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Hesitation re-visited

600 Views 5 Replies 5 Participants Last post by  white66coupe1
With regards to my post last week about hesitation with an Edelbrock 2121 and 1406 carb on my 289, I contacted Edelbrock and they recommended changing the step up springs and metering rods to a silver(8in Hg.) spring and a .073X.042(#1455) rod.

I did this today and re-adjusted the idle mixture and took it out for a spin. When cold, there is still some hesitation but is is virtually gone once warm. However I noticed a significant increase in response which means it was probably running lean to begin with.

Now, I have not had the car to a track yet but from the way it runs I would guess it would be around 14 sec. in the 1/4 if I could get traction. I have been considering changing the rear end from the non-posi 2.79 to a posi 3.25. I have a C4.

Well while out for my test drive I stopped on a lonely country road and without holding the brake I nailed the throttle. The tires are 195/75/14 and I immediately had rubber squeal. Then it stopped and I thought the trani was slipping but the tires had began to spin and smoke. I kept the power on and wound up leaving over 200 feet of rubber and smoking up the whole street. About 1/2 or so of the rubber was twin tracks. I was amazed that I could do this just by nailing the throttle with 2.79 gears. How did I get twin strips without having a posi?

Obviously this would limit my acceleration in a race. If I up the rear end ratio to 3.25 even with a posi this would make the tire spin problem worse. So now I am re-considering. What do you think I should do? Would fatter tires help?


Steve D
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The reason a open rear spins the right tire most of the time is because of the
torque put on the rearend by the drive shaft. If you put on the emergency brake
of a open rear end and give it the gas, both tires will spin because they both have
resistance. When you gas it in the dirt with a open rear end some times both tires will
spin. On the street if you hit it hard, both tires will spin for a while, then one will take
over. When torque is applied to a open rear end, both tires drive the car until there is
more torque than one of the tires can handle. In your case niether tire could handle the
torque. 3.25 gears will help because the tires spin slower at a given rpm than they do
with a 2.73.
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