Brake Bleeding + Fuel System Calibration

Brakes
I started around 1pm and didn’t finish until 5pm so this process took around four hours but I wanted to make sure I got the bleed just right. Since the entire brake system was overhauled (except for the rear calipers) the bleeding process took much longer than normal. For the fluid I’m using Torque RT700. This stuff is awesome and has worked wonders on my pig of a street car that sees the occasional track duty. Previously the race car was running on Motul RBF600, which worked fine given the extensive ducting system, however, I figured I might as well run Torque, especially given the higher friction pad compound (more friction equals more heat). As for bleeding process, since the entire system was new/dry, I was able to use the fluid recirculation method by running clear tubing from each corner and back into the reservoir. Additionally, speed bleeders were added to each caliper, allowing me to do a single person flush. The bleeding process went perfectly. I was able to get the air out of the front calipers almost immediately whereas the rear took a little longer. Given the lines and master cylinder were new, it took a while to get the air out of the rear. Also one problem with using new lines and master cylinder (that isn’t bench bleed) is that the fluid will become highly aeriated with small microscopic bubbles. This issue also arises if you pump (or bleed) the brakes too quickly or recirculate the fluid in too fast in the reservoir. To fix the issue you need to do a slow bleed and allow for 15mins of rest between each cycle. You’ll notice the microscopic bubbles in the recirculation (clear) hose will form larger bubbles after resting for a while. Eventually and after a few more cycles the fluid will become very clear and without any air. It’s a little OCD but you’ll get a perfect bleed.
Also for the pads I’m running titanium shims in the front with new Pagid RS29 (race compound) in the front and used RS42 (mild street/race compound) in the rear. Since I was having issues with the rear locking even with the bias control, I chose to add more bias by adjusting the pad compounds (previously I ran R42 front and rear).

Splitter
The splitter was mounted to the new brackets and requires some final adjustments before being tightened down. Same goes with the lip. Also the brake duct hose also needs to be installed. I should have this stuff done later tonight.

Adding fluids
2.25 quarts of Torco RTF and a half bottle of Torco Type F additive was added to the transmission and 6.75 quarts of Mobil 1 5W-30 were added to the engine (and prefilled oil filter). Yes that’s right, 6.75 quarts! It’s simply amazing how much oil this setup takes. After what seemed like a lifetime of cranking the motor without fuel and spark, I finally was able to build oil pressure.
Sunday

Fuel System
While normally this step would be as easy as pouring fuel in the tank, the dual bladder system and custom fuel level sensor requires me to go through a series of steps to ensure everything is calibrated correctly. I started at 10am on Sunday and didn’t finish until around 4pm. About six hours non-stop. Even Mr. Conley (coolhandluke) stopped by to play the role of my laboratory assistant.
First off was removing the sensor from the lower bladder and verifying it was working correctly. Per ATL, normally you would add one gallon of gas to the fuel system, wait sixty seconds and log the reading. You’d do it and over and over until the system is full and until you get a reading for every increment. While that seems easy enough, my system holds 100l or 26 gallons of fuel! So…. um… yeah… hmm. Since I run 100 octane (which costs $8.99/gal at the local pump ten miles away), I’d end up spending close to $240 on gas and would need to make several trips since I only have enough containers for around twelve gallons. Anyhow, a little common sense and ingenuity tells me that using a gallon container would more or less get the same results if I was able to move the sensor up and down at various levels. Also I would need to use gas in the gallon container as the level sensor is a capacitance style, meaning it requires the fluid to be non-conductive and of the same dielectic value (varies on fuel type). After what seems like hours (Ryan can attest to this), we finally got a system going that allowed us to get around 13 different reads at various level points. I took the data and created a custom sensor and math channel in the AiM software and using the Iron Canyon Fuel Sensor convertor (converts ohms to volt for the AiM display). Once that was done, I installed the sensor back into the bladder and added around 11 gallons of fuel, or enough to register about 3/8ths full. lol

Starting the engine
After adding distilled water and hint of Honda coolant, pressurized the fuel system and set the base fuel pressure, I fired up the motor. Everything ran perfectly. No leaks, no issues, no surprises. The motor warmed up normally, purged air out to the system (using a coolant bleeding container) and activated the fan at 190deg. I did a hot shut down to let everything cool off under ambient air and to ensure no leaks would happen overnight. All in all it was a very successful day and I can finally say it’s no longer a car sized paperweight (like my other race car).

(I sort of failed at taking pictures this weekend but I think Ryan may have snapped some)

Fuel System (level sensor) update:
I got a little too ambitious with what I thought I could finish yesterday, however, I did spend a considerable amount of time recalibrating the fuel level sensor and speaking with Mark at Iron Canyon Motorsports (great guy to bounce ideas off of). Previously the ATL sensor wouldn’t read anything below a quarter tank (would show as empty), however, it turns out ATL likely had it calibrated for this particular fuel system. Since the entire system is 100l (26 gallon) and is intended for endurance use, anything below a quarter, roughly less than six gallons is considered empty or requiring a refill. Also because the fuel level sensor can only measure the lower cell, it’s compensating by reflecting a quarter tank as being empty, a half tank as being a quarter, and a full tank being three quarters full. Since I’m likely going to keep a half tank of fuel in the lower cell (less than 15 gallons), I needed more resolution from the sensor. After a little bit of ingenuity with a rare earth magnet and the sensor, I was able to recalibrate the empty and fuel readings to get it spot on. Now an empty tank is truly an empty tank. A quarter is a quarter, half is a half and so on. If the lower bladder is full, the sensor will read full and if I fill the top bladder it just will continue to read full until the upper is empty. Also, since I’m not accustomed to reading the fuel level in the form # of gallons remaining, I rescaled the chart to a range of 0-100, more or less simulating % of full (like OE). Also I’ll configure a warning alarm in the display to alert me when get close to a defined %, and a hard warn if I drop below it. Here’s the revised chart:

New surprise item
Here’s a teaser for what arrived yesterday. I’ll likely install it once everything else is finished. Look for another update in a week or so.

Next up
– (Tonight) Double check all fasteners that aren’t marked
– (Tonight) Disconnect the rear anti-roll bar until alignment is done (to avoid misalignment and preloading)
– (Tonight) Reinstall front splitter, secure front bumper lip and reattach new brake duct hoses
– (Tonight) Reapply caliper temp strips (stupid brake fluid removed the old ones)
– (Tonight) Possibly install a new surprise item (more to come)
– (Tuesday) Install wheels, take car off jack stands and ensure suspension is functioning correctly
– (Tuesday) Level and test air jack system
– (Tuesday) Secure fuel cell lid
– (Wednesday) Test drive car, park and verify no leaks/issues
– (Wednesday, Thursday and Friday) Clean car and refinish paint before applying decals
– (Next weekend, maybe) Align suspension and corner weight
– (Two or three weeks) Dyno engine and run final checks

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