Throttle body questions

[V8VBoogies]

Hey everyone!
Got my 2007 Vantage in February and it’s absolutely awesome, loving every chance I get to drive it! I’ve been delving into the relatively easy maintenance things, changing air filters, replaced the thermostat and things like that and am already deeply indebted to all of you for you’re posts and how-to’s and insight.

Introductions and thanks out of the way, I have never messed with a throttle body and have questions. The car has about 40k miles and the throttle body definitely looks like it’s had never been cleaned. Besides being dirty, there was a tiny amount of oil at the bottom of the disk.




Is this normal?
Is this the oil that a catch can is supposed to mitigate?


After cleaning I noticed there was a tiny shallow groove on the surface where the disk comes closest in the closed position.

Is this normal?
I don’t think it’s from the two metal surfaces touching, maybe just gradual forms from years and miles of air being squeezed to/through the gap?

Lastly after cleaning and reinstalling I swear the intake/induction sounded different right from startup. There seemed to be more noise/blowing sound coming from the engine and I was sure I screwed something up. It ran fine though and after only a couple of drives the sound went away and hasn’t come back. Maybe the engine management system was recalibrating a little now that the throttle body was clean and the airflow was a little different?

Thanks in advance for any help/education!

[8Tech]

Completely normal, in fact better than I would expect if not cleaned before. As the engine breather blows smoky oil into the intake before the throttle body, this build-up is as expected.

[V8VBoogies]

Cool, much appreciated!
What about that groove? Any thoughts on that?

[8Tech]

Thats simply where the butterfly contacts the throat on closed throttle position. When I ported my throttle bodies, I had a similar mark on the closed position so went nowhere near that for the porting. I also had significantly more oil residue when I stripped them off at half the mileage your car has.

Unfortunately, I cleaned them before taking any pics as its a common issue, thats not really a problem.

You cannot really see the marks on the throats of my throttle bodies, but you can hopefully see the porting.

[V8VBoogies]

Excellent!
Thanks man

[paulrog1]

8Tech said:

Thats simply where the butterfly contacts the throat on closed throttle position. When I ported my throttle bodies, I had a similar mark on the closed position so went nowhere near that for the porting. I also had significantly more oil residue when I stripped them off at half the mileage your car has.

Unfortunately, I cleaned them before taking any pics as its a common issue, thats not really a problem.

You cannot really see the marks on the throats of my throttle bodies, but you can hopefully see the porting.

How did you port them? Plus did you get any extra bhp?

[8Tech]

High speed grinder and flapper wheels, then finished by hand. Was not done in isolation though, I installed the short runner inlet manifolds that I had ported and matched to the heads all at the same time as coils, plugs and a catch tank system.

Made an overall 60bhp overall with same exhaust and mapping. I did not remap again until I installed the 12 branch tubular manifolds with sports secondary cats.

Standard.



Ported.

[8Tech]

Here's the result briefly of the engine end of the manifold porting although it was ported all through....from throtle body matching to inlet port matching.

I did a very detailed post on it a good while back. Should still be online here somewhere.

[V8VBoogies]

Amazing work. That much extra oomph would really get it from “quick” to “fast”

Does that kind of work change the induction and exhaust note?

[8Tech]

No change to the induction tone but the 12 branch tubular manifolds and secondary cats only give the exhaust a real crackle. Louder than just deleting the secondaries and opening the silencer valves.