Turdbo Neon

After talking to Tim, he convinced me that getting some pre-bent exhaust tubing and welding it together would be a good way to get the intaking plumbing taken care of. So, I got a couple 2.5″ OD U-bends from Jegs for $17 each and took them over to Tim’s place. He helped me cut them up and weld them back together, with a slight change from the original plan. I’m going to keep the 2″ metal piping that runs out of the turbo. At then end of that there is a rubber adapter that used to go onto the PVC. The new intake tube will fit onto that coupler, go up, over the right-side engine mount, and then back down into a rubber 90 degree elbow on the intercooler. A smaller pipe will replace the PVC that used to go between the rubber elbows on the throttle body and the intercooler outlet.

I test fit the pipes the other night and it takes some forcing to get the wider OD pipe between the cam cover and the strut tower, but it will fit and it looks pretty good. The hood will even close, which is a bonus. I ground down the welds tonight and applied some JB Weld to the joints to improve their air-tightness. Tomorrow, I’m going to prime and paint the tubing.

In cooling system news, I put some Bars Leak in the radiator and ran it for about 15 minutes. The coolant stopped dribbling out of the radiator core and started more of a steamy hiss. Chris Greenhouse offered me a radiator and fans from his parts car, but he isn’t going to have time to procure it before the Rallycross on the 7th. In the meantime, however, he offered to let me borrow his rally spare for this event, so I’m going to pick that up tomorrow. I’m planning on trying to drive the car around the storage lot a little bit on Friday to see if the Bars Leak will fix things up, and if it doesn’t help, I’ll swap the radiator for the event and then take it back out when I return.

I did some measuring and now I need to determine how to build the piping for the intake.

Turbo outlet = 2″ OD
IC Inlet = 2.5″ OD
IC Outlet = 2.5″ OD (oval)
Throttle body inlet = 2.5″

Turbo -> 90 bend -> 15.25″ straight -> 90 bend -> 9.5″ straight -> 45 bend -> 9″ straight -> 90 bend -> 6.75 straight -> 90 bend -> Intercooler -> 90 bend -> 5.5″ straight -> 90 bend -> 7″ straight -> 90 bend -> throttle body

I stopped by the storage lot today to try to start getting things ready for the next event that I’ll be able to make, in August. I managed to get all of the intercooler piping out of the engine bay, but in the process, I noticed that there was a fair amount of coolant pooled on and under the trailer. Since the trailer is, uh, air-cooled, I’m figuring that the Neon is leaking. It appears to me that whatever chewed up the cooling fan also opened up some of the coolant passages in the radiator. What I would like to do is replace the radiator with a new one that has a single large fan on it. I don’t have anything with me today that I can use to take measurements, but I’ll come back and see what kind of clearances I have to work with.

Something else that I want to do is find the wiring diagram for the car and figure out what I need to wire up so that the fan turns on when the car is host. The two fans are daisy-chained so there’s only one set of wires going to both fans, but I don’t know what that wiring is set up to do.

In the meantime, I’m going to take all of this piping back to the house so I can measure it and decide what the best route will be as far as replacing it. I can get a section of 2.5″ exhaust pipe for very little money and then prime and paint it to prevent it from getting nasty and rusty. I can either have that pipe bent to just the right shape at a muffler shop, or I can cut straight sections and manage the bends with silicone elbows and T-clamps. While I’m at it, I’m going to get a cone air filter and an intake pipe for it. That should clean things up in the engine bay a little bit.

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.

So, I may have been frying those modules because my dwell settings were incorrect. I got the replacement module (Besslers again) and got it installed, and everything is humming along. I set the dwell to fixed, 7ms cranking and 4ms running. I also kept the heatsink attached. In order to fix it for the long term, I went back to Glen’s Garage and ordered up a transistor kit that will take the place of the 4g63 module.

For now, though, I’m going to enjoy having fire on all four plugs. The only question/problem that I’ve got now is how the tune needs to be changed.

I sourced a new coil from Besslers. Thirty freaking bucks. If I would have known it was that much before I trudged all the way back to the gate, I would have just bought a brand new MSD or something. Anyway, I still didn’t get spark on #4, so I dug further. As it turns out, I think I was only running on 2 cylinders, because neither #1 or #4 have fire. I did a complete test, first swapping OC1 with OC2 and then IB1 with IB2 on the power transistor. While switching the coil outputs changed the spark so that #1 and #4 had fire and #2 and #3 did not, changing the inputs from the Megasquirt had no effect. I’m going to try the other you-pull lot here in town this week to get a new power transistor and that should get things working again.

get it?

