ls1408cp

iTrader: (37)

Can you over throttlebody a efi motor? I sometimes hear you cant but wanted to hear what others thought.

JohnnyC

More information please... what exactly are you trying to determine? Be more specific.

ls1408cp

iTrader: (37)

not much more to tell would a 2600cfm throttle body hurt my car?

ls1408cp

iTrader: (37)

you dont need my specs to answer this

ringram

Generally no, but you do need to make sure your manifold has the correct runner configuration to suit the engine application.

Bink

....and that the suggested TB provides adequate "sensitivity" at low airflow. Otherwise idle tuning will be hell on earth

ls1408cp

iTrader: (37)

I am going to disconnect my IAC sensor and adjust idle like a carb one setting.

SStrokerAce

iTrader: (2)

please don't disconnect the IAC....

The general answer to this question is NO, you can't over throttle body a motor in terms of HP output. I would imagine that you could get to a level where you could, like you can over plenum a motor, but EFI usually kills the issues with transitional response.... so just thinking outloud I don't see that as a problem either.

Bret

ls1408cp

iTrader: (37)

why shouldnt I disconnect the IAC? It doesnt need it. I couldnt get it to idle with the accufab and it would die alot. It is just a pain in my ***.

ringram

Well you can, but you will have to let more air in than you need for most times. The IAC helps with idle transitions like coming to a stop and low speed parking etc, where accessories load the engine which then has to add air to prevent a stall etc. Also Mr AC will load it up at idle. If you dont use IAC you are going to have to raise idle burn more fuel and generally be antisocial

ls1408cp

iTrader: (37)

The cam is so big it doesnt like to idle under 1100 anyway. I have no accessories. I dont drive this car but to race or just **** people up on the street.

phantom meneSS

If driveability and throttle progression is not a problem then there is no problem although tuning will not be easy if you are worrying about anything other than WOT.

Mike454SS

iTrader: (4)

With a massive TB you're going to HATE how it drives at very low throttle angles (if you're stuck at a traffic light next to a police officer)...at least until you get used to it...make sure it's a VERY progressive linkage (cam on the throttle shaft) if it's a big TB.

ATVracr

iTrader: (5)

No you cant. Low TPS RPM tip in if it not a progressive linkage can be quite touchy, but in terms of torque output no you cant

GrannySS

ls1408cp

iTrader: (37)

any other thoughts on this

h.o.ls1

iTrader: (2)

... chris you crack my **** up on here

supersix

iTrader: (12)

I don't think you can.....take the harrop intake for example. It has 8 individual throttle bodies...we have been installing one at the shop. it is the 52mm version but that is still 416mm of airflow. Theoretically the more air the better......and when you get x amount of air your heads then become the restriction for flow. hope this helps

ls1408cp

iTrader: (37)

the itb intake would be way different which is the reason why it needs that much tb

tuff

iTrader: (15)

Are you still on stock pcm?When i went from the stock pcm to BS3 the car just was so much more happy.The stock pcm was a PITA and it never did idle very well.When we put the BS3 in we almost got her to idle like stock.

Argon Z

On an ITB intake manifold not all of the throttles are having air sucked through them all the time. On a plenum style manifold the throttle body almost always has air flowing through it.
This is because on a plenum style all the cylinders are pulling through the same throttle.

Hope that makes sense

James
Kinsler.com