E46 M3 Receives Cooling Overhaul, More Meat, More Track Day Woes

Jet Black E46 M3 on race track
Mid corner of turn 10 at Summit Point

My last track event was back in early September with Track Night in America at Dominion Raceway. During that event, I found my 2003 BMW M3 was overheating after just under a single hard lap. That put a quick damper on the fun and obviously limits how a driver can improve lap after lap.

Major bummer.

The overheat issue never really appeared on the street, even in 100 degree temperatures. Even then, I think the signs were in front of me the entire time. I had always noticed the temperate gauge seemed to read just a tick high. Instead of the needle pointing straight up, it leaned just slightly to the right. A sign I probably should have seen coming.

After the track day at Dominion Raceway, I immediately placed an order with FCP Euro for a fresh a water pump and thermostat. I addressed the radiator by replacing with a slightly larger unit courtesy of KoyoRad.

Josh's E46 M3 S54 engine with KoyoRad radiator installed
KoyoRad radiator installed

Fitment of the all-aluminum KoyoRad radiator was spot-on and couldn’t have fit better. As a bonus, I did measure the core to be slightly larger. Not that I could imagine a significant improvement in radiator design over the last twenty years, but I’d hope the cooling efficiency would be a tad better than factory.

While I had the car apart, I sprayed the oil cooler with a water hose to remove years of debris. It was full of tiny pebbles and random road grim. Ah ha! I could only hope that THAT was the cause of high oil temperatures that may have also contributed to higher water temperatures!

The cooling system was overhauled and now running a 50/50 coolant-to-water ratio. This was to meet the warranty requirements set by KoyoRad. I was feeling pretty good about the fresh hardware and semi-confident this would no longer be a problem.

I gave my long time buddy, Kenny, a call. He had been tracking his 991 Turbo S all year and I promised him my next track day would be with him. You may remember him from our latest NSX video. The date set for Summit Point with Porsche Club of America on the first week of November.

Next up, I was on the hunt for wider wheels and wider, stickier tires. The current setup was bronze Apex ARC-8’s wrapped in 245/40 Dunlop Sport Maxx RT tires. Camber was right about -2.5 degrees, eye-balled, up front and there was little I could do to get more without adding camber plates to the KW V1 coilovers. Even with the camber, the front end was washing out at Dominion Raceway on slower speed corners where I really felt it shouldn’t.

Searching the NAM3.com forums, I scored a set of 18×9.5 ET35 Apex ARC-8 wheels. My plan was to buy a set of Hankook RS-4 tires, but they were backordered everywhere! Next best option, it seemed, was the new-for-2020 Federal 595RS Pro. The 595RS Pro tires were supposed to be more of an endurance race tire, similar to the RS-4. I drive my M3 on the street from time to time, so longevity and wet weather traction were important. Plus, the complete set of four tires in 275/35/18 were delivered to my door for just $570. Nearly half of the other options.

Josh's black E46 M3
Hard parked in the driveway

I had CoHo Automotive in Manassas mount and balance the tires. The question remaining is – would all this rubber fit under the fenders without rubbing? Apex’s own E46 M3 wheel fitment guide suggested -2.5 degrees of front camber to clear 275 width tires on a 9.5 inch wide, ET35 wheel. I had to mount a 3mm spacer up front to keep the wheel off of the coilover spring. Clearance was tight, but a drive around the block didn’t reveal any audible rubbing and inspecting the tires didn’t reveal any evidence in the form of cuts in the sidewall. Nice!

Things were looking up. With the cooling system refreshed, wheels fitted and the test drive complete, I was much more confident the coming PCA track day would be a success.

991 911 Turbo  and E46 M3
Josh and Kenny’s cars parked in the paddock

There’s Always Something

The day had come. I left the house at 6 AM and reached the paddock at Summit Point by 7:15. Being a PCA event, the paddock was filled with 911’s and Cayman’s of all flavors. There were a handful of non P-cars, of course, mine included.

Kenny had arrived early and saved me a parking spot next to his beautiful 911. What a guy. Next to me was a lightly modified 997 Carrera, and across from that was a Z4 M Coupe. I spied another E46 M3, trailered, in red, stripped with a cage, looking like a proper racer.

