C5Natie

Im looking to start some mods to turn the car into a better road course car. Ive been thinking of a roll cage for safety and to stiffen up the chasis. I used to drag race the car and NHRA says a 6point cage is needed for an 11.99 or faster, though they never told me anything at 11.5 I was running. With my new motor my car should be a little quicker still but most importantly Im wondering how much will it help stiffen the chasis? I know for safety its needed but what handling/road performance can I expect? Also, if I mostly do just autocross or road racing, what cage would get the job done? 4point, 5 or 6? Thnx, below is a link to some cages Ive been looking at.

http://www.thunderracing.com/catalog...p&vid=7&pcid=3

mikahb

AutoX and Road Racing are two completely different animals and will send your car in two very different directions mod-wise. For autoX, a cage will be a waste of weight, money, and effort. For Road Racing, the type of cage you need is dictated by the rules of the sancioning body you'll be racing with. The cage you linked to will not satisfy the cage requirements of any sanctioning body that I'm aware of for road racing duty.

If you can offer more specifics about your plan (autoX for a while then road race, HPDEs, Time Trials, whatever you're going to do and when) you will get better advice about how to get your car there.

JimbeauZ06

Roll bar or cage are unnecessary for autox. A good harness bar with give you some extra chassis stiffness. I suggest you actually look at and sit in a car with a full T1 racing cage before going down that road. It's a commitment at that point to no door panels and holes cut in places you might not want them and it makes getting in and out an exercise in agility which is no big deal if you're short, skinny and extremely limber.

mikahb

Or tall, medium build, and extremely determined!

AU N EGL

Mikah is correct. That roll bar would not pass tech for just about any auto-x, and track day events is up to each organization. and Not even close for Wheel to wheel racing. SCCA or NASA. Might be OK for Drag racing, but not road racing or auto-x.

Most track day clubs use the SCCA or PCA rule books. and the more technical safety items you have the harder they look.

yes we all want to be safe on track. For true road racing, W2W, SCCA or NASA would require taking their competition school. which you must have a full race ready car, by THEIR standards, not yours.

to give you an idea, the below is from the 2 year old SCCA tech book. may not be current

----
Roll Bars & Cages
Production
Item 1:
a. The main hoop shall be continuous and as near to the roof as possible on closed automobiles.
Item 2.
a. The main hoop shall be continuous and not less than two (2) inches above the driver's helmet on open automobiles, with the driver seated normally and restrained by seat belt/shoulder harness as illustrated in Figure 7A.
Item 3:
a.. The main hoop shall be full height (over the driver) for at least 50% of the width of the hoop a minimum of 9 inches as illustrated in Figure 7A below. For measurement purposes, a flat ruler must have at least 9 inches in contact with the tube when placed on the flat, full height section over the driver's head.

Item 5.
Bracing - Open and Closed Automobiles; and add a new paragraph
to section 18.6.1.a as follows:
All main hoops shall incorporate a
a. Main Hoop Bracing:
Rear Braces: All main hoops shall have two (2) braces extending to the rear, attaching to the frame or chassis. Braces shall be attached as near possible to the top of the main hoop not more than six (6) inches below the top), be outboard as much as possible, and at an included angle of at least thirty (30) degrees. Rear braces may penetrate required bodywork provided the resulting hole serves no other function, and the holes are sealed around the braces.
Diagonal Braces: All main hoops shall incorporate a diagonal brace to prevent lateral distortion of the main hoop. The brace shall either be in the place of the main hoop, or extend from the top one rear brace (described above) to the bottom of the opposite rear brace. Automobiles with mid mounted engines can have the lower mounting point attach to the frame of the automobile within 6 inches of the main hoop. In the case of braces in the plane of the main hoop, the brace must span at least 50 percent of the width of the main hoop, and at least 75 percent of the height the main hoop. Refer to the figure.adjacent.








