Clutch helper spring delete

[Spart]

This seems like an awful lot of work to make the car subjectively better.

Wild to me that people will talk about a subjective difference when I went wayyyyy out of the way to provide objective measurements utilizing a load cell and then published the data for free.

Purely math here, Pearson's correlation coefficient or "r".

For the stock setup, r = 0.89
For the modified setup, r = 0.94

0 is completely non-linear, and 1 is completely linear.

So mathematically and factually speaking, the clutch pedal pressure curve is more linear with the helper spring removed than it is stock.

Speaking subjectively, is it your subjective opinion that a clutch pedal feels better the less linear it is? Is that the argument you're going with? In that case, can you argue why installing a heavier helper spring wouldn't make the clutch pedal feel better?

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[PNEUMA]

Wild to me that people will talk about a subjective difference when I went wayyyyy out of the way to provide objective measurements utilizing a load cell and then published the data for free.

Purely math here, Pearson's correlation coefficient or "r".

For the stock setup, r = 0.89
For the modified setup, r = 0.94

0 is completely non-linear, and 1 is completely linear.

So mathematically and factually speaking, the clutch pedal pressure curve is more linear with the helper spring removed than it is stock.

Speaking subjectively, is it your subjective opinion that a clutch pedal feels better the less linear it is? Is that the argument you're going with? In that case, can you argue why installing a heavier helper spring wouldn't make the clutch pedal feel better?

I for one can appreciate your findings and the effort you put forth getting there.
My opinion on the clutch pedal helper spring is I’m perfectly fine with the pedal feel the way it is from the factory and it would not warrant any of my time to remove it (the spring) to find out if I liked the feel, for better or for worse.
I will say that my FL5 is a pleasure car for me, and I only drive it barefooted because that is the way I enjoy it most. Having a 76 Chevrolet van with the column shift for 22years has built up my left leg to big boy status. The FL5 pedal 49 years later feels like my left leg is doing almost nothing!
I know that was a bit of a ramble, but I do commend you for your research, but mine is staying put

 

[Cueyo]

Wild to me that people will talk about a subjective difference when I went wayyyyy out of the way to provide objective measurements utilizing a load cell and then published the data for free.

Purely math here, Pearson's correlation coefficient or "r".

For the stock setup, r = 0.89
For the modified setup, r = 0.94

0 is completely non-linear, and 1 is completely linear.

So mathematically and factually speaking, the clutch pedal pressure curve is more linear with the helper spring removed than it is stock.

Speaking subjectively, is it your subjective opinion that a clutch pedal feels better the less linear it is? Is that the argument you're going with? In that case, can you argue why installing a heavier helper spring wouldn't make the clutch pedal feel better?

For you, the removal of the spring makes the clutch feel better, for many here, they really like how the clutch feels and don't want to change it. Simple as that. You posted on a public forum and got opinions, doesn't matter if you attempted to scientifically test. I appreciate the post though, if I feel like doing it some day I will, but currently it's not enough of a difference for me.

 

[Spart]

For you, the removal of the spring makes the clutch feel better, for many here, they really like how the clutch feels and don't want to change it. Simple as that. You posted on a public forum and got opinions, doesn't matter if you attempted to scientifically test. I appreciate the post though, if I feel like doing it some day I will, but currently it's not enough of a difference for me.

Okay so I just have to repeat myself:

Speaking subjectively, is it your subjective opinion that a clutch pedal feels better the less linear it is? Is that the argument you're going with? In that case, can you argue why installing a heavier helper spring wouldn't make the clutch pedal feel better?

 

[Cueyo]

Okay so I just have to repeat myself:

Speaking subjectively, is it your subjective opinion that a clutch pedal feels better the less linear it is? Is that the argument you're going with? In that case, can you argue why installing a heavier helper spring wouldn't make the clutch pedal feel better?

