Review: RJM AFP Clutch Pedal System

OTL

I just wanted to ask some questions regarding the settings of RJM. On the instruction, it says the initial setting at 70%. Do I adjust the setting from 70%? As in turning left or right from the initial setting being at 70%?
also, how far does the clutch rod have to be sticking inside the fork? Thank you!

1991Z32

Just pushed the buy button. Can't wait!

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2010 40th Anniversary #564 || NISMO CBE || Hankook Ventus V12 Evo2s || RJM Clutch Pedal Assembly

CanadianSteel

I was just gonna order it then I realized I ran out of fund for mods. I'll have to wait a couple months till my birthday and then definitely buy.
This has been a very helpful thread.

JARblue

I turned the dial all the way to the left and made a reference mark using a silver sharpie. Then I turned it all the way to the right to find the maximum, counting the number of turns. I found the 70% setting using those as reference points.

The fork that connects to the master cylinder rod is meant to be adjustable (pretty much the only adjustment you can make to the OEM pedal). I can't remember exactly, but I believe there is some guidance in the instructions. When I installed mine, I just made note of where the OEM pedal fork was and tried to make it about the same to start. Maybe someone else has some insight that is more helpful.

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Kamillio

I just bought mine I've been driving without the helper spring because I like the linear feel of the pedal. Excited to feel the difference after I will install it!

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370z

TBatt

Ordered mine on Wednesday and it arrived on Monday. I was planning on doing the install this Saturday but we had a cold front come through and the temps and humidity were going to be nice so I took today (Friday) off to do the install.

I followed Ryan's instructions to the letter and the install almost went perfect.........

The stock pedal came out with very little cursing and the new pedal was prepped and ready to go in. While installing one of the nuts that hold the pedal assembly to the master cylinder it made the sickening sound of falling through the mechanism. I pulled myself out from under the dash and started to look for it. The area is quite small so it should be easy to find BUT NOOOOOOO!. I pulled back the carpet, drug a magnet all over the area, searched behind the fuse box, pulled more carpet back, looked under the dead pedal foam block, drug the magnet everywhere it would reach, no joy. After about an HOUR I finally gave up and decided to take the other nut off and head to the parts store for a replacement. They had the 8x1.25 mm nut and flat washer so I headed home to finish up. The rest of the install went about as best as could be expected considering you are working under the dash of a small car. Did I mention that I'm 60 years old and over weight........

Finally installed and adjusted and ready for the shake down cruise. Man, the new pedal is SWEET! Everything seem okay except for the cruise control would not engage. I guess I didn't get the top brown switch adjusted properly. Got back home and started to dive under the dash again and there it was.....the damn missing nut laying next to the accelerator pedal. My theory is that when it fell off of the stud it fell in to a time portal/black hole. It just happened that when I returned that the time portal realigned and the nut reappeared.

I've owned a bunch of sports cars in my many years and all of them were manual transmission cars ( it ain't a sports car if it has a slush box) and the 370Z was the first car that I thought about getting rid of it because it requires 100% attention to operate the clutch. I don't know how many times I killed the engine at a light because I was not paying attention. No other car I have driven except maybe the 427/435 HP Vette my dad had or the Grand Spalding Hemi Charger that my high school friend had had such a tricky clutch. The RJM Performance adjustable clutch pedal is worth every penny and every ounce of effort to install. A beautifully designed and expertly assembled addition to one of the great cars of our time.

Headed to the Tail of the Dragon tomorrow for some fun.

Kamillio

I've installed mine now. It's even more tricky to drive this one than the stock! I don't know what I did wrong but my engagement point is really close to the floor but the clutch pedal rests almost even with the brake pedal with stock adjustments as recommended in the instructions.

I don't know how to improve my driving experience.

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370z

Ryan @ RJM

Kamillio, glad to hear you got it installed today. I'll walk you thru getting it dialed in better as your description is certainly not how it should feel when setup according to the guide's initial recommendations.

