Ok I want to know if any in our group knows if the acutal rubber Coker is using to reproduce the Bias Plys Tires most of us are running is different from the Original rubber . I am in a conversation on another board and being told we are all running as fast as we are because the rubber is Far better. See the memo below. Is this true? I have been under the impression that a Coker Red Line Was an exact reproduction of the original installed at the factory in the 60`s . Bias Ply material and rubber compound ,density and tread. Paul, The rubber compound is FAR different today thatn it was in the 60's, regardless of the type of bias ply tread you may be running. Today's tires, regardless of type are way better than we had. You couldn't run 1.6 or 1.7 short times on those tires unless you destroyed a clutch doing it! I remember reading the magazine articles of the day touting the 13 second GTOs and 442s, but in reality, VERY few were that quick. They were "tweeked" by the dealer or factory representatives, in many cases. The 426 Street Hemis of the day were 14 second cars with a good driver in most cases. They need a little TLC to go really fast, as did the 409's and 427's. My Coronet R/T was a high 12 low 13 second car in 1968-9. To get there I added headers, and ran them open, 7" slicks that were stock class legal, loose alternator belt and unplugged the alternator for less drag, a "cool can" packed with dry ice and alcohol for fuel cooling, had a ram air system w/o filter, bumped the timing, rejetted and "adjusted" the carburetor and always used full throttle power shifts for every gear change. With today's technology that car would be a LOW 12 second car, at least! Knowledge is a powerful tool, and better parts help too!! Paul, all said and done, you guys are flying! I almost built a "Pure Stock" Plymouth GTX back when NHRA had their brain fart and did away with slicks and headers in the mid seventies, but it didn't work out. Good luck to you ALL!
Paul, I don't know the answer to your question for sure but I would bet that the rubber is far better today. Just look at the leap and bounds we've made casting aluminum over the last 40 years. There would be no reason to use old methods and materials. I bet rubber is the same way.
In a word, yes! The rubber is different. I have spoke with John Kelsey and all of the tires that are being made for him are using the same durometer of rubber. Speaking of rubber, I have an experiment that I want to do at Martin. I am wanting to get 'footprints' of different tires and compile some numbers. Basically, I want to see how much of an advantage it is for some people to move up a letter size in tires or if they might be better off staying with stock size. So if I come up to you at Martin, don't be offended if I want to look at your feet!!!!:eek2:
Rusty, are you going to measure exhaust pipes, too? It's always struck me as unfair that cars originally built with smaller exhaust are allowed to step up. (Unfair in the spirit of comparison, not PSMCDR competition.) Anywho .... Paul, I'd be very surprised if the rubber compound used today for any tire is identical to that of the '60s and '70s. Things change too much. That said, I'm not saying that the rubber on today's wide ovals is any stickier, just different. BUT, the bigger difference, in my opinion, is track prep. I was pedaling a little red fire engine in my parents' driveway in 1970, not pedaling a musclecar down a dragstrip. But I've gotta believe the tracks are FAR stickier today than back then.
Kind of hard to say, but guessing yes! Of course, I am sure that any tire from 1969 would feel like a brickbat due to oxidation.
I have only heard that the compound is better, but no evidence to back it up. I do know that when I started racing in 1971, nobody sprayed the tracks that I went to. Traction is much better now on prepared tracks than it was in the "old days".
My dad insists the stickiest street tire he ever saw was a tire made in the sixties....... the Atlas Polycron.... good for about 10K miles if you just drove around town on them, and very sticky when heated.
I have a 1969 G70x14 Polyglas in my trunk as a spare. You're welcome to check it out vs the 10 year old repops on the car. Polyglast didn't come on my car, the radials I ordered were safety recalled and Goodyear told us to come in for a new set of whatever we wanted. I chose blackwalls. They were night and day better than those radials, but still little or no traction like today. You really had to pedal them to get them going. Most of us with 4 speeds or small blocks would never race from a stop, always on a roll. They were bricks when new. Nobody tried to do anything with them on the strips, nobody in their right minds would try to race on them other than on the street. (same went for manifolds or steel wheels with dog dishes...:laugh: :laugh The first year we raced F.A.S.T. there were two pro stock cars practicing. The old guy that owned one of them (Larry Morgan?) told me he still had a set of the old butyl (?) tires on the truck.
I was talking about the rubber compound new in 69 compared to the new today. Not 41 year old Rubber LOL. I am on the track of Steve there is allot of claims it is better but i have not seen nor can I find any data supporting it. I also figured the track prepping is better. I mean how much better can you vulcanize rubber ?? I figured there would maybe be a more pure component in the formula or something tangible ?? Paul
A freind of mine had a 69 Cyclone CJ 4 spd new and raced it ran a best of 13.18 back then.He was the one that told me to pump up the Polyglas tires to 45-50 lbs back in the late 80's when I raced in NMCA .It worked good I ran a 1.84 60 ft back then.I think the tires are better now than they were in the late 80's and certainly better than they were in the day.I am sure the track prep today makes a lot of the improvement also.:3gears:
I have no idea. I got out of drag racing in 1968 and didn't get back into it until the 90's when Rob was running NMCA. Olds racing always was through dealers or individuals (like Brady, Trovato, etc.) I doubt any Oldsmobiles did much of anything if it required cast manifolds. All W car performance packages were developed with headers and never intended to race with manifolds. Only development with manifolds was the 69 400 program where they were trying to do anything they could to get those pigs to run. The W/Z manifolds are not all that bad, but you can't run them on anything prior to 1970 that runs. Olds didn't even have a dual exhaust manifold for small blocks.
Pre 72 NHRA stock class cars could run headers and a max of 7 inch slicks. Later on they changed the 7 inch tire rule and allowed 7 inch slicks or 10 inch street tires. At some time NHRA had "pure stock classes" and allowed most any treaded street tire (max 7 inches) but required stock cast iron exhaust manifolds. 427 inch 4 speed station wagons were a big hit in the "pure stock" classes.
