So that’s your problem

We’ll, everything worked fine on Muddy’s run. So I took a turn at the wheel. 

The car seemed to be stalling on hard right turns like we were running out of gas.  As the problem was getting worse each lap, I brought the car in the check. 

We thought we had 10 gallons in the car and might have burned 3-4. With a 16 gallon tank, we should definitely be able to add 5 gallons, maybe a little more. 

We threw 5 gallons in the car and seemed to have plenty of room for more.  So we started on the second 5 gallon jug. Amazingly all 5 gallons went in. So we though maybe it has less gas than we think and started on the 3rd five gallon jug. All of it went into the tank. 

After a bit of head scratching, Torch looked under the car and saw a puddle…

So we pulled the access panel and realized the fuel tank was not closed up after the last of the fuel pump work. We were probably losing some on the track on hard turns as well as the rest just overflowed the tank when we were filling. At least the problem was obvious and happy to have it happen on Friday instead of Saturday. 

Practice laps

All done with tech and time to run some practice laps. 

Given the rebuilt front end and other changes, Muddy will take it out, get it warmed up and will come back and report. 

Setting up pits

A cold and foggy morning greeted us for the drive the morning. We weren’t in a particular hurry as the tech time is scheduled for 12:30. 

Both cars have arrived and we are at the end of the grandstands. Now setting up the compound for the weekend and doing final prep on the cars. 

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.

 

Tech and BS Inspection

 Off to tech and BS Inspection.  Life is good.

Earlier too tech, and all is well.  Jay and John are looking looking over the cars and are happy with the car safety items.

Trouble. BS, judge does not like the Turbo on the Miata. -15 Laps. Because we are a team both cars are listed as A with -15 laps.

Then there was a second trouble. The Timing Control Inspector was really unhappy about the Z number 137. To confess, I did change the number in the database. I had little hope of the Z to make the tack, so I changed the registration to the D. Thus they had the car number as 227 and thus failed the car.

My bad. I forgot about that. After some brake cleaner on the number, hand developed stencil, some black spray paint, and we were able to change the badging. So this weekend we will run as 227.

All is well.  Off to practice.

Landing at the Track

Good Morning all!

We left for the track close the 9:30 projected times.  With clear traffic we arrived at the track with plenty of time to setup.

For this race they have everyone more spread out then normal.  So we found a nice spot at the end of the line and grand stands.

Two cars ready to go!

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!!!

Revenge of the Underdogs - Day 2

Day two started off really well for me. My normal trip to the gas station to fill fuel cans (for the Z car ~60 gallons ) was not needed. So, we head straight to the track. When we got to the paddock little was needed, and we quickly rolled into my track favor breakfast, the Egg Croissant sandwich. Yeah baby!!!

After the quick drivers' meeting I suited and hit the rack again. Again like the previous day the 10 duked it out going into turn one. This time 54 cars and 6 of my Super Dog racing pals went storming into the morning. Again all went well. I found a little more time. This extra speed had me passing a little bit more often than the day before, and I finished my stint with no troubles. Z-mom and Z-dad again jumped in, and we had no troubles getting Lugnut back on the track within the 10 minute allot time.

Lugnut, put in a good stint, with no major troubles. He can in and again with the team jumping in, I was on track within the 10 minutes, accumulating more laps. By this time the car had changes some, the tires were most definitely not at their best. They were still round, but the shoulders had noticeable been removed, so there was little to lean on when we pitch it into the corner. However, we still ran at 2:08-2:06 pace.

I finished my stint, got to the paddock, the team jumped on the car, and we turned the car around within the 10 minutes. Just as the Lugnut left the pit he let me know that we were in 1st place, and we had 30 laps on the next place car. Wow! Ok, Lugnut stint must have been tuff. The tires were done, but drive he did. So, when the checked flag flew at the end of the day, the D was right there.

So, for Day 2 of the Revenge of the Underdogs, I give you the 1st Place in the Super Dog class!

The little D that did.  (Note; by the end of the race only 4 Supper Dog cars were running.)  No matter we got two checkers with not major trouble and in the end there was a lot of smiles on everyone faces.

Success!

Revenge of the Underdogs - Day 1

 Lugnut and I had an easy morning.  The car was placed in Torch and Queen's garage stall, so the rain that morning was not a problem for us.  We enjoyed our Breakfast Burritos, attend the Drivers meeting, and hit the track on time.  

The 10 cars from qualifying was gridded and then the rest staged behind. For Lucky dog they have a rolling start side by side, so charging up into turn 1 can be dicey. We were a bit too far back to make it any additional challenge into turn one, so our start with 87 other cars went well.

This continued for the rest of the stint. Only occasionally was I able to coax the D around other cars. The pit stop went smoothly with the help of Z-mom and Z-dad. The team was able to turn the car around in the allotted 10 minutes, and away we went.

This theme repeated itself all afternoon. The Car keep running, we keep coaxing, and laps were accumulated. In the end of the Day, we landed 2nd in Super Dog. Not that anyone counts this class. We finished the day with a quick checks, oil change, and rubbing marks covering. Within 30 minutes the Stack and Lobbers it the grill and again ended the day with smiles.

Practice and Qualifying

Following the successful enough tech inspection we quickly turn the car around and got it on track. As expected the D performed D like and scooted around the track. It was quite clear that the other cars were not $500 car, but just cars that were 15 years or older.

