Skip Cannon's Miata Powered Caterham SV

[scannon]

A work in progress, I plan to have it on the road and track by Spring '07. The whole story and more pictures are >HERE:

 

 

 

 

 

http://www.usa7s.com/forum/uploads/20061223_102921_DSC02659.JPG

 

 

 

Skip

[scannon]

New website updates.

 

The project is up and running and will have its first track event on Saturday.

 

Licensing is inching ahead smartly.:banghead: I talked to the highway patrol trooper in charge of assigned VINs today and he has red flagged my name and will call me as soon as he receives the new VIN plate from the state DMV.

[11Budlite]

Skip,

 

You're doing a great job on your car. Keep up the good work and good luck at the track!!

 

Bruce

[slomove]

the highway patrol trooper has red flagged my name

 

That does not sound good.....:nonod:

[scannon]

 

That does not sound good.....:nonod:

Actually, I think it is good as he seemed interested in helping me get the car registered. He said he picked up 60 new VINs to install last week and it may be that his people haven't got to mine yet. All he does is certified VIN inspections and installation of new VIN plates. You have to get reservations a week or two in advance to get the inspection.

[slomove]

Actually, I think it is good as he seemed interested in helping me get the car registered. He said he picked up 60 new VINs to install last week and it may be that his people haven't got to mine yet. All he does is certified VIN inspections and installation of new VIN plates. You have to get reservations a week or two in advance to get the inspection.

 

Just pulling your leg....

[scannon]

First Track Event Report

 

Not a perfect day, but not too bad for a new car that has only about 10 miles on it. The track is the Colorado Highway Patrol training track which is not really a race track, more like regular road with a center crown, but after losing our three best tracks in one month a couple of years ago, we can't be choosy. It is essentially a large triangle with a series of four 90* turns on one side and a large whoop-de-do on one of the others. It is far more a horsepower track than a handling track.

 

A couple of problems were obvious right from the start. The engine was running rough and would go off song between 3,500 and 4,500 rpm, losing power and making funny sounds. Below and above it was strong, especially above. I downloaded the fueling and timing maps and comparing them to ones from my Miata decided there was a lack of fuel across the board so I used the master fuel control to enrichen the whole 96 zones. This helped some all around but the gap at 3,500 - 4,500 didn't improve much.

 

There was also a problem with the oil pressure gage. It would flicker up and down, then off. I had seen this before in the few street drives and it seems to be a problem between the British spade connector on the sensor and the SAE connector on the wire. I decided to ignore this and press on.

 

Handling seemed soft, but I decided to spend my time on engine tuning and live with the handling. I had the tires at 20 psi front and rear (cold) and since I couldn't find my tire pressure gage, just left it alone. I'll work on handling next time. I think there are probably stiffer springs and shocks in my future. I will also get the adaptors made soon so I can use the Miata track wheels and tires.

 

Most sessions were short until after lunch when I decided to try to keep the revs over 4,500 and see if it would overheat. So far heat had not been a problem even with the air temps hovering around 100* except that the cooling fan wasn't adequate to cool the engine after a run. The temp would actually go up in the pits without the benefit of moving through the air. I will get a larger fan and see if that does it. I ran 10 laps using full throttle down the long straights and eventually hit the overtemp limiter set for 110*. The limiter puts the ECU into limp home mode allowing only 3,000 rpm. I got about 1/2 lap at a much lower speed and pulled into the pits. Knowing the fan would not cool in the pits, I shut it off and after a few minutes, heat soak over filled the recovery tank and dumped a bit of coolant on the ground. Once it cooled off, the pressure tank sucked back most of the coolant left in the tank so perhaps I had too much in the tank to start with. I might need a larger recovery tank.

 

During this last session I had the laptop onboard and connected to the ECU and dataloged the whole session. Looking at the data, it appeared that there was a problem with the throttle position sensor data so I decided to calibrate the sensor again. This involves taking a reading at no throttle and at full throttle and ajusting the ECU to a value of 10 at idle and 100 at WOT using the keypad. As I pushed the throttle to WOT (engine off, key on) the throttle felt funny and the pedal stayed on the floor. After checking things out, it appears that the problem is the throttle cable as after freeing it up and disconnecting it from the throttle body, I could feel a grittiness moving the cable back and forth. At this point it was time to call it a day and load it on the trailer.

 

The last session was fun even with the above problems. I was feeling comfortable with the handling and braking and pushed it much harder that before. I will replace the cooling fan, throttle cable, investigate the TPS and have the experts at Flyin Miata take a look at the datalog.

 

Tomorrow I have an appointment with the Highway Patrol to get the new VIN plate attached to the car and then I should be able to register it and do some street driving and tuning of the ECU.