355 DIY thread on how to convert F1 355 to manual

A year ago I bought a beautiful, clean silver/black '98 GTB. I had been looking for a long time, and it was the car I wanted, it was local, the price was right, it had just had all the expensive maintenance done -- but it was an F1. I bought it knowing I would probably convert it to manual. This is not a knock on the 355 F1 system, which is actually pretty enjoyable. I just like shifting gears myself -- personal preference.

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Over the course of my first 6+ months of ownership I researched the conversion and compiled parts, and enjoyed the car with paddles. I want to give a shout-out to @kenneyd who answered a bunch of questions throughout this process and was very helpful on many occasions.

I carried out the work in my home garage using a floor jack and jack stands. No lift needed, but it would definitely be easier with a lift. It took me a couple of months start to finish not because it's an especially big job but because I'm busy with kids and work and at most could only spend a few hours a weekend on it plus occasional evening work. The conversion requires no especially advanced skills, but it does require a decent level of competence in an array of automotive mechanical areas. I don't want to sound boastful but I am pretty competent in this regard.

Doing this job you quickly realize how the F1 system was really grafted on a car that was designed as a manual, and how straightforward it is to un-graft it and add the manual parts. There is no cutting of wires or grinding of metal or any kind of hackery or bastardization because every 355 F1 started life as a 355 manual. Obviously each owner (and potential buyer of a converted car) can decide for himself how to add or detract value for these modifications. I love the car and can't foresee selling it, so this wasn't of significant concern to me. But anyone who says a converted car is "hacked up" or whatever -- he simply doesn't know what he's talking about.

One other introductory note: there are basically two levels of conversion, what I would call reversible and permanent. Reversible is how, for example, Ken’s car is set up, with the F1 wiring harnesses left in place and the clutch line set up so the F1 plumbing can be easily reconnected. "Permanent" (and even this could be reversed if you wanted) involves installing the factory clutch line at the transmission and removing the F1 harnesses for a cleaner, more complete, more original conversion. The latter is what I did.

I'm going to break this job up thematically into the following sections:

1. Removing the F1 system
2. Pedal box
3. Clutch master cylinder and plumbing
4. Manual shift linkage
5. Wiring
6. Misc

 

1. Removing the F1 system:

A. Remove the pedal box. In the driver's footwell (push the seat all the way back and get under there on your back with a flashlight -- not very comfortable) you need to:

- Remove the four 13mm nuts from pedal box studs in the footwell. The rear left one is inside a bracket and partially blocked by the brake light switch -- slow going with a wrench, not a ratchet.
- Remove the big aluminum brake pedal cover (it gets in the way when you pull the box out from the top)
- Remove 13mm bolt and nut holding the brake master cylinder (MC) fork on the actuator arm.

Now move up top to the trunk. After removing the rear carpeting piece to expose the brake booster/pedal box, you need to:

- Remove 13mm nut holding wiper motor shaft to wiper linkage (use a prybar or large flathead screwdriver to pop the bracket off the spline).

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- Remove 13mm nuts holding the brake MC to the booster.

- Pull the rubber brake booster vacuum line out of forward face of the booster (it's visible in the below pic -- bright blue fitting. Pull firmly and wiggle until it pops out).

- Remove two 10mm nuts holding brake fluid reservoir bracket and move reservoir out of the way.

- Now you're ready to pull the MC off the brake booster. Here you're going to just muscle the MC off the booster. The hard hydraulic lines attached to it are designed to have plenty of flex -- they will bend to accommodate moving it out of the way (and back).

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- Now it's time to start removing the pedal box itself. Pull it up and forward and get the four studs out of the sheet metal of the car body, so it's free and wobbling. But it's not completely free yet, because the wiper motor is still bolted to the top of it.

- Remove the several 13mm nuts holding the black steel wiper motor cover bracket onto the pedal box. This is a big PITA since three are obvious on top, one is obvious on the left side, but two more are on the right side up against the AC evaporator housing. Very little room and slow going. Get all the 13's off and you can remove the bracket, and then you can move the motor out of the way. There's no way to unplug this motor so this is the only way to do it.

This is now what you're going to be looking at -- a big jumble of disconnected parts. Big black disc in the center is the brake booster, aluminum thing behind it is the pedal box. 5 o'clock is the brake MC. 1 o'clock is the wiper motor. 2 o'clock is the brake fluid reservoir.

