therealtime

I am not a road racer yet, but I am doing research for future projects. I was reading over the NASA CCR book and I came across the roll cage section. Specifically, section 15.6.11.A states:

Does this apply to the Del Sol? If so, that would mean that the cage could theoretically consist of a main hoop with a diagonal tied to the floor and both upper seatbelt bolt locations and three door bars. This means I could keep the rear window and firewall (in case I put something back there that needs a firewall).

Thanks,
James

Tyson

the petty bar rule is absolutely covered in that exception for the del sol.

there's also another rule in the HC ruleset for the del sol:
13. The Del Sol is allowed to remove or replace the rear window with Lexan in order to
accommodate rear roll bar braces. This body modification is for the sole purpose of rear
roll bar brace installation.

i still dont get how ppl call the del sol a wet noodle. or any more so than a regular honda chassis. and especially with a well designed roll cage how it would be any worse, if not better, considering the extra chassis mounting allowance. the chassis is engineered to be stiffer than others because of the removable top. theres a HUGE C channel down the middle like a driveshaft tunnel thats obviously there for bracing. the rear shelf has extra bracing too.

but why are you trying to keep the rear window on a race car? i would replace with lexan and strip all the motor and tracks out. that way you can tie the rear shock towers to the main hoop with basically a horizontal bar thru the lower sheet metal and triangulate it for extra stiffness, and lower center of gravity and weight than the typical rear brace configuration.

therealtime

I'm not sure I made my question clear. I want to know if I HAVE to have rear bars that go through the rear wall, or if I can attach the main hoop to the shoulder harness points and leave the rear bars off.

This car is intended to be a street/track car and thus I would like to leave the rear wall and window stock. I do not want to get into the discussion of running a roll bar in a street car, that's a personal decision and not why I started this thread.

The roll cage that I have in mind will start as a roll bar as shown in my quick paint sketch (see attached).

As for the stiffness of the Del Sol, I'm afraid I would have to disagree with you. In stock form, the lack of a fixed roof seems to make the del sol quite flexible (my roof gaps open and close 1/8th inch or more as I drive over rough roads here in MI). But the roll cage required by any sanctioning body will stiffen it up and I like the targa top and shorter wheelbase.

Tyson

you dont have to follow the CCR if you just want to HPDE.

in my opinion, you could omit the petty bar if its anchored to the B pillar. i wouldnt want a petty bar for a street car, you still keep the passenger seat that way. dont forget the diagonal inside the main hoop. thats most important.

the side diagonal would be fine, i dont see why you put two tho. proper door bars on a real roll cage require the front arms from the top halo, running down the A pillar to the floor. youre just trying to make a rollbar.

targa del sol

What is the HC ruleset?

I'm building for Targa Newfoundland and would like to copy that rule for to try and apply it.

slammed_93_hatch

Mike should see this thread he built a few cages for the del sol's, and is the reason the HC rule set has that rule

JOE BD-0

Does this mean that lexan is allowed in H4 for the Del Sol only????

Tyson

13. The Del Sol is allowed to remove or replace the rear window with Lexan in order to
accommodate rear roll bar braces. This body modification is for the sole purpose of rear
roll bar brace installation.

I believe its pretty clear that the rule is limited to Del Sols.... good luck.

therealtime

But, what if I want to TT?
At first I was unclear on what a Petty Bar was, so I googled it. I was mistaking it for the diagonal in the main hoop. Would a bolt in Petty Bar be legal for NASA TT?
Again my mistake, I was just focusing on the main hoop attachments before I settle on a full cage design. The actual cage would have a front hoop that the door bars would attach to. I drew two of them because the rulebook states that any newly tech'd cars need two door bars on teh driver's side.

Just so everyone is clear: I am asking about rules as they apply to NASA Time Trials.

Tyson

a roll cage is not required for HPDE4/TT. anything increasing your safety is suggested and recommended, provided it meets general safety standards and practices such as in the CCR.

a rollbar would be adequate to meeting a reasonable level of safety in HPDE4, in my opinion. even if its not required.

therealtime

Good call. I just went through the rules again and couldn't figure out why I thought it was required.

Anyway, is the Del Sol considered an "open car" that requires a roll bar per section 11.4.7, or is the OEM rear hoop adequate?

If it does require a roll bar, is the main hoop attached to the B pillar all I need? (with diagonal and harness bar inside the main hoop)

If there is no roll bar or cage requirement, it certainly reduces my investment.

Thanks for the help,
James

Tyson

put the top on, its not an "open car" anymore...

its not "required" regardless. but your car is always subject to the scrutiny of the tech inspectors and safety stewards. there's a generic "broom stick" test ppl use. a del sol will pass, its not a full convertible. and different regions have different people calling the shots on what is subjectively a reasonable level of safety.

but when youre at the level of HPDE4, you ought to have something better than stock seatbelts, in my opinion. and a rollbar as i described above would be more than adequate, again my opinion.

however, it seems like you havent even had any track time yet. its good to consider safety first and in the long term, but you really wont need even a rollbar until youve got at least several trackdays under your belt.

Andrie Hartanto

Petty bar is not on the same plane as the rear hoop. It attached from the rear hoop to the front bottom point.

89civicdx

What you gotta do is do the broomstick test yourself because even with that rollbar or the factory B pillar it isn't going to help you if you don't sit within the area of the broomstick test. Most of the time it isn't going to help you if you land on the A pillar anyways.

Also most people don't know how to bend main hoops properly so unless its tight agaisnt the B pillar and you are sitting low enough its not much use.


Buy a cheaper car you don't care about and put a full cage... people roll all the time.

therealtime

At first I was considering a harness bar. This would allow 4 point harnesses with stock seats or 5+ point harnesses with racing seats. But most of the harness bars I have seen for the Del Sol require ugly modifications to fit, and don't look very safe. By installing a main hoop with a diagonal and harness bar, I can have some rollover protection, a place to mount a harness, and a place to mount a camera (so I can review my driving whenever I do get track time).

Thanks for the clarification. I also caught that a few posts back.

I am only 5'7" and I was thinking about buying an S&W main hoop and having it professionally installed to fit as tight as possible to the B-pillar hoop. (the hoop comes taller than the factory hoop and is cut to the desired fit, see the attached image). And eventually I would like to add some forward bars to stiffen the chassis (see the Miata image attached)

-James

89civicdx

What you gotta do is take a picture of the car from the side with you sitting in it...in your race seat or whatever, then put it on your computer and use a ruler on your screen or photoshop a line from the bottom of the a pillar to the top of the b pillar and see where your head is(below or above the line).

I'm 5'7 too and that's a problem..... in a civic or any hatch because you usually sit high and near the steering wheel away from the B pillar and any protection. I'm not sure how it is in a delsol....but you gotta make sure you understand how to check these things out asnd just because you have a rollbar doesn't mean you are safe if you aren't sitting near it.

What happens if that miata rolls more on the back that bar looks like its going to flip forward and those bent door bars are not going to keep it up maybe its a show car or something