| They used to call it "snake oil", something of dubious | | | | plate would be one where it could be controlled by |
| value sold as a cure all for any medical condition. | | | | the driver, maybe by his foot." Oh yeah, we already |
| Nowadays, the consumer assumes that there are | | | | have that. It's called a throttle plate and accelerator |
| enough laws to protect the consumer from false | | | | pedal. The magazine review was favorable, probably |
| advertising. However, in a highly specialized market | | | | to get advertising dollars. Even if you want to kill |
| like racing, companies can get around the "false | | | | power for traction control, this is NOT the way to do |
| advertising" rule by pushing the limits on what they | | | | it. A restrictor plate does not kill low RPM torque that |
| say, but not going over the line. | | | | much, like coming out of the corner where you need |
| A good example of this are the "split" electrode | | | | it for traction control. However, it does kill top end |
| spark plugs. (We are not going to use actual product | | | | HP, where you want as much as you can get and |
| names, hopefully to keep us out of court.) The claim | | | | are not worried about breaking the tires loose. |
| was that you had 2 sparks to better ignite the | | | | Now in defense of some of these products: |
| mixture. That would be an advantage if it were true. | | | | Carb spacers canhave an effect on performance, but |
| However, the spark will jump from just 1 electrode, | | | | not from swirl. Their insulating properties can effect |
| not both, for each firing. On the next firing, it could | | | | the carb and fuel temperature in some conditions. |
| jump from the other side, but never from both at | | | | Their height and design can effect plenum volume, |
| the same time. If you notice the recent ads, they | | | | intake tuning waves, and possibly A/F distribution. |
| show just 1 spark from 1 side of the split electrode. | | | | These can be real (although small) effects. But swirl is |
| Something the racing consumer must realize is that | | | | not one of them. |
| products are made by companies who purchase | | | | Also, in this era of Electronic Engine Controls, an |
| advertising space in magazines. A magazine has no | | | | engine modification could affect how the computer |
| reason to give a poor product review to advertisers. | | | | "sees" what the engine is doing. This in turn can |
| The more advertising you see for a product, the | | | | affect the amount of spark and fuel the computer |
| more you have to take editorial reviews with a grain | | | | delivers. A good example of this is a recent claim that |
| of salt. | | | | an air cleaner and inlet tube change produced a 50 HP |
| Some recent products which are making some | | | | power gain on a 500 HP production engine. There is |
| unrealistic claims include: | | | | actually some truth to this claim. What happens is the |
| The "twister" that you put in the air inlet tube to | | | | air filter and inlet tube "screwed up" the air flow going |
| induce swirl to the air/fuel mixture to promote better | | | | into the air meter. The controller thought the engine |
| burning. Well, we sell swirl meters, and swirl induced | | | | could use more spark and less fuel (leaning an overly |
| right at the valve to the mixture going into the | | | | rich condition) and it produced more power. The air |
| combustion chamber can effect burn rate and | | | | cleaner and inlet tube by itself would likely have only |
| performance. However, any swirl induced up by the | | | | a 10 HP affect by itself. Now, after you leave this |
| air cleaner can have little affect on the mixture | | | | modification in place, the controller adapts and most |
| motion as it enters the combustion chamber. What | | | | of the power gain goes away. |
| the "twister" can do is provide a huge restriction to | | | | You may ask, why does the production tune not |
| air flow, drastically hurting performance. This is a | | | | produce optimum power. For most engines, |
| product which actually does the opposite of what it | | | | production tune is near optimum. However, new EPA |
| proposes. | | | | requirements for emission tests to go into full power, |
| You've probably also see the carb spacers which | | | | government engine noise requirements, catalyst heat |
| induce swirl. Again swirl under the carb is gone by the | | | | (grass fires) restrictions, emission component |
| time the mixture gets into the chamber. | | | | durability, general engine durability, put all sorts of |
| One new product recently reviewed in a magazine | | | | demands on the automakers. When you have very |
| was a variable restrictor plate. For those of you who | | | | high output engines, the automakers may have to |
| don't know, a restrictor plate is a thin flat plate with | | | | limit full power for government requirements and to |
| 2 or 4 relatively small, precise holes placed under the | | | | keep their warranty costs down. This is the reason |
| carb. It is required by some circle track classes (like | | | | for aftermarket chips and other calibration adjusters. |
| Nextel Cup on the super speedways), to limit engine | | | | They can improve power, but at some cost in some |
| power and top speed to keep things safer. Well this | | | | other area, typically an area of no concern to most |
| device is being sold as traction control. It's claim is the | | | | motorheads. |
| crew chief can dial in this air restriction to limit torque | | | | So when you read the magazines, keep your guard |
| coming out of the corners. As I read it, I was | | | | up. Not everything is as it is sold. |
| thinking "The next generation of variable restrictor | | | | |