Flat back Festiva drums

[blake4591]

I have been looking for the flat backed redrillable drums for a bit and I'm starting to think the last supplies of them have dried up. Autozone is the only place that pictures the flat drum and when you actually go to the store they are ribbed. All other online sources either picture them with ribs or confirm that they are ribbed when asked. I think that the days of redrilling drums may have come to an end. I may try on one ribbed drum to see how it comes out but this is going to be an experiment more than making an actual usable part.

I was looking for these drums specifically to reduce the rear braking basis of car because with the aspire swap any trail braking becomes a delicate balance of not locking up the rear tires. I think once you start increasing the front weight of the cars (moving the engine forward, taking out the rear seat and spare tire, etc.) any increase in rear braking power over the stock drums is too much. So I'm going to be working on some options to get Festiva rear drums with a 4x100 bolt pattern over the next couple months. I'm open to any ideas on this subject since I'm sure i'm not going to be the only person with this problem.

[Advancedynamix]

I'm working on that same project too. I may have found a source.
I've successfully filled and redrilled the ribbed style now as well. It's been holding fine for a year with some track work. I just thread lock in small pieces of m12x1.5 bolts and drill just under the original holes. That way the stud is still supported by the rib, and the threaded in plug can't move because it's locked in by the wheel stud. I am confident that (with quality press in studs) this is still stronger than using thread in studs.
I'll try to get pictures of it this weekend.

[mikemounlio]

Thank you for trying this! Good to know it works

[blake4591]

I'm working on that same project too. I may have found a source.
I've successfully filled and redrilled the ribbed style now as well. It's been holding fine for a year with some track work. I just thread lock in small pieces of m12x1.5 bolts and drill just under the original holes. That way the stud is still supported by the rib, and the threaded in plug can't move because it's locked in by the wheel stud. I am confident that (with quality press in studs) this is still stronger than using thread in studs.
I'll try to get pictures of it this weekend.

This was pretty much going to be my approach as well. But I'm a little concerned about how the press fit will be effected (possible pressing off center) with the interference from the original hole. Based off you already trying it though I'll make up a set and put them on the car for next summer.

I'm also working the feasibility of putting a festiva wheel cylinder in an Aspire drum brake. Quick math says approximately a 20% reduction in braking with the smaller cylinder, but to confirm that I'll have to make a set to test.

[Advancedynamix]

The holes just barely overlap. Here is a picture that Dragonhealer sent me of the set he just did.

The Festiva hub center is too big for a lot of 4x100 wheels, so we also turn that down to match the aspire front hub center.

[Dragonhealer]

This was pretty much going to be my approach as well. But I'm a little concerned about how the press fit will be effected (possible pressing off center) with the interference from the original hole. Based off you already trying it though I'll make up a set and put them on the car for next summer.

I'm also working the feasibility of putting a festiva wheel cylinder in an Aspire drum brake. Quick math says approximately a 20% reduction in braking with the smaller cylinder, but to confirm that I'll have to make a set to test.

That's an excellent solution, I did the same thing on my '68 MGB GT track car, used the smaller wheel cylinder from the roadster, worked Great!
If the cylinder swap turns out to be a PITA, just sleeve down the Aspire cylinders and use the Festiva internals.