Weird Rev Limit Resolved

I reported in my recent trip to NJMP that I was experiencing weird rev limits as Bumblestook's oil temperature rose. Unfortunately, I left my tuning laptop at home so I couldn't fix it on track and it was frustrating to have the limiter kick it as low as 7000 rpms at times. I was convinced it was due to engine protection settings on the car due to oil temps but that turned out not to be the case.

Engine protection screen on my Haltech tune - 6-28-2020

According to that page if any of the following conditions are met, the car will go into limp mode and limit my revs to 3500rpms.

• Coolant above 110C (230F) for at least 2.5 seconds
• Oil temp above 135C (275F) for at least 2.5 seconds
• Oil pressure below 172.4 kPa (25psi) with TPS at 25% and RPM above 2000

The last condition I already experienced when my oil pressure sender failed two weeks ago so it can't have been this because the car didn't go into limp mode. It simply had a lower rev limit. I looked at my track video and looked at what my Racepak dash was showing me. At the hottest the car was at 213F coolant and 248F oil so I was well within the engine protection values. 

I reached out to Jeff Evans and he told me to check my rev limit table since the Haltech rev limit can be configured to scale based on coolant temp and sure enough that's where the problem was. This is actually a really neat feature and gives you the ability to limit revs until the car is up to temp. 

Coolant based rev-limit (old values) - 6-28-2020

Similarly, it can be used to limit revs if the temps get too high. What was happening was that the car was going above 100C on the coolant temps due the high ambient temps that day and because the rev limiter was configured for 2000rpm at 120C, it was scaling down my rev limit as the coolant temps went up. This explains why the rev limit seemed variable. Since I've already configured other warning lights regarding oil and coolant temps. I changed the 120C value to the normal rev limit so I won't run into this issue again. I also took the opportunity to lower the rev limit at 60C to the stock limiter of 7900. Seemed like a reasonable thing to do until the engine gets to full operating temp. 

Coolant based rev-limit (new values) - 6-29-2020

Remote Mounting of S2000 Oil Pressure Sender

People remote mount their aftermarket oil pressure sender on their S2000 all the time but oddly it's hard to find details on what they used and even fewer photos. Last week I replaced my failed oil pressure sender but I had to mount it directly onto the block like it was before since I ran out of time. After a successful track day at NJMP a few days ago, I figured it was time to tackle this to reduce the chances of the new sensor either failing due to vibration or maybe even snapping off.

AEM stainless 100PSI oil pressure sender remote mounted - 6-28-2020

Here are the details if you want to do it yourself assuming you're using an AEM oil pressure sender or similar sender that has 1/8" NPT threads (pretty much all aftermarket oil pressure senders use 1/8" NPT). I chose to use this Prosport Remote Oil Sender Install Kit from Tatis Motorsports. The kit is technically designed for a WRX but the kit includes two  pieces you'll use; 24" of braided stainless hose that's 1/8" NPT on both ends and a 90 degree female NPT to female NPT adapter. It also includes a rubber cushioned  mounting bracket but that's for 1.5" diameter senders. The AEM is about 1" is you can either go buy one that 1" of those or just zip tie it into place somewhere like I did. 

Prosport Remote Oil Sender Install Kit - 6-28-2020

You'll also need a 1/8" female NPT to 1/8" male BSPT adapter since the hole in the block is 1/8" BSPT. I applied some hondabond to the thread then snugged the NPT to BSPT adapter together. You don't want to over tighten this.

1/8" NPT to 1/8" BSPT adapter connect to one end of hose

You'll do the same thing on the other end this time connecting the 90 degree female NPT to female NPT adapter included in the kit. Snug up one side to the braided hose and the other side to the oil pressure sender itself. Again, you want this snug. Don't over tighten. 

AEM oil pressure sender attached to other end of hose.

Finally, apply a bit of hondabond onto the threads of the 1/8" NPT to 1/8" BSPT adapter and thread it by hand into the block. Make sure to snug it up. Don't go crazy tightening this or you can and will crack the block then you'll have a really bad day. Let the hondabond cure for 24 hours before starting the car and verify there are no leaks. If any of the connections leak, chances are you probably just need to tighten just a little bit more. It's really that simple. 24 inches of braided hose is enough to locate your sender wherever you need. Ideally you'll want to move it away from the header if possible to reduce its exposure to excess heat. I guess a lot of people just zip tie it to the cross bar on the frame. I left mine roughly where it was before since I didn't have a lot of slack in the wire going back to my ECU to play with. 

