[y5e06]

While out on my run last night I was pondering the issues I'm having w/ my new clutch (arrghhh!). I then began to wonder, "How do race cars break in their clutches when they can't drive them easy on the street first?" So that then expanded to other items such as engines, rear end (gears), etc.
If the car isn't street legal, and you need to put in 500 miles or so on a specified part to break it in, what do you track only guys do? Are the items you use 'race only'? i.e. they don't require the same breakin proceedures and come near 'ready to use'? What methods are used on a clutch, or even an engine, when you can't put in those easy miles before beating on it?

[CMC #37]

I can relate to all of this having essentially replaced everything on my CMC car at one time or the other. Two seasons ago I decided to change gear ratios and posi. The car dynoed fine and my sponsor ran it on his own dyno (a smog dyno) also to help with break-in. I went to Thunderhill for a test day a week before our first race at California Speedway. First lap I babied it, going into turn one on the second lap *BANG* and lots of noises you know ain't the good kind. My new gears and posi were not set up right and this is not something that showed up on the dyno. So, I was faced with a decision, whether or not to go to California Speedway without a test day to see if the new gear set and posi was going to be good. I decided not to, and that turned out to be a great decision as that is our highest speed track (150mph+ on the banking) and doing that with a new gearset would be really foolish. Heat cycling and not too much at one time for new components is the name of the game.

Test days are gold - I teach and earn track time at Thunderhill, perhaps other tracks offer the same deal? I also instruct for NCRC for free track time during that day, other organizations like NASA have that same deal. This is ideal for keeping your skills sharp and those all important break-in days!