6 months to live build thread

[jreissenweber1]

damn ....

just found this thread ..
looks like you are really enjoying yourself ..

thanks for sharing ..

Sent from my SM-G950U using Tapatalk

[itsnotanova]

Thanks for the interest everyone. Sorry I've been up in Alaska hanging out with my Dad for the last few weeks. Trying to get away from the constant 100+ days we've been getting down here in Texas. On that note about Texas heat. My rallycross boxster does not like when it gets over 90. It can't handle two people racing it at the same event. The last two events it overheated after just a few runs. It might be able to handle just one person racing with it's current cooling system, but not two. At the last event in June my partner and I got in two runs each. On my second run(4th total), it was hovering at 190 at the starting line. By the time I crossed the finish line 1 minute later it had jumped all the way up to being pegged. We let it run for a few minutes and it barely cooled down. The whole system had become heat soaked and wasn't showing any signs of cooling down. We packed it up and went home. I had thought maybe the water pump had gone out but after closer inspection, the pump was in great shape and had recently been replaced. So I've been thinking on how I can rectify this problem. If you look at the whole cooling system, it's not that great. It has puny little base coolant tubes going to only one radiator and a mechanically driven water pump. Address any one of those problems, and it will probably fix the overheating problem on very hot days. I've decided to start with the water pump. I like the idea of using an electric water pump. It gives me the ability to regulate the water flowing through the motor with the engine running or not. I think with the EWP I can come into the pits, shut the motor off but continue to circulate coolant through the system with the electric fans still blowing over the radiator. I'm hoping the few minutes between runs should be enough time to cool everything down. Some other reasons I like the EWP is that it will free up some horsepower and I don't have to worry anymore about little pieces of water pump clogging up a water passage inside the motor.

In preparation of using a EWP, I took a low mile water pump and drimmeled off the propeller. I also removed the thermostat as I'll be controlling the flow of coolant with the EWP. I ordered a Craig Davies water pump. They sell a little LCD control unit too, but I'm to cheap to buy one of those. I plan on using a simple ON/Off toggle switch for now. The EWP was only $200

Jon, That rally Boxster is nice! The 2.7turbo motor is inspiration for my street boxster

[itsnotanova]

Here's a pic of the modified water pump and thermostat

Here's the new electric water pump installed. As of now i have it wired to run when the ignition is turned on. I tested it today and I'm not quite sure it's going to help. Its in the mid 90's and I let the car idle for about 20 minutes. I then kept the rpms up to 5000 and held it there for about a minute. Towards the end it was creeping past 180. I then shut the motor off but kept the ewp and fan going. The temps didn't drop as quickly as I had hoped. I have a race on Saturday, so that will be the real test as it's suppose to get to 103. Pretty sure I'll need a bigger radiator.

[itsnotanova]

The electric water pump passed the test. I had two days of racing in 100 degrees and it worked perfectly. The first day of racing I would hook up a spare battery to the car and let the water pump/fan run in between runs. There would be a 15 minute gap between runs and the car would cool down by 20 degrees. The temps never went higher than 180. The cooling system got a real test at the second race. At that race, there was no cool-down time. There was only 5 minutes between runs. Not enough time to even shut the motor down. The coolant side of the cooling system worked great and the coolant temp never went past 190. Now the oil temp was another story. After about the 7th run, the low oil pressure light would come on at idle. For the last three runs I had to keep the rpms up to keep the pressure high enough so the light wouldn't come on.
So after getting it home I put the car on a lift so I could give it the post-race inspection and oil change. I switched to a 10/30 for the upcoming fall/winter racing. I might go with an even thicker oil for next summer. I also inspected the cooling system and discovered that the placement of the electric water pump was not ideal. Air pockets were collecting inside it and that would affect performance and lifespan. The radiator and water pump needed to be moved into a different position. The water pump needs to be lower than the radiator. At first I tried working with the single boxster radiator but I decided if I have to re engineer it, I might as well go with a bigger radiator. I went to the local pick-n-pull with a tape measure. I measured a bunch of radiators but most were too wide. Like Jon, I ended up using a 2001 toyota corolla radiator and cooling fans. It fits perfectly and looks like it holds as much coolant as a single radiator but has a much larger cooling surface. I grabbed the mounting brackets off the corolla and fabricated my own radiator mount.


I also found a set of wheels off a 996 with brand new winter tires on craigslist for $500. That was a rare find here in Texas! Most people use winter tires for racing rallycross if they can't afford real rally tires.

[78F350]

Looks good, nice buy on the wheels & tires. One issue with the current Toyota radiator set-up that I don't like is that the fan blows directly on the brake reservoir and ABS unit. I don't know if it's hot enough to really be a problem, but it worries me. I'm going to cut a section of aluminum heat shield from the piece that goes over the transmission and use that to deflect the air across and up. If that doesn't work, just mount a fan on the other side instead.