I removed the whole exhaust system (or, at least, what was left of it), and decided to make sure it was really fixed. The front section was a little misshapen from dragging along the ground, so I hammered it out and then, using a block of wood, hammered it into the rear section. Once it was pretty firmly seated, I took a u-bolt clamp and torqued it down until I thought something was about to shear. That seemed to do the trick. I threaded that back through and connected the flex pipe in the front to the manifold, again with the torque. Should be good now! (famous last words).

I replaced all of the injector pigtails the other night with some connectors that I pulled off some Dodge in the junkyard. These are actually the correct types of plugs, so they snap in to place and don’t need bailing wire to keep them attached. I was operating under the theory that the car was running on three cylinders because one of the injectors wasn’t getting power, however, I managed to prove that point wrong. As it turns out, #4 isn’t getting any spark. I can get spark using the #4 wire with the #4 plug when it’s connected to the #1 position on the coil, but I cannot get spark on anything connected to the #4 coil position. Next step is to test the coil.

I was unable to return from Dallas in time to get tires mounted for the 01MAY2010 rallycross. The 05JUN2010 event, however, went much smoother!

I picked up two 14″ Neon rims from Besslers as well as four injector pigtails with actual clips. I had the Kuhmo R700s mounted to the front and two of the old Bridgestone Potenzas mounted to the rear. The front passenger side needs new lug nuts and studs in a bad way: there’s a whole lot of stripped nuts. The day went sort of like this:

– Car came off trailer and made it up the very steep hill, no problem.
– First run was over 80 seconds. Ignition was waaaay retarded.
– After fixing the timing by advancing it about 10 degrees across the board, I was able to run around 52 seconds.
– Third run, the exhaust came loose in the middle and was dragging. I decided to ignore it.
– Fourth run, the front exhaust section came off of the downpipe. I retrieved it from the ground near the finish line.
– Fifth run was pretty good, but I got a re-run because timing was screwed up. I decided that one of the noises I was hearing wasn’t something banging around — it was detonation.
– Sixth run was pretty good. Still in the low 50s
– For the seventh run, I adjusted the fuel table a bit to get things a bit richer when in boost
– Right before the eighth run, while I was idling and stationary, the car started making a different sound. It sounds suspiciously like a car that’s running on only three cylinders. Run time was right about the same as before.
-Ninth run was also on 75% motor, but still right in line with the other times.

The exhaust needs to be patched up better. The injector pigtails need to be replaced. The lugs need to be replaced. The fourth cylinder needs to come back online. All before the 26th.

I did come across a four-door 97 R/T with a manual transmission and some clanking in the engine. I’m thinking about trying to pick it up as a parts car to do the manual conversion, use the whole exhaust, and pick off the lug studs and nuts. Then I can part out the rest and haul off the shell. Alternately, I could pull the turbo motor from the Sport coupe and put it in the R/T and have a driver with a clean title. We shall see.

I’m leaving very shortly to go to Dallas for work, however, I had a chance to get some parts and make some magic happen today.

I went out yesterday and got a new tube and gasket from the Dodge dealer. I still can figure out how I never noticed how warped that flange was. Upon returning home to install it, however, I managed to drop one of the bolts and I simply cannot find it. I went to Pep Boys today and got some replacement bolts so that I could continue.

I cut the hard tube short so that it would fit properly, and I removed the red 5/8″ tube that I was using and replaced it with the blue -10 AN hose. I know that I have some AN push-lock connectors and other stuff around here somewhere, but I’ll be danged if I can find them. Pep Boys thinks that they carry AN fittings, but what they really have is NPT stuff. Which I don’t want.

For now, I put a tiny flare on the end of the tube and roughed it up a bit to try to keep some bite. I put it all back together and started it up and no more oil spewing. There’s still a little drip from the oil pan where the return bung is located, but it’s not a big deal in my opinion.

Long-term, the turbo needs to be rebuilt, and I’ll probably do that this winter. At that time, I will also get the right AN fittings to do the return line “right”, which will also involve dropping the oil pan out and putting an AN bung on it. For the 2010 RallyX season, though, all I need are tires and a little fine tuning of the fuel map.