A lot of things wound up breaking at yesterday’s Rallycross, however, I would still consider it a success. The biggest problem that I was fighting was the surface of the field; it’s just absolutely punishing on the car. The first thing to rattle loose was the exhaust. Again. This time, though, everything stayed attached to the car, but the flex section slipped off of the downpipe. Not a big deal, but I need to consider how best to fix that. Then there was the overheating. I think the ghetto coolant overflow needs some work, but it might just be that the system is way low on coolant. I seem to recall having to drain a bunch of it out for some reason, and I’m not sure if I filled it back up. Something got into the blades of one of the cooling fans and totally destroyed them. No idea what happened there, but this might be an opportunity to replace the two fans with a single one. The big problem I had, though, was that the intercooler piping kept coming apart on me. When the intake was holding together, though, the car had enough power to actually be somewhat frightening. It was pulling very strong and building a good 8 pounds of boost.
Exhaust
This shouldn’t be too big of a deal. I think I’ll get a more flexible flex section and clamp it on as tight as possible. Another option would be to relax the stiffness of the first exhaust hanger on the straight section. It could be that it’s just too rigid there and needs some play. The biggest problem with doing that, though, is that adding anything to the hanger will lower the exhaust, and it’s already cutting it pretty close to get on and off the trailer.
Overheating
The more I think about this, the more I really think that this is being caused by a lack of coolant. I’m going to check the level and make sure that I’m topped off.
Fan Damage
There are two fans on the Neon. One of them is for the A/C and the other is for normal heat dissipation. I’m not sure which is which nor am I sure under what circumstances the ECU turns them both on. What I might do is pull both of the fans out, install one large one, and wire it to be controlled by Megasquirt. Alternately, for the short term, I may just remove the chewed up fan and then make sure that the remaining fan is the one that gets turned on when the ECU sees the heat get to a certain level.
Intercooler Piping
This is probably the most immediate concern. I could try to use JB Weld or something to force the system to hold together, but I’m thinking that the right way to do this would be to either get aluminium piping with beaded edges and silicone couplers & elbows, or just straight silicone. While the pure silicone hose route would reduce the amount of heat, the materials are pretty expensive. The aluminium, though, would need to be cut to size and then have beads rolled onto the ends. This would be a little more difficult to adjust to get the right fit, although, I do have a perfect template on the car right now. I may go to the storage lot and pull all the piping so I can measure it up, check all the angles, and see what my pricing would be. Regardless of which way I go on that, I am also going to take that opportunity to replace the stock air filter with a cone.
Fuel/Spark Tuning
It’s hard for me to tell where the tune is right now. It seems like it’s running pretty well, overall, when I have boost. I suspect that it’s running very poorly when the intercooler pipe is busted because I’m entering parts of the fuel map that just haven’t been possible before, so the tune is just completely out of whack. So, it’s really hard to tell how close I am at this stage, but overall, it feels like things are pretty close. The one area that I know isn’t quite right is the launch: Revving the motor in neutral and the slamming it into gear results in quite a stumble.