I'm just gonna stop engaging, I never said a heavier spring was better. I said I like it how it is, not gonna argue a moot point I don't care for. Already said all I wanted to in my first post, should answer your question

You're clearly passionate about clutches, so don't let me stop you

 

[Spart]

I'm just gonna stop engaging, I never said a heavier spring was better.

I'm asking you to argue a conditional hypothetical in support of your subjective opinion that clutch pedals feel better when they're less linear. I didn't insinuate that you ever said that a heavier helper spring would be better, what I'm saying is that if less linear clutch pedals feel subjectively better to you than more linear ones, then it follows that a heavier helper spring than stock would make the clutch pedal feel subjectively better than stock by decreasing the linearity.... unless you have some argument to the contrary that somehow doesn't contradict your previous statements?

 

[Icehawk]

Not sure a linear pedal is better, probably a lot of variables including (mainly) personal preference. The main thing is I don't want a heavier pedal and I find the action of the stock one totally fine. Cool that this is a tuning option though, too bad it's not easy to reverse. I'm more interested in trying a clutch delay delete tbh.

 

[cryptolime]

Not sure a linear pedal is better, probably a lot of variables including (mainly) personal preference. The main thing is I don't want a heavier pedal and I find the action of the stock one totally fine. Cool that this is a tuning option though, too bad it's not easy to reverse. I'm more interested in trying a clutch delay delete tbh.

be careful with that CDV delete. I did it on my old Corolla, and while it felt better, subjectively, the one time my foot slipped off the clutch the drivetrain shock was so bad it broke my exhaust in half

 

[Spart]

The CDV delete is the only thing that really made my MkV Supra drivable/enjoyable. BMW's version of the CDV seems more intrusive than Honda's as I don't really notice it in the ITS, but it's currently warm out and these things have a magnified effect in the colder months when the fluid is more viscous. I'll be deleting the CDV primarily because I intend to drive the car all year long. It won't be my primary winter vehicle, but I did buy a set of snow tires for it so it will be available.

 

[Sporky McGeuschky]

Hi.

As the self-decidedly most junior "senior" member of this forum, I welcome you here.
Man, what a way to make an entrance, with geometry and physics.
I'm all here for it.
Wish I knew what it meant.

You used the example of one of your other manual vehicles, which is a manual Tacoma. It does not have this clutch pedal helper spring, and it feels natural to you.

After seeing your chart and watching your video (great job, by the way), it does make sense that the DE5/FL5 feel perhaps unnaturally smooth in clutch pedal travel.

I have a bit of experience with manuals myself, although probably not nearly as much as many people here.

Lemme have at it.

Every motor vehicle I have ever owned has been a manual:

1994 Dodge Caravan Base, 5MT.
2004 Toyota Scion xA, 5MT.
1998 Subaru Forester, 5MT.
2005 Subaru Forester XT, 5MT.
2011 Subaru Forester, 5MT.
2015 Jeep Wrangler Sport 2 Door, 6MT.
2025 Honda Civic FL5 Type R, 6MT.

Also for reference, I don't race. I have never done AutoCross or driven on a track. Just street and highway.
Out of all of these vehicles that I have owned, the ONLY TWO that I ever felt had "heavy" clutch pedals were the '94 Caravan and the 2005 Forester XT. The "T" stands for "Turbo", and for some reason, that XT had a really heavy clutch.

Does this mean that the Dodge Caravan and Forester XT were the only two vehicles I had that did not have a "clutch assist spring"?
Or does it mean that all my other manual vehicles, including the other two Subarus, were just built "smoother" from the start...?
Or does it mean something else?

I'm not a geometrician, nor a physicstician, so I don't think about the scientificalness of stuff none too much.
I usually just drive.

This is an intersting phenomenon that I didn't know existed until today.

Thanks for your input.
We do value it here.

 

[Zpeedster M]

FL5 is his 1st manual transmission car, he still learning to shift, adjust seat, wash it etc etc. He has no point of reference to your clutch pedal feel.

