First Autocross with the DSC Sport Controller

Over the winter I installed the DSC sport controller and 3-axis accelerometer in the Cayman but never got around to properly testing it. An autocross with the NNJR SCCA seemed like the best way to really put it to the test. I completely forgot what tire pressures I run which apparently was supposed to be 27psi all around based on my old notes but I initially ran 30/32psi which made the car extremely loose. I lowered it down to 30/31psi and that made it more balanced especially as the tires heated up. 

NNJR SCCA Autocross - 4-30-2022

Let's forget about tire pressures for a second and let me focus on my observations about the DSC sport controller. I could immediately tell that it was able to handle bumps and undulations much better than before and the nose didn't dive as much under braking. It's definitely a big help but my two year old Yokohamas are starting to show their age. I felt that the dampers were capable of so much more but the tires couldn't give me the grip I needed. Under braking, the 235s up front just aren't enough to get the car slowed down fast enough and I kept overshooting corners probably made worse by the fact that I've been driving the S2000 more which has much shorter braking distances. This hurt me in the transition as well as the reduced lateral grip made it hard to quickly change directions in the slaloms. The tires are worn enough that I should probably get new ones soon so I may change my tire sizes to have a more optimal setup.

NNJR SCCA Autocross - 4-30-2022

Also, since I can no longer run in STU with the Bilstein Damptronics coilovers with the DSC sport controller, I've started to run in XS-A (Extreme Sport A) instead. This is convenient because technically all my other autocross capable such as the S2000 and 911 are all legal in this class as well which mean I just need one set of numbers and class letters and I can just choose which ever car I want to have fun with on any given weekend. 

First Autocross of 2022 - Oil and Tire Testing

I wanted to see if the fixes I made to Bumblestook resolved my oil pressure reading issues so the first autocross of 2022 with the NNJR SCCA seemed like the perfect place to give it a go. It would also be a great way to test out how the new Continental ExtremeContact Force would be as an autocross tire. 

NNJR SCCA - 4-16-2022

The first good news is that it seems that my oil pressure issues are gone. I got the oil nice and hot and really pushed the car and not once did the oil warning light go on. Since my head and eyes are constantly moving around at an autocross course, I checked my videos just to make sure I didn't miss any occurrences of it and I'm glad to report there were none.

Bumblestook @ NNJR SCCA Autocross - 4-16-2022

As far as tire testing was concerned, I will say that these tires live up to their "Enduro" focus in that they take quite a while to get up to temp (about 4 runs in 70F ambient temperatures, single driver) but they did seem to be ok with heat after that. I also found that they liked lower pressures and ended up running 28psi front and 27psi rear to get neutral balance. They tended to be a make a bit more noise at the limit than I'm used to with the Yokohama A052 but I think that's fine because I could use it to easily hear when I was at the limit of grip. Overall, I think they're decent summer tires but are far better suited for track use which isn't surprising at all since that's what they were made for. 

Jeep Cooling Upgrades

The plastic ended radiators on JKs are known to crack and leak over time. I'd rather not wait for stuff break especially since this is my wife's truck so I had SJF Performance put in some preventative upgrades for me so I wouldn't have to worry about anything later. The radiator was replaced with a more efficient Mishimoto all aluminum radiator. New Mishimoto silicon radiator hoses and a new 203F thermostat was also put in while it was out. Unfortunately, this radiator doesn't have all the same brackets as factory so it's not quite a direct replacement but it does, otherwise, fit in quite well.

New coolant getting vacuum filled in

The heater core failure is also fairly common on these Jeeps and I definitely don't want to have to replace that later. Regular coolant flushes seem to be the recommended preventative maintenance for that. Of course, a new radiator means new coolant going in anyway so getting that maintenance out of the way worked out nicely too. I just went with standard Mopar OAT purple coolant here which is what they recommend for 2013+ Jeeps. SJF noted that he pressure tested the coolant system prior to filling and it held vacuum extremely well (no movement in the needle whatsoever) so I know everything is sealed nicely. 

New thermostat, radiator and hoses installed

New thermostat, radiator and hoses installed

One of the things we notice every time the Jeep is on the lift is that there seems to be quite a lot of tension on the brake lines with the wheels hanging down. This is no good for when we take the car off road since at maximum articulation, even at stock height, having something pull on a brake line is the last thing you want. My initial plan was to replace them with stainless braided lines but everyone that makes stainless lines for the Jeep designs them for a lifted setup. It was clear that those were going to be too long since we're sticking with stock height so we just put in fresh OEM style brake lines and got relocation brackets to move the line further down a few inches to give the necessary slack needed to avoid turning the brake line into a musical instrument. 

Brake line relocation

The Jeep now runs a bit cooler and we're ready for some off road fun in May without any further brake concerns.

Maintenance Update:

Mileage: 70,463

- New Mishimoto Radiator 

- New Mishimoto upper and lower silicon radiator hoses

- New 203F thermostat

- Approximately 2.5 Gallons of Mopar OAT purple coolant

- New OEM style rubber brake lines

- Brake fluid flush with Bosch ESI6-32N DOT 5.1 Brake Fluid

- Diff fluid change front and rear with Royal Purple MaxGear 75W-90 (1 qt front, 2 quarts rear)

Oil Pressure Sensor Fixes

My new oil pressure sender arrived the other day so last night while it was pouring out I thought it'd be a good time to get the car back together.

New AEM 100psi oil pressure sender

Since I applied a dab of hondabond on the threads to seal it better, I'd have to give it enough time to dry so letting it sit overnight was going to work well. 

