The Breakup (Miata build)

[drummingpariah]

Wait. 1.62" DOM? That would be 1.75" OD .065 wall?

1 5/8" OD (those were the dies that were available for this bender), .095" wall. After it was delivered, I realized it wasn't a mandrel bender ... and now I'm stuck with all this tube.

[sachilles]

put it for sale on forum.neow.net. it's a new england based off-road forum. Someone will use it to build a tube buggy.

[walterclark]

1 5/8" .095 wall DOM is not a common size for a cage, which is why I asked. 1 1/2" and 1 3/4" are common and are generally listed in most cage rules (usually as a minimum, sometimes depending on car weight). A scrutineer may question a cage with this OD tubing even if the car could have a 1 1/2" tube cage - so I would recommend you give the tubing purchase paperwork to whoever buys it and suggest they keep it handy for any logbook or tech. The suspicion would likely be that the material is not suitable for a cage (e.g. not intended for structural use, such as schedule 40 pipe), so having the A513 Type 5 purchase paperwork should end that part of the discussion.

[jkale]

If you need some help bending that stuff, I have a 1 5/8" die for my bender.. I would be glad to help get that thing prepped for the hills..

[Mopar 151w2]

Actually, we included the 1 5/8 tubing spec. because it is quite common in DRAG RACE cages. Best guess is that this was done because a lot of (good, OLD) tube bending equipment has dies for (nominal) pipe sizes, which are different than tubing sizes. The only one that's close is 15/8" (1.625) tubing, which can usually be bent in an 1 1/4" nominal pipe die - Actual size of that being 1.660. Trouble with all of this is that cheap-ass pipe benders tend to kink thinwall tubing and/or flatten it (die size issue)

[drummingpariah]

1 5/8" .095 wall DOM is not a common size for a cage, which is why I asked. 1 1/2" and 1 3/4" are common and are generally listed in most cage rules (usually as a minimum, sometimes depending on car weight). A scrutineer may question a cage with this OD tubing even if the car could have a 1 1/2" tube cage - so I would recommend you give the tubing purchase paperwork to whoever buys it and suggest they keep it handy for any logbook or tech. The suspicion would likely be that the material is not suitable for a cage (e.g. not intended for structural use, such as schedule 40 pipe), so having the A513 Type 5 purchase paperwork should end that part of the discussion.

Duly noted, and it makes perfect sense to be suspicious ... now that I have a better idea of what my available resources are (good machining skills/equipment, excellent welding skills/equipment, virtually no suitable bending equipment), I can move forward a bit more meaningfully.

If you need some help bending that stuff, I have a 1 5/8" die for my bender.. I would be glad to help get that thing prepped for the hills..

I may very well take you up on that, but you're way up by Burlington, yeah? I'd have to come up with a way to get the tubing up to you, since the only vehicles I own are race cars and motorbikes.

I should have the prebent components for a modified spec miata cage (1.5" x 0.095" DOM) coming in next week, so I'll at least have SOME kind of caged car. I may just go through the same fabricator to get the bends made, since I already have all my measurements for both the FC and the s30, and his prices turned out to be kind of incredible (under $700 shipped for the tube, but I'm on my own for gussets).

Miata Update
I had been hoping to put my new wheels and tires to use this season, but the offset is a little wider than what I was running last season. I dropped the car off to have the fenders rolled, but they obviously didn't test it at all. There's still fender interference nearly every time I turn while I'm off the throttle (proposed solution: pedal to the metal always!). I'll either have to move my spring perches up a notch on the dampers (there are three settings) or run the same wheels (with the Rival tires I have on them for daily driving, rather than the RA1's I'd really like to run) as last season. Moving the spring perches is a pretty big hassle though, especially without a nice spring compressor.

Too low. Suspension shop disappoints me.


One of my successes yesterday was making a new seat bracket. The old one bolted to the stock sliders, weighed more than I do, and I wasn't in love with my welds on it, so I broke out the plasma cutter and some aluminum and made something quite a bit nicer and lower. It's pretty close to perfect, now I can see my gauges through the steering wheel opening, and won't bonk my helmet on the roof any more (which would be an even bigger concern after installing the cage). I only wish I had left the seat an inch or two farther forward, since I'm extending my left leg a lot for the clutch pedal.


I just need to pack up my camping gear, and I think I'm ready to head to Ascutney tomorrow. I still haven't been able to talk to anybody there, so I'll just have to grab whatever sites aren't reserved for my volunteers and me.

[walterclark]

Looks those wheel stick out a fair bit. Maybe you need to go with flares and radius the fenders and wheel well liners. The rear looks close too.



I had some rubbing on my rears and while the stock GTI "flares" cleared, the stock Golf fenders under them didnt. I ended up cutting the fenders and wells, used a 2x4 to roll them a bit and added some aluminum to tie in the fender wells back to the fenders, then riveted the flares back on.

[drummingpariah]

You're right, Walter. They're not quite the right offset, and the fronts definitely rub even after more 'massaging' of the fenders while the wheel is turned and suspension is compressed. It's all on the outside of the fender, thankfully. We tried sitting a bunch of people on the rear, and could get it down to the bump stops without any fender interference ... so hopefully I can just leave those as-is. I'll start early tomorrow morning to move the front springs up one notch on the dampers.

For now, I'm about to go out and swap the wheels for my high-treadwear summer tires, and get these loaded up on the trailer. HOPEFULLY, with some luck I'll be able to race with these good tires this weekend, and not on the generic summers. It'll take some thrashing to make it all happen, but that's what hillclimbs are all about, yeah?

If that doesn't work, I'll bite the bullet and order some flares for it. Either way, I'll be at Ascutney tomorrow, hopefully in site 5 and one site next to it ... by noon (? planning to remove and replace springs in a Miata is difficult ?).

[3rdgendennis]

Too low. Suspension shop disappoints me.

You mean you actually want to drive your car and not just #hardpark it?

[drummingpariah]

You mean you actually want to drive your car and not just #hardpark it?

Crazy talk, I know.

I'm pretty much done messing around with this, it's a silly issue to have in the first place. Strongly considering ordering wider fenders, such as these front fenders.

Any idea if they'd affect classification in SP at all? Other than being a little wider and having the bottoms cut out, they're stock profile. I just want to be able to fit my quality wheels/tires without fabricating my own fenders or going crazy with the fenders I have. I've rolled them about as far as I can, and overfenders don't look right on a miata (imho).