I'm asking you to argue a conditional hypothetical in support of your subjective opinion that clutch pedals feel better when they're less linear. I didn't insinuate that you ever said that a heavier helper spring would be better, what I'm saying is that if less linear clutch pedals feel subjectively better to you than more linear ones, then it follows that a heavier helper spring than stock would make the clutch pedal feel subjectively better than stock by decreasing the linearity.... unless you have some argument to the contrary that somehow doesn't contradict your previous statements?

 

[Spart]

You used the example of one of your other manual vehicles, which is a manual Tacoma. It does not have this clutch pedal helper spring, and it feels natural to you.

After seeing your chart and watching your video (great job, by the way), it does make sense that the DE5/FL5 feel perhaps unnaturally smooth in clutch pedal travel.

[snip]

Out of all of these vehicles that I have owned, the ONLY TWO that I ever felt had "heavy" clutch pedals were the '94 Caravan and the 2005 Forester XT. The "T" stands for "Turbo", and for some reason, that XT had a really heavy clutch.

So I want to be as clear as possible on this point: the pedal feel and the pedal weight are only tangentially related. This purpose of this exercise was not to make the clutch pedal heavier, that was a side effect. The clutch pedal is still among the lightest of the higher-performance cars I've ever driven. It was already light and a 16% increase isn't going to make a light pedal feel heavy. A 16% increase certainly isn't going to make my wallet feel heavy.

The clutch helper spring pushes in two different directions on the pedal depending on how far you push it down. This causes the clutch pedal to behave differently at different points along the full range of motion. This is not intuitive behavior, and when you're trying to *rapidly* find the perfect bite point on the clutch for a given situation, it's just a disaster.

I have a feeling that a LOT of you have not done track driving before. Don't take it as a slight, it isn't meant to be. The majority of people who own track capable cars never take them to a track. Track driving requires a combination of precision and speed that most people have never consistently put together in their lives. They might be able to do one or the other, but not both. It takes a lot of practice and screwing up. It also will just destroy your ego around your driving abilities, and most men aren't mature enough to give up on the idea that they are god's gift to driving.

If you are braking from 140mph-40 in order to enter a turn, you might be heel-toe downshifting two or three times in rapid succession (say 5th to 2nd in this example) while also pressing the brakes as firmly as you can without getting too far into the ABS or locking them up if your car doesn't have ABS.

In that situation, anything weird going on with the clutch modulation, the brake modulation, or the throttle modulation is going to cause you problems.

In particular with heel-toe while braking hard, if you fumble that you are going to cause the drive wheels to lock up momentarily. A little too much engine braking from a not-quite-right downshift can be a disaster.

This translates to street driving as well (and I'm sure someone will be along to tell me yOu dOnT nEeD tO hEeL tOe oN yOuR dAiLy cOmMuTE) because those skills you use on track are quite perishable and need to be tuned for specific cars. I have a turn at an intersection I make every day where I'm slowing down from 60mph to 15mph or so, and I make sure to downshift from 5th to 2nd every time. I usually just rev match the 5th-4th shift, and heel-toe the 4th-3rd and 3rd-2nd. Why? Because it's excellent practice even if I'm not braking hard. It all translates.

And for the record: any kind of auto-rev matching stays off in my vehicles. I've only ever owned two that have that feature. Auto rev-match will mask the poor clutch feel because it does something that a heel-toe blip cannot: it can blip the throttle and then perfectly hold RPM, which will hide your errors with timing and clutch engagement. I don't buy manuals in order to have the car do part of the manual experience for me. If I was into that, I would just get a DCT and push buttons and ride around on D all day.

 

[Sporky McGeuschky]

This purpose of this exercise was not to make the clutch pedal heavier, that was a side effect. The clutch pedal is still among the lightest of the higher-performance cars I've ever driven. It was already light and a 16% increase isn't going to make a light pedal feel heavy.

~~~

The clutch helper spring pushes in two different directions on the pedal depending on how far you push it down. This causes the clutch pedal to behave differently at different points along the full range of motion. This is not intuitive behavior, and when you're trying to *rapidly* find the perfect bite point on the clutch for a given situation, it's just a disaster.

I have a feeling that a LOT of you have not done track driving before. Don't take it as a slight, it isn't meant to be. The majority of people who own track capable cars never take them to a track.

