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Shocker Tuning Info
Shocker Tuning Info

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Product Code: VPR-232-INFO


The Shocker is designed to be a Plug and Play unit...just bolt it on and go!

However, being racers ourselves, we know you can't wait to play with your Shocker.

Outlined below are the components that will effect the Shockers operation. Please understand, regardless of what you may have heard or read elsewhere, this is a very simple device. Centrifugal clutches have been in use for a hundred years...there is a lot of smoke and mirrors used in the clutch industry. Let's face it, vendors love to sell tuning components, it's profitable. Profits are not imperative at Viperizer, but it's not a bad word either.

We offer the following tuning components at very affordable prices.

Flyweights: These simply perform the function of applying the torque of the engine to the belt. It's simple, as the RPM's of your engine increase , the flyweights begin to apply the pressure on the moveable face. Next, the moveable face starts to travel, it begins to apply pressure to the sides of the belt. As pressure is applied the belt is squeezed between the Fixed Face and the pressure applying Moveable Face, Now, your belt starts to rotate the Secondary Clutch AKA(rear Clutch). As engine RPM's increase, the Moveable Face continues it's journey applying more pressure, since the belt is "V"shaped the belt has no choice but to climb up the sheaves, which ultimately change the torque reduction ratios. Since the above motion is derived through means of centrifugal forces applied on flyweights, the basic bottom line is the heavier the Flyweight, the greater the effects of centrifugal force and the faster the Movable Face moves throughout it's entire journey.

Currently, we offer two versions of Flyweights, we have dubbed them Thick (1/4 Wide) and Thin (1/8"wide). The thin is half the weight of the thick. Think of your engine in terms of big block or a small block. Big blocks like a load, they have the torque to carry the car thru the pass, small blocks like RPM...they need to be rev 'ed to make power. This apply's to your Junior too. If you have a 7.90 big bore Junior, your Junior is going to like the heavier Flyweights, a 12.90 car is going to like the lighter Flyweights. Remember the lighter apply's the load slowly as RPM increase, keeping your engine up in its power band. Simple huh?

Since the shocker has four arms, it is permissible to place thick Flyweights at lets say 12 and 6 o'clock, and two thin Flyweights at 9 and 3 o'clock. In fact, this is how we send out our 8.90 clutches.

Wait, your engine wants a little more weight? Add a dab of MIG weld to the sides of each Flyweight, use a gram scale to match each Flyweight. Added too much weight? That's easy grind some off, it's that simple. No need to buy anything.

Springs: The Shocker spring is exactly the same as the Polar line up of springs. So if you have a box of old polar stuff or your buddy does, your in luck, no need to buy anything. The spring directly effects the engagement RPM. Again, think big block, small block, keep it simple.

Just like the Polar, our Purple spring is the standard spring, engagement should take place around 4800 RPM. Please keep in mind that engagement RPM will be effected somewhat by the weight of the Flyweights. Your results may vary.

We stock the following springs:

Black 4300 RPM

White 4500 RPM

Orange 4600 RPM

Purple 4800 RPM

Green 5000 RPM

Black -Yellow 5300 RPM

Remember, the shocker has a adjustable spring seat, we suggest leaving the seat in the neutral position ( flush with front cover). Once you have selected the spring that hits your hot spot, then start to tinker with the spring seat. Screwing the spring seat inward will increase engagement RPM, outward will lower. Go a turn or at a time, once you have found your hot spot, we strongly suggest staking the adjuster in place.

We will be releasing our spring seat adjuster tool shortly.

Belt Gap Shims:

Want to fool around with your belt gap, no sweat. You will need two tools to make your like easy.

#1 Viperizer clutch holding tool.- This is simply a piece of Jack Shaft of which we welded a 3/4" nut on one end, and tacked a 1" piece of 3/16" Key stock in place on the other end. Clamp the nut in your vise, slide the clutch on, now you got a handle on the Shocker.

#2 Viperizer Shocker Spider tool - If your handy with a welder...you can make this item from a nice piece of pipe and a large nut and four bolts. We sell a pretty one at a reasonable price.

Using the spider tool, turning counter clockwise, remove the spider. To adjust belt gap simply add / subtract 1.375" ID , .015" wide shims from the underside of the Spider. Since, the shims will be between the Moveable Face that slides on the main post and the Spider that is threaded in place, the moveable face will be forced inward .015" for every shim you add. Thread the Spider back on, tighten it up, don't be afraid to put some muscle into it, you wont break it. No worries the belt friction will help tighten it too.

Spider Shims:

Adding a shim or two to the seat of which the Spider rests will have a direct impact on the angle of attack of the Flyweights. The further the Flyweights have to move prior to contact of the Spider rollers, the greater the angle of attack. The angle of attack will directly effect the load placed on the engine at time of engagement. We sell these shims in .025" width.


The Shocker clutch can utilize any Polar Belt. We recommend our M-90 Polar belt. Its a little wider then the typical Polar belt, but might require a shim or two in the secondary clutch. Again, any polar style belt can be used, its entirely up to you.

Bottom line..change one item at a time..keep good records...try to test on a day when the weather is not moving all over the place...and most important...KISS...keep it simple and fun!!!!!

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