Which Acuity parts needed to just remove lateral slop on shifter?

[ashmostro]

Thanks! Which shift knob do you run?

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[Victorofhavoc]

Thanks! Which shift knob do you run?

Custom lathewerks shift knob. Full titanium, copolymer top, burnt ti trim ring, weight at 330g, and the acuity titanium collar to match up. When one of my friends and I were swapping between his Gt4rs and my its on track, he thought it was oem until he thought to ask, . I like it a lot. Chris is an awesome artist.

 

[ashmostro]

Agreed. I used one of his products on my C7 GS back in the day.

I didn't know he was doing hybrids now. I'm gonna check them out.

That said, the one I got is a beast at 500g, and I love it! It might end up being the one that gets the most uptime.

 

[ken_teggy88]

Just installed this Billetworkz beauty. 500g. It really smooths up the shifts dramatically, and looks gorgeous. Keeping the leather Honda knob as a backup for extreme weather.

How has the shifting changed for you? I was debating between the sphere and the lightbulb shape. Also, is that the stock boot retainer?

 

[ashmostro]

How has the shifting changed for you? I was debating between the sphere and the lightbulb shape. Also, is that the stock boot retainer?

The syncro engagement is more damped, and generally all vibration is damped much more. The actual size of the sphere is large, which reduces hotspots if you are shifting frequently and in anger (or on a track).

I've had similar weight and shape shifters on other cars so I knew what to expect, and that I would subjectively like it. It's not for everyone though.

Edit: oh and yes, that's the stock boot and collar. Perfect fit and look imo.

 

[Victorofhavoc]

The syncro engagement is more damped, and generally all vibration is damped much more. The actual size of the sphere is large, which reduces hotspots if you are shifting frequently and in anger (or on a track).

I've had similar weight and shape shifters on other cars so I knew what to expect, and that I would subjectively like it. It's not for everyone though.

Edit: oh and yes, that's the stock boot and collar. Perfect fit and look imo.

I like the 2" sizing. The factory knob and factory titanium are just too small for my hands, especially on track with nomex/silicone gloves.

I've had heavier (550g) knobs before and they're kind of necessary with short shift and heavy spring kits. On this car I liked the lighter spring weight, so I kept it lighter on the knob, but the solidity of pure metal is fantastic regardless of weight.

 

[ashmostro]

Agreed, dude. I just went for an extended drive and I'm loving the new feeling!

Looking forward to getting the following parts installed next (they are in transit):

Clutch-related

• CDV deleted slave cylinder (CDV delete only; I'm retaining the OE clutch damper unit)
• Gate-only HD detent spring replacement, not doing the throw detent spring

Other

• H&R Sport Springs (already have 15mm spacers installed)
• Larger CF Rear Spoiler from Street Driven Performance
• Black PPF on roof
• Blacked Out A mark and Type S emblems
• Matte CF Dash and console trim from Jogon

I'm going for the full storm trooper look!

-Ash

 

[Spart]

CDV deleted slave cylinder (CDV delete only; I'm retaining the OE clutch damper unit)

Can I ask why retain the damper? I honestly believe it induces delay.

In my high speed video data, there's a clear difference in the rate of engagement in the before/after of stock vs CDV+damper delete.

There's also a clear difference in the delay before getting to full rate of engagement, however the decrease in delay is greater than the increase in rate.

This leads me to believe that the damper induces a delay in movement between the pedal and the clutch. And if you think about how everything works, this makes perfect sense. The CDV does not have a variable volume of fluid it retains, so if the pedal is moving the clutch slave must be moving. The CDV just alters the rate, it's not a true "delay" as its namesake suggests.

The damper however does have a variable volume of fluid, meaning fluid in the damper can begin to fill the master before fluid from the slave can do that. And that's a real, measurable delay as I have found.

 

[ashmostro]

That's an interesting bit of data that I'll have to evaluate for my needs. Thank you for sharing. My theory, not backed up by data, is that the CDV, which technically does have a variable volume by the very movement of the check ball, should be inducing delay in both directions. Whereas the damper's role is to quell the higher frequency variations in pressure, like from the pressure plate springs actuating, the flywheel-clutch interface wobbling, etc. most drivers find that feeling in the pedal helpful in evaluating the friction level of the clutch, and they're not wrong. I just happen to not like that feeling and instead index my movements to pedal height rather than feel. So, with those needs in mind, I want a predictable engagement point but with as smooth a vibrational feel as possible.

In practice on this application, I could be making a mistake. But it's a cheap experiment if I decide I also want to do the damper delete later since I do all the work myself.

