Building a track car

[j0000stin]

Sweet! Tysm that’s the exact angle i was looking for.

[Cobra1956]

Originally Posted by Cobra1956

Day did not go as planned. Missed connection with the tuner as he was traveling to Colorado. Wish he would have explained his schedule better as I would have gone to the car a day earlier but we will get it next time.
Finished the day up with this. Noise changes with speed but no vibration. Will have the shop at track look into it while I source some bits to send down.

Jacked up, in gear

Reporting back on this. It was caused by the driveshaft support brace being left loose. It was loosened at the shop to move the drive shaft a bit during the diff swap. I had yet to be that far under the car but when they went to find that noise they also found I have an aluminum "flex" disc and everything under there looked good except for the missing bolts. Work done by two different shops. Valvetronic done!

Now I need to open my old diff. I put it in the truck to bring home from the track and noticed that both axels turned in the same direction when I moved the prop shaft. A quick turn of the shaft reviled the ratio is as promised but if I understand my options this diff was either welded or converted to an lsd.
Will be opening up tomorrow. Here is what we got today:https://youtube.com/shorts/o4iwDQMptZY?

[Cobra1956]

Car is back home. I do not track again until April 7-8. Still waiting to tune the transmission and hopefully get that box checked off soon. I started two projects today that I thought might go together. Floorboard installation and the two manual gauges. Removed the carpet and the insulation on the driver side. Will need to get what's left under the dash/counsel but that is for a later date. Needed to figure out what a few things were under the dash and one said ABS so that threw me for a second. A search says its part of the bluetooth antenna so no worries. Found at least three spots to run wires through the firewall. The best choice appears to be the hole left for the hose to the clutch master. To figure out where it is on the outside I pushed a long zip tie from inside out and it came up right behind the vacuum booster.Weight reduction.

Plugs on firewall. Behind gas pedal assuming for non drive by wire.

Left side of the box

Gromet where the engine wiring harness goes through the firewall and just to the right the hole for the clutch hose. You can see daylight coming through. This picture is upside down showing my camera skills still suck!

Zip tie on the engine bay side showing the hole location behind the booster.

Hopefully what the footwell looks like by tomorrow.

[Cobra1956]

Gauge install almost done just have to secure lines and screw in dash. Had to use hole behind the pedal or the coolant temp [robe would not get to the bung.
This took longer than I thought as I forgot about clearing the air intake. Pressure gauge does pick up the pre oiling so that is nice.


First start with pre oil.

Both gauges working. You can see in the first video that
the temp was not reading yet. I did test it before installing with the obligatory boiling water test.


https://www.youtube.com/shorts/jnKbH7cV7SM

[Cobra1956]

Battery day. Out with the old in with the not so old.


You still have a post on the positive side and the safety fuses on both ends however I doubt they work as the airbag module has been removed. Another option is a small buss bar but current should not be an issue. The plugs will be converted to eyes to fit the post.




Will weigh tomorrow but think about 40 pounds gone

[Cobra1956]

Got the weights today. Anti gravity battery weighed in at 3.6 pounds versus the oem battery at 58.2 pounds. I made a different lead for one of the small current b+ cables. I thought about just tying it into the posts on the chassis and may do that if this is the go to and it does not create any issues. I did disconnect the positive lead on the negative cable that fires the fused link in the event of an accident.
Battery is pretty small at basically the top footprint of a 3x5 card. I was able to fire the engine but it cranked like I had a dead battery but did finally start in my third attempt. My initial guess is that the negative terminal either need to be cleaned or I need to entertain some terminal shims as the posts do seem to be a touch smaller than a normal battery. Measured them with a micrometer and they are very similar but it appears that the small battery post is tapered just a bit more at the top. I will clean up the contact points and see if that improves the cranking.
Blue plug is the positive lead for negative cable fuse. Not much room on top and need to be careful not to short out stuff when tightening the 10mm bolt. Notice the negative lead lug with bolt fully tightened.


With the engine running I did a quick voltage check to see what I was getting. Everywhere I check was within a hundredth or so. Will clean the terminals and try again tomorrow.

[Cobra1956]

Short update on little things that needed addressing before I get to the track next week. Finally got the DCT tuned and curious to see what changes that makes. Had to add a bit of weight as my old lithium battery struggles to start the car now event when warm so I got a new one and went a size larger to the 24 cell . A little bonus is the posts are about 1.5 inches further apart so that will help when securing the cables.


I do not plan to run a fan, subject to change but I put the shroud back in because the heat exchanger for the DCT screws into it. I am considering repurposing the oil oil cooler and mounting it where the ac condenser currently resides. Useless information is the fan weighs 8.6 pounds. If you need one you can have it as any replacement will be relatively small for paddock use only. These bolt to the shroud with 3 8mm bolts.



