What is a Break-In Tune?

Updated: Mar 2, 2020

Conventionally, a startup tune is an ECU calibration with a best-effort guess as to the settings you will need to get your car running after a major change.

For example, if you install a large cam, your car will need some additional airflow commanded to actually stay running, without your foot on the throttle. A mild factory idle setting of 500rpm isn't suitable for most cams.

Many changes can make a car un-drivable at a time when you frankly just need it to work.

- Cam Swaps

- Cylinder Heads

- Larger Fuel Injectors - MAF / MAP sensor changes - Transmission Swaps - Drive By Wire throttle changes

The OnKill Difference

Having performed a number of cam swaps, and plenty of major engine modification, I know how crucial and time consuming the initial run-in of new parts can be. When you take a motor apart to modify, you introduce contaminants, and disturb parts that may have been fastened since they left the factory. The more you unsettle, the greater chance for trouble.

A startup tune from us is your chance to have Ryan (our tuner) look over your vehicle during its first heat cycle, in hopes of preventing problems that would otherwise stop us from being able to tune your car.

When we are on-site writing a break in tune for your car, we make sure it will start and idle when it is cold, and after it has reached operating temperatures. We additionally do a best-effort check for exhaust leaks, vacuum leaks, misfires, and other common build related problems.

Most of you are mechanically inclined. I'd rather tell you what your car needs and give you the chance to fix it yourself, than have to charge you hourly to do the same repairs. It saves you money, and allows us stick to what we specialize in.

What happens after the break in tune?

After your vehicle has a break in tune, you'll be able to drive it around and put some miles / heat cycles on its new build. This is your chance to work through issues before bringing it to us for your final tune. As there are contaminants and foreign chemicals (assembly lube, etc.) in the motor from putting it together, we ask that you change your oil before coming for a tune. Tuning is hard on a motor, and the last thing we want to do is expose it to stress when the oil is contaminated.

Does this cost me more money? Planning on a startup tune can actually make your tune more affordable, considering that it will allow you to split your total tuning cost into two installations. One charge will occur during the startup tune, and another after the final tune is complete. Getting a startup tune at your home may also save you the cost of towing your undriveable vehicle to the shop for calibration.

Call us today to work out the details of your startup tune!


(417) 986-5455

306 South Washington Street Walnut Grove MO United States 65770