hydraulic clutch conversion Options

[jpnovak]

I just bought my first 914. I have had several early 911s and know my way around these cars.

The 914 will get an engine swap. It is being built as a GRM $2010 Challenge car. The car will then function as a DE car and potential DD if I can get the AC to work. There will be more details in another thread.

has anyone converted to a hydraulic clutch setup? The swap will not run through a 901 box. Non-Porsche parts going in. Yeah, i will make some purists cry. Don't worry, its a flat four but it is water cooled.

The slave cylinder is mounted to the drivetrain. I suppose I could go with a Tilton/Wilwood dual pedal setup. This should be easy to implement yet there are problems. Usually, the MC setup will not fit in the pedal area of a 911/914. The floor pedal sections are not too much different in terms of roominess.

just looking for suggestions.

[IronHillRestorations]

You'll spend no less than 20% of your $2010 budget on a hydraulic clutch set up. No cheap way to do it.

My set up used a 928 master cylinder and a CNC slave, with the braided stainless flex lines for the fluid run through the clutch tube. It requires a custom mount for the slave and master cyl, and modifications to the clutch pedal to actuate the m/c.

[puff adder]

What about an annular throwout bearing? I know they make them for the 911/915, not sure about the 914/901 but if they do, that would be my choice.

The car I just got has one, and Man it is easy, nothing to align, seems easier than the slave/arm/throwout setup.

[IronHillRestorations]

What about an annular throwout bearing? I know they make them for the 911/915, not sure about the 914/901 but if they do, that would be my choice.

I couldn't find one 12 years ago.

[stewteral]

I just bought my first 914. I have had several early 911s and know my way around these cars.

The 914 will get an engine swap. It is being built as a GRM $2010 Challenge car. The car will then function as a DE car and potential DD if I can get the AC to work. There will be more details in another thread.

has anyone converted to a hydraulic clutch setup? The swap will not run through a 901 box. Non-Porsche parts going in. Yeah, i will make some purists cry. Don't worry, its a flat four but it is water cooled.

The slave cylinder is mounted to the drivetrain. I suppose I could go with a Tilton/Wilwood dual pedal setup. This should be easy to implement yet there are problems. Usually, the MC setup will not fit in the pedal area of a 911/914. The floor pedal sections are not too much different in terms of roominess.

just looking for suggestions.

Hey jpnovak:

I've been running my 914 Chevy with a 930 for over 5 years and have been very happy with My Wilwood hydraulic clutch system. I also have the Wilwood dual-master cylinder with balance bar and it all fits nicely in the footwell.

I checked SummitRacing.com today and the Wilwood master cyl and pedal assy w/ remote reservoir (which mounts nicely under the front trunk) is Summit # CMB-14-0005 for 3/4" for $125. If you don't mind spilling brake fluid while on you hand and knees, the local reservoir version is $116.

At the back end I am using the Wilwood Pulling-motion slave cyl (WIL-260-1333) is $74. It's pretty simple to make a bracket to bolt to the trans side cover and there is plenty of adjustment. If you prefer, Summit has a Push motion slave cyl for $50 that would use the standard pushrod actuation and custom mounting bracket.

Check out my attached photos to see how easy it is to do. Since all my hydraulics are Wilwood, they are NEW and American thread. As old as 914s are, it is certainly a good idea to replace it all.

Best,
Terry

[ghuff]

Wow that pedal setup rules.


How hard was the install? Can you go into more detail? What did you do to the throttle pedal there?

[JazonJJordan]

(IMG:style_emoticons/default/smash.gif) (IMG:style_emoticons/default/popcorn[1].gif) (IMG:style_emoticons/default/sawzall-smiley.gif)

[jpnovak]

Terry, Great setup.

I agree with all that I will have trouble getting this done for a reasonable price. Read: within the GRM budget. I have figured out a way to run a cable setup off the stock pedal cluster. I will need to fab a mount but it should work with minimal issues.

maybe I will have to somewhat replicate the 911/01 clutch cable setup. If you don't know, its the Rube Goldburg of pull type clutches.

[Downunderman]

Tilton.

[stewteral]

Tilton.

