98 Chevrolet Throttle Body Plate

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Joined
Jul 28, 2018
Messages
24
Reaction score
7
Location
Crystal City Mo.
Hello, I was looking at the front underside of the throttle plate and noticed a flush riveted wide piece of sheet metal on the plate. The other side nothing, what is purpose and should it stay?

Thanks
 

df2x4

4L60E Destroyer
Staff member
Super Moderator
Joined
Mar 1, 2012
Messages
11,131
Reaction score
12,617
Location
Missouri
Hello, what is the purpose of the air deflector on the front of the throttle bore plate? Anyone know if it can be removed for better, or worse airflow?


Having done this mod to one of my trucks (and then un-did it by putting an unmodified plate back in later) I would not recommend it to anyone. Made my throttle pedal feel like an on/off switch. The lip is there to promote linear throttle response.
 

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
12,543
Reaction score
15,131
Having done it to my 5.7, I'd never go back to having a lip. Df2x4 has a 4.3, his results and preference vary.
 

df2x4

4L60E Destroyer
Staff member
Super Moderator
Joined
Mar 1, 2012
Messages
11,131
Reaction score
12,617
Location
Missouri
I almost want to drop my modified blade into the throttle body on the Suburban for a few days just to see if it really is any different on a V8. I'm sure it's possible, but something tells me I probably still wouldn't like it.
 

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
12,543
Reaction score
15,131
I almost want to drop my modified blade into the throttle body on the Suburban for a few days just to see if it really is any different on a V8. I'm sure it's possible, but something tells me I probably still wouldn't like it.

And if that's the case it's just a matter of preference. It will be slightly less dramatic on the V8. We really don't know what the OP will prefer here.
 

df2x4

4L60E Destroyer
Staff member
Super Moderator
Joined
Mar 1, 2012
Messages
11,131
Reaction score
12,617
Location
Missouri
And if that's the case it's just a matter of preference. It will be slightly less dramatic on the V8. We really don't know what the OP will prefer here.

Very true. But at least now he knows what it's there for and has the necessary info to make a decision.

I'd recommend that anyone trying this mod buy a spare blade, either pre-modified or to modify yourself. That way if you aren't happy with the results like I wasn't you can always just swap the factory one back in.
 

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
12,543
Reaction score
15,131
Agreed. OP the reason I like the mod so much is because the truck holds a gear with more torque before downshifting. I live in CO at 6000' and it helped a lot in that regard. It is very snappy at sea level, but I like it still. Even if the motor isn't making more power with more throttle input at a certain point, that throttle input is still useful because it triggers a downshift which brings about more power. It suits my driving style.
 
Joined
Jul 28, 2018
Messages
24
Reaction score
7
Location
Crystal City Mo.
Thanks for the replies. What I was looking at was WOT, that the "lip" is reducing airflow. Now if removing the lip causes a lean condition or was an air deflector at WOT, so that the front four runners in the intake are seeing the same air as the rear four because of the offset of the throttle body then that would seem plausible.

Without a doubt it causes both air deflection and reduced airflow at all throttle positions. Much like not getting WOT on your carburetor. How much reduced airflow at WOT? I would fathom at part throttle quite a bit.

I will get engine up and running and see how much different. I have three throttle bodies, so no loss if it pukes. I am just looking at simple no cost mods right now. After 20 years there should be a lot of intel out by now. Thanks for your thoughts.
 
Top