Hi, Much has been said recently about gasser "type" cars being built...how fast can you go (per NHRA) for instance before you need a roll bar? I dont have a copy of a rule book...I have seen a couple of old race cars recently that have what looks to be "water pipe" for roll bars...how safe is that today? It seems to me if you are building something that goes beyond "the look" you need to be able to compete somewhere... Thanks, Bill
when i built my "gasser" street car .....i built pretty much a 8 point cage....the car that most of the parts came out of only had a 4 pointer.....which was probably good for something .....but not much ....the new owner has been racing it ....but sure how fast it running .....brandon
As far as the breakdown when you need a cage,you need a roll cage if the vehicle has an altered floor or firewall, or exceeds 135 mph. Otherwise from 10.00 - 11.49 seconds you need a 6 point rollbar. In a 'vert you need a rollcage running 10.99 or quicker or a 6.99 or quicker 1/8th mile. Also with convertibles you need a 6 point rollbar if you run 11.00-13.49 in the 1/4 or 7.00-8.25 in the 1/8th. IHRA rules state that with an OEM frame you must have a roll bar welded to the frame, in unibody cars it must be securely attached with 6" x 6" x .125 steel plates on top and bottom of the floor, bolted together with at least four 3/8" bolts & nuts. If the bar is welded to the rocker sill area with .125" attachment plates the 4 connecting nuts are not required. The material used should be 1 3/4" OD x .118" mild steel or .083" chrome moly tubing except for the cross bar on the main hoop which should be 1 1/4" OD x .118" mild or .065" moly tube. Hope that helps.
There are always going to be concessions for safety...If you ever plan on racing the car, it's got to pass Tech (go to NHRA/IHRA website to find the specifics). If you're not going to race a gasser-styled car, what's the point?! Mine is coming home from the shop very soon: '57 Chevy 2dr 150 wagon; white wall cheaters on black steelies in back, 14-inch Torque Thrusts up front. Nose high (back end too, for that matter), no inner fenders, fenderwell headers, suede black and white paint. Even putting in a rubber floor mat. At the shop, we're putting in a Leaf-link adjustable rear suspension (so it'll leave), and a 12-point roll cage. With fiberglass doors and front fenders, it seems like the smart thing to do! So do new 5pt racing harnesses. With a 480-inch 409, it'll need all the stiffness and launch it can get, and with that much hook and power, I need to be safe. Other than the full cage, the car is going to look very period-correct. I don't mind that concession...in fact, I never gave it a second thought. -Brad
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