Booster delete kit

Last year with my recent interests watching the GT3/4 & TCR racing I decided to research the cars a bit more around specific components they use. I've always known of manual brake pedal boxes for racing, but was surprised when this level of motorsport all use it. I had also listened to a HP Academy podcast with an Alcon brakes engineer at the time and learnt various factors as to why you'd want to not use a booster. As well as all this, Honed provided their data around benefits of manual brakes, in relation to their booster delete kit they sell.

Honed provide reason as to why people in the past have had bad reviews of other booster delete kits, and this is usually either because they don't relocate the clevis hole on the pedal for the push rod to achieve the correct pedal ratio, and/or they don't change the master cylinder to suit the brake application size.

I decided it'll be best to give it a try for the Civic, liking the benefit of the pedal being modular. I went ahead and ordered the kit as apart of the 2nd order with them to purchase everything else I was missing. I also purchased a used EK 13/16" master cylinder through them, a service they offer as it'll save me going to wrecking yards trying to find one.

Comparison

** Disclaimer for the comparison, I didn't think to include the delete plate studs or push rod for the manual setup, as well as the booster vacuum hose **

Let's compare the booster setup and the new manual setup core components. The booster w/pushrod itself is 3.65kg, the Honed booster delete plate is 0.27kg itself, as mentioned above I forgot to add everything else, BUT looking at their weight comparison's they did with everything, it's around a 2kg weight difference overall!

Booster ~ 3.65kg

Booster delete ~ 0.27kg. Plus the 6 studs & pushrod

With the studs inserted afterwards.. muppet.

Master Cylinder comparison ~ The bigger looking one is DA9 7/8, and the smaller (new one) is an EK 13/16.

DA9 is 0.82kg, EK is 0.69kg, so only a slight weight reduction of 0.13kg. Atleast the EK one looks more refined and not as bulky.

Modifications need to be carried out on the pedal box to fit the mnaual brakes. Firstly you need to remove the brake pedal, the returning spring can be removed as the force from the master cylinder will return the pedal to the correct location. You then use the provided template & bolt from the kit and bolt it into the original push rod clevis hole, and align the side of the template with the edge of the pedal. This will locate the new hole 25mm above the original and inwards a bit, as shown below. Drill your pilot hole, followed by the required 8mm hole. Now assemble the provided push rod with the original clevis onto the pedal first, then bolt the pedal back to the pedal box assembly.

As I had the pedal box out of the car, I decided to run some stitch welds around it. I haven't heard of the hatch/sedan ones breaking, but I have seen the wagon ones snap. As we're here, might as well.. I didn't take any photos, but once welded I sprayed the assembly black and reinstalled.

The booster vacuum hose is no longer needed with the manual brakes, Honed provide a blanking cap for the port on the manifold. I relocated it to face downwards for a cleaner look.

Before

After

Bleeding issue

Speaking from in the future.. When trying to bleed the system the pedal seemed to be getting caught when releasing the pedal, maybe at the last 20% before fully extended. It was really rough and loud, you'd have to pull it back by hand. I remember when receiving the master cylinder there was some rust around the end of the cylinder. At the time I thought nothing of it as I had seen it on some before.

I removed the master cylinder from the car, removed the circlip and pulled out the valves. You can see the rust had gone into the bore a bit at the start, and further down where the fluid enters in the middle from above there was a tiny bit there.

I cleaned out the rust as gently as I could using various small tools, making sure to only touch the rust surfaces as I didn't want to scratch the bore. I managed to get it all out luckily. Flushed some standard fluid through the master cylinder to get out any crap that might have fallen in.

The end of the valve thats exposed to the outside also had some rust around it, and annoyingly had the slightest bit of pitting. Not much I could do here except the same process, also making use of some scotch brite.

Reassembled the master cylinder, bench bled and reinstalled. It felt much better now, finished bleeding the system. I can't wait to test this!

Hydro clutch conversion

Old setup - Cable to hydro converter

The DA9 Integra which supplied the B18C motorswap came with a Hybrid Racing cable to hydro converter (pictured below) which allows you to still run the original cable, which has worked perfectly fine since the swap. I was told at the start they are prone to stretching the cable, however it only ever stretched 1 cable which was about 2yrs ago.

It's definitely a lot more mess in the engine bay, but for something you can bolt onto the hydro gearbox, it's an awesome bit of kit. My tuner made a small bracket to bolt the master cylinders slave off of the strut tower when he was tuning the car.

New setup - EF/ED Hydro conversion kit

Since doing the motorswap, EF/ED Conversions located in Australia designed a proper hydro conversion kit for the ED/EF chassis. There has been a few kits before/diy guides, but they were never good. This is a complete kit, which has you cut off the old clutch pedal from the pedal box to use their own pedal system. A CNC'd plate for either side of the firewall to mount the master cylinder correctly in the engine bay. I sourced the master cylinder and braided line myself. Great bit of kit this is!

Whilst I had the pedal box removed for the booster delete stuff, I tended to cutting off the original pedal and it's brackets.

Now, something I didn't realise was I had to drill 3 holes through the firewall to mount the master cylinder through the engine bay into the cabin for the pedal, until after I had resprayed the engine bay and reinstalled the engine.. sigh.

Anyways heres the bracket for the engine bay side, it's a bit annoying to line up correctly with the groves on the firewall. Got it into the best looking position and marked the firewall with a center template provided for the middle hole. Once the middle hole for the push rod was drilled, we marked and drilled the 2 smaller holes for the master cylinder studs.

The EF9 being useful for a quick drill bit sharpening.

Nicely painted fire wall.. Atleast it's done now. I applied some black paint via brush on the cut edge for the 3 holes to prevent rust.

The only thing I didn't like about the kit was the CNC'd piece for inside the car sat over the fuel return & vent hardline holes, which meant 1 was squished up against the side, and the other didn't even fit. It looks like some people just run the lines bent to the side, even then you can't run the grommets.

I decided we'd take the die grinder to it to make a small window to all the bottom hardline to still go through the fire wall. I then cut half the inside of the grommets so they'd still sit flush against the firewall. This means they won't seal 100%, but it's better than nothing, and prevents the hardlines from rubbing on the edge of the firewall. You'll see this in the last photo below.

Finished product for both!

Very happy with the outcome of both the brake booster delete and hydro conversion. Makes the engine bay look a lot neater, with the inherited performance and maintenance benefits.

Hardlines fitted and bent to reach the new master cylinder, the ports were in different locations. The back one was fine, but you can see the front top one only just fit.. I plan to add a brake pressure sensor in the future, which I'll look to remake the lines then.