Breaking in an engine on a race car

[nsx2tall]

Hi guys,

I find myself in a strange predicament. My Subaru has undergone transformation into a track only car while at the same time received a new motor. I've got to break in the motor, but I can't drive it on the street (legal and safety issues). The two most obvious answers are 1) an engine dyno and 2) drive around my office parking lot 10000 times. A certain amount of my own ignorance led me to think driving it on the street would be ok-- not true.

Any ideas or opinions on how to go about accomplishing the break in, or what a good break in procedure would be is greatly appreciated. Would letting the car idle provide any benefit whatsoever?

-RJ

 

[92 white 0650]

Since it's a stock motor, I'd have a knowledgable (or 2 or 3) mechanic or rebuilder advise you on the methods/duration etc. And then go to a track day, pick the appropriate group and break it in that way.

As a single data point, our rotary 13-B motors only get an hour or 2 break-in on the re-builder's engine dyno and then we're good to go. But we set the rev-limit kinda low at 6800.

 

[nsx2tall]

This is actually a 2.5L stage 3 short block capable of doing 8500 rpm and 550 crank hp. In my car it'll only be going 7000 rpm with 270 awhp.

I sent a note to the engine builder asking him to come up with a break in plan that requires A) lots of idling and B) figure 8's in a small parking lot. Those are basically the resources I have at my disposal.

What is the general purpose for break in?

 

[Gansan]

When I had to break in my built race engine (Integra), I set aside a track day with a local club to do it. Of course, we did the normal idling for a little while and driving around the lot a bit, but for the real break in, my builder believes you should run the engine in similar conditions to its primary use. So off to the track we went.

For each 25-30 minute session:

Session 1: rpms below 5000 and 50% throttle.
Session 2: rpms below 6000 and 70% throttle.
Session 3: rpms below 7000 and 80-90% throttle.
Session 4: rpms below 8000 and 100% throttle.

And that's it. The engine's limiter is 9100, but I didn't go to 9000 until the first race weekend. The engine ran with no problems after this through a lot of hours of dyno tuning and a couple seasons (18 weekends or so) until I took it out to get it refreshed.