The racing is tight and you...
The racing is tight and you are looking for anything you can do to give yourself an advantage down the stretch. Here are some ideas.
The season is winding down. With only a handful of races left, you are looking to make one final push in the standings. Or maybe you have yet to win a race this season and are willing to take a few more chances than before to finally grab that brass ring. After all, you almost certainly will have the engine refreshed during the off-season, so if there was ever a time to gamble this is it, right?
With that in mind, here are 10 tips for squeezing out a little more power from your race engine. Not every tip is guaranteed to apply to you, but they can help you get the wheel turning for other ideas to bump up the power for the last few races.
Late in the season, the cooler...
Late in the season, the cooler weather can allow you to make a jetting change to make more power.
RESET THE JETS
We may not think about it much, but race cars are quite temperature sensitive. This can be a pain in the summertime when the track feels slick and the car is constantly on the edge of overheating, but as the temperatures cool toward the end of the season, it is time for you to take advantage.
One way to do this is by taking a look at your carburetor jetting. Typically, in the early fall the air not only cools down, but also loses humidity. You may find that the carburetor jet settings that worked well for you in July are now a little too lean. This is because the cooler air is denser and more of it is flowing through the venturis. You may find that you can actually coax more power out of your engine by fattening up the jets a little bit.
SLOW THE FLOW
If you are running a stock-size water pump pulley on your race engine, you should be able to free up a horsepower or two by running an oversized race pulley, a smaller crankshaft pulley, or a combination of the two. The resized pulleys will slow down the water pump's impeller. Since the pump is not trying to push coolant through the block's water jackets as quickly, less power is required. Stock-style water pumps are designed to flow enough water through the engine to keep it at proper operating temperature after long periods at idle. This is a good idea when you are sitting in traffic trying to get home from work, but it really isn't necessary on your race car. At racing rpm levels, the typical pump is trying to push way too much volume. Also, race-quality pulleys are usually constructed from aluminum, and even though the pulley may be larger than stock, it will still have much less rotating weight than the stock stamped-steel pulley.
Also, if you are running a flow restrictor in your water neck, get rid of it immediately. The idea behind the restrictor is to slow the movement of coolant through the engine to allow it to draw more heat. But the combination of a restriction to water flow and a fast-spinning water pump is not only a big drain on power, but also the cause of pump cavitation, which aerates the coolant and destroys the system's efficiency. Furthermore, the speed the coolant travels through the engine really has no effect on overall temperatures.
Esslinger Engineering is now...
Esslinger Engineering is now offering Mini-Stock racers a three-step header that is designed for Midget racing and capable of producing significant power gains over most other headers out there.
Toward the end of the season, many racers begin planning the upgrades they will make to their race car during the off-season. Esslinger Engineering's Cary Maruyama believes that instead of waiting, this may be the perfect time to spend a few bucks wisely on products that will help you this season and next.
"Usually you can do a couple of bolt-on pieces here or there that will help you more than anything else," he says. "At Esslinger we specialize in Ford four-cylinder engines, so that is where my experience lays, but some of these will work with any engine.
"A windage tray is an easy upgrade if you don't already have one. It just bolts to the main caps, and they can literally gain you over 10 hp. That's about the best bang-for-the-buck that you are going to find anywhere and it doesn't require tearing into the engine.
"On the Ford four-cylinders, we can help guys pick up some serious horsepower quickly by upping the compression. A lot of times, if a guy is only running 10:1 compression and racing with 110-octane race fuel, we can take him up to 12.5:1 easily by shaving the cylinder head. I've found a lot of times guys won't have as much compression as they think they do. They won't know the cc's of the valve reliefs in the pistons, the thickness of the head gaskets, and other things like that. If we find they can use more compression, they can send us their cylinder head and we'll take care of it for them. The Ford head is an overhead cam configuration, so you can cut the deck and put it back on without worrying about screwing up the valvetrain geometry.