~~~

If you are braking from 140mph-40 in order to enter a turn, you might be heel-toe downshifting two or three times in rapid succession (say 5th to 2nd in this example) while also pressing the brakes as firmly as you can without getting too far into the ABS or locking them up if your car doesn't have ABS.

In that situation, anything weird going on with the clutch modulation, the brake modulation, or the throttle modulation is going to cause you problems.

~~~

And for the record: any kind of auto-rev matching stays off in my vehicles. I've only ever owned two that have that feature. Auto rev-match will mask the poor clutch feel because it does something that a heel-toe blip cannot: it can blip the throttle and then perfectly hold RPM, which will hide your errors with timing and clutch engagement. I don't buy manuals in order to have the car do part of the manual experience for me. If I was into that, I would just get a DCT and push buttons and ride around on D all day.

I disabled the "Rev Match" digital downgrade as soon as I realized it was a thing. I disabled as many digital assistants as possible as soon as I got the car home. Not down with that ghey shit.
This is a Type R, not a Prius (was about to say "Tesla", but there's that whole political climate BS surrounding the brand right now, so... to avoid any confusion, "Prius"). At least the original Insight and Civic Hybrid were each available in stick.

The FL5 CTR is definitely the lightest clutch pedal I have ever used, and it must be due to this dual action spring. However, if removing the spring only increases pedal "up force" by around 16%, then this clutch pedal would still somehow be the lightest pedal I've ever used. Mind boggling.

Upon seeing your video, I was thinking, "Too bad the spring is so easy to remove, yet so difficult to reinstall". If the exact opposite was the case, then I would probably want to remove the spring. That way I would know the difficult part was finished. Then, If I ever wanted to return the car to factory, then I could just "pop the spring back into place". As it stands, that is just a fantasy.

The whole requirement to go through the firewall in order to reinstall the spring seems a bit much.

This leaves me with the question...

Is there a way to "wear in" this spring, particularly on the back half of travel, where the pedal is closest to the floor? Can this be done without excessively wearing the spring at the front half of travel, so that the return-to-zero assist remains intact?

The idea is to get that 0.89 ratio closer to, say, 0.91 or 0.92, rather than the full 0.94 "natural" ratio.
It wouldn't be a "spring fully removed" feel, but it would be as close as possible. Perhaps instead of making the clutch feel 16% heavier, "wearing in" the spring could make the clutch pedal feel about 9 to 10% heavier, thus making the entire travel more realistic than the travel with the brand new, stiff, unworn clutch assist spring...?

Does my question even make sense?

Am I dreaming inside of a fantastical rabbit hole?

Do I need to listen to Tom Petty's "Don't Come Around Here No More" so I can snap out of it?

 

[Spart]

Do I need to listen to Tom Petty's "Don't Come Around Here No More" so I can snap out of it?

You'll spend more time thinking about it than it would actually take to reinstall the spring.

The clutch pedal assembly is meant to be worked on/replaced the same way much of this car is engineered.

• Unplug two sensors.
• Remove clevis pin to master cylinder arm.
• Remove three bolts from firewall.
• Remove clutch pedal assembly.

That's it. It's not hard, it's just hard-er than wedging that spring out of there. You'll need extensions and a universal joint for the top bolt. I considered removing the pedal for the video just to demonstrate the spring more clearly.

And besides, given what you've told me I'm about 92% certain you won't want that spring back in there anyway.

 

[Sporky McGeuschky]

You'll spend more time thinking about it than it would actually take to reinstall the spring.

Ha! That's what she sai...!!! ... uhh, I mean, OK. If you say so.

...
And besides, given what you've told me I'm about 92% certain you won't want that spring back in there anyway.

Hmm. It would appear that you know more about my own train of thought than I do myself.

You: . Me: !!!

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