Haha sorry... Didn't mean to come across quite so strong. I just firmly believe that the car is going to have way more than enough power:weight even with the rollbar that I think feathering the throttle is going to be more important than removing a life saving piece of safety equipment.

 

Its not the power to weight that matters with the roll bar. Its the fact that its 50 pounds very far away from the roll axis, so it makes the car roll more and makes the car change direction slower than not having it.

 

I dunno. I saw the results of some STS2 (back in the day) testing with a roll bar and without. Neither condition resulted in one being faster than the other. Most have decided to leave it off/out of the prep probably because of easy button. One would assume 50-60 lbs up high would make the car slower. But the test didn't seem to bear that out.

Now I have seen one DP car rip the landing plate for the rear support out of the car. I have also seen the deformations around the roll bar plates on my car when I removed the HardDog to put in the "properly designed" Appendix C roll structure. There just may be something to the extra stiffness provided by a roll bar. A stiffer chassis means the suspension can do its job better.

Back to STS2, those were all rather heavy off the shelf bars. I'd bet you could make a "lighter" roll bar that provided similar chassis stiffness at less of a weight penalty.

 

While that roll bar might make that 2 feet worth of chassis stiffer, it really doesnt do much for the rest of the car, and overall its not a big change. As you saw with your car, it actually increased the flex in other parts of the car, like where the landing plates were.

I know both wemmons and rampage miata both got faster when they yanked their bars and noticed less body roll without it.

 

.01 second penalty > cracked skull





of course, for a trailered car only seeing parking lots, the point is mostly moot. Although I have heard people claiming to have seen miatas roll at an autox event. I know I like my head without a one ton roadster on top of it.

 

This isnt a risk at all. In scca you cant run a harness without a roll bar, no harness = no 1 ton roadster on your head, you just scrunch down in the seat. If this was a real safety issue in the slightest it would be required by the liability lawyers at the scca's insurance company, even if it was a perceived safety issue it would be required, because sue happy world. Maybe if my car wasnt road legal I'd run something, but no ******* way am I getting in a car with a roll bar without a helmet on.

 

What the rules/lawyers/law say it's safe to do and what I'm willing to risk don't necessarily coincide.

 

Lol. You're funny.

 

You can be competitive locally with the extra weight from the rollbar. However, I'd look into stuffing some 275 a6s onto the car.

 

I've only ever seen crappy econoboxes and BMWs want to go shiny side down in an autox situation. And then it is only softly sprung stock stuff with R-comps.

Not saying it can't happen, but if you manage to flip a Miata at an autox, especially one with any suspension prep... I somehow feel you deserve whatever is coming to you there.

 

I've also heard of lancers (non-evo), VWs, and Saturns. Again all on super soft suspension, and the lancer in particular was doing something dumb like tire pressure in the 40s in the rear and teens in the front or something ridiculous like that.

 

That's just such a terrible way to look at it though. Stuff fails, and unexpected things happen. Even if you're careful. What if the pavement heat buckles, or your wheel studs snap due to the force from your sticky sticky rubber, or a ball joint separates, etc. etc.

Might as well never wear your seatbelt while driving down the road, because if you end up running off the road you deserve what's coming to you.

I did giggle at "shiny side down" though.

EDIT: I'm not saying you're absolutely guaranteed to end up upside down and anyone who doesn't use a rollbar is an idiot; I'm just saying that I don't think shedding the negligible weight on a fully built miata is going to make such an astronomical difference in time that it should be considered essential.

Spend a few seasons tightening the nut behind the steering wheel before you consider removing a potentially life-saving piece of safety equipment for the sake of 1/4 second.

 

Ball joint failure is just going to make your fender get torn up and destroy the tire, it happens all the time to miatas running 275s. Studs failing? Even the ART studs that emillio and sav say are death traps arent going to kill you. The local CSP car missed half their runs at summer nats prosolo because the spline part of the studs had been failing all season so you had to pull the lug out with your hand while tightening the nut or it would just spin. They finally failed enough after half the season that apparently they couldnt get tight any more, someone stopped them as they were pulling up to the burnout line because they noticed the wheels almost falling off, lol. They probably would have stopped after the launch anyways when they noticed something was VERY wrong, before anything bad happened.

 

What part of crappy econoboxes did you misunderstand? The photo of that Saturn on 2 wheels is legendary.

It is going to take hyper-catastrophic failure coupled with bad driver inputs to put a Miata in a roll over chance. That or a curb. Again, unless the course was poorly designed, that risk is low. Especially if you go 2 feet in (and not on the gas) when things start going pear shaped. Most accidents at autox tend to involve "hero mode" moments when people think they can save it.

And I say "I deserve it if I manage to flip my car at an auto-x". Usually in conjunction with my self built roll bar. It is why you won't find my car on track. Chances of flipping there are MUCH higher. Auto-x, you're more likely to hit something with your broadside in a Miata than anything else.

 

Haha, I had never seen this before hearing it mentioned earlier in discussion. Amazing. My girlfriend drives that same car for her DD. I should slap my old toyos on it and see what happens.

 

I know of a Miata or two that flipped at autoxes, but they were as a result of sliding into a curb. I don't know how far away the curb was from the course, or if the course would have met the SCCA course regs (neither was an SCCA event).

I have a rollbar in my car, but I'm not trying to build a nationally competitive SSM car, and the ability to run the car at track days is worth more to me than the tenth or two that the weight is worth at autox. Of course, if I wanted to build a nationally competitive SSM car, I don't think I'd be using a turbo Miata at all.

--Ian

 

With the new weight penalty for 51% rear weight the lotus and mr2 look less attractive. The Rx7s and everything else are too big or need to be too heavy, they will be eclipsed eventually once the miata prep and driving levels catch up. In street mod you pick the smallest car that can take a turbo 4, because the rules let you fix everything but the size of the car. That few inch width advantage the miata has over most things in the class adds up over an entire course.

 

Honestly, the LNF engine has so much capability without touching it over the brick Mazda BP motors it isnt even funny. Add to that you can fit RX7 sized rubber under them with minimal work. Reduce the weight at the same cost as those RX7. I have a hard time believing the slightly smaller than an RX7 but slightly larger than a Miata, GXP Solstice isnt the ticket.

I'll give you it is the same wheelbase and slightly wider in stock form. But I doubt you'd have to add as much girth to get the rubber under it as those RX7s. It is only a 2" difference stock in width. But it is a whole foot shorter in overall length.

Of course I might be biased. Of all the cars you can build for SSM. A Coupe Solstice GXP is the only one that intrigues me.

 

Why the coupe? The Sky vert is going to be cheaper to get light since most of the body is already not metal. And the sky looks cooler. But either way, I worry that you wont be able to get those over weight pigs down to 2300 pounds legally.

I kind of want to build a Vega with an LNF in it for SM. Take the weight break for 275s and solid rear axle, it'll be so light.

 

I owned a Coupe Solstice, base not the GXP. There is a BUNCH of weight on that pig. That hood is steel and very heavy. ~500lbs might be hard but I'm not sure it is impossible. Looks are subjective. I'm not a fan of the Sky plus the coupe will have better airflow over a wing.