As per all track days, I took the car through tech inspection and checked-in to get my blue colored wrist band, signifying my run group for the day.

Josh's black E46 M3 and Kenny's 991 Turbo S
Parked in the paddock at Summit Point

Blue group’s first session was around 8:30 AM. The call had been made for drivers to make their way to pit lane. I checked my phone for the temperature and to take notes about the session. My phone indicated 49 degrees. High temps of the day were supposed to be near 70.

Still, I wasn’t ready to go.

I reduced tire pressures to 32 psi all around, and took a quick attempt to get the GoPro setup. Gloves on. Headsock on. Helmet on.

GoPro on…on…still off? Futzing around with the camera only further delayed me. All told I was about 10 minutes late getting out on track. I wasn’t in a rush to be out on track with tmperatures under 50, plus PCA was generous with their run group sessions at 25 minutes each. I’d be getting plenty of track time today.

The first session out, I felt I was everywhere but on the correct driving line. That didn’t come as a shock to me. The last time I drove at Summit Point was back in 2008’ish. I figured all I needed was a single session and the racing line would come back to me. Unfortunately, I was too busy with my hand out the window giving point-by’s to GT3’s and monitoring engine temperatures to focus on the driving line and relearning the track.

Checkered flag already? It was just the 7th lap out. Good news is I felt confident the car wasn’t going to overheat or burst into flames.

Back to the paddock. Quickly grabbed the pressure gauge to check hot tire psi. 40 hot. Wear on the tread wasn’t quite reaching the sidewall markers. Dropped psi down 4 psi all around.

9:45 AM. The announcement for Blue group was made over the loud speaker. Time for the second session. Temps were now up to 55 degrees. The car was feeling good. Lower tire pressures should increase grip. Time to put my right foot down!

This session I was intentionally late to the pit lane. The blue run group was full of cars seemingly quicker than my M3 and I didn’t want to begin this session giving a million point-by’s. I tucked in behind the Z4 M Coupe, figuring pace would be similar.

I was wrong to make the assumption. The pace of the Z4 was considerably slower and the cars ahead of the Z4 had gapped by considerable distance. Way too much for me to catch up. What I really needed was…yes!…great timing! Coming up behind me was a bright orange something. A 996? I was lighter on the throttle around the rest of the track to allow for this car to earn an early point by. Arm out the window. A first generation Boxster crept by. The exhaust on it, if it even had one, overpowered the noises of my own car. This not only hurt my own ears, but made it challenging to time my shift points.

Argh!

It didn’t take but just a few laps on the heels of the Boxster to relearn most of the racing line. I was quickly getting up to my expected pace.

Exiting turn 10 at Summit Point

The front straight at Summit Point is long enough for my M3 to touch 135 MPH, or higher with a perfect exit out of turn 10. Unfortunately, my brake pedal was getting a little soft. And softer the next lap.

A few corners later, after diving through turn 4, braking hard for the left at turn 5, that’s when I heard it – the unmistakable sound of rotating rubber on something that it shouldn’t be touching. With the additional tire grip and speed I was carrying through the corner, the suspension must have been compressing enough for the tire to contact the fender.

E46 M3 Tire Rubbing

Grrrrrrreat.

Foot off the gas to cool off. Up the hill and on to the track exit. Back in the paddock. Gloves off. Tossed the helmet onto the passenger seat. Session over. Time to check the damage.

At the last track day, I was plagued with engine cooling issues. Now it’s a soft brake pedal and tire rubbing. My frustration level was rising. It wasn’t even 11 AM and I could see my day coming to a halt. On the bright side, I was sitting in a fold-up chair under a fold-up tent on a beautiful, sunny, 60 degree day. Absolutely all I could ask for of a Friday in early November.

Inhale that crisp late morning air.

Exhale.

Reached for my Google Pixel 2 XL to jot down some notes. Posted a pic on my Instagram account.

What’s Next?