Hey Downunderman,

With out a doubt your peddle setup takes the "cool & beautiful" award. Would that I had your budget!!

I like the clever install on the slave cylinder: Neat, clean and it obviously works!
I only went to a hydraulic clutch because I HAD TO: I had cable all built in, only to find that everything would bend and the clutch would not move! The clutch to handle the 500 HP & torque was too much for the cable approach!

What engine & trans are you running? As I have an upside-down 930 tied to the Chevy, I didn't recognized your stuff.

Best,
Terry

[stewteral]

Terry, Great setup.

I agree with all that I will have trouble getting this done for a reasonable price. Read: within the GRM budget. I have figured out a way to run a cable setup off the stock pedal cluster. I will need to fab a mount but it should work with minimal issues.

maybe I will have to somewhat replicate the 911/01 clutch cable setup. If you don't know, its the Rube Goldburg of pull type clutches.

Hi JP Novak:

Your clutch SHOULD be workable with a cable and it will ALWAYS be cheaper than hydraulic....so good luck with that approach. As I explained to Downunderman, with the clutch pressures to handle 500 HP were simply too much for cable and Brad Roberts gave me the tip to go hydraulic. That's why the hydraulic line is routed in view as an after-thought.....because it WAS!

Terry

[stewteral]

Wow that pedal setup rules.


How hard was the install? Can you go into more detail? What did you do to the throttle pedal there?

hey GHUFF,

My first question is what are you trying to achieve with all the work and cost?
In my case, I built the car up from a BARE mnocoque with a full V8 conversion and changed EVERYTHING!

If you are running a 411 or 911 motor, cable is cheap and easy and you will only need to replace the cable every few years. (BTW: can you drive your car home when that cable breaks?: start the car in 1st gear and then shift as though you are double-clutching. I've driven 90 miles this way to get home.)

For the BRAKES: I HATED the spongy stock brakes because of the proportioning valve mounted on the engine firewall. Having driven REAL race cars, I HAD to have the dual-master cyl/balance bar setup w/ Aeroquip flex-lines as they gave me a ROCK HARD pedal that hardly moves: it just makes the brakes work.

OK to answer your question: first, to get into this kind of fabrication you need access to important tools like steel cutting, drilling and welding. For me, when I spent the $400 for a wire-feed welder w/ gas, it was an amazing break-through! I could not only create strong reliable welds, but the ability to hold a part and tack-weld became vital.

To mount the pedals in a 914 (assuming you are 6' tall or less) is very easy as they will fit down in the footwell and still leave you enough legroom to drive. The stock sheet metal floor is too thin to take the loads, so I layed out a 3/16" thick sheet that I designed to bolt to the floor. I simply mounted the master cylinders to the plate and then bolt the plate (with spacers for the bolt heads) to the car. If you use 1/4" plate or thicker, you could simply drill that tap the master cylinder mounting holes allowing the plate to bolt flush to the floor. On the underside of the car, be sure to back up the plate mounting bolts with large diameter washers. The goal is spreading the load! I could have WELDED the plate, but I wanted the flexibility for later changes and bolting works fine.

For Brake lights, I took the stock wires and ran them to a "micro-switch" wired "normally open" and then ran simple "ball-chain" to the pedal. I used a small piece of aluminum angle to make a mounting bracket. Thus, when the brake is NOT used, the switch is held in the OPEN position, but as soon as I push the brake and slack the chain, the switch closes. You can find the switch at
Radio Shack and the "ball-chain" will be at most any hardware store.

Next step is to run brake lines to the brakes. As our cars are AT LEAST 33 years old, I highly recommend replacing ALL the hard brake lines. Since I changed everything over to American thread (Wilwood cylinders, calipers and clutch stuff) it was very easy. You have a choices: you can put in new metric lines to the Wilwwod cylinders and flare the tube with an American end (Flaring tools are not expensive---see Harbor Freight) or you can go American all the way and just use an American-Metric adapter at the German calipers. American brake line is CHEAP!!: 4-ft sections are only around $6 from NAPA. A poor-boy approach would be using a "coupler" to splice from the old lines to a new piece to the master cylinder.

