There are some products out there that claim to be able to improve on the already significant engineering that has gone into your motor. The 4.0 engine in the Jeep Wrangler TJ is well known to be a hard engine to get power out of in terms of "bolt-on" modifications. You don't stand to gain any power on these engines from cold air intakes (that's been debunked by the Jeep engineers themselves in this thread) and another big one that I keep seeing people waste their money on are throttle body spacers.
Designed to be installed between your Jeep Wrangler TJ's throttle body and its intake, these devices claim to be able to create an intense “vortex” of air which will help better atomize fuel when the two are mixed together. According to the manufacturers, this is accomplished by a series of grooves which are carved inside the device itself.
Unfortunately, there are some flaws behind the engineering in this device. From a common sense perspective, if it were really that easy to add significant amounts of horsepower or fuel mileage gains, then these spacers would be stock equipment from the factory.
Automakers need every competitive edge they can get in today’s market (especially when it comes to fuel economy) and none of them are leaving anything on the table in that area. The idea that a “vortex” could help the air and fuel mix together is not a bad one. However in the modern fuel injected engine air and fuel are not mixed together until they both find themselves in the cylinder.
In primitive forms of fuel injection (such as throttle body injection or old-fashioned carburetor models), where fuel was sprayed directly at the throttle body and then mixed with the air immediately before being routed to the cylinders, then perhaps a spacer would be of some benefit. However, the technology used in the Jeep Wrangler TJ's fuel injection system precludes any useful effect from such a device. The chances that the air would still be feeling the effects of a vortex by the time it got through the intake to the cylinder are very low.
Bottom Line: Do not waste your money on a throttle body spacer. They will not give you any power gains on a Jeep Wrangler TJ, or any modern vehicle for that matter. There is no throttle body spacer out there that will give you any power gains on your Jeep Wrangler TJ
Designed to be installed between your Jeep Wrangler TJ's throttle body and its intake, these devices claim to be able to create an intense “vortex” of air which will help better atomize fuel when the two are mixed together. According to the manufacturers, this is accomplished by a series of grooves which are carved inside the device itself.
Unfortunately, there are some flaws behind the engineering in this device. From a common sense perspective, if it were really that easy to add significant amounts of horsepower or fuel mileage gains, then these spacers would be stock equipment from the factory.
Automakers need every competitive edge they can get in today’s market (especially when it comes to fuel economy) and none of them are leaving anything on the table in that area. The idea that a “vortex” could help the air and fuel mix together is not a bad one. However in the modern fuel injected engine air and fuel are not mixed together until they both find themselves in the cylinder.
In primitive forms of fuel injection (such as throttle body injection or old-fashioned carburetor models), where fuel was sprayed directly at the throttle body and then mixed with the air immediately before being routed to the cylinders, then perhaps a spacer would be of some benefit. However, the technology used in the Jeep Wrangler TJ's fuel injection system precludes any useful effect from such a device. The chances that the air would still be feeling the effects of a vortex by the time it got through the intake to the cylinder are very low.
Bottom Line: Do not waste your money on a throttle body spacer. They will not give you any power gains on a Jeep Wrangler TJ, or any modern vehicle for that matter. There is no throttle body spacer out there that will give you any power gains on your Jeep Wrangler TJ