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Author Topic:   Quick shock question
Racer17V
Dirt Roller

Total posts: 24
posted July 02, 2001 09:20 PM
I get confused with the compression and rebound codes. I have a 77-2 on the RF now and I also have a 76-3 that we ran last year. The 77-2 is bottoming out. When would you use the 77-2 vs a 76-3 or what are the differences between the two? What changes might I notice going from the 77-2 to the 76-3 again? Thanks.

irace74
Dirt Roller

Total posts: 24
posted July 02, 2001 10:29 PM
I have found that the right front shock is better characterized with a 50/50 shock like a 1074 or 1075. when you use split valves on the front is either slows the unloading of the left rear making it tight going in or makes it loose comming off becaust it is inhibiting the weight transfer from the right front back to the left rear. There have been a number of occasions where i stiffened the right front spring and softened the shock in order to tighten the car going in a touch and promoting weight transfer back to the left rear to give greater bite comming off the corner. This allows energy to be stored in the spring during cornering and the rate os energy release back to the left rear is dependent on shock valving. Furthermore Afco and others indicate that soft compression and stiff extension on the right front shock promotes cornering and slows bite comming off. The converse is true. For now I would sugggest that you forget about split valves until you run into a special situation and go with a 74 or 75.

Racer17V
Dirt Roller

Total posts: 24
posted July 03, 2001 12:39 AM
Thanks irce74....but I have another question. If I race a track that is always dry-slick...wouldn't I want a split vlave shock to slow the bite coming off so I don't break the tires loose? Most modified shock charts advise you to change from a 75/76 to a 76-3 for a slick track. Thanks.

irace74
Dirt Roller

Total posts: 24
posted July 03, 2001 10:10 AM
A 76/3 is an easy up shock. This shock should allow for quick energy transfer back to the left rear comming off. If the track is slick, wou probably will not bury the car into the corner because it is slick. THerefore there will be Less stored energy in the spring to be planted on the left rear to help the car come off. The split valve would allow for a tighter car on entry and slightly tighter comming off due to the stiff nature of compression and the soft rebound. Would it not be better to stiffent he front spring and soften the shock to allow for better corner entry and more stored energy planting the left rear better?

Racer17V
Dirt Roller

Total posts: 24
posted July 03, 2001 10:41 AM
Thanks again irace74...but what would a 77-2 do that a 76-3 wouldn't? What kind of handling characteristics would you look for to make the switch. I assume the 77-2 is stiffer with quicker rebound, correct? Thanks.

Limited5
Dirt Maniac

Total posts: 141
posted July 04, 2001 01:52 PM
Remember, 95% of all races won on any given weekend are won on 50/50 shocks. Split valves are a crutch. Call CJ Rayburn, he'll tell you the same thing. Unless your a chassis expert (few are, we all work 8-5 and race for fun on weekends) don't mess with splitvalves, they get confusing and expensive. Work with the 50/50 setup, you'll spend less money and go just as fast.

I was once told by a chassis builder that there are maybe only 5 to 10 racers on dirt that could actually tell a difference when they made a shock change. I'll bet I could change a shock on any weekend racers car and he'd never know it. Keep it simple and don't go for the "trick of the day" stuff.

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