GR86 GR86 - The clutch pedal thread

On the GT86 I replaced the slave cylinder with a smaller TRW one, made the pedal throw shorter with some more force required.
 
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Posting from the other thread.......some people have complained about the clutch pedal on the GR86 having an unnatural binary on/off switch feeling.

I haven't test driven one yet, but it sounds like the same issue the GT86 had. There's a spring on the clutch pedal, which serves two purposes - as you push the pedal down, it provides some assistance to make the clutch feel lighter.
It's on a pivot, so that as you release the pedal, after a certain point it switches from pushing the pedal down, to pushing it up - thus, it keeps the pedal fully in the up position when your foot is off it.

However, the spring is quite heavy (it has to be to provide any meaningful assistance when depressing the clutch). So as you are bringing your foot up, when you get to the point where the spring switches it's fulcrum, it suddenly puts upward pressure on the pedal, which feels unnatural and gives that sudden 'snatchy', binary feeling.

Solution is quite simple - replace the spring for a weaker one. It makes the clutch feel heavier and more 'sports car like', and reduces that odd, binary-feeling on pedal release. MTEC made one specifically for the GT86; I assume it will fit the GR too.

There's already some discssion about this on gr86.org in this thread:

...and in there, someone has posted this excellent video where someone takes out the pedal assembly and mounts it on a bench so you can see exactly what I'm talking about above.



You can also just remove the spring entirely - however this is generally not advisable, because that spring also keeps the pedal in it's full upright position. Without anything doing that, the pedal may end up with a deadzone at the very top where it feels loose.
 
Genuinely believe this is a design flaw. There is no reason for it to be this way, what is wrong with using a torsion spring like most cars probably do, its a simpler design and there is no pivot point, they work on rotational force not linear.

torsion-spring.webp
 
It's a shame. I get the impression that some of the improvements on the GR86 were a direct consequence of some criticisms raised about the GT86, and this was quite a common one. You'd think that as they took the trouble to improve the gearbox with better synchros, that's they'd also just switch out the clutch spring for a slightly lighter one. I'm going to guess it's a marketing thing where they want to make the manual more accessible by decreasing the pedal force.

Still. At least it's easily rectifiable. For RHD vehicles, you need to take out the clutch pedal and do it on a bench, but it's not particularly difficult. I did it, and I'm an idiot. Good how-to below:

 
I had a GT and never found it was an issue, I think you just get used to it even if it seems a bit odd to start with.

I bet though now I know I'll notice it every time and want solution 😉
 
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It's a shame. I get the impression that some of the improvements on the GR86 were a direct consequence of some criticisms raised about the GT86, and this was quite a common one. You'd think that as they took the trouble to improve the gearbox with better synchros, that's they'd also just switch out the clutch spring for a slightly lighter one. I'm going to guess it's a marketing thing where they want to make the manual more accessible by decreasing the pedal force.

Still. At least it's easily rectifiable. For RHD vehicles, you need to take out the clutch pedal and do it on a bench, but it's not particularly difficult. I did it, and I'm an idiot. Good how-to below:


Love a good ‘how-to’ video - so relaxing… 💆‍♂️
 
I'm quite used to it by now (2 weeks with MTEC spring). Getting moving from standstill quickly is still "difficult" though. Too much revs usually pr not smooth enough, must be a combination of the throttle mapping and the clutch bite feeling. I suspect this feeling will stay...
Never had this issue with any other car.
 
I've been doing a bit of research on clutch springs recently and I have found other options than just the MTEC. These springs I have found are between £5 and £7 each as opposed to £32 that MTEC charge! They are also available in various spring rates giving you more options! The only downside is delivery is £12, I can bulk buy and distribute for cheaper but that needs some interest first.

The stock spring is rated to about 150lb/in, the MTEC is 65lb/in so about 57% weaker than stock. The options on the table rate between 85% and 58% weaker than stock. I will update this with info and supplier soon.
 
I've been doing a bit of research on clutch springs recently and I have found other options than just the MTEC. These springs I have found are between £5 and £7 each as opposed to £32 that MTEC charge! They are also available in various spring rates giving you more options! The only downside is delivery is £12, I can bulk buy and distribute for cheaper but that needs some interest first.

The stock spring is rated to about 150lb/in, the MTEC is 65lb/in so about 57% weaker than stock. The options on the table rate between 85% and 58% weaker than stock. I will update this with info and supplier soon.
Please do! I'd like something as close to the MTEC as possible, as it's a known quantity, but you're right, £32 for a spring is a bit much.
 
I've been doing a bit of research on clutch springs recently and I have found other options than just the MTEC. These springs I have found are between £5 and £7 each as opposed to £32 that MTEC charge! They are also available in various spring rates giving you more options! The only downside is delivery is £12, I can bulk buy and distribute for cheaper but that needs some interest first.

The stock spring is rated to about 150lb/in, the MTEC is 65lb/in so about 57% weaker than stock. The options on the table rate between 85% and 58% weaker than stock. I will update this with info and supplier soon.
I'd definitely be keen too (y)
 
A pair of decent driving footwear should help a lot , after some research on US sites I came up with these , Redwing IronRanger, massively popular in the US of A , they have a good width to span the brake/throttle, good tread so should be ok in wet/snow , nicely weighted (just under 2kg for a U.K. 8 U.S. 10) so should help smooth out the clutch action (if you have one ) plenty of ankle support and come in several colours , mine are Rough & Tough Copper , should tone nicely with bronze alloys and Ignition Red.

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Great choice Andy. I love Iron rangers in R&T copper, they are next on my list. My first pair of Redwings are these Irish setter Moc toes. No good for driving though.

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700 miles in and it still catches me out sometimes. Still find myself lurching every so often, if I don't concentrate, especially if I'm wearing anything heavier than trainers. I'm still set on replacing the spring when I can.
 
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Second that. MTEC still felt a bit off but 800km in it feels great. Not sure if it's me or the clutch though. I think exhaust will make it perfect, more audible feedback and hopefully better throttle response.