Bolt on Hubs

[ERA2076]

Can anyone tell me the bolt spacing for the bolt on hubs?

Can the ERA rear be fitted with bolt on hubs?

Do the bolt on hubs maintain the same scrub radius as pin drive?


x-cliff

[ERA Chas]

Cliff-call Peter and ask. Bob's away on vacation and no other factory guys monitor here.

[kevins2]

Good advice from Chas to call ERA. If you get too technical with Peter, he'll probably have you talk with Doug in Bob's absence. Doug really knows his stuff but I can forewarn you that he's not a fan of the bolt ons.

Regards,

Kevin

[ERA2076]

Yea I called over there - no one around to help me. Supposed to be back next week. Just trying to front run it.

Trying to figure out a set of Watanabes.

[ERA Chas]

I wouldn't want 4 bolt wheels on a Cobra...

[ERA2076]

The ones I am looking at are 5 on 4.5 and extremely lite. The widths are nice 8.5 and 10.5 which would really add some wall stiffness.

Are you concerned with the 5 on 4.5?

x-chr

[mickmate]

I'm pretty sure you have 5 on 4.75" per Jag rear and GM stuff on front. The 4.5 is a Ford bolt circle.

[ERA Chas]

Originally Posted by ERA2076

The ones I am looking at are 5 on 4.5 and extremely lite. The widths are nice 8.5 and 10.5 which would really add some wall stiffness.

Are you concerned with the 5 on 4.5?

Wouldn't be my choice. I never tried but I don't think 8.5's and 10.5's will clear ERA suspensions. Ithink the front a/r bar links and tie rod ends would hit and don't know about the rear.
Then there is the tire hit to inner fender in front and behind cockpit.
Again, I'd contact Doug and ask if they set any up with widths like that in past.

[ERA2076]

that's what I'm looking for - I will be talking to them next week.

thanks Chas

[Jim Holden]

Chevrolet - Jaguar 5 bolt are the same pattern.

Jim

[ERA2076]

Originally Posted by kevins2

Doug really knows his stuff but I can forewarn you that he's not a fan of the bolt ons.

Regards,

Kevin

Based on aesthetics or function?

[kevins2]

Originally Posted by ERA2076

Based on aesthetics or function?

Function, the 6 pin hubs are stronger. Also, made of stainless so won't corrode.

[Jim Holden]

...I should note that a couple of ERA owners that did a lot of track time did convert their pin drive wheels back to 5 bolt so that they could use steel "NASCAR" type wheels. Their logic was that going into the (for example) downhill turn after the front straight at Watkins Glen, they wanted the security of a wheel held on by 5 bolts rather than just one ol' wingnut... and, as I recall, the total unsprung weight was a bit less. But then I defer to the racer types.

Jim

[ERA2076]

Un-sprung weight is my interest. It looks like I could get 15 lbs out of every corner depending on what hubs are used at the rear. I would like to have that if I can. The strength thing does not concern me much. Lot's of stuff, much heavier and with much more HP, run 5 lug patterns.

Don't get me wrong - I appreciate you guy's experiences and thoughts.

Building is a lot of time and money - I hate to make too big of a mistake.

That is why I ask.

chr

[ERA2076]

Bob - thanks for talking with me. I am trying to fit the widest rear wheel recommended by Roger Kraus Racing for the Avon CR6ZZ 295.50.15.

Using the Jag five lug hubs the rear wheels push outboard .375.

Mounting a 10.5 Tye R wheel and increasing backspace to 4.5", the rear wheels should push outboard an additional .025.

Most of it goes to the inside and as you said there is lots of room in there (although Chas has some concern). Will have to look at that when I get home for function and aesthetics, but it seems promising.

I am thinking of purchasing and drilling a proper sized Rock Crawler steel rim for the 6 pin, mounting the tire on it, spacing it 3/8", and cycling it.

I Plan to start with Wilwood for the front hubs. Are the bolt on front hubs you use off the shelf?

I look forward to seeing the info you sent.

x-cliff

[strictlypersonl]

Cliff,

I've just sent you a couple of relevant drawings.

[iismet]

Bob thanks for the drawings - I ordered the Wilwood hubs and we started fitting the front this morning. They are very nice pieces. They shift the Trigo wheels in board .100. Since we are going to use 4.5 backspace, this should not be a problem.

We are just touching the caliper adapter so we will need to mill about .100 off the hub at the hub to adapter mounting surface. I looked at your drawing and that is what seems to be indicated so onward we go.

I ordered up some steel wheels to check everything.

Wilwood tech was not at all concerned with strength or application. I was able to get drilled bolts for safety wire for the rotor to adapter. We will have to drill our own for hub to adapter.

Running a heavier GT 48 rotor we still get 15lb of un-sprung reduction.







Will need to mill hub mounting surface .100 which will drop adapter down for clearance with brake caliper adapter.

[ERA Chas]

Wait-are you Cliff / ERA 2076?? How did you become "iismet'??

[iismet]

Originally Posted by ERA Chas

Wait-are you Cliff / ERA 2076?? How did you become "iismet'??

Oh my - yes it is me. I ran into problems when I first started here so after a while I tried again with another name. Since I use iismet everywhere, I inadvertently forget who I am when I am here. Unfortunately both names are registered and let me thru which confuses the hell out of you guy's.

2nd (3rd?) time it has happened - hopefully, () the last.

chr

[ERA2076]

Gees - couldn't even get that completely right