Back to the master cylinders: I bought the set with the REMOTE reservoirs. The reservoirs easily mount under the front hood behind the gas tank and not gives you a LOT OF FLUID, but the reservoirs are easy to see for fluid level and filling. without SPILLING!!!

As far as the throttle goes, I chose to change the angle of the throttle so it was sit next to the brake pedal in the right place for Heel-and-Toe braking & downshifting.
Also, since I have a bunch of HP underfoot, I wanted to SLOW the opening of the throttle and all of this was achieved by lengthening the stock throttle arm ABOVE where the standard throttle cable attaches and then making a longer push-rod the the throttle pedal. The only other thing I did was create a very positive throttle STOP as I had a couple heart-stopping occasions where the throttle stuck OPEN by hanging up on the old stop. It was the 1st time that I found I had MORE HP than I had brakes to slow the car down. In one case, I was just about to end up in someone's living room! You may notice the black tube looping around the throttle: I copied this from a NASCAR throttle as it will allow me to PULL the throttle closed. when needed. If you have less than 300 HP, this is not necessary.

So did I give you enough info? Do you have the tools available....or maybe a very skilled bud? Actually the DOING is more about CONFIDENCE with a proper goal in mind, than skill. Let me know if you have any more questions.

BTW: I HIGHLY RECOMMEND reading the Carroll Smith books!! Start with "Prepare to Win", then "Drive to Win" and follow on through his series. They are racer bibles!

Best,
Terry

[Downunderman]

Its roughly 2.7 RS twin plug with PMO's, about 250 hp and weighs 970kg.

[stewteral]

Its roughly 2.7 RS twin plug with PMO's, about 250 hp and weighs 970kg.

Hey Downunderman,

Looks like a very nice setup. Quick, light and great handling.
Do you ever take to the track? I don't know where in OZ you live, but I LOVE Bathhurst. I have driven Laguna Seca and the Corkscrew was was fantastic, but Bathurst looks like 3 times that downhill! What a kick!

As for my project, I wanted something "challenging" and set a goal of 5lbs/HP.
So in went the 6.3 liter Chevy, 510 HP, 480 ftlbs torque. It is very fast, but I picked up a lot of weight: the commercial truck scales said 2575 lbs.

The price I have been paying is HANDLING. It's been a real battle getting to the right spring rates, 2 swaybars and shock adjustments to combat the endless UNDERSTEER. I got it just about right but that created a bad wheelspin problem coming off corners, so in went the Quaife and then back trying to correct the NEW understeer. I've had many times when I thought "What the heck have you gotten yourself into." However, with the addition of the rear bar, I now have a car that is amazingly responsive, neutral and stable. Unfortunately, I have to wait until December for my next tract day for the "Track Proof."

Enjoy your beauty,
Terry

[Downunderman]

Terry, only super sprints and track days. The East Coast Classic which was a tarmac rally used a lot of the Bathurst circuit which was fun. I did a couple of those before it folded. I've been to Laguna Seca, which struck me as being a mini Bathurst. The 1000km taxi race is on in a couple of weeks at Bathurst.

There is only one other meeting a year, sports car meeting in April, when mere mortals can get on it. Its a public road most of the time.

[andys]

Jamie,

If you're not building a track car, then perhaps you can approach a hydraulic clutch as I did (depending on your fabrication skill level). I ran linkage from the stock clutch lever to a bellcrank system with a Wilwood clutch master. My center console will hide the master from view.

Andys

[stewteral]

Terry, only super sprints and track days. The East Coast Classic which was a tarmac rally used a lot of the Bathurst circuit which was fun. I did a couple of those before it folded. I've been to Laguna Seca, which struck me as being a mini Bathurst. The 1000km taxi race is on in a couple of weeks at Bathurst.

There is only one other meeting a year, sports car meeting in April, when mere mortals can get on it. Its a public road most of the time.

Howard,

It's great to know you're having all that fun down-under. I'll just have to put Bathhurst on my "To do" list.....would you know anybody who could loan me a car for a day? :)

The Taxi race must be a HOOT!

Cheers,
Terry