Material:
A. Seamless, or DOM (Drawn Over Mandrel) mild steel tubing
(SAE 1010, 1020, 1025) or equivalent, or alloy steel tubing
(SAE, 4130) shall be used for all roll cage structures. Proof
of use of alloy steel is the responsibility of the entrant.
B. Minimum tubing sizes (all Formula, Sports Racing, GT,
and Production Category automobiles, and all automobiles
registered prior to June 1, 1994) for all required roll cage
elements (All dimensions in inches):
Vehicle Weight Material
Without Driver Mild Steel Alloy Steel
Up to 1500 lbs. 1.375 x .095 1.375 x .080
1500-2500 lbs. 1.50 x .095 1.375 x .095
Over 2500 lbs. 1.50 x .120 1.50 x .095
1.625 x .120
1.75 x .095
C. Minimum tubing sizes for (all Showroom Stock, Touring
and Improved Touring Category auto-mobiles registered
after June 1, 1994) for all required roll cage elements (All
dimensions in inches):
Up to 1500 lbs. 1.375 x .095 DOM / Seamless / Alloy
1501-2200 lbs. 1.500 x .095 DOM / Seamless / Alloy
2201-3000 lbs. 1.500 x .120 DOM / Seamless / Alloy
1.625 x .120 DOM / Seamless / Alloy
1.750 x .095 DOM / Seamless / Alloy

An inspection hole at least 3/16 inch diameter, but no greater
than 1/4 inch diameter shall be drilled in a non-critical area of
the front and rear hoop as well as the one of the supplemental
braces to facilitate verification of wall thickness. Formula
Cars and Sports Racers with alternate roll structures are not
required to have inspection holes, the wall thickness will be
indicated on the back of the homologation certificate.

General Construction
A. One (1) continuous length of tubing shall be used for the
main hoop member with smooth continuous bends and no
evidence of crimping or wall failure. The radius of bends in
the roll cage hoop (measured at centerline of tubing) shall
not be less than three (3) times the diameter of the tubing.
Whenever possible, the roll cage hoop should start from the
floor of the car, and, in the case of tube frame construction,
be attached to the chassis tubes by means of gussets or
sheet metal webs with support tubes beneath the joints
to distribute the loads. It is recommended that gussets be
used
B. Welding shall conform to American Welding Society
D1.1:2002, Structural Welding Code, Steel Chapter 10,
Tubular Structures. Whenever D1.1 refers to “the Engineer”
this shall be interpreted to be the owner of the vehicle. Welds
shall be continuous around the entire tubular structure.
All welds shall be visually inspected and shall be acceptable
if the following conditions are satisfied:
1. The weld shall have no cracks.
2. Thorough fusion shall exist between weld metal and
base metal.
3. All craters shall be filled to the cross section of the
weld.
4. Undercut shall be no more than 0.01 inch deep.
C. Aluminum bronze or silicon bronze welding technique is
permitted, but extreme care shall be used in preparation of
parts before bronze welding and in the design of the attaching
joints.

Touring Roll Hoops page GCR -106
TOURING ROLL CAGES
1. All cars registered after 1/1/03 shall conform to these roll cage
rules. Effective 1/1/08 all Touring cars shall conform to these
roll cage rules. Full width roll cages are required in all Touring
automobiles. Roll cages installed in Touring automobiles are for
driver safety and shall be contained entirely within the driver/
passenger compartment without removing any panel or accessory
not specifically authorized in these rules. The carpet/padding may
be cut around the mounting base plates.
A. The cage shall be welded to the car, and all mandatory tubes
shall use welded joint construction.
B. It shall attach to the car at no more than eight (8) points,
with the forward section of the cage attaching to the front
bulkhead or front fender wells (see GCR Section 18.2.,
Figure 1).
C. The front down tubes of the cage shall be mounted to the
floor of the vehicle.
2. For tubing sizes for front hoop, main hoop, and all required
bracing, see GCR Section 18.1.6.C. It is recommended that
gussets (flat steel, tubing, etc.) be utilized to strengthen the
joints of all required cage elements.


