http://cgi.ebay.com/ebaymotors/vorte...mZ140261699000

is that the ls4 throttle body that would be an upgrade for our cars, thinking about getting one, not sure yet. I've changed my mind over it a hundred times. But I've been talking to someone with the upgrade recently and he said the gain in the lower rpms is worth it.

 

that should be the one. can't just slap it on tho, gotta retune the idle scalar value or some **** like that

 

i bet it makes the low end better because you need less throttle to let more air in, so technically you will feel more response but not gain much. Does that make sense?

 

Wouldn't the actual gains be in the upper RPM's?

 

eh I didn't like the way my car was with it... throttle was a tad too touchy and the closing rate seemed a little slower

 

I'm still debating it. I may wait and try it next year just to see if there is any gains. Dyno test it and track test it next year. I know the driveability changes completely, so I want to see the gains to justify changing the way I drive the car.

 

that's exactly what it is. the throttle doesn't have to open as much to let in the same amount of air as the stock tb, and when opened to the same % it lets in more air b/c it's got a bigger opening. mine gave me a pound or three of boost in the lower rpms, and you can definitely feel some extra down low torque.

in the upper rpms, the stock tb is not really a restriction as it's letting pretty much the maximum amount of air into the s/c. the ls4 tb might give it a couple hp but the real gain is down low.

touchy it definitely is, took me a couple weeks to get used to it (had it for about a month).

but we're good now!

haven't really had any issue with the closing rate at all. no more than stock tb anyway

 

Gotcha. Makes sense.

 

i dont get it...
you realize the car is ingesting the most air per cycle at max torque right?
and you must also realize that its ingesting the most air per time unit in the higher rpms...


so i dont follow how could it possibly not be a restriction high up?

so what your actually saying is that by getting a bigger TB your engine is ingesting more CFM at lower rpms... magically right?


oh and to OP since i know your build quite well, i would suggest against it. Your not moving anymore CFM (maybe marginally) then stock therfore a bigger TB wont do anything except make your throttle more touchy (not more powerfull)

 

Yes, I am fully aware of how an engine works.

I never said it was a restriction up top. I just said the stock throttle body is not a restriction up top so the ls4 tb would not offer that much, if any, more hp up top.

The ls4 tb is allowing more air at lower rpms to enter the s/c and intake manifold, resulting in more boost. If you open the stock tb to, say, 50%, it would allow X amount of cfm to enter the supercharger/intake manifold and engine. if you open the ls4 tb, it will allow more just because of the increased size of the throttle body, making more torque.

do some more research and then make suggestions buddy

 

ive seen the dynos on this....

lower rpm band has the gains....then it levels off. Rebel did a dyno on it somewhere.

 

**** I'm making over 400whp on the stock TB, I see no need for an upgrade at this point

 

i guess... lol

400 whp... wow that's acually what i'm aiming for

 

I have the same issues when I went from a 2.2 TB to a 2.4 TB on my LS

 

That's not the ls4 t/b...the ls4 is the same design as the lsj t/b except it's larger.

 

[QUOTE=Tennpenn83;2827953]Yes, I am fully aware of how an engine works.



I never said it was a restriction up top. I just said the stock throttle body is not a restriction up top so the ls4 tb would not offer that much, if any, more hp up top.



The ls4 tb is allowing more air at lower rpms to enter the s/c and intake manifold, resulting in more boost. If you open the stock tb to, say, 50%, it would allow X amount of cfm to enter the supercharger/intake manifold and engine. if you open the ls4 tb, it will allow more just because of the increased size of the throttle body, making more torque.



ok, i looked at the dynos. i dont get it. Im sorry if i sound edgy, but i dont actually get why you would gain torque down low.


the reason i dont understand is that the throttle bodys only restriction would be its max CFM and it shouldnt be reaching that at such a low rpm. and without the motor ingesting more air how is it creating more torque? just because the bigger pipe is there doesnt mean its forced to take in more air just allowed to

 

bump. good info.

 

i have one in my garage waiting to go on with my 2.7 and 3" intake. i figured, the more air it can move the better. bigger opening=more airflow.