11 replies to this topic

[stewart]

Thanks for recomending losing Hard Dog bar and getting caged in my last post "seat troubles". I'm picking up car from Mark in Akron Monday and want to continue build throughout the winter. Here are my questions; What gauges are truely neccessary? Do most racers have push start ignitions and kill switches? What to do with thermoastat (read thread with mixed feelings)? Just trying to do it right the FIRST TIME!!
stewart

[Keith Novak]

Push start buttons aren't legal. Kill switches are required and really important. (Read up on the rules now before doing too much stuff.) You definitely want a water temp gauge and an oil pressure gauge and I'd recommend idiot lights for both.

I've made a habit of checking my water temp gauge frequently and it's saved me motors. Even the best cars sometimes spring a leak somewhere, especially if work has been done recently. If it runs nice and steady all the time, you may stop looking at a gauge so a light saying, "Hey look at me NOW!" is a good thing. Don't know about the 99 but with my 95, the stock OP gauge is really an on/off switch, not a real gauge.

For the thermostat question, you'll have to see where your car runs temp-wise at your local conditions. My car often runs too cool unless I block part of the radiator. Others in hot places where the rain setup is jackstands and a folding chair complain more about overheating. I don't think there's a magic formula.

[dstevens]

Most race cars have push button starts. Just not allowed in SM. Gauges at a minimum are tach, water temp and oil pressure. I wouldn't use either street car gauges or sensors and go with some good VDO or Autometer gauges. Some guys in SM have fuel gauges. I'm of the race cars don't have fuel gauges, except maybe for pressure camp. I've got a basic 6 ch data system for my car. Those basic gauges will keep you from tanking the engine, hopefully. For improving driving some sort of lap timer is a must. And an inexpensive camera is a good idea too.

[KentCarter]

Attach a yellow warning light to the switch on the t-stat housing that controls the fan... it comes on around 207F or so. That gives you a heads up to watch the gauge. Mine is next to my AutoMeter temp gauge.
A red light that comes on at 250F is a good idea if you still can't watch the gauge with a yellow light on.

I have a flashing red LED on my dash next to my AutoMeter pressure gauge. It comes on at less than 20PSI. It often flashes at idle when the engine is warm, but never at pace.

Make sure your Alternator light works. It's the first sign you've lost your waterpump belt.

We have experimented with a coolant pressure switch to try to detect a holed radiator, but haven't found that the Miata coolant circuit builds up much pressure. Makes sense since we usually run about 200F with the big radiator, so there isn't much pressure made.

[stewart]

Running one more year of HPDE and practice sessions would you recomend putting in the racing radiator so I get used to where the car runs temp wise and learn to watch it? I know it's going to run cooler than racing due to spacing of the cars.

[Keith Novak]

Absolutely. Sure it's going to run cooler than during a race but as a friend of mine says, practice doesn't make perfect. Perfect practice makes perfect. You want all the data you can get. You don't want to be figuring it out on race day if you can avoid it.

You definitely want to take note of where your car runs normally at speed so you don't get surprised on track and start questioning what the gauges are telling you which will consume valuable brainpower you should be using to drive the car. Then when something gets out of the normal range, you know it's something you really should consider. You also don't want to be testing new equipment on race day if you can avoid it either. Anything brand new is an untested potential failure point.

[Keith Andrews]

+1 on the light in the gauge, I learned by watching my in car video I had driven my car for half a race with higher than normal water temps. I new my lap times were way off and it wasn't until I saw my video at home after the race that I realized what had happened. I am changing gauges to add an "idiot" light to the gauge face.

[KentCarter]

Oh... and I 'clock' my instruments so that normal is straight up. If the needles are all pointed straight up, all is well.

[Randy Thieme]

The factory tach is OK but you may want to "calibrate it" Learned this trick from another racer. Remove the clear protective plastic and place a piece of masking tape behind the needle around red line. Take the car out with a pen or pencil and redline it (in gear) a few times so the rev-limiter kicks in. Don't use 1st gear as things will happen too fast. Carefully mark on the tape exactly where the needle is when the rev-limiter hits. Double check the mark by redlining a few more times. Get some model paint and put some marks on the dial so you know exactly when the engine is about to hit the rev limiter and not 50 RPM earlier. Eventually you may want a shift light but this trick is cheap and will work for now.

Water temp and oil pressure are minimum. The factory oil pressure guage is not worth anything. Get a remote oil pressure sensor kit. It's basically a manifold block you mount on the fire wall with a SS braided line from the engine block to the manifold. They usually have around 3 - 4 tapped outlets, one for the inlet and 2 or 3 left over for both an oil pressure gauge and an oil pressure switch connected to an idiot light.

The water sensor typically goes into an aluminum block inserted either in the radiator hose from the thermostat or in the heater hose in back of the engine. Diverse opinions as to which is best. You'll need to match the threading of the sensor with the threading of the block. By that I mean if the sensor is 1/4" NPT the block will need to be 1/4" NPT or you'll need adapters and it will quickly become a kluge. Shop around for sensors - check several vendors before buying. I bought one sensor and the business end was about 1/4" diameter and 1" long, big enough to start interfering with water flow. So be picky about the sensor you buy because there are some bad designs out there. For an idiot light you can connect an LED to the wires that power the cooling fan, or buy a dedicated water temp switch. Radio Shack sells 12VDC LEDs which are easy to use. No calculating what resistor to use and then soldering the thing together as they already come with the correct resistor attached.

Thermostats are an area of diverse opinion as you will find out.

+1 on "clocking" the gauges so normal is straight up.

[stewart]

Thanks for replies. Another 99' in the works, with your help.

[KentCarter]

Whatever you do, get rid of the factory temp gauge. No worky right. It's worse in some ways than the psuedoidiot light oil pressure 'gauge'

[Blake Thompson]

Thanks for recomending losing Hard Dog bar and getting caged in my last post "seat troubles". I'm picking up car from Mark in Akron Monday and want to continue build throughout the winter. Here are my questions; What gauges are truely neccessary? Do most racers have push start ignitions and kill switches? What to do with thermoastat (read thread with mixed feelings)? Just trying to do it right the FIRST TIME!!
stewart

If you're building a car I will go out and assume you don't yet have your license. I spent a lot of time reading the GCR before my first build and first school, the kill switch install isn't trivial and it's an important part of your build. Download or get a physical copy and take it to the tiled office with you

I agree about the factory temp gauge. Useless and it has cost me a lot of money and a 2nd place finish. I'm not particularily fond of the factory fuel gauge either, I rely on my scale and calculator instead. I have been through a FEW of the factory oil press and gauges, and one time I hit a pothole in corner 5 at BHF and my entire gauge pod shut down. I removed it and analyzed the bus in the rear but couldn't find a problem. Went over my fuses too, no luck. Since I have parts I swapped in a new gauge pod which "fixed" the problem. Kind of puzzling but it did have nearly 250k on it.

OH YEAH, I have broke a few speedo cables too (stop laughing, 99ers), it's annoying. My racepak manages to keep pretty good track and stand in for the 20 year old stock analog equipment. I've seen a lot of folks lately just covering the factory dash entirely and ignoring it. I'm not so confident of my electrical abilities