throttle body swap

[ricklovin93]

Hey guys well im going to be putting a new thermostat in my 3100 for my 96 cutlass, i was thinking that while i had the throttle body off id swap to a bigger one, what choices do i have out there? Which ones are bolton (direct fit), and can i still use the same sensors,intake duct, and will my throttle lines work, cruise control is a big must have.

[AL]

I think any 3400 throttle body will directly bolt up and any 2000 and up 3100 TB will fit... Just for peace of mind, you might wanna swap in your old sensors

[Ramblin Garage]

I have the TCE 65mm it should bold right up, you can get a ported 3400 throttle body which would be a nice upgrade for you and bolt-on

[RobertISaar]

wot-tech.com for aftermarket ones, or grab one from a 3400(56mm IIRC), the stock 3100 is a 52mm unit.

[ricklovin93]

could i still use my intake duct with the tb from a 3400, i still wanna keep my stock airbox

[RobertISaar]

should, since only the inside of the TB is different, IIRC. the OD of the mouth didn't change from what i remember, but you may want someone else to verify that.

[ricklovin93]

can i use the upper intake manifold from a 3400 on my L82 3100 i know the 3400 had larger intake ports?

[RobertISaar]

i BELIEVE the bolt patterns are the same between the small and large port manifolds, however, there is a rather significant change in shape and size, which is kind of a waste since it kills airflow. best bet there would be to grab a 3400 LIM as well. you'll have most of the updates of the LG8/LA1, with the exception of the heads.

[ricklovin93]

if i did that would i use a gasket set for the 3100 or for the 3400

[RobertISaar]

these may help:

 

http://wot-tech.com/shop/articles/small-port-vs-large-port/cat_63.html

http://wot-tech.com/shop/articles/choosing-3100/3400-manifolds/cat_64.html

http://wot-tech.com/shop/articles/94-99-3100-large-port-swap/cat_73.html

[19Cutlass94]

large port and small port manifolds are completely different in terms of bolt patter. Small port uses 12 bolts while large port uses 6. Youll have to change the UIM and LIM when swapping between the two.

[RobertISaar]

large port and small port manifolds are completely different in terms of bolt patter. Small port uses 12 bolts while large port uses 6. Youll have to change the UIM and LIM when swapping between the two.

 

yep, there are a few good pics in the articles confirming this as well.

[ricklovin93]

i think ill stay away from swaaping the manifolds, if i use the 3400 tb do i use the tb gasket from a 3400 or the tb gasket for the 3100

[19Cutlass94]

Use the gasket from the 3400TB. A good time to change to the manifolds is when doing the LIM gasket.

[ricklovin93]

okay, so if i do use the 3400 manifolds i should use the intake gasket set for a 3400? and i would need to also buy the newer egr, and i would need to tap the manifold for the coolant line?

[19Cutlass94]

There are 3400 manifolds with the pressed in coolant line which you should have. Also, they make an EGR adapter to keep your current EGR.

 

http://wot-tech.com/shop/gm-60v6/90-95-egr-to-2000-manifold-adapter/prod_75.html

 

Use 3400 gaskets.

[ricklovin93]

the adapters for 90-95 mines a 96 the article said that with a 96 engine you need to use the new egr, and that the manifold can be tapped to accept the 3100 coolant lines

[19Cutlass94]

96 then yes youll need a new EGR. Dont tape the manifold. Just use the pipe for the manifold, then clamp the hose onto it.

[ricklovin93]

can i use the 3100 fuel injectors?

[RobertISaar]

yeah, and unless you have some kind of tuning capability, it's recommended, since otherwise the PCM won't have any idea that larger injectors are installed.

 

keep in mind, the 3100 stock injectors are too small for even a stock motor.

[ricklovin93]

so i can use the stock injectors and everything like that right the fuel rail and pressure regulator. So all i need is the manifolds, gasket set, and newer style egr valve, sounds simple enough.