Throttle body spacers

Anybody using one? What are your impressions? Did you get more power? Better MPG? Anything?

Hardly noticeable other than a whistle. Adds nice underhood bling though. :rof:

you're probably going to hear all kinds of opinions across the board about tb spacers. a lot of people swear they're a complete waste of $$$, and i believe that's true on some motors. with a good intake design, it should be totally useless(unless you're running a carb and using an insulating spacer to keep the carb cool). the 4.0, excepting the 99-up motors, doesn't have a very good intake design. i believe that it makes a slight difference in both throttle response and top end by lengthening the very short, very abrupt turning plenum. i've got bored out tb's and spacers on both my '88 and the '96 and i have pulled the spacers out, run the jeeps, and put the spacers back in again. i can tell the difference. i'm fairly certain that the superairvelocitydoublehelixvortexswirl-bore couldn't possibly do a damn thing though. my '88 whistles like a turbo diesel, the '96 is absolutely silent....who knows?

If you do get one, make sure its 62mm straight through because it wont split up into 6 "mini-vortexs" haha.

i should also note that i drive both xj's like go-karts and the tach needles slide into the red zone with regularity. some jeeps never see that kind of top end use.

The smooth bore spacers are the good ones. But not much of a difference.

Dr. Dyno has mentioned several times that he used a stopwatch to estimate the hp/tq gains.

I think he said like 2 hp/3 lb-ft overall, but like 5 lb-ft gain at low rpm.

My 93 ThumperXJ only benefits from the smooth bore spacer as stated by High Ten. I did the stopwatch thing and also calculated fuel mileage over a four week period both with and without the spacer. "Seat of the pants" increase in throttle response was noticeable, but the times were in the hundreths of seconds. IMO, it would be better to change up to a more modern design intake if yer sporting a late 80s early 90s, and rather unnecessary on anything with the "New design" Intake.

Something from Gojeep's website. He's a member here too

http://go.jeep-xj.info/HowtoTBspacer.htm

They work on a 4.0 because it raises the throttle plate out of the intake for when you open the throttle if nothing else.