Main Roll Hoop:
A. Main roll hoop (behind the driver) shall extend the full width
of the driver/passenger compartment and shall be as near
the roof as possible. It shall incorporate a diagonal lateral
brace to prevent lateral distortion of the hoop (See Figure 1).
Any number of additional tubes/braces are permitted within
the structure of the cage. It is required that the horizontal
brace behind the driver’s seat (described in Section 18.2.10)
continue from the diagonal to the passenger side main hoop
upright or that a second diagonal be installed in the main
hoop.

4. Front Roll Hoops:
A. The front or side hoops shall follow the line of the front
pillars to the top of the windshield (as close to the roof as
possible) then horizontally to the rear attaching to the main
hoop. These two side hoops are to be connected together by
a tube over the top of the windshield, or
B. A front hoop following the line of the front pillars and
connected by horizontal bars to the main hoop on each side
at the top may be used, or
C. A top “halo” hoop following the roofline from the main hoop
to the windshield with forward down tubes following the line



5. Bracing:
The main roll hoop shall have two braces extending to the rear
attaching to the frame or chassis. Braces shall be attached as
near as possible to the top of the main hoop but, not more than
six (6) inches below the top and at an included angle of at least
thirty (30) degrees. On cars where the rear window/bulkhead
prohibits the installation of rear braces (e.g., Honda del Sol), the
main hoop shall be attached to the body by plates welded to the
cage and bolted to the stock shoulder harness mounting points.
This installation design must also incorporate a diagonal bar
connecting the top of the main hoop to the lower front passenger
side mounting point (“Petty Bar”).
A. Rear hoop braces may pass through the factory bulkhead
or panel separating the driver/passenger compartment from
the trunk/cargo area/, fuel tank/fuel cell area, provided the
bulkhead is sealed around said cage braces. Metal tape may
be used to seal the openings between the bulkhead and the
tubes.

6. Side Protection:
Two side protection tubes (door bars) are mandatory on each
side of the car. NASCAR-style side protection is required on the
driver’s side and is optional on the passenger side. The driver’s
window safety net may be mounted to this side protection and
the top cage tube. NASCAR-style side protection tubes shall
extend into the door. The door window glass, window operating
mechanism, inner door trim panel, armrest, map pockets, and
inside door latch/lock operating mechanism may be removed
only if it interfered with the installation of NASCAR-style side
protection tubes. The inner door structural panel may be modified,
but not removed to facilitate this type of side protection. The
stock side impact beam and the outside door latch/lock operating
mechanism shall not be removed or modified.

D. The mounting plate may be multi-angled but must not exceed
these dimensions in a flat plane.
E. Any number of tubes may attach to the plate or each other.
8. The driver’s seat shall be firmly mounted to the structure of the
car. In cars where the seat is upright the back of the seat shall
be firmly attached to the main roll hoop, or it’s cross bracing, so
as to provide aft and lateral support. Seats homologated to and
mounted in accordance with FIA standard 8855-1999 or higher
need not have the seat back attached to the roll structure. The
homologation labels must be visible. Seat supports shall be of
the type listed on FIA technical list No.12 (lateral, bottom, etc).
A. Each mounting plate shall be at least .080 thick.
B. Each mounting plate shall not be greater than 100 square
inches and shall be no greater than twelve (12) inches or less
than two (2) inches on a side.
C. Whenever possible, mounting plates shall extend onto a
vertical section of the structure (such as a rocker box).

-----
Wheel to wheel road racing cages for reference





http://www.rollcageguy.com/

Good Luck

BrianCunningham

What class are you running in?

for stock class they are disallowed!

C5Natie

Thnx for the advice. Im just beginning in this field so the cage will be in the future but I wanted to get an idea of what I will need. Im looking into SCCA and NASA events. Im looking to enroll as a beginner in some events this fall Ive seen on SOLO2.com. Im sure AutoX is fun but I want to get into actual road racing. Thing is I dont know if I have too many engine mods for the stock racing class. I would like to run stock and get some seat time under me. Is there a class where you can run a moddified (powertrain, some chasis) without going all the way with cutting up you car and getting a full all out cage?

