pic of uninstalled Jet TB spacer

95Yukon · December 21, 2001

In case anyones wondering what the inside of the Jet looks like compared to the Helix or whatever brand, here's a pic.

Greg · December 22, 2001

What does this thing do and where does it go?

chevy4x4trucks · December 22, 2001

It's about an inch tall and goes between the throttle body and the intake manifold. For the new trucks it would be one large circle. The purpose of it is to swirl the air. If air is spinning it will move faster. If you like to play w/ water and want to see the principle it works on take two 2 liter bottles and fill them w/ water. Have one person just dump yours over and you take the other one and give it a little spin. The tornado that your water makes allows the water to flow much faster and smoother while the other one keeps glugging. That's the principle behind this. It'll give you a whistling noise and some say that it doesn't increas hp, some say it does, but I haven't seen any actualy dyno tests to prove either way.

95Yukon · December 22, 2001

Some of the designs do whistle, (or hiss) but those are the ones with grooves cut on the inside that go the entire circumference, 90 degrees to the airflow. This one claims to make no noise because of the design. I'll find out today. True, the numbers are probably not actual dyno numbers (which I have not seen either) but the principal of increasing plenum volume, raising up the injectors and spinning the air should give more torque and mileage to some degree. It also acts as an additional insulator from the heat of the manifold so the TBI unit and fuel going in runs a little cooler.

chevy4x4trucks · December 22, 2001

Yeah, I'm not doubting the numbers, I'm just going by what I've heard. I was going to get one for my truck but since I got the K&N FIPK on there I'd have to trim the fan shroud, so I'd rather just leave it as is and put the money in some other mod. Let me know if you feel any power gains.

DigUout · December 23, 2001

Cool -

95Yukon · December 23, 2001

Well, it's on, and there is some difference. You can feel the difference mostly when up to speed and you press down on the gas a little bit, it feels like theres a little more power there in the midrange without having to downshift. It doesn't make any noise.

As a footnote, installation would have taken 20 minutes, had it not been for that one nut holding the fuel line bracket to the transmission mounting bolt. It's the ones that are intensionally out of round so it fought me the whole way off and there's no space to get a hand or ratchet in there. Had to use a wrench and go 1/8 of a turn at a time and then stop to pick the wrench up off the driveway every so often. GRRR ;)

MountaineerTom · December 23, 2001

Glad to hear you got good results from it.

Likarok · January 11, 2002

I put one on a 1990 5.7 with the old sytle trottle body and I felt in comdination with a k&n filter plus removing restrictive air box and replacing with straight air pipe. Hard to say where i gained the power but wow, big difference. Also had Gibson cat back on it to and also remember back in the early 90's the pick-ups did not have the platimun plugs in them so I added those to.

PS I had no whistleing either on the tbi block!!!