graymetalicsilv

Hello

My car: 2008 350z with Exedy stage 1 clutch, with mod described in thread: https://my350z.com/forum/engine-driv...tch-pedal.html

This is an attempt to reduce clutch pedal effort. The connection point of the clutch fork from the master cylinder is moved higher to increase leverage. The picture shows the stock mounting point (bottom hole) and the new drilled connection point (top hole). The hole size is approximately 13/32 in, or about 10.5mm. There was a plastic sleeve in the hole which is not shown in the picture.

With the higher attachment point, the clutch resistance felt like what a sports car clutch should feel, almost as light as one from a 4 cylinder car, and more progressive engagement. The resistance was also very linear and smooth. However, the clutch fork had to be moved out as far as possible to allow enough master cylinder movement for disengagement. This resulted in long pedal travel, and pedal on the floor to shift. This mod spread the engagement zone throughout the entire pedal travel. One must compress clutch to the floor to shift, and release all the way for full engagement. Despite the significant reduced effort and a linear resistance, the very long pedal travel frustrates spirited driving.

This picture does not show, but a third hole was drilled beneath the original to reduce travel required, with the understanding that pedal resistance would be increased. This mod resulted in an impossibly stiff clutch pedal. Its light on top but quickly stiffens to a leg press. The travel can be adjusted very short (via the fork), and engagement begins high on the last 1/3. The engagement is quick, but manageable.

In conclusion, the stock connection point seems a good compromise. Though I imagine if it was slightly higher the pedal effort can be reduced without too much extending the travel. But one can only drill the hole so close.

I know there is an adjustment bracket for 2006 Z, but its more than $100: https://my350z.com/forum/engine-and-...l-bracket.html

I wish the Z had a vacuum assisted clutch like the Mitsubishi 3000GT.

Important Notes:

For those who want to drill the new hole on top of the original. Please drill hole more towards the firewall (more to the right in the pic). I had to max out the fork length to get the clutch to barely disengage.

Using a hole other than stock will make the clutch rod go in at an angle to the master cylinder, this may cause uneven ware of the master cylinder wall.

RJM Performance

iTrader: (2)

graymetalicsilv, I applaud your effort and that you discovered exactly why the brackets I'm producing are fully adjustable. A very small change in the fulcrum point makes an extremely large change in the engagement width and pedal pressure. The usable adjustment range is very small and would put the new hole partially on top of the existing. Even then at the end of the day there is no way to adjust the feeling/engagement width or to correctly re-align the clutch rod linkage angle to the mastercylinder. Raising the fulcrum puts the linkage in a bind mid pedal swing and could cause mastercylinder damage in short order running that way.

I started out exactly the same way modding my 06' G35 before designing my first adjustable system. Every car is different and so is every clutch setup so having it adjustable is key. Drilling fixed holes you never know what you'll get and may not be vary drivable in the end like you discovered.

The new AFP System clutch kits will be available for the 07'+ 350Z HR's, G37, and 370Z's in about a month or so. They're currently in development and will be a complete bolt in pedal assembly that’s fully adjustable for fulcrum, pedal travel, engagement height and engagement window. Also the adjustment mechanism is much easier to fine tune then the previous generation kits due to being a complete redesign from the ground up.

graymetalicsilv

Thank you for your response. I noticed on the 06 bracket instruction the pedal assist spring was deleted. Will the bracket for 07+ incorporate the pedal assist spring?

Thank You

RJM Performance

iTrader: (2)

Yes, the spring will once again be done away with. The change in fulcrum length makes the pedal noticeably softer as the pedal leverage increases so the "Assist" spring in not needed or wanted. Most people don't like the feel of a very soft pedal so by removing the spring completely you get back some pedal pressure which helps the overall pedal feel while still giving you the benefits of a wider engagement window.

The new design doesn't require the spring to help support the pedal arm like the factory piece so there is no issues with the pedal becoming wobbly, loose or having additional side-side play like people report or are concerned about when removing the spring from the factory pedal assembly.

The new pedal arm in my design will also ride on bearings rather then plastic bushings which will tighten everything up for no slop yet be super smooth and precise.

RJM Performance

iTrader: (2)

Just took a closer look at your photo and the clutch bracket shown is the same as the 03'-06' model I currently sell. Your car doesn't seem to have the new pedal design??? Do you have any more photo's? I'd received photo's from other memebers early on in the development of the 03-06 confirming their cars had gotten the new style assembly but the removable cross bolt is a dead giveaway you have the early style brackets.

In the new style brackets Nissan did away with the cross bolts in favour of mushrooming over the ends of a solid piece of shafting. This makes the unit completely unservicable with no way to remove the pedal arm from the brackets. That's the reason for the complete redesign for my upcoming product as nothing could be reused like I currently do with the 03'-06' Kits.

graymetalicsilv

My car is a 2008 model with the VQ35HR engine. But the date of manufacture is in 2007. Perhaps an early 2008 model before the part change?

RJM Performance

iTrader: (2)

graymetalicsilv Thanks. Your post got me started in hunting down a definitive answer and when I was originally doing the prototyping for the current clutch kits there was a lot of confusion and conflicting information floating around. I've now confirmed with Nissan and multiple owners that the 07'-08' non-Nismo cars did not change from previous years and the current kits will fit just fine. I updated the website and some of my sales posts to reflect the new information.

07' was a transition year for both the Z and the G with the new HR engine and the G35 Gen 2 Sedans coming out. As such the conclusion was wrongly reached the kits would only fit the 03-06 cars but now all that has changed.

The only question that remains is what brackets did the Nismo editions get as a member here had sent me pics of his 07' Nismo 350Z which showed the new style 370Z brackets. It was these photos that ultimately lead to the 07+ 350Z's being excluded when the kits were developed back in October in the belief they changed styles when the HR's were introduced.

So Thank you for sparking a renewed interest in finding the answer.