CMP Test Day

Note:  This event took place on 30 July 2015, just getting caught back up with posts.

Setup in the shade at CMPMy last test day at Carolina Motorsports Park ended prematurely when my radiator popped off its mount and the belt cut into the coolant expansion tank.  With the car back home I pulled the plugs to check the compression since it saw temperature spikes over 250F.  Fortunately the numbers came back good, actually matching the numbers I had taken when I first installed the engine.

I put the car back together, this time with a new CSF OEM+ radiator and a cooler 80C thermostat while ditching the stock fan, and headed back to CMP to get some testing in.  I knew the car needed some chassis tuning after its first race post-crash.

Adjusting the front barIt was a low turn out at the track, so we were able to double up on track time.  That’s 8 full 30 minute sessions.  That’s a lot of driving in a single day, so I cut a few sessions short and skipped the last one.  What I did discover was that I needed a little more rear end grip.  The week prior I had done some ride height adjustments and corner balanced the car at a friend’s house.  The first couple sessions were a mess, I either spun or got into some serious tail out action.

I brought the car in and decided to stiffen the front bar one notch.  This had an immediate positive impact, the car was much more neutral, at least as much as I could get it on CMP’s slick surface.  Either way it felt much better and gave me more confidence going into my upcoming NASA race at Road Atlanta.

As for the engine temps; the car ran much cooler.  I was seeing a high temp of around 202F, albeit in completely clean air.  Looks like removing the stock fan and shroud allowed for better flow through the radiator.  I also had done a little work with foam rubber insulation to force air through the radiator rather than around it.

 

Spec E46 Test Day Ends Early @ CMP

Note: This event originally occurred on 12 July 2015, I’m a bit behind in my posts.

Following my first full race weekend, which was a mad dash to ready the car, I knew I had a few bugs to work out.  Chief among those issues was a persistently warm running engine.  Of course this was in the heat of the South Carolina summertime, but I wanted to get my temps a little lower.

To that end; I installed a larger CSF all aluminum radiator specifically for the E46 non-M chassis.  Unfortunately the mounting points weren’t ideally designed to interface with the factory plastic mounts.  I did my best to modify the mounts to work, installed it, and off I went to Carolina Motorsports Park for a day of testing.

Spec E46 Testing at CMP

I went out on my first lap and found that the temps were much lower.  Prior to the new radiator I was averaging ~212-215F in the heat of the day.  Now I was sitting at around 202F, much more reasonable.  I pushed on harder for the next couple laps, besting my previous times by more that 2 seconds.  Then on the third or so lap I got a warning light briefly for engine temps.  It went away as I looked down at the dash to decipher what the problem was.  Then a few seconds later it reappeared.  By now I was paying closer attention to the numbers, and I watched as the water temp spiked to over 250F then back down.

I immediately let off the throttle, short shifted, and brought it in to the paddock as quickly as possible using as little engine as possible, coasting the last hundred feet or so with the engine off.  Hopping out I could see steam rising from the engine compartment.  A peek under the car showed hot water dripping to the ground.  This certainly wasn’t any good.  Popping the hood confirmed my concerns about the mounting of the CSF radiator.  It had slipped from its mounts and shifted rearward where the expansion tank made contact with the serpentine belt.   The belt made quick work of the plastic tank, sawing right through it.

My day had come to an early end with a destroyed expansion tank, a radiator that wouldn’t sit securely, and possible engine damage.  Later on, after everything had cooled, I also discovered that high temps had destroyed the expansion tank cap.  The lower portion that retains the sealing o-ring was completely missing.

Damaged Expansion Tank Belt Cutting Expansion Tank

The good news: CSF was quick to help rectify the situation.  They sent me one of their OEM+ radiators, covered the cost of the expansion tank, and promised to redesign their all-aluminum radiator.  Hopefully they get it corrected soon, because other than the mounting problems, it’s a solid piece.

And finally a short video of my one hot lap before the radiator mounting failed:

httpvh://www.youtube.com/watch?v=-DuvY_UuF9I

Spec E46 Race @ Carolina Motorsports Park

Note: This Event originally took place on 27-28 June 2015, sorry for the delay in posting.

Having finished the requirements for my provisional racing license, I was looking forward to the next opportunity to race my Spec E46.  The upcoming NASA-SE event at Carolina Motorsports Park (CMP) looked very promising, with a possibility of five other SE46’s in attendance.  One slight hiccup; my car was still in pieces.  Several delays in parts shipping meant I was way behind my anticipated competition date.

Rob's 609 Spec E46I had already committed to this race, having already cancelled the previous Road Atlanta event due to the crash, and I really didn’t want to miss another opportunity to get some much needed track time.  The week leading up to the event became a mad thrash.  I was working until the wee hours of the morning right up to the day before the race.  The good news: CMP is only an hour away from home, so at least the few hours of sleep I did get were in my own bed.

I also needed an annual tech inspection the morning of the event, so everything had to be just right.  I escaped with a few minor discrepancies which were easily corrected and was able to make the race.  I had barely got the car off the alignment rack the night before, so there was zero time to shake down the car, much less tune the chassis.  I’d run what I brung as the saying goes.

My setup in the grass Fellow SE46s in the paddock

I missed the first practice, fiddling with a few last minute things, but was able to go out in one of the HPDE sessions to get a feel.  I knew the track was slick from my previous test day, but having an untested car made it much more of a challenge.  My goal was to just keep the car on track and avoid any contact, speed was way down my list of things I was worrying with.

View of the Spec E46 groupI qualified at the back of the SE46s, as expected given the all-star veteran competition I was up against.  No big deal, I was here to learn.  We, as a class, decided to start at the back of the Thunder run group in our own separate start rather than gridding on pure time.  The first race started off cleanly, but I was out of it both mentally and physically.  The lack of sleep had caught up with me big time, and I couldn’t maintain my concentration and felt like garbage, my times were reflecting my condition.