New oil pressure sender installed

Since I took the VTEC solenoid apart last week, I ordered a new gasket kit from Kraken Automotive. I was surprised that the 17 year old gaskets that were in there were still pretty flexible and in decent shape. Still, rubber does eventually break down so getting this replaced now is probably a good thing. I applied a bit of fresh oil on the gasket and made sure it was all lined up, then torqued all the 10mm bolts down to 12Nm.

New VTEC solenoid gaskets

New lower gasket with screen installed.
Upper gasket also installed but not pictured

I double checked the wire going to the oil pressure sender and found two spots where the insulation had worn through. This might have actually been the cause of my issues. I taped them up and re-routes my wires to avoid this happening again.

Frayed insulation

More frayed insulation

Everything back together

During lunch today I put in fresh oil and took her out for a drive. Everything still works. I checked for leaks and there were none. Once warmed up I did a few pulls in VTEC and it was pulling hard with no problems at all. So far so good. I just need to put her through her paces and see if the problem reoccurs on track. I also got an 8GB MicroSD card for my IQ3 datalogger dash so that if this happens again I can look at the telemetry to see what I might not be catching on the screen. 

MicroSD installed ready to datalog

Maintenance Update:

Mileage: 60,875

- 6 quarts Amsoil 10W-30

- 1 new Honda oil filter (15400-PCX-306)

- 1 new AEM 100psi stainless oil pressure sender

- New VTEC solenoid gaskets (upper and lower)

Box This Lap - Lime Rock Park

The track bug hit me hard after the last event with S2K Takeover so when I found out we were going to have another event at Lime Rock Park on a weekend, I couldn't say no. I had my first track day ever in 2006 at Lime Rock Park and hadn't returned since due to my cars always being too loud for that track but the Mugen exhaust is well within the sound limits of LRP so it was great to be able to return. 

Lime Rock Park - 4-2-2022

It was a bit on the chilly side but sunny so we were all set up for a nice track day especially since we had our own run group that wasn't too large so we had plenty of room to enjoy the track. I was mostly excited about testing my new tires, a set of Continental Extreme Contact Force. The first session went really well. The tires have a bit less peak grip than the Yokohama Advan A052 but remained consistent and very predictable lap after lap. The car was also a bit more playful at the limit and I found the balance to be quite good with just a bit of manageable oversteer at the limit. I ran 30psi front and 29psi rear cold. I may try lower pressures next time. 

Limp Mode

The second session didn't go as well. I started noticing that my oil pressure warning light kept blinking several times throughout my laps but looking at my dash, my oil pressure was always well at expected values of 70-80psi depending on load. Unfortunately, a few laps in, as I was going into West Bend, the car suddenly dropped out of VTEC and I had no power. I got off the racing line and checked my mirrors for any debris but saw nothing. My oil temp gauge was still showing good pressure but I couldn't get into VTEC anymore. Thankfully the pit in was only two corners later and downhill so I was able to pit in easily and I noticed the car behaving normally again. I got the car to grid and checked everything. No leaks and the car started and ran normally. Oil level was still good and I was able to drive around the paddock without issue as if nothing happened. I didn't bring a laptop to be able to view my camera footage to see what had happened but seeing as the car was running I decided to pack it up and go home just in case I had a real issue. The drive home itself was uneventful. The car drove perfectly at any gear for the 100-mile drive home though I was careful not to engage VTEC in case the issue was with the VTEC solenoid. 

Back home safe

When I got home I checked the GoPro footage to the exact moment when I lost power. I noticed the oil pressure warning light blink a few times despite the dash showing normal pressures (> 70psi) but you can see the car go into limp mode. I checked my tune and I have engine protection on to go into limp mode anytime the oil pressure drops below 25psi when I have more than 25% throttle and the RPMs are greater than 2000 so this is what must've tripped. Since the car was running normally I don't think it was related to my recent cam intake replacement or valve adjustment. Either I was having random and very brief real drops in oil pressure, enough to trigger the light but not long enough to register on my dash, or something was going on with my AEM oil pressure sender. 

Oil drained, new filter in

Today, I dumped all the oil out to check for anything unusual. It was debris-free and nothing was on the magnetic drain plug. There were no leaks anywhere. I double-checked the Mocal oil sandwich plate and it was a tad loose so I tightened it up but that was just likely from unscrewing the filter. I put in a new filter and torqued everything back down. 

VTEC solenoid upper gasket

I inspected the VTEC solenoid. The upper gasket was sealed and free of debris, same for the lower gasket and screen. There were a few specs on it but nothing of concern. I'll probably replace both gaskets with new ones while I'm already in there since these are now over a decade old years old but they look to be in good shape. 

VTEC solenoid screen is clear and unclogged

I didn't really think I had a VTEC solenoid problem after reviewing the video but I wanted to physically check for peace of mind. It was clear to me I never lost oil pressure so my current suspect is the AEM oil pressure sender. I already had a failure of my previous sender two years ago where I thought I had zero pressure when it was just the sender dying on me. 

Connector looks ok

The oil pressure sender connector looked ok. Nothing was loose and the seal was intact so it wasn't debris or moisture getting into the connector. I also didn't see anything physically wrong with the oil sender itself. 

Oil pressure sender

Given the symptoms, I suspect something is going on internally with this oil pressure sender. Although it does work normally under typical driving conditions, it may be occasionally sending momentary low readings to the ECU that's causing the engine protection mode to engage. I don't see, hear, smell or feel anything else physically wrong with the vehicle. If I had my tuning laptop at the track I could've actually just disabled engine protection, had it ignore the oil pressure value, and continued driving but it's one thing I actually don't want to disable as a safety net in case I actually do suddenly experience sudden oil pressure loss. I've got a new sensor ordered so I'll swap that in to see if it fixes the problem. Unfortunately, I can't reproduce this problem on the street even when I get into VTEC so I won't know for sure if it fixes anything until the next track day.