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Now comes the fun part. As best you can clear a path for the pedal box by moving stuff out of the way (a helper here would have been amazing) and wrestle the box up and out. Halfway out:

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Post-partum:

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Now that it's out, remove the 13mm bolt that pins the pedal shaft into the box (this bolt not only pins the shaft into the box, but fixes the shaft so the pedal rotate on it, vs the shaft rotating in the box), and then use a long 3/8” ratchet extension and a mallet to tap out the shaft. This is the shaft that the pedals hang on, and with it out the brake pedal drops out of the box.

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Pedal and rod removed:

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Now for Part B, removing the F1 pump, actuator, etc, from the engine bay.

This is all very straightforward disassembly and needs little narration.

- Get the car in the air and remove the left rear wheel, wheel well liners, left diffuser, and rear undertray.

- Drain the ATF fluid, but don't do it from the reservoir -- too messy. Disconnect the lower of the two rubber lines that run from the reservoir down to the pump in the left rear corner of the bumper. Drain all the fluid into a container, but keep it handy because there will be more.

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While that's draining, go up top and remove the fluid reservoir from the subframe and the red/orange heat shielded hydraulic line and mount. There's still fluid in the reservoir, so put a dropcloth or rags underneath.

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- Disconnect the wiring harness from the F1 pump.

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- Remove the two brackets that hold the heat shielded bundle of hydraulic lines in place on their path from the pump to the accumulator.

- Then get under the car and to the actuator (at the front of the transmission) to carry out the second unpleasant job in this project. First remove the bolts holding the actuator in place in its bracket and the electrical connection there, and then remove all the 17mm banjo bolts on top of the actuator that connect the F1 pump's hydraulic lines. There will be fluid dripping everywhere.

- With that done, you can remove the actuator and then from the wheel well, remove the F1 pump and lines, heat shield, etc.

Looking down on the F1 pump from above:
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Looking at it from the wheel well:
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Bracket the pump mounts on, before removing the bracket as well:
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At this point you will have a big tupperware container full of removed F1 parts:

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Back on top of the engine, I didn't like how the removal of the F1 reservoir and clutch line left the subframe looking shabby. The four mounting studs are unpainted and at the base of them are more unpainted areas.

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I used some touch-up paint to fill in bare metal areas at the base and used heat shrink tubing on the studs. You barely notice anything was there now.

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Now that step 1 is done, removing the F1 system and pedal box, we move to step 2, building the manual pedal box.

First some prefatory notes:

This step is unnecessary if for some reason you can source a '98-'99 Bosch ABS manual pedal box. I've been looking for a year and haven't found one. They are exceedingly rare since so many 355's in the last two years of production were F1 cars. And no, the earlier pedal box is not the same and cannot be made to work -- huge differences in where the MC's mount, the booster, the lines, everything. We are used to the 2.7 vs 5.2 divide on 355's, but there is also the Teves vs Bosch ABS divide, and this occurred (to the best of my knowledge) with the '98 model year.

All the F1 cars have Bosch ABS, and therefore the late style pedal box, and therefore unless you can find a late manual box, you will be doing some cutting and welding. You will have to delegate this part of the project to a fabricator unless you have the tools to do it yourself. It is not especially complicated.

The aluminum pedal box housing is identical between manual and F1 cars, as is the rod the pedals rotate on. The F1 box has a blockoff plate over the cutout where the clutch MC bolts on. Ferrari didn't actually cast a new F1 pedal box, they just used the manual one. This is good. There's no work needed to the pedal box -- just the pedals.

You are turning this:

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Into this:

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To be continued...

 

Pedal box, continued....

To add a clutch pedal to the F1 pedal box, there are four main steps:

1. Weld on a clutch pedal;
2. Weld on the clutch MC actuator/pedal stop/return spring assembly;
3. Cut the pedal tube (not the rod that runs through the tube) in half so that the clutch and brake pedals operate independently;
4. Install bushings in the ends where you made the cut.