I continued to press on, just looking to finish when a red warning light illuminated on my AiM MXL digital dash, water temps.  I was at 230F and it looked as though it would keep climbing.  I had pressed my luck enough already, so I pulled off that lap and putted back to the paddock area.  I couldn’t find any obvious issues with the cooling system, all signs pointed to trapped air bubbles.  This is the price you pay when rushing to get a car ready at the last minute.

Sandro's Spec E46I decided to pack up for the day, let the car sit and cool overnight and get some rest.  Another SE46 driver had already had worse luck when one of his rear shock mounts failed, resulting in a destroyed MCS shock.  I left early to get caught back up on sleep and hopefully have better luck on Sunday.

The next day I jacked up the front of the car and bled the cooling system thoroughly.  It looked like my suspicions were correct and the engine had some significant amount of air trapped in it.  Feeling recharged from a long night of sleep I headed back on track, this time in a much better frame of mind.  The car still wasn’t working as well as I had hoped, oversteering terribly on exit and pushing on entry, but it would have to do.

Saturday's Race(Note how I was still missing the trim under the headlights and decals from the new fender)

Again I started at the back of the SE46 pack, where we started as group behind the rest of the Thunder field.  This time I felt a little more confident making passes and tried my best to hang on to the back of the SE46 in front of me.  I certainly wasn’t pushing for overtakes, rather waiting for the safest opportunity to get by slower traffic.  Towards the end of the race I could see I was closing back up to the next SE46 up the road, but every time I tried to push, the car would just lose traction on exit.  I was at opposite lock over and over, watching the Mustang and other SE46 in front grow the gap.

My Spec E46 at CMP

Despite the headaches and lack of a good setup, I still had a blast driving with other SE46s and finally getting a chance to mix it up in traffic in an actual race.  This was, after all, the first race where I got beyond the first lap.  It was great to meet and hangout with other racers in the paddock, gleaning knowledge wherever I could.

Finally a little video from the weekend.  Due to my zombie-like state on Saturday, I neglected to bring the memory card for the camera.  I made sure to get it for the Sunday race.  Here’s the race in its entirety:

httpvh://www.youtube.com/watch?v=GFrz5KTHV20

Spec E46 First Shakedown

Before a race car turns a wheel in anger, it really should be put through its paces in a test or shakedown drive.  Since this car isn’t street legal and you could never truly test in on public roads, you need to schedule some track time.  Fortunately I’m only an hour away from Carolina Motorsports Park (CMP) in Kershaw, SC.  They even have their own track day organizer, Turn One, that has multiple events a month, making it fairly easy to get track time.

Spec E46 Alignment

After alignment, I loaded up the car on the trailer and headed for CMP to see how all my work handled.  It was a weekday event, so the track was fairly empty, great for some testing and tuning.  Just like any track day event, the car went through a short tech inspection.  Normally this wouldn’t be necessary on a race car, but I hadn’t received an annual tech inspection yet.

Spec E46 Loaded for Testing

The first session was just a an exploratory lap, since I had never driven this track before.  The tires were also fresh sticker and we were receiving some light rain, so it was a bit slippery but grip gradually came in.  That said, CMP is a very slick track, nowhere near as grippy as NOLA, COTA, or Road Atlanta.  It reminded me a lot of Motorsports Ranch Cresson, which is very old pavement and very slick in light rain.

Towards the end of my first session I was black flagged, which was odd because I had no off track excursions and there were only 2 other cars on track.  I pulled into the pit lane and up to the pit exit marshal who told me several corner stations were hearing a loud metallic screeching sound from my car.  He did a quick walk around of the car and noticed a lot of aluminum shavings on the rear left wheel…. great.

Cut Apex Wheel Wheel Shavings

I pulled off the pit lane, headed back to the garage to see what had happened.  Turns out I picked up a rock, which became jammed between the caliper and wheel.  It then worked just like a lathe, cutting a 1mm deep groove around the inside of the wheel.  My guess is that I picked it up during the tech inspection, as the tech shed and weigh station is off a gravel road (terrible layout.)

I pulled the wheel and gave it a good inspection, even called the friendly folks at Phil’s Tire Service to see what they had to say.  I forwarded them some photos, which they in turn sent on to Apex Wheels.  After a close inspection, I determined it was reasonably safe to continue on for the day.  I took it a little more carefully, avoiding the curbing as much as I could.

Spec E46 Testing

The car continued to run well throughout the remaining sessions.  Temps were within safe margins and the engine felt decently strong.  I knew the alignment could use a bit more dialing in, and a corner balance was definitely in order.  It was certainly nice to finally be in a true race car with a proper race seat and harness, making it much less physically demanding to drive the car while also easier to feel what the chassis was doing under me.

Then towards the end of the fourth and final session I suddenly lost power steering.  It was a sudden stoppage, like I had experience in my E36 when it popped a line at Road Atlanta.  I pulled back into the paddock to check what happened.  A quick glance under the power steering reservoir cap revealed the telltale signs of a ruined pump, as it was sparkling with a metallic sheen.  And so ended my test day.

Steering Pump Shaft Ruined LF20 Pump

Once back home I pulled the power steering pump to discover the pulley shaft was completely disconnected from the pump and free spinning.  No doubt this was a design function, a break-away shaft much like those found on the air turbine starters on jet engines.  I further disassembled the pump to discover the vanes which slide in and out of slots where dislodged and had jammed up the pump.  My guess is that this was the original pump and at 220k miles it had just had enough.

All in all, not a terrible first run of the car.  It showed its weak points, and that is the point of testing after all.