14 replies to this topic

[DoriDori]

My 850 NA original throttle plate closed flush or perfectly perpendicular in the throttle body. This one off a 960 I installed doesnt sit flush like the old one but seems to make a seal. Does anyone else with this mod have this issue?

[DoriDori]

another view

[Hanks]

hmm well the old one shouldnt have sat flush. that pic looks exactly like mine did.

[DoriDori]

Okay, thanks for response!

[ozzimark]

There is a stop adjustment screw for the TB that adjust how far open it sits when "closed". As Hanks says, it shouldn't be totally closed when resting on the stop. If it doesn't cause the engine to idle high, leave it alone

There is a specific range of angle that it is supposed to be set at, but I don't know what it is off the top of my head, and that would apply to the smaller stock TB, not the larger one.

[bergmjs]

If indeed the old one sat flush and this one doesnt, loosen the two screws and wiggle the plate while trying to close it. If you tighten the screws without actually closing the valve it can be slightly off center and bind when closing.

[brad850]

yup as long as it isn't scraping at any point and you're idle is normal you're fine.

[lookforjoe]

If indeed the old one sat flush and this one doesnt, loosen the two screws and wiggle the plate while trying to close it. If you tighten the screws without actually closing the valve it can be slightly off center and bind when closing.

BAD idea - unless you BACK OFF the base idle screw first! IF you simply loosen the set screws for the butterfly, it will definitely cock in the housing.

So, if you are going to do anything, back off the base idle screw, see if the plate sits flush (hold the housing up to the light so you can see if there is an uneven gap). If it's good, clean the rest of the crud out that is visible in that pic, and tighten the base idel screw 1/4 turn AFTER it contacts the lever, done.

EDIT: You did bore out the intake to accept the larger throttle plate, correct? Can't tell from your pic, and you didn't mention doing it....

[Oreo931]

EDIT: You did bore out the intake to accept the larger throttle plate, correct? Can't tell from your pic, and you didn't mention doing it....

He has an NA

[bergmjs]

BAD idea - unless you BACK OFF the base idle screw first! IF you simply loosen the set screws for the butterfly, it will definitely cock in the housing.

So, if you are going to do anything, back off the base idle screw, see if the plate sits flush (hold the housing up to the light so you can see if there is an uneven gap). If it's good, clean the rest of the crud out that is visible in that pic, and tighten the base idel screw 1/4 turn AFTER it contacts the lever, done.

EDIT: You did bore out the intake to accept the larger throttle plate, correct? Can't tell from your pic, and you didn't mention doing it....

I think you thought I meant something other than what I meant. I meant the actual procedure to replace just the throttle plate, no adjustments, no set screws. Just the two screws in the middle of the plate that hold it to the axle, when you swap the plates, it's possible to install the plate not perfectly concentric with the housing. I was simply suggesting to check the concentricity of the assembly.

[lookforjoe]

He has an NA

Then WTF is this posted in Performance for?

[Kevin.]

NA POWUHHHHH

[DoriDori]

Then WTF is this posted in Performance for?

Easy, guys!! I'm working with what I got here lol! Once the heads back on it I will fire it up and see how the idle is.

[mojojo]

He has an NA

So, with the larger n/a throttle body, what is the purpose of adding the 960 plate (instead of the 850 n/a plate)?

[Oreo931]

So, with the larger n/a throttle body, what is the purpose of adding the 960 plate (instead of the 850 n/a plate)?

Removing the white plastic plate which restricts airflow and creates "turbulence"