 

[Victorofhavoc]

That's an interesting bit of data that I'll have to evaluate for my needs. Thank you for sharing. My theory, not backed up by data, is that the CDV, which technically does have a variable volume by the very movement of the check ball, should be inducing delay in both directions. Whereas the damper's role is to quell the higher frequency variations in pressure, like from the pressure plate springs actuating, the flywheel-clutch interface wobbling, etc. most drivers find that feeling in the pedal helpful in evaluating the friction level of the clutch, and they're not wrong. I just happen to not like that feeling and instead index my movements to pedal height rather than feel. So, with those needs in mind, I want a predictable engagement point but with as smooth a vibrational feel as possible.

In practice on this application, I could be making a mistake. But it's a cheap experiment if I decide I also want to do the damper delete later since I do all the work myself.

You're so close! The cdv is responsible for reduced rate of flow in only one direction (clutch out).

Correct, CDV removal will increase "linearity" in the clutch pedal travel in that clutch in and clutch out will have the same engagement rate. In practice, and what I "feel" from this clutch, I believe that will bring your clutch out engagement closer to the floor, but also lengthen it a tad.

Correct that the "slave cylinder fluid damper" is responsible for reducing vibrations from the clutch engagement, feel of the spring tension, and general spinning forces (the "wobble" you dislike but others find crucial to "feel"). Removing it will make the pedal firmer also, but not a ton.

You can remove one, remove the other, remove both, replace with a straight through, or bypass the slave entirely.

Worth noting that some cars (I don't know if this one does but I suspect yes) have plastic innards in the slave, and with lots of launching I've seen them melt, fail, or bust. You just delete the slave, save a headache, and move on in this case.

On a different area, the clutch helper spring has a function of push and pull, with a dead zone in the middle. It's job is to make the pedal more linear so the foot feels a more constant pressure rather than a constantly increasing pressure, while also being softer /firmer in the pressure. (I've removed it on other platforms and liked it... I removed it here and I didn't )

Edit: to note, by clutch out I'm talking release of pedal and reengagement of gear. Not clutch disengagement.

 

[ashmostro]

Thanks for detail! I will try just the slave and see how that feels before evaluating whether I want to do the damper as well. I see what you mean about the unidirectionality and it makes sense.

That said, I am less concerned about disengagement than re-engagement for performance driving (ie, power re application rate is more relevant than power interrupt rate). I don't mind if this results in a jerkier shift due to revs not falling fast enough. But, let's face it, the throttle plate rev hang is way more dominant of a factor.

If I was having trouble pulling the trans out of gear fast enough, then I would care more about disengagement speed, but that's not an issue that I've experienced on this platform.

 

[Victorofhavoc]

Thanks for detail! I will try just the slave and see how that feels before evaluating whether I want to do the damper as well. I see what you mean about the unidirectionality and it makes sense.

That said, I am less concerned about disengagement than re-engagement for performance driving (ie, power re application rate is more relevant than power interrupt rate). I don't mind if this results in a jerkier shift due to revs not falling fast enough. But, let's face it, the throttle plate rev hang is way more dominant of a factor.

If I was having trouble pulling the trans out of gear fast enough, then I would care more about disengagement speed, but that's not an issue that I've experienced on this platform.

Yeah, clutch in is fast. Way faster than anything else in the process, lol.

You're right the throttle plate rev hang is worse than a clutch delay. It's still not the worst. I can easily drive around it by being back on throttle faster, which is good to help with the turbo lag anyway.

Modern turbo engines man... Tiny engines, big power, many electronics, many many nannies

 

[ashmostro]

I plan on tuning the car sooner than later, just to get rid of the rev hang. It's the worst part about the car.

 

[Victorofhavoc]

I plan on tuning the car sooner than later, just to get rid of the rev hang. It's the worst part about the car.

Have you tried coming off the throttle earlier and back on throttle earlier? (just assume you always have a 300ms lag)

Even with a tune (and ffs) I still have to work around the turbo lag, it's just not quite as bad. It does get a lot sharper in sport+ though.

 

[ashmostro]

Nah

Have you tried coming off the throttle earlier and back on throttle earlier? (just assume you always have a 300ms lag)

Even with a tune (and ffs) I still have to work around the turbo lag, it's just not quite as bad. It does get a lot sharper in sport+ though.

Nah I don't believe in changing my driving style as a patch for that. I'll accept the rev hang (really more like overboost) in the meantime.

The turbo lag is acceptable to me, and that can be mitigated with a flat foot shifting tune option anyway.

Induced rev hang just annoys me.

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