Who does not like a great take-off? If you ask me, I’d rather have a good take-off than a greater top speed, but when you can get a good take-off without even disturbing the top speed, then it is not even a question.

Let’s take a glance into the modifications you can actually make to its driven pulley and a really brief glance into the adjustment of the driver pulley for good take-off (Jump to the final section if you desire better take-off).

The focus of this guide is on the thirty series torque converters, but there is not much difference in concept; the weights and springs may be diverse in the forty series.

Spring On The Driven Pulley:

Let’s first have a glance at diverse types of springs and the diverse possible spring settings for its driven pulley and assist you in selecting which choice is the great one for you.

Types Of Springs:

In the market, there are three types of springs available that are mostly utilized in the thirty series, the yellow spring, the red spring, and the Green spring. The yellow is rigid (stiffest), and the green one is the least stiff of them.


Yellow Spring > Red Spring > Green Spring

Holes In The Driven Pulley’s Cam:

When you dismantle the driven pulley in comet thirty or clones, you will see three diverse holes in the cam; the cam is the secure item that remains secure and keeps the spring from bursting off. There are three holes in the cam; it may come labeled as 1, 2, 3, or it may not.

If you put the cam such that the holes are in the descending position, then numbers 1, 2, and 3 are from left to right. If you place the spring in hole number three, the spring will be the tightest, denoting that it’ll need more force to compress the spring.

Hole number one will need the least amount of force for compressing the spring.

Which Hole And Spring Is The Best For Your Purpose?

The stiffer spring will need more power from your engine to get to the certain gearing (the CVT will actually have variable gear ratios. So you will acquire more torque out of your engine in any provided gear from the stiffer spring.

The stiffer springs are more helpful for off-road driving or any condition where you need more torque, the top speed would not be affected that much, but the stiffer springs will demand your engine to generate more power for moving to a diverse gear ratio.

There are nine combos of springs and holes; if we’re to rate the stiffness on a scale of one to five, where five is the stiffest and own is the least stiff combo, then the rough estimation of stiffness is:

Hole 1 Hole 2 Hole 3
Green Spring 1 (least stiff) 2 3
Red Spring 2 3 4
Yellow Spring 3 4 5 (Most Stiff)

These numbers are only a rough comparison of stiffness; they’re not relative to the value of k (stiffness)

Why Does The Spring Stiffness Affect Torque?

For our purposes here, we’ll simply concisely glance into the working of the driven pulley without being anxious much about the driver. As the engine’s rpm increases, the driver clutch is forced towards your engine because of the weight-spring system’s centrifugal force in the driver clutch.

When the clutch goes towards your engine, it pushes the belt up, stretching its belt. Because of that stretching, the belt applies force to the driven pulley’s movable component. The driven pulley’s movable component is connected to the springs.

So as the driven pulley’s movable part experiences a force from its belt, the spring in the drive also faces the force, and as you know, the spring will apply some force opposing the belt’s force. It denotes that if its spring is stiffer, then more force will be needed for pushing the driven pulley’s movable component back and changing the gear ratio.

Since the driven pulley’s movable component will need more force from its belt to be pushed in, denoting it needs more work to be done on it by the belt, or it needs more power from its belt (since power is time/work) and as the complete system is powered by your engine, it needs more power from your engine. So the stiffer spring needs more power for shifting the gear ratios.

Power = Torque x RPM

It denotes that if you make use of a stiffer spring, you’ll acquire more torque for the same RPM/gear ratio in comparison to the less stiff spring.

How Can You Adjust The 30 Series Torque Converter?

Tools Needed:

  • 1 Impact wrench or other tools for removing the 5/8 Nut
  • 1 Spring of your preference
  • 1 Snap ring plier

Step-By-Step Guide:

  • First of all, remove the main 5/8 hex nut from the driven pulley system.
  • Take the snap ring plier and take out the snap ring; the ring is holding on to the secure cap; once you take out the ring, the fixed component can be removed.

Note: Be cautious while removing the fixed component; the spring may shoot the cap onto you.

  • Dismantle the spring and make certain the secure cam has all six buttons still there with the face/movable component of the driven. If any of these buttons are lost, you will have to get the new ones; significantly, you don’t make use of the torque converter without the buttons.
  • Once you have all these buttons ready, attach the spring of your preference to one of the three holes on the cam of your preference.
  • After that, simply fix the other side of the spring onto the hole of the driven pulley’s movable component (there’s just one hole in the movable component). Now it is time to reassemble it all.
  • If you see the cam, the cross-section in the center has two rounded sides and two flat sides; similarly, in the movable component, there are two round and two flat sides. You have to align the cam’s flat side with the movable part’s rounded side and push the cam down.
  • Then, rotate the cam anti-clockwise such that the cam’s pointed part is between the two buttons. After you get to the in-between of two buttons, rotate it a bit further anticlockwise, so the pointed component is behind these buttons.
  • Put back the nut and the snap ring.

And you’ve successfully reassembled the entire thing, so go ahead and check it out!

Modifying The Driver Pulley:

The vital part of the driver pulley is the weight-spring system in the clutch; this system will decide the RPM at which your clutch engages. If you reduce the weight, the engagement RPM will increase; the same comes about if you make use of stiffer springs (the driven pulley springs); the engagement RPM will be greater.

There are diverse weights and springs combos accessible for the driver pulley;

The following table shows the diverse RPMs of engagement of diverse combos on the 30 series Torque Converter:

Spring Color Zinc Weight (320 Gram) Alum-Die Cast (146.8 Grams) Mod-Alum (90 Grams)
Black 1400 rpm 2100 rpm 2300 rpm
Purpl 2000 3200 3400
Blue 2200 3300 3700
Orange 1500 2300 2500
Pink 1800 2300 3100
White 3100 4000 4500

For the 40 series, you have fewer choices:

Rollers Yellow Spring Red Spring
Light 2400 rpm 3100 rpm
Medium 2200 rpm 2600 rpm
Heavy 1600 rpm 2000 rpm


How To Get Better Take-Off?

  • First off, learn at what RPM the engine makes the most Torque.
  • Explore the chart given above and select the weight and the spring which engages at the RPM near the RPM that generates max torque on the engine.
  • Purchase the weight and the spring and swap out the older ones.