First off getting the friction point too low is absolutely just as difficult to drive as too high since you have no room to modulate before it starts grabbing.
The minimum recommended initial friction point as tested on level pavement is 1.5" up from the floor. Any less makes it's difficult to drive and there is a possibility for not fully disengaging the clutch. Now when you say you currently have the pedal almost even with the brake I'm guessing you mean the pedal is too low and not up level. It should be either level with or up to 1/2" above the brake when setup per the guide.

To bring the initial friction point up to where it's more comfortable you'll need to loosen the lock nut behind the clevis and thread the clutch rod counter clockwise to raise the pedal and in turn the initial bite point.

In addition to this you may want to recheck you have the AFP setup correctly to between 70-80%. To do this you can loosen the AFP lock bolt and turn the red knob clockwise until the sliding plates are fully retracted. This is the 0% point. Now keep careful count as you turn the knob counter clockwise 7-8 full turns for 70- 80% AFP. Mark the knob with a sharpie marker to make counting full turns easier if your knob doesn't have a mark already.
Once the AFP is set you can push the pedal arm down about half way to remove all slack from the pin while you tighten the AFP lock bolt.

Once you've ensured the AFP is set correctly and raised the friction point up a little it should feel much better then stock.

Let me know how it goes.

Thanks,
Ryan@RJM

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Home of the A.F.P. Upgraded Clutch Pedal System. Smoother Launches, Smoother Shifts & Improved Clutch Control Like No Other Pedal Mod You've Experianced Before Guaranteed!
Visit www.RJMPerformance.com or Email Ryan@RJMPerformance.com Also Don't Forget to Like us on Facebook www.facebook.com/RJM-Performance

Kamillio

I think my problem is with the lock nut behind clevis and rod counter. I have no idea what any of that means.

The only pieces I have seen that were adjustable were the slider that moves the pedal up and down vertically. This had to be in the lowest position for me so that the clutch cylinder rod was aligned at a proper angle so that the seals don't wear out prematurely as stated in the instructions. The second one is the knob, the knob does not change the engagement point though.

I checked I do have about 1.5 inches of clearance, just that engagement point takes even more force to push and is shorter than stock.

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370z

Ryan @ RJM

Kamillio, yes the AFP adjusting knob most certainly does affect the engagement point and the feel. As I stated before you'll need to go back and readjust both the AFP to the correct starting point of 70% following the directions I've posted above (or from the guide) and also increase the clutch rod adjustment to raise the pedal height.

The 3 main adjustment points are:
1) The Red Knob which controls AFP setting. The AFP affects both the feel of the engagement width, the firmness of the pedal and indirectly affects how low the friction point is. Increasing AFP makes the pedal Softer, Engagement Smoother and Friction Point Lower.
Saying your pedal is currently harder then stock to press means your AFP setting isn't set correctly. When setup to 70-80% the pedal will be softer to press then stock and wider engagement zone.

2.) The clutch rod that threads into the clevis fork. This rod threads in deeper to directly make the friction point and overall pedal height lower. Threading it out makes the friction point higher and overall pedal height higher. Use a 12mm wrench and loosen the locknut to adjust this. Once the nut is loose turn the rod clockwise (when facing the firewall) to raise the engagement point. Then tighten the nut again before testing the new engagement height.

3.) The whole center section of the pedal assembly moves up and down to adjust the angle of the clutch rod to ensure it pushes the master cylinder rod as straight as possible. It's preferable for the rod to be setup to be level at mid stroke and just slightly above level with the pedal full up. Because the pedal linkage travels in an arc about a center point the linkage moves downward as it rotates thru it's stroke. So the linkage will start slightly above level and dip to be straight at mid-stroke and then rise slightly up again at the bottom of the stroke.

As well after the above changes you'll need to ensure that the upper cruise control switch isn't holding the pedal arm down, stopping it from returning fully up. Adjust the two nuts on the switch so that with the pedal fully up the switch button is fully pressed and the white bumper just lightly touches the metal body of the switch.