The easiest way to do this is to buy a 348/early 355 pedal box and use it as a parts donor. I scored one on ebay for $250 and it even included the clutch MC (lucky find). Either the clutch or brake pedal arm are usable as the clutch pedal, and the MC actuator/pedal stop cluster is identical to the late manual box. Plus you need a return spring and mount from the donor box. Some pics:

F1 pedal box showing brake pedal:
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From left to right, these three pedals are: F1; 348/355 brake; 348/355 clutch with pedal stop/MC actuator.
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I used the right side pedal as a donor. You have to be careful when cutting the pedal arm and stop/MC actuator cluster off the pedal shaft that you don't reduce their height. Cut the pedal tube on both sides of each part and then grind the tube away from under the pedal and MC arm.

Some detail pics of the cluster, since it does four different things: 1) clutch MC actuator arm; 2) adjustable pedal stop for depressing the clutch motion; 3) stopper pad for the pedal box adjustable pedal stop for the return motion; and 4) a tab that the clutch pedal return spring hooks onto.

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Where do you weld these two items on the F1 pedal? See below. Left to right, the small silver line is where you cut the tube in half *after* you weld the other stuff on. The weld spot to the right is for the clutch pedal; the weld over at the far right end is for the clutch MC/stopper cluster.

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Several important details to note:

- You have to get the angle right between the clutch pedal and MC actuator arm, since they travel on the same half of the pedal tube. There's some margin for error here because the MC fork depth is adjustable. But the actuator arm sits at about a 10 degree different angle to the clutch pedal. Eyeball it before cutting up the donor pedals and you'll see it.

- After I welded the clutch and actuator on, I used a chop saw to cut the pedal tube in half. Cutting the tube removes a few mm of material, so you need to replace this lost metal with a greased-up washer between the two halves of the tube. You can see this washer in the pics below.

- After you cut the tube in half, you now have to get the inside of the tube where you cut it machined to accept bushings. This is a pain and unless you are a machinist you will want to have this done for you. Give the machinist the pedals, the pedal rod, and the bushings, so he can remove the correct amount of material from the ID of the pedal tube and press in the bushings.

You can get the factory bushing: https://www.ferrariparts.co.uk/part/ferrari/103163
Or this is identical:
https://www.applied.com/c-brands/c-garlock-bearings-llc/2015du/Self-Lubricating-Metric-DU-Cylindrical-Bushing/p/101986619

With that done, you can assemble the pedal box. I used a dremel to clean up the welds a little and some black semi-gloss enamel spray paint to make it look factory. Here is mine.

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I would install the clutch MC and its fork while you have the pedal box on the bench in front of you. Much easier than when it's back in the car. This concludes the hardest part of the conversion. From here everything goes fast.

 

Sorry guys, got distracted....will finish this thread in the next few days. Tarek, good to meet you over the weekend!

 

Nothing needed here, can be unplugged and left in situ, or you can remove the F1 harness.

The ECU does know the TCU is gone, and it generates a CEL. ECU Doctors in Florida can remove this, but I am looking at a local option of just flashing a manual program onto the F1 ECU.

You can replace the dual gauge in between the tach and speedo with the manual part, but that part is unobtanium. Cannot find one new or used. If anyone has one, please hook a brother up. When you do the conversion, the digital display simply shows "--" so it's not the worst thing in the world.

All you do here is jumper a relay in the passenger's footwell.

Yup, correct. Will have more on all this when I get a chance to write it up...

 

Ah, I see what you're getting at. This is as easy as it gets -- the wiring from the manual reverse switch plugs directly into a plug off the main wiring harness. No cutting or splicing. Literally plug and play. The only wiring work you have to do for the conversion is plugging in the reverse lights and installing a jumper on a relay. No cutting of any factory wires needed.

 

Agreed on the coupler. There are actually two problems with the factory manual part that goes there, the ID is too large for the selector shaft of the trans, and it's too short. The only real difference between manual and F1 gearboxes is the OD of the selector shaft, and its length. It's longer on the manual and so the coupler is shorter than what's needed on the conversion. The guy who says he made a new coupler has gone dark on me and Ken but I have a better idea for this since his part doesn't look long enough to me. More to come.

 

Here's what I did...


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I like that! Isn't this $5 one the same thing?

https://parts.autobarnvwcountryside.com/p/Volkswagen_2014_CC/Accessory-Power-Relay-BRIDGE/48258489/3C0971249.html