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Hesitation re-visited

599 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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Lower gears will spin less out of the hole. You need some 8 inch wide tires or 9's if they will fit. Once it starts to try and hook you'll probably also get spring wrap up so some slapper bars or overrides/underrides will help that. If you keep burning down the tires with your open track you'll wind up breaking a spider gear in the rear end. They are especially prone to that if you start spinning on grass or dirt and then get up on the asphalt. If you still have a little hesitation on initial launch try going a notch closer to the carb on your pump shot lever. More initial timing can also help a launch stumble.

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