Tech Forum : 5-Lug Conversion....

Posted Thursday, Aug 23rd 1:08am [Edit] [Quote] [IMS] [View car]

Post nr. 1344

OK, I have a beautiful set of Hartge 7.5x16 wheels sitting around. However, they are 5 bolt pattern.

It seems to me that the conversion wouldnt be hard. The most expensive thing would be either the time or money in dissasembly and reassembly of the drive shafts.

However, I think it would be rather easy and cheap to get a machine shop to create a plate that is identical to the one with 4 holes....except with 5.

If I am not mistaken, those plates, retain the wheel bearings, and are made out of cast iron.

Would there be any problems machining them out of billet metal?

FRONT:

REAR:

Posted Thursday, Aug 23rd 6:06pm [Edit] [Quote] [IMS] [View car]

Post nr. 1347

Read through Ray's write up. This is what others have done....but I am concearned about putting steel against cast iron.

Posted Thursday, Aug 23rd 11:47pm [Edit] [Quote] [IMS] [View car]

Post nr. 727

You might want to explore the option of having 4 hole hubs drilled and tapped to five lug. The big problem is brakes at that point.

Posted Friday, Aug 24th 3:38am [Edit] [Quote] [IMS] [View car]

Post nr. 1348

I would be fearful of taping cast iron parts. I think they would break....unless someone can tell me different.

What would the brake problem be? Arent the calipers and rotors the same?

Posted Friday, Aug 24th 7:19am [Edit] [Quote] [IMS] [View car]

Post nr. 192

Many parts are cast iron and drilled and tapped with no issues... engine blocks, transmissions, hubs, differential carriers and a bunch more.

Hubs could be made from aluminum by a good machine shop easily but it won't be cheap.

Don't e3/e9 hubs fit front and rear?? Seems to me I heard that a while ago. There was a Bavaria at the local pic-a-part that I was going to scavenge to check it out but couldn't find any 5 lug wheels I liked at a reasonable price (CHEAP!!) so I'll just stay with 4 lugs.

ken

Posted Friday, Aug 24th 2:37pm [Edit] [Quote] [IMS] [View car]

Post nr. 1349

Ken, the issue here is that this isnt a big block of cast iron. It is a 1/4" disk that has other holes in it already, and you would drill holes very near the edge of the cast.

I like CHEAP too. I live for cheap.

But things get expensive when a hub breaks off at 80mph.

If I remember, that post talked about e12 hubs with some brake and rotor issue that was untested and undefined. I cant see why there would be a problem as the brakes and rotors should stay the same.

Is there a difference....other than in the hole pattern in a 5-lug rotor?

Posted Friday, Aug 24th 7:21pm [Edit] [Quote] [IMS] [View car]

Post nr. 728

It is impossible to cast threads. The hub is thicker than a 1/4". And many times where people drill and tap a block is MUCH thinner than that. If you drill the right hole for the tap it shouldn't be an issue. But I can't make you feel any better about it. If you worry, then you worry.

Posted Saturday, Aug 25th 2:15pm [Edit] [Quote] [IMS] [View car]

Post nr. 1350

OK, ok...good points....

So what are the brake issues everyone refers to? Are there 5-Lug rotors.....from say an E30 that are geometrically the same as an E21? If so, there should be no brake issues.

Posted Tuesday, Aug 28th 3:08pm [Edit] [Quote] [IMS] [View car]

Post nr. 180

I have noticed alot of high performance cars have 5 lug wheels. Where is the performance level where you would go from 4 to 5?

Posted Wednesday, Aug 29th 2:44am [Edit] [Quote] [IMS] [View car]

Post nr. 729

MayanArch wrote:

Caliper placement might be different? I really don't know. I don't know anyone with 5 lug hubs and rotors who could comment either. You are in uncharted (or very poorly charted) waters.

Posted Thursday, Aug 30th 12:07am [Edit] [Quote] [IMS] [View car]

Post nr. 309

Some very useful infomation on this thread.
http://e21.tricord.be/forum/view.php?view=1303&highlight=5+lug
Just a shame the links to photos are NLA.

Posted Friday, Aug 31st 10:07pm [Edit] [Quote] [IMS] [View car]

Post nr. 192

I pulled the front suspension and brakes out of my '82 (I think it has '77 hubs)... Once the brake disks were off I can see there is no way to re-drill them to 5 lug, the outer dia. is too small to accommodate the 5x120 pattern.

ken

Posted Saturday, Sep 1st 2:57pm [Edit] [Quote] [IMS] [View car]

Post nr. 1360

KenDanielson wrote:

That was my feeling. I think you have to make them from billet.

Ken, can I talk you into getting the critical measurements so we can put it into CAD and look into getting them CNC'd???