The time we put down in the D was good enough for the first qualifying. Lugnut took the 15 minutes and put a time of 2:05. If we had all the correct equipment, that would have put us in the lower reaches of the B class. However, since we were not running the series spec tires we were placed in the Super Dog class. For that class we were the slowed of the ruffle 10 cars in that class.

No worries. He had a car that ran. We had little work to prep the car for the next day. So, there were smiles as we enjoyed our Bratwurst and beer.

Arrival at Track and Tech Inspection

We arrived at the track by at 9:30. The first practices was occurring, and we looked longingly at the track. However, we had work to do. Lemon's rules and Lucky Dog rules are similar, but there are subtle differences. The D has been running since 2011, and has evolved as the rules evolved. So, there is a bit of patch work nature to the car. More was now needed.

The most obvious problem was the lack of seat. The seat was pulled two weeks ago for a bolster fitting. We need to wait for Queen and Torch to pick up the seat from Lugnut house and get it on track. The next problem was we did not have a window net. So, a quick trip to the pro shop, we acquired the hardware, and proceeded to install the net.

We did many more changes, however, was left with one that would take us all day if ask. A dash bar to the roll cage. The car does have a stock bar, but to the rules are the rules.  So, once we got of the changes, stickers, and seat in time to tech.

In tech, I had to talk to the race manager, and plead for the change in cars. Then when she took one look at the D she just laughed. "There has to be a good story for this". I was not sure if she was talking about the car change, the theme of the car, or the shabby nature of the whole thing.  When I looked, I think I understood.  The last the D ran was in 2019, and it had an adventure through the fields, and is was still covered in mud (not me for once). With her grace we proceed to talk with the head Tech Inspector.

That started out well, until he looked at the inside of the car with his first words " I am not thrilled". Oh, I knew I had some work on my hands at this point. With a lot of yeses, we are two, this is the car's last race, and this is not what was planned. In the end he did pass us. However, I was not give a new inspection book like new to them cars get, and a curious note on the tech sheet of one time acceptance.

Ok, we can live with that, and it is now time to hit the track.

Well that did not go as planned

Lugnut and I work through the day to get and load the trailer and RV. By about 3:30 we looked round and said "ok lets load the Z". Well, the car would not start. Well... Ok, we then start the checks to figure the problem. We first started with the classic checks, Fuel, Air, and Spark. Well no spark. Also, after a few cranks it was noticed no fuel either.

Ok... historically we have seen this trouble with position sensors. There are two upper cam sensors and one lower crank. The crank, is in an exposed spot, so that was the first one we worked on. No joy. On to the uppers. No Joy. By this time we were getting past my 5:30 planned launch time.

Time to implement plan B. Sparky!!!! What are your thoughts? After another hour, we exhausted what we could do on the phone.

So, Plan C, a visit from Sparky. Looking at the clock if we did not leave by 7:30, we would not make tech. After another hour of Sparky going through many of the system, we still did not have an operating car. As another hour went by, it was clear that we were not leaving that evening. Lugnut and I then took a break for dinner. When we came back, we still did not have a starting car.

Plan D??? Press the D into service. Lugnut and I turned to the D and did the prep need to get the D going. By 11:00pm, we called it quits and plan to leave at 8:00 for the track. In the morning we promptly load the D and headed to the track.

Next Race... Revenge of the Underdogs, February 12-14

Well the December race was a bit of a bust. 24-hour Hours Lemons was forced to cancel the race for the Holiday Covid closures. 

However, two months later, and we are at it again. It still looks like a go for the race hoisted by Lucky Dog Endurance Racing at Sonoma. To get ready we only really need to dusted off the Z, refreshed the safety equipment, and apply a coat of paint (I suck at painting so Picasso you will have a bit of work to recover from my mess).  And with that, I think we are ready.

For this race, there are still a lot of Covid restrictions, so this will be a light affair for the team. Only Lugnut and myself will be piloting the Z. On Friday we will have an extended practice in two sessions, followed by a qualifying session. First qualifying, of the lower half paced cars will be from 3:00-3:45. Second qualifying, will be from 4:00-4:45. The Z should be quick enough to be in the top half, but one never knows until we hit the track.

Then for the race the schedule will be:

Saturday 9:00-5:00

Sunday   9:00-4:00

Now, we will try to run the video for most of this. Sparky will not be there, so it is up to me to see if I can make it work (no guarantees I can get it to run or keep it running). We did perform an upgrade that might help. Sparky added an axillary battery to the system that will keep parts running and connect while we are pitted and refueling. This will mean we only need to launch the system in the morning, and it should run all day. I am meeting with Sparky tomorrow to review how to operate it. I will post the url address in a later post, so you can gain access to the video.

We also have two other upgrades in the rear differential that will get their shake down cruise. 

The first part is the rear differential has been replaced as a result of the catastrophic failure at Laguna Seca last January 2020. This new differential is thought to give a little better speed out of the corners. Two place it should show up, is turn 2 exit and 7B through turn 8A. Out of turn 2, it should give a better feel when you get on top of the hill and the road goes off camber all the way through the exit. For turn 7B the old setup required a lot of finesse on the exit and all the way through 3rd gear. The new setup should get you through with more pedal and thus more speed. In addition to the differential core change, the ring and pinion was exchanged for a Q45 setup. 

This give us a little high gear ratio and should allow us to use more of the gears (i.e 2nd might be an option and look at those nice teeth.  The last ring in there had those as optional). 

So, 5 days to go.