Arse Freezes 2021 - Early Prep ()

We have made it!  Trailer is packed and the RV needs the final cooler tomorrow before we lunch.

Project work took until this morning to get done. Here is a list of the various items completed today:

• Finish the front end project
• Paint
• Freshen up the Car  numbers
• Install the rear diffuser
• Finish the fuel pump connections
• Weigh and cross balance the car
• Alignment
• Pack and load was also to complete.

One fun item was the weigh balance. Unload the car weighs 2863. We have about 10 gallons in the tank, so +- 2800 empty. This is in line with previous unload weight in the 2,800 range. Here is the final balance result:

Arse Freezes 2021 - Early Prep (Brake Upgrades)

To start, I do like the performance of the current brakes on the Z.  We are running the StopTech Sport Slotted Cryo Rotors and Hawk Performance DC-60 brake pads.  However, since this is an arms race, improvements are always the goal.  With that in mind, there are two items that I would like to improve the brakes.

The first upgrade is to get an increase in brake pad longevity.  Currently, when we run the car for the 7-8 hr we are going through about 60% of the Hawk DC-60 front brakes.  This means we replace pads after every major stint.  Looking around, I have been able to find and believe we can upgrade to a mixed version of 350z rotors and caliper setup "with a little bit of help with an A-daptor kit".  The router and pads are the same material, so this should increase pad and rotor size by ~15% and keep the desired performance.  Even as the car evolution continues, and we get faster, this increase in brake size should see brake wear get below the 45% per stint and allows for one set of brakes per weekend.

The front brake change will exacerbate the second issue.  The brakes are too sensitive and lacks the preferred fidelity.  The cause of this we believe is the bore size of the master cylinder.  We have examined the unit, and it is stated to be a 17/16", Torch measured it and the bore size is really only an 1".  This has proven to be a consistent problem as I have sourced Master other OEM cylinder from three other manufactures and all were found to be 1".  Thus, upgrading to the 350z brakes, we will then really have a hot mess.

Normally the solution is to increase bore size.  Since we are have such trouble with this, I am thinking of going to a Wilwood Master Cylinder setup.  They have 17/16" and 9/8" bore size options.  Now the question is just changing bore size be enough?

To answer that question, we need to look into braking pressure.  I don't know the peddle's ratio, so this will be all a guess from a 7:1 @ 100 lbs peddle pressure chart I found (shown below).  From this, my guess is that we want to drop 200-300 psi to give us some better feel.  Then, moving forward with the proposed 350z break system, if I assume a linear increase of brake size to pressure, a 15% increase in brake size could result in a relative increase brake pressure of 250-300psi.  Looking at those combined number, we are looking at a 450-600 psi brake pressure drop.  Bore size change is not going to cover that, so our attention turns to the brake boosters.

Looking at the brake booster, the 300z and the 350z diaphragms are similar in size, so no help.  This had me look, at the Nissan's 240SX single 9.55" booster.  The booster did have the same mount points as the Z, except the studs were about an 1" short.  No trouble. With some welding by Torch, we had some stud extension, and it fit right in.  So now, I estimate that we get a brake pressure reduction of about -225 psi.  This might be enough reduction to give us better brake sensitivity in our current setup.  We will find out in about 4 weeks.

Then, when we move to the 350Z brake system, I would propose changing the master cylinder from the current 1" to the Wilwood 9/8" bore.  The referenced chart indicate that we would get a brake pressure change of ~ -320 psi, and with hope matches the 350z brake increase.

How could any of this cause a problem? 

Arse Freezes 2021 - Early Prep (continues)

Work on the Z has continued, with some headway being made. We still have most of the major work still to finished before getting into the punchlist.  I am think in the next two weekends we should be able to complete these changes. Here is a review of the three major projects:

Front Bumper rework

The one area I have plugging away at for most of the fall is the front bumper area. It has been an ambitious project, and we will see if it is worth the endeavor. The general framing, ducts, and vents have been completed. Here is the front leftside view:

For a closer look of the vent system we have the side curtain vent (top), Brake duct (middle), and splitter diffuser (bottom):

I now need to add the crash absorbing elements, aluminum sheet flashing, and paint.