AU N EGL

here is the NASA SoCAL web site http://socal.drivenasa.com/

Start off with some HPDE to get seat time and get to know ppl

NASA Racing is based of HP to wt ratio.

Classes Ratio Car example
Super Turing 2 = 8.7:1 stock C5Z, stock Viper
Super Turing 1 = 5.5:1 Stock C6Z & modified C5z or C6Z
Super Unlimited = ALL HELL breaks loose. Many old ASA or Busch National Road race cars.

That would be the HPDEs to get seat time then Time Trials

BrianCunningham

Yes, SSM (Super Street Mod) used to be SM2 (Street Mod 2)

a full interior is actually required.

Still not for the faint of heart, that's the class I'm going into with rodend suspension and a supercharged engine.

waktasz

Your car could be in ASP or SM2 or XP depending on mods.

If you have any engine mods, you're out of stock class for sure. The only thing you can do to the motor is replace the air filter element.

RX7 KLR

You need to open a rule book. Not only are they allowed for all classes (except karts), but they are "strongly recommended".

3.3.2 Roll Bars
Roll bars or roll cages are strongly recommended in all cars. A roll
bar meeting the requirements of Appendix C, or a roll cage meeting
the requirements of Section 9.4 of the General Competition Rules
(GCR), is required in all A, B, C, and F Modified vehicles, and all
open cars in Prepared Category and in D Modified and E Modified.
The intent of this requirement is that all open cars using racing slicks
must at a minimum have roll bars which meet Appendix C, regardless
of Regional variations in category definitions and/or preparation
allowances. For open cars in the Stock, Street Prepared, Street
Touring, and Street Modified categories, the roll bar or roll cage
height may be reduced from Appendix C or GCR Section 9.4 requirements
to the highest possible height which fits within an installed
factory specified hardtop or convertible top.
Double-hoop roll bars must fasten properly to the chassis/unibody
as required by Appendix C, particularly at attachment points in the
center of the car.

BrianCunningham

WTF?

What happened to the rule for them adding too much stiffness?

EDIT

OK I keep remember this rule when I added my harness bar
But a rollbar is fine

RX7 KLR

In the sixteen years I have been doing this I have never seen any such rule. If you want the stiffness, you get to carry its weight. Seems like a poor choice in a stock class car to me, but some people like them, and have won with them in place.

There is no reason to ever exclude a safety item.

BrianCunningham

depending on the car, a rollbar is worth the weight for the stiffening they provide.

C5Natie

Thnx guys. Gonna look into it. Really looking forward to getting some quality seat time and meeting some people for good racing advice. Thnx guys.

C5Natie

That sucks. I was also thinking of a harness bar for some structural stiffnes.

JimbeauZ06

You can get a whole bunch of experience with HPDE and AutoX with your car as it is, determine the direction you really want to go, and build your car to that end.

I started HPDE 3 years ago with the idea that I wanted to road race, and while I'm still progressing in that direction, it won't be with my current Corvette. Along with all the other key learnings in the last 3 years one very important bit passed along from friends who've already fallen down the slippery slope is "never build a race car. Buy a race car already built from someone else". You can literally pick up a used race car in decent shape for pennys on the dollar versus the amount you'd spend building your own.

Just know you're about to start to start sliding down the same path along with the rest of us. Welcome to the "slopes".

C5Natie

Found these, opinions, legal?

http://www.livermoreperformance.com/...te_safety.html

C5Natie

Sound advice, thnx. Still, Ive been thinking about safety upgrades to the car. You never know, it could save your life on the track or even on a weekend drive.

BTW, I dont think my wife would want a race car in the driveway. Its hard enough as it is.

rfn026

The biggest problem with a roll cage is that you now have a dedicated track car. Your Corvette is no longer useful as a street car - unless you want to risk severe brain damage in a fender bender.

If you want a race car buy one already built. The norm is that a used race car goes for $0.50 on the dollar. This past year people have been lucky to get that much. Building a race car has to be the biggest waste of money I can imagine. It is a lot of fun though.

If you enjoy putting $100 bills into your shredder you're going to really love building a race car.

Richard Newton