The soft brake pedal wasn’t anything a quick bleed session couldn’t fix. The brake pads however may have been contributing to the lack of stopping power. I had no idea what brand they were. They had more than enough pad depth left to pass tech inspection. That’s all I know.

This was all my fault, after all. I modified the car. I tossed on wider tires. I should have done a better job bleeding the brakes. Why was I getting dogged down the front straight by a Boxster? Was my S54 weak? All of the questions.

It didn’t help that Kenny proposed the notion of buying a P car. Jerk. Just kidding Kenny — <3

I skipped the first afternoon session entirely to walk around the paddock, collect my thoughts, and myself. Of all the tools I brought, a brake bleeder wasn’t one. Luckily, the paddock was full of people willing to help. Big thanks to the guy with the other E46 M3. Sorry, I don’t recall your name. But you offered up a bottle of the good stuff — Motul RB600. 20 minutes later, Kenny and I had all four corners bled.

But that still left the tire rubbing issue. There was no sense of going back out on track as the car sat. I didn’t want to risk destroying a tire or putting anyone in danger.

My KW V1 coilovers did not have adjustable camber plates and the strut top alignment pins had already been removed. There was no more camber to be found. My only option was to raise the ride height, which would slightly throw off the toe, and then I would just cross my fingers.

With the front wheels still off, I adjusted the plastic coilover spring perch collars on the KW V1’s up. Only an inch, I thought. Twisting and twisting, I was on a roll. Perhaps I over did it a little, but I wanted to be sure to alleviate the rubbing.

I checked my phone. 2:45 o’clock. 74 degrees. There’s one more session and this track day’s a wrap.

4 PM EST. The call for the final blue group session of the day had been announced. I watched the other cars head for the pit lane. But not me. I was intentionally last again. I didn’t want to cause a train. The day really felt like a test-n-tune. It was only the second track day with this car, so I suppose it was.

The GoPro still wasn’t turning on.

Cars ahead were starting to move. I held my arm up and out the window to show my blue wrist band. We were off.

6,000 RPMs.

7,000 RPMs. I pulled in on the right paddle shifter.

Up to 7,500 this time. Pull it again.

Repeat it through the gears. 110 MPH and into the brake zone for turn 1. Brake pedal pressure was feeling solid. Whatever brake pads were installed, on the other hand, left something to be desired. Good enough for now though.

Summit Point track map
Summit Point track map

Out of turn 1’s right hander and up the hill toward 2, stab the brakes and steer left over the turn 3 crest. The train ahead was moving quick this session. Down the hill fast through 4 and hard on to the brakes for 5, turn in smooth. This is the turn that compressed the suspension enough for tires to make fender contact.

And, what’s that sound?

Nothing!

Nothing but howling tires and the roar of the flat six cylinders ahead of me. Nice!

Through the carousel and out to the far end of the track, carrying speed out of 9 and up the hill and under the bridge toward the last turn, 10.

Second lap, now. Up to 130 MPH down the front straight. No need to go all out. Unwanted events tend to happen on the last session of the day.

On to the brakes hard. Push… push more. The brakes were holding up as well as I could hope for unknown brand street pads.

Now that the car was fully functional, it was truly time to focus on driving.

Optimal weather. Optimal conditions!

The only problem now is that my rear view mirror was filling with egg shaped head lights. Chase through the corners. Get dusted on the straights. Hand out the window to let them by. Over and over again. There were a good number of cars in the session and the majority were race cars, GT3’s or Cayman GT4’s.

In this run group, on this day, with these other cars, I simply couldn’t keep pace.

I glanced down at the temperature gauge. The water temperature needle had risen, nearing danger zone.

What!? How?!

I backed off the throttle. Temperatures dropped slowly.

Just as I did at Dominion Raceway, I eased off the throttle coming out of the last corner and putted down the front straight, giving point-bys, and ample time to cool the water temps down.

With the water temperature back in normal range, I was able to give the beans out of turn 1 and all the way up through the last corner. Repeated this process for the next 20 minutes.

The checkered flag waived.

Same boat. Another day.

Is this what the FK8 Honda Civic Type-R owners deal with?

November sun setting over Summit Point Motorsports Park

Bonus Images

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