On this particular car they run a wing and while wings do provide downforce they also require a good deal of power to push through the air, because of the drag. Clearly spinning the engine past its power peak would result in a less than desirable condition. Not to mention that as the level of rpm is elevated the loads on the engines components rise significantly. Granted some level of over rev may be required due to how tight the corners may be at a given track, but the data says that a gear change may be in order.

This engine does not have an abundance of power when compared to a 360 or an open 410 Sprint engine and how the car is being driven may be a consideration. The act of backing a Sprint Car into the corner may look cool and be flashy but that kind of driving takes some real power to accomplish. It may make sense to try to adjust the setup on the car to a less aggressive style. The driver may need to blue groove the car or keep the car as straight as possible to avoid scrubbing off to much speed.

Placing an engine on the dyno also allows you to see the engine in operation from a unique perspective that we can't observe while it is in the car in a racing environment. In this particular engine test we were able to see a fuel leak that we wouldn't have been able to detect with the engine installed in the car. There was a cracked fitting in the fuel system that was leaking at high engine speed and at the highest fuel pressure levels. Aside from the tuning issues this type of leak can cause, there was the added component of potential fire hazards created from this leak.

Clearly, once you dyno your engine and develop a data package you are going to have to ask a good deal of questions as to how you can best use this information. I have yet to run into a racer who wants less power. The issue is that no matter if you are a hobby racer or a professional, you are racing. Understanding the type and level of power your engine is developing is very valuable and critical information. This data set can make many tuning decisions much easier. Especially those questions centered on how the final gearing will be set. The gear in the car not only will affect the rpm of the engine, it also will determine how the torque the engine makes is applied to the track. How the car is geared is often a very under utilized tuning tool.

Conversations with your engine builder will let you know just what level of power you should expect from a given package so you will know if you are close or way off base to what a given engine package will develop. If you are in the ball park great, if you are low you may need to do some more work and try to understand just why your particular package is not making the power levels it should. There are some simple rules to follow during your analysis and implementation.

* Don't spin the engine any faster than you really need. If it stops making power at 6,300 rpm there is no good reason to spin it much past the peak. You will just be decreasing the life of the engine and risking expensive internal damage.
* Do not try to read more into the data than is really there.
* You do not need computers and fancy statistical software to make good graphs. Just some graph paper, a ruler, and maybe some colored pencils are all you really need. Scale the graphs to make the data as clear as possible, 500 rpm increments are usually more than adequate.
* Refer to the data often.
* Don't be afraid to ask questions and employ some critical thinking.

This is not as complex as some would have you believe. There are many great engine shops all across the country that will be glad to help you through this process without having to get a second mortgage on your house. Get the data and spend time looking over the results. If you have questions ask the engine shop or the dyno shop that did the work. They have a vested interest in your success.

SOURCE
Renegade Sprint Series RPM Engine Development
1207 N. Miller Rd.
Tempe
AZ  85281