NJMP Thunderbolt - First Track Day of 2020

After spending the first part of the year mostly just randomly driving around to get my driving fix, it felt great to finally be at the track again with S2K Takeover. This time we were at NJ Motorsports Park's Thunderbolt track. I've been to NJMP several times before on the Lightning track but after seeing videos of Thunderbolt, I was definitely excited to give this a go. This was a joint event between S2K Takeover and the NEDC.

Parked for the evening - NJMP Thunderbolt - 6-24-2020

I arrived Wednesday evening just before sunset, got my tech inspection out of the way then settled into my room in the suites right by the front straight.

Enjoying the sunset - 6-24-2020

I was pretty excited to get on track so I got up nice and early at sunrise and started getting ready for the first session. I have to admit, after having done no real performance driving since September 2019, 9 months ago, it took me about two sessions just to get comfortable again. Unfortunately, due to the heat, I was starting to run into some issues with the car. Nothing was mechanically wrong it but when I got the car tuned a few years ago, engine protection was put in when oil reaches 248F limiting me to just 7000 rpms, a whole 1600 rpms shy of my true redline. Of course, the oil I use would've easily handled higher temps but I left my laptop at home so I couldn't change the tune to raise the limit. I normally don't do track days during the summer so I never ran into this issue before.

Lunch time photoshoot - 6-25-2020
Photo by: David Phimsipason

After lunch, all (ok, most) of the car went on track for a big video/photoshoot. Normally I'd probably say this was a waste of time but we had more than enough track time scheduled so having a little break to digest while taking a photo op wasn't such a terrible idea.

NJMP Thunderbolt - 6-25-2020

Overall, it was a pretty fun day. I'm excited to go back without the engine protection capping my power. I also see plenty of time I left on the table after reviewing my video so I really want to get my lap time to a more respectable level. For now, I'm just glad to be back on track, have a giant smile on my face, and get the car home in the same shape it left. 

Bumblestook @ NJMP Thunderbolt - 6-25-2020 - 1:39:4

Here's a really cool video of the event by TIULIVE on YouTube that includes some video of Bumblestook.

NETC Season Opener with S2k Takever

Oil Pressure Scare

Last weekend was pretty gorgeous weather so naturally, I was excited to Bumblestook out for a top off cruise. Well, that turned out short-lived because right as I was flooring it to merge onto the highway the car immediately went into limp mode. I quickly pulled over to look under the hood and didn't see anything wrong. Nothing looked broken and I had no fluid under the car.

New oil pressure sender in - 6-18-2020

I started the car back up and it sounded fine so I eased it to the next exit where I was able to pull over in a safer area and go over the car again. I pulled the dipstick and oil was exactly where it was when we changed the oil a few weeks ago. I started the car up again and realize that the oil pressure was showing 0.09 psi. That's definitely not right. I gingerly drove the car back to the garage because the car still sounded normal and drove fine as long as I didn't try to get into VTEC. My tune is configured with protection to immediately go into limp mode if there isn't enough oil pressure read by the sensor. I didn't see the temperatures rise and if I didn't have a Haltech dash showing all my readings I would've been none the wiser. Admitted this was probably no the smartest thing to do but I know the car well and if it had sounded or felt off even the slightest bit I would've pulled over.

No oil pressure - 6-13-2020

I suspected the AEM oil pressure sender failed somehow or maybe the wires got frayed. I was only two miles from my garage so I let it sit while we took the Cayman out instead but later in the afternoon I came back checked again. Still no pressure so I started the process of removing the PasswordJDM intake so I could get to the oil pressure sender which is plugged into where the factory oil dummy switch is located just above the oil filter. There was no physical damage to the sensor itself or the wires. There was nothing else I could really do so I ordered a new AEM oil pressure sender from tatismotorsports.com and it arrived just a few days later.

New AEM 30-2130-100 100PSI oil sender - 6-16-2020

I swapped in the new sensor today and was extremely relieved to see a pressure reading 85 PSI again at cold idle confirming my suspicion that the old sensor had just failed. I put a tiny bit of hondabond on the threads to help seal it properly so I'll need to leave it for 24 hours to let it fully dry. Also, it's important to note that the AEM oil pressure sender uses 1/8 NPT threads but block is 1/8 BSPT so you need a 1/8 female NPT to 1/8 male BSPT adapter to ensure proper fitment.

New oil pressure sender with 1/8 NPT to 1/8 BSPT adapter - 6-21-2020

Oil pressure reading is back to normal - 6-19-2020

I'll need to test the car this weekend to make sure there are no leaks after letting it run longer since we're going to be at NJMP in a week for the first track day of the season and the last thing I want are oil leaks that closer to the header.

