Project 718 Cayman T: Part 17 – Spark Plug Swap and Track Testing Water Injection and Tires

More gravel and rubber.

There was rubber stuck in the air vents in the front inner fender liner too.

I’m getting a bit of tire rub on the fender liner due to a combination of factors of my setup: taller than stock tire, a ton of castor, and I’m thinking stickier-than-stock tire contributes too.

It looks like I’m getting tire rub on the top of the wheel well too. And, all along the inner fender liner. At least I think it’s actual tire rub and not just tire rubber getting flung against it.

I added a sock typically used on brake fluid reservoirs around the cap of the water reservoir. With the water level near the top of the reservoir and aggressive driving, water was splashing out.

I took oil level measurements before and after the track days. 3.7mm is roughly 150 mL of oil lower after 12 track sessions. My S2000, when it was stock and using Mobil 1, would go through about 500 mL in 2 sessions. The oil consumption rate of the S2000 went significantly down after I added an oil cooler and changed to Motul 300V, but it was still around 3x higher oil consumption rate than my 718 is doing. I would say I did a good job breaking in the engine. I also had a 2006 Infiniti G35 which burned 500 mL in just a thousand miles of street driving; that year VQ35 had the cheap piston rings that would go bad after about 40k miles.

So, doing the spark plugs on a flat-4 engine wasn’t too bad. The water injection system did a good job of reducing the intake air temps. Based on the water consumption rate and data logs, I can increase the water injection rate a bit more the next time out. With the new wheel and tire package, I have exceeded the capabilities of the stock SPASM suspension. Even when I was on the stock tires, I was wearing down the air deflector located before the front tires during track use. For now, I’m going to take out some of the front castor to avoid the fender liner rub and add more negative camber front and rear. I’ve started looking at coilover setups, but we shall see what the budget allows.