Hello, I figure a good introduction is to show you what I've been working on lately. I'm James, I'm 28 and I live in Shakopee by the way.

Anyway, my dad and I got involved in something called the Chump Car racing series. It's endurance racing for $500 cars. It's a good change of pace for us as we used to run the local events at Shakopee and Elko. 1 or 2 endurance events is easier to schedule than 20+ shorter events. As for our car, we race a Chevy Chevette that we stuffed a turbocharged Mitsubishi motor into with a Mustang transmission. We bought a custom bellhousing to convert the motor to rear wheel drive. The guy who made it is amazing. http://projectzerog.com/forum/viewtopic.php?t=1875 Aside from that, every other custom part was made by my father and I.

Here's some pictures and video from our last race a couple of weeks ago.
http://www.missedshift.com/2011/09/project-jdmvette-synopsis/

I'm going to become a member before winter and I'd love to figure out how to get a trailer to the space to show this thing off.

I also need help from you guys addressing a few issues.
1)The tach currently reads at 50%. The ECU outputs 5v ad the tach needs 12v, so I'm currently pigtailing off one of the coil packs for now. There are 2 coil packs so I'm only reading half. I need to figure out how to convert a 5v signal to 12v. Hopefully a sparky can help me with that. MSD sells a box but it's $90. I'm sure there's a cheaper solution.
2)The stock brakes suck. We need to figure out a combination of factory parts to upgrade them. Parts store availability is key, I don't like using custom parts. They make track side repair harder.
3)Can anyone weld aluminum? We need to add a radiator cap to our radiator. Our radiator hose setup is very mickey mouse and our current setup isn't ideal.


Thanks for inviting me into your community.

Welcome carracer! As for #1, is it a voltage source or a signal? I don't know much about cars, but I could help you get 12v by either a converter or transistor, but it depends on the answer of the last question. If it's a signal, then I also need to know if it's bidirectional. If it's a voltage source, then I need to know what current is needed and what current is available on the 5v line.

The tach signals from the coil packs at least will be a pulse each time a cylinder fires. Take the tach wire from each coil pack through a diode, to prevent any possible interactions between the packs, and then connect both to the tachometer. Should work, in theory anyway.

mcsteve's right. The coil packs are the proper place to get the tach signal. All you need are a couple diodes and you can feed the pulse train from both packs into the tach. Either that, or check the tach - some aftermarket ones can be reconfigured to double/half the incoming pulse rate.

Thanks for the help. I don't know anything about diodes, how do I select the correct one? Is there a best one for my setup? What's the best way to wire it so that it is vibration, water, and heat resistant? I'm guessing I just solder them inline and then join them after.

Setting dip switches on the tach is out, it is adjustable but it only halves the signal again with the 8 cylinder setting.

CarRacer,

That's a great project! I love the old 'vettes... chevettes that is.

I'm currently working on my own Frankencar - An '85 Toyota Corolla with a Lexus V8, Supra transmission and Ford Explorer rear end. There's a couple of Checy parts in there, too. It's a ways from being done, though. It might be a ChumpCar someday.

I don't know a lot about tachs other than it's generally picked up off the IGT pin on the ECU (in Toyotas, anyway). I'd have to look at your wiring (physical or schematic) to see how you're getting signal and why only half. Which motor is that, the 4G63?

Anyway, welcome and I'd love to see your car some day.


Jon