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Home of the A.F.P. Upgraded Clutch Pedal System. Smoother Launches, Smoother Shifts & Improved Clutch Control Like No Other Pedal Mod You've Experianced Before Guaranteed!
Visit www.RJMPerformance.com or Email Ryan@RJMPerformance.com Also Don't Forget to Like us on Facebook www.facebook.com/RJM-Performance

TBatt

Kamillio, make sure that you loosen the 3/16 socket head AFP lock screw BEFORE adjusting the red knob. If the AFP is locked by the screw the adjustment won't work.

My install resulted in a near perfect clutch pedal.

Kamillio

Thank you Ryan@RJM and TBatt, I will check and adjust my pedal sometime soon when I'll find the time, cause for now Z is sitting anyway.

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370z

wsarver

Hey Ryan@RJM my pedal is very soft for the first half of the throw in the morning but stiffens up as I build some heat. I'm just confirming my thoughts. Does it sound like I need to bleed the clutch? I'm wondering if I may have bubbles somewhere.

TBatt

I just changed the fluid in the clutch system and found out that you MUST adjust the AFP setting to 0 (turn the adjusting knob fully clockwise). Ryan put a note at the beginning of the instructions about this so don't forget to loosen the lock screw and turn the knob clockwise until it stops. After bleeding the system, turn the knob counter-clockwise about seven turns and re-tighten the lock screw using a 3/16 allen wrench.

Also, be aware that the cast aluminum cross member has some very sharp flashing on it. Check and see before sticking your arm up there. I was getting red fluid dripping off of my elbow which was brake fluid mixed with blood. The metal was super sharp so I didn't feel the cuts. A little 80 grit sandpaper fixed the problem for me.

Ryan @ RJM

Good evening, this is a classic case of the master cylinder not fully returning and causing fluid to be trapped on the high pressure side of the master cylinder. When the car sits overnight the fluid in the line contracts causing the squishy pedal feel until the car warms up causing the fluid to expand again and feel normal. There is a tiny fluid port inside the MC that allows fluid to flow between the reservoir and the high side of the system which is only open when the master cylinder is 100% up and closes upon the slightest amount of MC travel down the piston bore. The port staying closed causes the feel you're describing.

Two main causes for this are:
1) the upper cruise control switch adjusted too tight holding the pedal down slightly. This keeps the port closed all the time leading to changing pedal feel from cold to hot.
2.) if the two side tension bolts that take up side-side play in the pedal are adjusted too tight the pivot bearings will have extra drag and the pedal may not fully return to the top under it's own power 100% of the time. This can cause the feeling you describe to happen either randomly or all the time depending on how tight the bearings are.

To check for this is easy. Go under the dash and press the pedal down by hand then release the pedal very very slowly. Then note where it stops on its own. Did it go all the way to the top and hit the upper switch firmly? If so likely the switch is set too tight. If it stopped short of pressing the switch and you can pull it up more by hand after it stopped then the bearings are too tight. In this case loosen the two side tension bolts evenly a 1/4 turn each and retest. Do this until the pedal comes fully up when releasing slowly.

That should take care of it.

Also TBatt made a good point about setting the AFP to zero for doing a full bleed. This is needed to push the highest volume of fluid thru the system and to ensure the MC goes full stroke to get all the air out of it. There is one exception here though - you only need to do this if you have air in the system you need to get out. Such as when you've had the system opened up to replace something. If just doing a simple clutch fluid flush for maintenance with one person pumping the pedal and another opening/closing the bleed screw then you don't need to adjust AFP first since there shouldn't be any trapped air you need out.
That note Is mostly just for guys or shops who installed the pedal along with a new clutch, CSC, clutch line or MC at the same time which is quite common.

__________________

Home of the A.F.P. Upgraded Clutch Pedal System. Smoother Launches, Smoother Shifts & Improved Clutch Control Like No Other Pedal Mod You've Experianced Before Guaranteed!
Visit www.RJMPerformance.com or Email Ryan@RJMPerformance.com Also Don't Forget to Like us on Facebook www.facebook.com/RJM-Performance