Installed the driver floor board for real. Used rivets on the dead pedal and used 2 rivnuts on the floor to allow quick removal if necessary.


Removed the amp from the left rear corner of the trunk. 3 8mm bolts. 4.6 pounds.

Identified some auto clearancing going on. Will monitor and decide if a little trim is needed or if it takes care of itself.


All work was certified by the neighbors cat.


Hope to remember how to hold my phone when shooting pictures before I die...

[Cobra1956]

Battery day. Last thing I wanted to get done before next event. As always, my brain locks up on simple things and I could not figure out how I wanted to mount it Think simple and cheap. Found a real nice battery box but did not want to wait and thought I can get this done easier. Last battery was mounted in the stock location but I cut up an old delrin cutting board , secured it to where the battery would be after cutting out an outline of the battery's footprint. So I opted for similar. Plywood left over from splitter work. Traced the oem battery to cut a piece to start with. Then bolted it into place and hooked up the battery to see if this one will start the car. No issues! Traced the footprint of the new battery.


Remove the wood, drilled holes in the inside corners of the outline as I want this to be a tight fit. Cut with saw and test fitted until the battery would fit tight but flush.


Drilled two holes and cut a slot for the strap so the load would be similar on both sides of the battery. Use a remnant from an old ratchet strap with a plastic clip and bolted it in place. You can see from the slightly larger size of this battery there is plenty of room for both terminals. Will consider still using the oem metal bracket on top with a spacer if needed but from my last car this setup performed well for many years.

[j0000stin]

How’s the build coming along? Looks like you’ve been making some good progress.

[Cobra1956]

Originally Posted by j0000stin

How’s the build coming along? Looks like you’ve been making some good progress.

Ran the car last Monday through Thursday. Having an overheating issue that needs to be dealt with. WIll be replacing the pump and thermostat as a precaution as I am sure they ar original. Mechanical gauge ran hot on monday and cold the rest of the days. Could be cheap gauge but I did get a high temp warning on track on Thursday. Also thing venting the hood will help as the floor panels limit air flow. Think of the engine bay like blowing a fan into a box. You need to exhaust the air to get flow. Top hose is hot but this plumbing is counter to anything I have had in the past. DCT tune helped quite a bit with shifting. Making steady progress.

[j0000stin]

Yeah, i heard cooling is a major issue with the n54’s. Have you considered using bimmerlink to get an accurate reading?

[Cobra1956]

Originally Posted by j0000stin

Yeah, i heard cooling is a major issue with the n54’s. Have you considered using bimmerlink to get an accurate reading?

I have N55. Things I know:
I can plug in my scanner and get the temp but only assume its accurate unless checked against something else. I tested the gauge prior to install and it seemed accurate enough to provide data. Even if the reading is not correct if it is consistent you do get data. Gauge read high on Monday but that was the first time using it in the track. Tuesday morning it read a bit in the warm up but I was more focused on getting oil temp due to the dual coolers and thought that the gauge might be low because of the cooler morning temps. No real issues Tuesday and Wednesday. Thursday was actually the first time I pushed the car hard. Got the yellow warning on the dash and after a bit of off and on it went to red so i backed out of it and turned the heater on full blast as there is no fan. Lack of fan should not have been an issue as it was sub 70 degrees but the air flow design sucks with the floor pans in place as there really no way to exhaust the heat. I wondered if the harder driving also cause more heat in the DCT which would then be transferred into the cooling system adding to the problem. My plan was to pull the gauge sending unit located in the top rad hose but the gauge is probably not working as the dash warning indicates higher temps. Can confirm that by plugging in any type of scanner to the ob port as you can get coolant temps there, was using it to test when fans would kick on which is pretty high as it has to be after the thermostat opens most likely. Looked up some info on the thermostat and the electric part is designed to open it earlier so you could open the housing and just go to a restrictor since track car is always going to be generating high heat. Not a big deal to just swap out the pump and the thermostat as they are most likely original to the car. Just looking at other possibilities to cover while I am in there. Hood vent was on the list and could be even more important due to design and air flow. At speed of any sort there is or should be very little use for a fan but I do not know if all the electrical crap is tied together and does something with the pump speed.

[j0000stin]

Hmm is it a possibility to run no thermostat at all or would that throw codes?

[Cobra1956]

Originally Posted by j0000stin

Hmm is it a possibility to run no thermostat at all or would that throw codes?

