug Fuchs (new repros) 246/45 Yokohama A032R RR
2.2L 6 (tearing down now)
46 X 40 ported heads drilled for twin plug (on the way from CA)
Tec 3R controled EFI (still figuring out what I'll do for TBs)
Tec 3R twin plug crank fire
11:1 compression Forged pistons
GE-80 cams
I would estimate about 210 ft/lbs of torque @ 5700rpm

[cruiksdr]

Originally posted by silver2.0
Stupid question- Why does everyone convert to a 5 lug? I can understand if you want to use special wheels for monster brakes, but if you are just using 320i brakes like me, on a 4 stud, what's the big deal? Is it so you can run better quality wheels? I know you can put more power to a 5 lug, but there is no way on earth you will shear 4 lugs with less than 250 lb ft of torque. (from my experience). Thanks for humoring my newbie question.

Many convert to the 5 lug so they can have a better choice of rims and can go with bigger/better brakes. The 320 set up is supposed to be pretty good, but you don't get vented rotors which does affect braking perfomance (fade). Also, the added strength is a must if you have a six (although I've heard a number of people say that the 4 lug can handle plenty of torgue. Who knows I opted for the 911 hardware because it allowed me to more or less replicate the 914-6 and stick with all porsche parts. I was mostly after the brake upgrade, and also I wanted to beef up the strenght since I do have a six. Oh, and it looks really cool

[F1BADUDE]

A 914/6 and a 1.8T
Your all right

[F1BADUDE]

Originally posted by cruiksdr
I'm not sure about the 911 rear hub/stub axle. the 911 hub will not work with a 914 stub axle (different splines).

Do 914/6 axles have different spline?

[Acox914]

they do (pretty sure)

[F1BADUDE]

Originally posted by Acox914
they do

Are they the same as 911?

Seems like I saw rebuilt 914/6 axels at PP, AA or somewhere.

[Acox914]

i believe they are

[cruiksdr]

As far as I know, they are the same as the 911s but have a smaller diameter for the half shaft to fit in the rear trailing arm. They show up on ebay peridically, too. They tend to be pretty expensive.

[Acox914]

cheapest way is use 914 stub axles, and redrilled 914 hubs