Dave Talks About ClutchesHey Everyone!

We're often asked about clutch upgrades and what we suggest. I've put this guide together to help guide you in the right direction. This is going to be a long one so stay tuned!

A few things to consider when buying a clutch kit for your car;

With labor rates at most independent shops around $125-150hr and dealership rates even higher than that, a clutch job isn't anything you want to pay for more than once. Getting the correct clutch kit the first time is going to save you a lot of coin in the long run.

FCP Euro Clutch JobFCP Euro Mk7 Clutch Installation Blog

Even if you're a DIY'er and doing it with some friends in the garage, it's easily an entire day job if it's your first time. Some more experienced DIY'ers can bang it out in 3-4 hours, that's still a valuable chunk of your time to want to devote to the same job twice, not to mention the costs associated with replacing the same part twice.

1) How much power do you realistically expect the car to make?

How much torque do you need it to hold? To answer that, lets take a look at the EQT IS38 Turbo Stage 2 E85 Tune for the GTI.

Here we see that our Development GTI was able to generate 429.1 ft-lbs of torque at the wheels so we have a rough idea of how much torque handling capability we need.

**Realizing that Clutch Kits are almost always rated in Brake Torque, or Flywheel Torque numbers we need to do some estimating, for this application we're going to say it's around 460-465 brake torque

Now, there is a more mathematically correct way to calculate crankshaft torque from wheel torque, and back again. However that's an entire article worth of information in itself.

If you're interest in the math, then I advise you go to the following link and check out what X-Engineer has to say. 

https://x-engineer.org/calculate-wheel-torque-engine/

The best way to measure crank values would be to use an actual engine dyno, the math is at best an estimate.

Moving on, We now need to do some further estimating.

If we know that our engine can produce 465 ft-lbs of torque at the crankshaft, we need to add some wiggle room to add longevity to our clutch and ensure we're not in there again. 

A clutch and a brake aren't too dissimilar, there is a friction material and a steel. We would never expect our brakes to last if we commanded 100% of their potential stopping power all the time, so why would we expect the clutch to last at 100% of its potential? 

For this I tend to add 10-15% to this to ensure my clutch lasts for a while and has plenty of capacity.

465 ft-lbx x 1.10 = 506 ft-lbs.
465 ft-lbs x 1.15 = 534.75 ft-lbs.

So now we've figured out we're looking for a clutch rated to hold somewhere in the 500-530 range. Now we can start shopping!

2) What is your end goal and purpose for the car?

The math at the tail end of Step 1 estimated for 10-15% over our current needs, but if you're looking at a bigger turbo setup in the future, or going to a built engine you may want to go a little further and go to the next rated clutch.

Kyle Gurny On TrackEQT Tuned Customer and Track Racer Kyle Gurny at Road Atlanta

What is the purpose for the car? Do you have a street car / weekend warrior? Is it a Road Course or AutoX car? is it a full blown drag car? 

This guide is primarily applicable to Daily Driven Street Cars. If you need help finding a clutch suitable for your Race Car, either Road Racing or Drag Racing please reach out to Sales@EQTuning.com.

Justin ThompsonJustin Thompson's GTI Wearing some serious rubber for FWD Racing

3) What climate do you live in?

Much like brake pads, some clutch material do not perform well until they are at temperature so your initial "cold bite" may be poor on one material, and not on another. 

Golf R Snow
Keep this in mind when purchasing your clutch kit, and note that certain materials hold more torque than others but dont perform well in cold conditions so you'll need to adjust your driving accordingly to prevent slippage of the disk which will reduce its life and effectiveness.

That said, you shouldn't be ripping on the car until it has reached operating temperatures.

4) What sort of pedal feel are you after?

Are you looking for the pedal to feel like a stock, or OEM+ car? or are you okay with the stiffer heavier pedal?

South Bend ClutchSouthbend Stage 3 Clutch - Heavy Pedal Feel

Pedal feel is primarily determined by the poundage, or the amount of force excerpted by the pressure plate. The higher the amount of force the pressure plate puts onto the disk, the stiffer the pedal will feel.

Ringer Racing Stage 3Ringer Racing Stage 3 - Lighter Pedal Self Adjusting Pressure Plate

Some clutch manufacturers option their clutch kits to have a strong pressure plate, and a less strong friction material to achieve their torque ratings. While others will put a more aggressive disk material with a lighter pressure plate. 

Ultimately they will both achieve a similar torque rating, however one will be more enjoyable to drive than the other due to its lighter pressure plate.

A heavier pressure plate is usually not advised as the force from the pressure plate also gets transferred into the end of the crankshaft which may lead to premature failure of the thrust washers in the engine, ultimately resulting in engine damage. (aka: Crank Walk)

Thrust WashersHoons DIY'ish Engine Build (GolfMk7.com)

5) Stock Flywheel or Aftermarket Flywheel?

The next major decision to make when deciding on a clutch kit is if you want to use the stock Dual Mass Flywheel, or replace it with a Single Mass Flywheel. Commonly referred to as a Conversion Kit.

For this, I'm going to reference a video below by Charles The Humble Mechanic where he discusses how the dual mass flywheel fails

For those more inclined to read, I'll review the pros and cons of the Dual mass flywheel (DMFW) vs the Single mass flywheel (SMFW) below
Dual Mass Flywheel
 Pros Cons
Silent Operation of the Clutch Failure Prone
Stock like drivability Expensive Replacement Cost
Heavy / Excessive Rev Hang
Limited Clutch Upgrade Options
Limited Power Handling Capability
Single Mass Flywheel
 Pros Cons
Removed Failure Point May produce more noise
Decreased Sprung Mass (Mo Powa!) Takes more throttle to get moving
Decreased Rev Hang Higher Initial Cost
Serviceable Flywheel (Machining)
More Available Clutch Selections
Ability to reuse the flywheel for multiple clutches
Superior Power Handling Capability

6) While you're in there...

The famous word every car guy knows, "While you're in there.." comes to bite you. 

Here are some suggestion companion parts we suggest you replace or upgrade to during your clutch installation since they're accessible ONLY with the transmission removed

Rear Main Seal

We highly suggest recommend replacing or upgrading the Rear Main Seal to either a 034Motorsport or iabed industries unit.

034Motorsport LogoRear Main Seal

Transmission Oil

We also suggest replacing the transmission oil with a performance oil such as our Red Line Manual Transmission Oil Cocktail.

 

Hydraulic Slave Cylinder / Release Bearing (Throw Out Bearing)

 Another major component of the VW Clutch system is the Hydraulic Slave Release Bearing, commonly referred to as a Throw Out Bearing.

We highly suggest replacing any 2-piece plastic units with the 1-piece all metal as they no chance of leaking hydraulic oil inside the transmission bell housing

These can be purchased from your Local VW Dealership
Throw Out Bearing

TLDR: Summary - Dave's Top Picks

Ringer Racing

Front Wheel Drive (FWD) - Stock Flywheel (DMFW)

Front Wheel Drive (FWD) - Aftermarket Flywheel (SMFW)

All Wheel Drive (AWD) - Stock Flywheel (DMFW)

All Wheel Drive (AWD) - Aftermarket Flywheel (SMFW)

All Wheel Drive (AWD) / Front Wheel Drive (FWD) Drag Racing Use Only Please reach out to Sales@EQTuning.com

850 Super Single