On the old car most of that stuff got turned off. From what I have found the thermostat electronics are to open it earlier, as in cooler than normal. On the track we should have an abundance of heat to get rid of as in thermostat being open longer or to control a flow that allows the best heat transfer. The pump speed is the issue I am curious about as the speed changes based on the temps, or at least that is how I am understanding it. Need to transfer heat to the coolant and then from the coolant to the air. My simple brain says that the faster you move things, at some point it is similar running your finger through a flame without getting burnt, (don't do this) but you lack the ability to transfer heat. The size of the radiator and the flow should be involved with some kind of math that allows this all to take place. My issue could be simply that the thermostat has failed, or the pump, or both. There is some sort of warning on the pump but I might have missed that when I read the codes and since the fans turn on at such a high temp it is likely that you would only see them on when heat soak takes over coming off the track. I do get a fan warning so it does look for that. You could negate the code by closing the circuit. What I don't know is how the systems play with each other. My assumption is that if you do a bleed procedure you can see the pump moving water but you do not know if the flow is sufficient to do the job of cooling. I will have a better idea in a few days. I should have pulled the codes but I was just too tired after 4 days and the codes will most likely be gone due to disconnecting the battery.

[Cobra1956]

If you watch the second video and the map of the thermostat is accurate and the basis for it correct, in a track car most of what they have built for you is bullshit (technical term) as you can see under load, regardless of speed, they want the thermostat open much lower than the oem range. So you are now running the car depending on whether or not the electric portion works, which makes me uncomfortable. going to be some more sketchy work being done by me in the future.......

[j0000stin]

What alignment specs do you recommend for CMP?

[Cobra1956]

Originally Posted by j0000stin

What alignment specs do you recommend for CMP?

I have a touch over negative 3 in the front and -2.5 in the rear. This is going to change as I work up the new fenders. The plan is to figure out what I need to get everything to fit with the 255's and then I am looking into a flare from Jendosa as an alternative and that will allow me to do a bunch more things plus a little wider spacer.

[Cobra1956]

Starting to get ready for the summer projects which will include flares for the front end of the bus. I have found a flare that I like along with a flare for the 1 series but I think the 1 series flare would not cover all of my needs. Jendosa makes a lfare that I think would work best. Saw them being run by Eric Kutil and like the way they cover most of the well and I should be able to tie in the upcoming splitter with spats or similar. Also can go to a wider fender as I think all of the vertical portions of the bumper cover and oem fender will be trimmed back quite a bit. Here is the flare I am looking at courtesy of Eric Kutil. Check him out on youtube. Lots of fun videos. Hood vent has also shipped so we're getting to cut some oem metal soon!

[j0000stin]

Originally Posted by Cobra1956

I have a touch over negative 3 in the front and -2.5 in the rear. This is going to change as I work up the new fenders. The plan is to figure out what I need to get everything to fit with the 255's and then I am looking into a flare from Jendosa as an alternative and that will allow me to do a bunch more things plus a little wider spacer.

Nice! I actually went full 1m front end should i ever need/want to go wider in the front without limitations

[Cobra1956]

Been a bit since I have had time for the project due to serious life issues but some of that is under control so back at it. Next track day is Friday the 30th. Will have two students so not a ton of time to play during the day but have a list of what I want to get done. Might stay down at the track or bring the car home.
I want to replace the mechanical coolant temp gauge as the one I installed failed already. I do have access to an AEM dash and am planning on seeing if I can get it to function. It should be pretty simple but that could change as I am pretty stupid when it comes to this!
The low temp thermostat I ordered from Mishimoto does not work so I am trying to find another option which may end up with drilling holes in the existing thermostat to allow flow when closed. Short explanation is that during any type of cool down after a track session the oem design has the possibility of actually holding heat in the car the longer you try to cool things down. Think the design team was still pissed about WWII. Fender flares are just getting finished and I should have them soon. I ordered two sets for the front, 2 and 3 inch. Plan is to fit them to the fenders on the car and then after I get to what I like transfer all my silliness over to the oem fenders that I removed when the project started. So I will have a set of fronts in one of the two sizes if anyone wants them when I am done. (Free).
My flares. Picture provided by Jendosa. Mine are the inside and outside
Have a great holiday weekend!

[Cobra1956]

Track day yesterday. Did not sleep well the night before and rain was forecast for the day. Weather cooperated and we only had rain for the last session of the day. Was able to get a little something done. Love the looks on peoples faces when the grinder is heard in the paddock!

[Cobra1956]

FYI 33s plugs for the N55 can be bought at Summit Racing for less than $13. They confirmed they are the s plug if you are running oem.
Me:You have a Bosch plug listed at a price that is about $10 less than anywhere else . Just verifying these prices are correct for this model plug. ZR5TPP33S Thank you!

Them:Thank you for the email. We have them listed at $12.99. That is correct from us.

Thank you,

Adam
Sales Agent