Brakes

Torch came over on Sunday and did a lot of work on the brake system. Repiping from the cut line was the main focus. With some scrounging the shop, enough 3/16 tubing was found. We are now one compression coupling away from closing the system. Also, the new brake boost was test fitted and found to not quite fit. Some extensions on the four mounting studs should correct the trouble. We should see the fruits of this labor this weekend, and I'll post another blog just on this brake up grade plans.

Fuel System

We have had a devil of a time with the fuel system since the installation of the VQ35. My earlier plan of connecting the two lobs with a line between the drain plugs is now scrapped. Finding the right check valve has proven elusive. I have thus gone full circle and now revisiting the initial OEM design setup.  In that design, Nissan used a Venturi Pump to aid in the transfer of fuel from one lob to the other.  Here is the general Venturi pump design:

The OEM Venturi pump failed when we increase the fuel pressure to support the VQ35 motor. At that time I looked, but could not find an adequate pump replacement. So, that led us down several other paths. This time, when I looked, I did find a company that produces a Venturi pump with a wider pressure range. A second factor is the name of the company, Radium. Now, how can I go wrong with this?

The second item we are fighting is the dynamic nature of the car. The OEM tank cause a lot of slushing of the fuel at low fuel levels. So, to control fuel movement, we thought of several plans. The one we liked to try is this swirl pot that Lugnut found:

The trouble we ran into is that literally that the pictured swirl pot would be fitting a square pot into a smaller round port. So, the search was on and what we found was a waste product out of the Hal-Life Racing HQ kitchen.

With some rummaging around the pantry, and some negotiation with Z-Chef, a Hunt's can of Crushed Tomatoes was procured (negotiation was made easier as the sell by date had elapsed.)  After emptying the contents (which turn into my dinner tonight), removing the label, and optimizing the form, I think we are in business. After some tinkering, we test fitted our new system.

Thus, we have a plan. So, this coming weekend, Torch is planning to return with his bore scope to aid us in the installation of our new fuel system. With a lot of hope, let's see if we can get the car to start again this weekend.

Arse Freezes 2021 - Early Prep

Sorry for leaving you hanging. Blogging in racing is hard for me. I look forward to the next race, where I will see if Sparky can help with the race communication. As for the last April race, we get the cars going at Sonoma. We tried way too hard to ruin that.

We started Saturday well with both cars running through their first stints. Things got tougher after that. The Z got parked from contact damage to the right front, which resulted in some suspension bending. While the Z was still going through the repair process, the Miata in its maiden Lemons run, developed an oil leak from some teething issues. We caught that before it did real damage. It still put the car up on blocks for several hours. Here is that disturbing image, as rumblings and roaring were coming from over yonder on the green flagged track.

Both cars did get their repairs completed, and valuable race labs were run.

On Sunday the Miata did a Miata thing, it just kept running. Driver change and fuel adding was the cause of any stops. The Z ran afoul with more of the contact bug. Again we saw some fair amount of time off track. We also discovered a fuel problem. With the higher heat, we found at low fuel, the lift pumps overheat and blow the pump fuse. It is suspected to have caused the major incident (car crash). After refueling and replacing a fuse, we sent the car on its merry way. In the end, both cars did finish both days. Yeah Us!!!!

Now moving forward. We are schedule to race in the Lemons Arse-Freeze Apalooza on December 4 and 5th. To get ready for this, we do have a list of work to completed before we can get to the punch list. Here is the list of work that has started and will need to be completed in about a month for us to be ready:

Task		Status	Notes:
Driver’s Seat
	Change the Z ‘s floor pan, install seat sliders.	Done	Torch did all of that work.
Fuel System
	Restore fuel lines from Z’s seat installation.		Have compression fittings and piping.  Install required.
	Install new fuel pump in the tank.		Walbro in-tank high pressure pump acquired. Some assembly required.
	Connect lower fuel tanks to allow transfer of fuel from the lower lobs of the tank.		Have compression fittings and piping.  Need a check valve and Install required.
Brake System
	Change brake booster to provided better brake feel.		Brake booster ordered awaiting arrival and installation.
	Restore rear brake lines from Z seat installation.		Need compression fitting and Install required.
	Reinstall brake calipers
Rebuild Front Bumper
	Rebuild the front end of the Z.  Add vents, splitter, and bumper support.		Fabricate, weld, tape, and paint.