GTS Classic GranTurismo Seats + Oil Debris

The great news is that my custom GTS Classic GranTurismo seats in brown leather and plaid Thompson camel centers arrived and are now installed in the car. The roll bar limits rear travel a bit so you can't slide all the way back which is fine since my seating position is actually perfect for where the seats are now and I really don't care if taller people can't fit in my car. That's not my problem. Go buy your own car.

GTS Classic GranTurismo Seats - 6-11-2020

The headrests didn't install as smoothly as you'd hoped. They had to take off a few inches from the metal stem and smooth out the adjustment notches to make it move properly but other than that, no real issues. Really love how it looks inside the car. For reference here's how the interior used to look. Needless to say the new look is more up to par with the standards I place on my cars. It's a nice snug fit and the bolstering is perfect. It definitely completes the interior.

Old look with torn stock seats - 6-6-2020

Valve adjustment is done. They didn't need to be adjusted much which is a good sign that the engine is wearing well. Leakdown and compression test was done earlier and the engine is nice and strong. As part of the oil change after break-in, they tear open the oil filter to inspect for anything inside and it wasn't as clean as we'd like especially considering this I just changed the oil 500 miles ago and put in a new filter.

Some black particles in the oil filter

The conclusion is that this is debris coming from the oil tank. We suspect the previous owner let the car sit for long periods of time with the oil just sitting in there allowing moisture to accumulate and rust to build up top. Now that I'm actually driving the car and changing the oil, the agitation is loosening those particles. The oil filter will take care of this but this is not acceptable to me so the car is staying at the shop a bit longer and a brand new oil tank is going in. After all this work, allowing sludgy/rusty oil to contaminate the engine from the oil tank would be a stupid thing to do.

No More Rubbing and Fire Suppression

Last year when I switched the Cayman over to Advan A052 tires, I was optimizing for autocross performance which meant going with as wide a tire as I could legally run for the class. For the rear, this meant 265/35/18 tires for improved gearing and 245/40/18 tires in the front to maximize grip (this was equivalent in width to the 255 RE-71Rs I was running before). Outside of autocross, this setup bothered me for two reasons; the rear tires were too short so the wheel gap looked huge and never looked right and the front tires rubbed the front fender liners badly. The rubbing was bad enough that I had to do a 12 point turn to get my car turned around in tight spots. During the winter I changed the rear tires to a 265/40/18 and after being fed up with all the rubbing and destruction to my front fender liners, I caved and went down to 235/40/18 which matches the OEM diameter.

Fresh 235/40/18 Advan A052 tires for the front -
SJF Performance - 6/6/2020

As you can see, my main concern with the rubbing was that it was starting to expose a bolt behind the fender liner and I really didn't want that cutting into the tire.

Wearing through the fender liner

Needless to say, if I was going to address the tire clearance issue then it made sense to replace the fender liners with new ones. I hate leaving things broken. My cars may not always be clean but I do try my best to not leave them in a state of disrepair.

Brand new OEM fender liners - 6/6/2020

New fender liners installed - 6/6/2020

I had also bought a black Rennline EZ Adjust fire extinguisher mount for Scarlett but decided to go a different route so I decided it should go on the Cayman instead. Fitment is pretty awesome and with the billet mounts for the Element Fire Extinguisher I'm glad I did this. It's a pretty stealth install that doesn't interfere with regular seat usage.

Rennline fire extinguisher mount with
Element Fire Extinguisher - 6/6/2020

Big thanks to SJF Performance for squeezing me in between alignments today to get these things taken care of. For the 911, I ended up choosing to go with a rollbar mount for the Element Fire Extinguisher. It seems like a good place to put it for easy access and it won't interfere with the thicker coco floor mats. Why would I put a fire extinguisher in a car that I'm not likely going to take to the track at all? Well, it's an old car and frankly, I'm afraid of something randomly failing and causing a fire so I'd like to be able to minimize the damage if it comes to that.

Rollbar mounted Element Fire Extinguisher - 911SC - 6/6/2020

Finally, the best news of all is that I'm finally done breaking in the engine and transmission on the 911 so I dropped her off at Speedsport Tuning so they can finish up the final tweaks on the car next week including a valve adjustment, putting in fresh regular oil (non-breakin), and of course, the new seats that GTS Classics made for me. Hopefully, this is the last time I have to drive on these old ripped seats.

Drop off at SST

Good-bye OEM seats

It was also super hot and muggy today so I'm so glad the AC works on the 911 and that I was constantly moving so I wasn't worried about overheating. However, even at max cooling, the interior temperature was just bearable. I may have to reconsider driving this car at temps above 90F especially when it's humid and I have a chance of hitting real traffic. I have some interesting ideas about how I can address this in the future including a full electric AC conversion but we'll see if I go down that rabbit hole.