I have a 1997 GC Laredo 4.0L I6 I am thinking about putting a TB riser on it to increase horsepower and gas mileage.

Has anyone done this? are the claims true or just marketing??

TKS

 

it wont do anything.

 

x2

 

if you wanna do something with your throttle body to gain anything at all, get it bored out, even then you wont see huge gains unless you get like decent intake or improve the stock one, and match it with some performance headers and exhuast. you have to pretty much open the whole system up other wise you wont get much.

 

My cone filter (I bought the AIR RAID system) made a big difference... TB spaces made no noticeable change at all. (well now it whistles sometimes when i'm wasting gas)

 

x 3

 

X4!!

 

didn't do a thing on mine. These engines are direct port injection so all thats going in the throttle body is air anyways. On a TB injected motor it may make a difference though.

 

The spacers do serve a purpose .... but the rest of the motor has to be sufficiently "modded" to take advantage of it.



What the spacer does, is effectively increase your plenum volume. However, if your head cannot flow any additional air (stall speed) ... the the extra capacity to fill the chamber will not do anything.


How can you increase the air flow? A better exhaust is a place to start. Improving the scavenging will help draw the air into the chamber (intake and exhaust are open together for a very tiny bit of time). Any additional flow requires opening up the engine (porting, back cutting valves, etc).


The spacer also gives the incoming air additional "room" to bend around into the runners of the intake. If you look at the shape, it's just a log with 6 branches coming off the main body. That definitely doesn't lead to smooth flowing air.



And 99NCXJ .... the motors are not direct port injected. The injectors are still placed in the intake manifold and the air/gas mixture must travel thru the head before it gets to the chamber. A direct injection would be something like the newer Cummins diesel where the fuel is fired directly into the chamber itself. The term best used could be multi-port .... yes, I'm nitpicking, but trying to help everyone understand what they are reading or saying.



Joe