 

Sears Pointless 2021

Onto the next race. This coming weekend April 3-4, the 24-Hour Lemons - Sears Pointless Race is occurring at Sonoma Raceway. Work for this race has been ongoing since the last February race. Several work sessions have occurred to figure out the Z electrical troubles. Sparky has spent several days coming through the wires to figure out the trouble.

For the first weekend wires in the Z were traced, and sensor checked. Three wires were found exposed and had low power to at least one. So, like all good Sparky's, the volt present seem weird (stead 5 volts), so testing the line seem like a good idea. Yea, after that all ECU combination stopped. Whoops. It i now believed these wires ran the controls to the AC unit (no longer on the car), were covered by tape, and bundled away. After the many races the tape appears to been removed, and likely did a small short, doing enough damage to prevent the ECU allowing a starting, but still communicating.

Ok,

So, the search for the next ECU started. After a thorough search, it was determined the current VQ35 motor in the car is a 2006. So, like a good solider, I search and could find a new 2006 Manual Transmission (MT) ECU. Great, Sparky then arrived two weeks ago, and after another day of work, we got no further in starting the car. Harrumph!

After some head scratching, Sparky decided to take all the ECU back to his house, build a test bed and see if he could determine the trouble with the ECU and why it will not let the car start. 

On a parallel track, we did determine in the process of getting the car to run the first time we had used a 2003 MT ECU. So, I search E-Bay can could fine 1 2004 MT that is similar spec to that first generation ECU platform.  That ECU was schedule to arrived Monday the week of the race. Being so close to the Race, we turned to the D to get ready. Torch and I then jump on the D last weekend it is now for another run. So here we go.

On Wednesday, morning I finally received the new ECU. Well what could go wrong? I plug it into the Z and:

Ok, after a quick talk with Sparky, a change of plans. This evening we had the team over to prep and pack for the race. Sparky was kind enough to come over, clean up and rebundle the wires, terminate the loose ends, and away we go. After finishing the repair, we loaded the Z, and we are posed to hit the track tomorrow.

Here We Go!!!

Race prep Checklist for Arse Freeze Alapaloolza December 5-6

 Work to get the cars ready for the Arse-Freeze at Sonoma Raceway has been going on for some time. We are about 15 days out with work planned this weekend.  Below is the punch list of items to get us ready:

 

Electrical Systems			Status
		Items	300z		Type D	Comments
	1	Power disconnect switch				Test
	6	Racecapture /Traqmate
	7	Battery charged
	13	Cooling fan				Z- Fan to come on at 190°F+
Engine and Drivetrain
		Items	300z		Type D	Comments
	1	Engine compress test			Done	Z-  1-, 2- , 3- , 4- , 5-  , 6-    D1- 180,2- 190, 3- 180, 4- 190
	2	Spark plug			Done
	3	Replace oil filter				D - Install new filter housing
	4	Replace engine oil
	5	Check transmission oil			Done
	6	Check differential oil			Done	Z- Need differential from Dan
	15	Run engine to temperature
	18	Check Engine Mounts

 

 

Suspension and Brakes
		Items	300z		Type D	Comments
	1	Check strut and tighten
	2	Inspection ball joint
	3	Check wheel bearings
	4	Front and rear sway bar mount
	5	Check rear and front bushing
	6	Check rotors				Z – Replace front rotors
	7	Check brake pads
	8	Bleed brake lines
	9	Alignment
	10	Tires and rims				4 Dr-38 17x9x 114.3 +17 offset order for Z 8x Z and 4 x D Mount
	11	Check tire pressures				Z – 29 f 28 r D – 28 f/r
	12	Strut tower support
	13	Springs and Perch Inspection
Safety Systems
		Items	300z		Type D	Comments
	1	Check fire extinguisher			Done	New Install New
	2	Fire suppression system				Required Connector
	8	Check tow hitch				Make sure they are labeled
Chassis
		Items	300z		Type D	Comments
	1	Wipers			Done	Most likely not needed.
	2	Front skirt
	3	Rear diffuser
	4	Rear spoiler
	5	Door Latch Inspection
	6	Door Panel Repair
	7	Fender repair
	8	Front and rear bumpers