Does a throttle body spacer really work on a 2004 Chevy/ GMC Silverado/ Sierra 5.3? I only ask, because I read in a performance magazine (I for got which one)that a throttle body spacer only works if it has both AIR and FUEL flowing and mixing while goingthrough it, thus allowing a farther drop into the plenum; such as, a TBI system.
I only ask, because I was looking into one, but like I said I read that magazine article and have mixed emotions on it. And after reading the forum post I am still having mixed emotions.[sm=WTFsgign.gif]

Also I have the K&N series 77 CAI and I see I will have to modify the Fan shroud to make it fit correct? Also how will it affect my performance and MPG? Does it whistle? And will I have to reprogram my computer again with my Hypetech? [sm=feedback.gif]

 

as you can see from my sig i have the exact set up that you are looking for.
you do not have to modify the fan shroud to make it fit. just a little elbow grease an a tight fit to the throttle body will make the tube bend around the shroud(slightly) and not effect the inake flow too much.

just do a quick search on this site and you will find that alot of guys on here have a similar set up and are very very happy with it.
the tbs created a huge gain in throttle response from the engine, as well as a little better MPG and a stronger pull all the way through the motor.

go for it man, and if you have any more questions hit me up!

good luck.
also to eliminate the whistle go with transdapt... it hasnt on me yet!

 

Get the torque curve, more noticable results under normal driving

 

I was told that w/o modifying the shroud, i'd have a hard time to get a TBS on with my K&N FIPK. I still would like to know any pros or cons to adding a TBS. I have the single in, dual out catback system, and the K&N CAI. I have the 4.8L. How thick is the TBS anyways? I already modified the shroud a little bit when installing the CAI. Is there a noticeable difference, and if so, where? MPG would be nice, not really into lowend as our trannys don't really impress me, the way they shift, when really getting on it. I'm not impressed with the cableless throttle. I figure i get around 15-16 mpg in summer months, with my kind of driving conditions. I live on outskirts of town, i work on other side of town, maybe 3 miles away. I go through town, but could take turnpike but elect not to, as its kinda out of the way. I rarely do much turnpike driving, and if i decide to go to my moms, its like 17 miles away and mostly 55 MPH. I do tow an 18' Bass Boat during summer months and occasionally tow a 2 place snowmobile trailer during winter months. Other than that, mostly a mixture of town and highway miles. Does the TBS affect anything during cold winter months ? Starting etc ? Will it throw out a code if i install it? Let me know what everyone thinks. Thanx, Jim

 

its a tight fit if you choose not to modify the shroud. but it will fit and work. although you will see a more significant difference in a TBI system you will still see a difference on your truck. i loved the improvement it had on mine.

 

Ive heard mixed things on it. I think if you tap it and run some NOS thew it you will get true gains.

I know they work on carbs but like you said I dont think it works when their isn't fuel and air going thew it .

 

Well RXSTEVEN I do not know if the TBS really makes a difference or not, but a lot of people have them. So the TBS must be doing something or it is a Psychological thing.