# 2.0 ABA Throttle Body mod ??



## Ether811 (Jun 2, 2008)

i have an extra 2.0 throttle body for my car laying around and noticed it isnt round inside, more of an oval shape? is there any benefit to bringin it to a machine shop and having it "ported?" like i said, its an extra that i just have laying around????


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## tdogg74 (Mar 1, 2002)

*FV-QR*

I just wrote this on another thread....

_Quote, originally posted by *tdogg74* »_Just bringing this back....
So I ported the **** out of the spare throttle I had sitting in my basement. I mean, velocity bumps _completely_ gone. I have been driving on it for a couple of days, and using the wideband and Scangauge as references, here is what I found:
*Gas pedal is like an on/off switch now. The stock TB was progressive with the beginning stages of the throttle due to the velocity bumps running parallel with the throttle plate. With the ported TB, you have a very small window of pedal play before its open so much that I go pig rich. The velocity bumps limited the air flow to build progressive, smooth acceleration, then once the throttle plate was past the bumps, it would be wide open. I can tell you that my AFR is a full 1-2 points richer if I just floor it as opposed to just progressively giving it more pedal on accell. For instance, if Im in 5th cruising @ 45mph and I floor it, I go to a 10AFR and the car just bogs. With the stock TB, it would go maybe to high 11's or low 12's. I have to slowly give it more pedal to keep it in the 13.5AFR target range. I definitely have to change the way I drive this car to make it perform. I also feel the car needs a new tune to cope with this throttle body change. Its getting significantly more airflow at a much lower rpm and the fueling maps cannot cope. Like I said, if I dont feather into the throttle in higher gears, I go too rich. But, feathering into the throttle produces quicker acceleration in lower rpms, then once past a certain point, I can go full throttle and keep my AFR at the 13.5 fueling target. 
*Throttle response. I want to address this once and for all. I feel the reason people say "throttle response has improved" is because of what I just previously wrote: With the velocity bumps gone, it now acts like an on/off switch. When rev-matching on down shifts, it takes less pedal to blip the throttle. When getting on the throttle to pass, or downshift to pass, it takes less pedal to bring the rpms up. And this is because the velocity bumps are no longer there to limit air flow. Maybe I feel this effect more due to the design of my intake manifold. (84.5mm bells on tapered velocity stacks and just aft of the TB flange, there is a taper to build velocity into the plenum) There is no such exaggerated taper on the stock manifold, so maybe the felling is less. But if thats the case, then there would most definitely be more of a laggy feel at lower rpms. 
*Idle quality. Well, it just sucks now. Car runs @ 850rpms solid with the stock TB. Its all over the place now that the velocity bumps are gone. Between 1000-2000rpms on cold start. After its warmed up, Ill be luck to see 980rpms. TB is having a hard time adjusting. 
*More power. Yes, I will say there is more power to be made with the throttle bore opened up in wide open throttle launches. Played with this getting on the hiway and such. The car feels noticeably stronger past 5000rpms (for me, anyway) up to redline. More airflow, obviously. My AFR, like stated before, stays at the 13.5 target range.
So all in all, I'd say that the real only good thing about porting out the velocity bumps is the top end acceleration. Because, drivability kinda sucks now and Ill be putting the stock TB back on next chance I get. 
But I will say that if you could shave off enough of the bumps to increase the velocity and airflow, yet keep enough there to keep the pedal response progressive, you would be good. I would guess taking half of the bumps away and shaving the rod the throttle plate slides through, thats pretty much going to be the best of both worlds. Not a lot you can do with these until drivability goes down.


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## MecE2.0 (Dec 20, 2005)

*Re: 2.0 ABA Throttle Body mod ?? (Ether811)*

i did a partial de-hump (mostly just a polish) of mine. my throttle is definitely more responsive, but i'm not getting the bogging, likely due to the fact i didn't remove the ramps entirely. i'm also obd1 though, and i haven't heard anything good about trying this on an obd2.
furthermore, i think the only benefit of taking it to the machine shop would be a slight decrease in curb weight from your wallet being significantly lighter. i only did it because i was bored one weekend last summer and had everything i needed at hand.
don't waste your money.


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## vdubxcrew (Jul 25, 2004)

*Re: 2.0 ABA Throttle Body mod ?? (MecE2.0)*

I do very good throttle body porting/modifying. If your going to send it to a machine shop, they are going to charge by the hour. It'll end up ALOT more than what you are probably willing to pay. I have a few ported TB's in the classifieds. Or just IM me and we can work something out.


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## tdogg74 (Mar 1, 2002)

*FV-QR*


_Quote, originally posted by *vdubxcrew* »_I do very good throttle body porting/modifying. If your going to send it to a machine shop, they are going to charge by the hour. It'll end up ALOT more than what you are probably willing to pay. I have a few ported TB's in the classifieds. Or just IM me and we can work something out.









Im sending him one of my spares to go silly with.


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## MecE2.0 (Dec 20, 2005)

*Re: FV-QR (tdogg74)*

what i'd want is a new butterfly valve with the shaft taken down. that things awful big.


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## independent77 (May 23, 2003)

*Re: FV-QR (MecE2.0)*

after 3 years, i have gone back to stock.

drivable has improved. 

thanks travis.


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## tdogg74 (Mar 1, 2002)

*FV-QR*

See? I told you. Nobody ever believes me when I post stuff. What i plan on doing is doing some pics of all three throttles; Stock, one of Dietrich's, and the boned out throttle on my motor now. 
And I hate to admit this, the difference @ WOT with this fully ported throttle vs the stock is friggin amazing. Car is TRE stronger to redline. I love it, but everything else about it not very fun to deal with.


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## independent77 (May 23, 2003)

*Re: FV-QR (tdogg74)*

i found off-idle drivable to be frucking brutal.
I might swap it back on for the next autoX event, but for daily driving.... not anymore.


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## sickgixxer69 (Feb 24, 2007)

*Re: FV-QR (independent77)*

I dehumped my OBD2 TB and it made a little difference. Throttle response is alot better and my intake is louder. http://****************.com/smile/emthup.gif My idle is not bad. Its the same as stock other then the lope of my 260 cam. Its a good free mod IMO.


_Modified by sickgixxer69 at 5:53 PM 6-17-2009_


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## vdubxcrew (Jul 25, 2004)

*Re: FV-QR (sickgixxer69)*

I find it amazing that you guys with OBD2 de-ramped TB's arent having bucking/crazy idle problems. The OBD2 VR TB's can't be de-ramped otherwise they are junk. Since they are esentially the same piece, made by the same manufacturer only one is larger, I would imagine the results would have to be the same. But here I am reading of people de-ramping their OBD2's. I can't imagine the part throttle drivability is any where near good. WOT, sure.


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## jetta09black (Mar 12, 2009)

*Re: FV-QR (independent77)*


_Quote, originally posted by *independent77* »_i found off-idle drivable to be frucking brutal.
I might swap it back on for the next autoX event, but for daily driving.... not anymore.


what do you mean by brutal? Like its to touchy from a stop?


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## Ether811 (Jun 2, 2008)

i guess i should have just searched a little harder, LOL Thx for all the responses, i think im gonna do it since after all it is an extra


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## independent77 (May 23, 2003)

*Re: FV-QR (jetta09black)*


_Quote, originally posted by *jetta09black* »_

what do you mean by brutal? Like its to touchy from a stop? 
Weak Idle, popping the clutch at 1,000 to 2,000 it is jumpy, and will stall easily. 
It will not hold revs at 1,200 to get moving, it will rev from 1,000 straight to 2000+.

Pretty bad for city driving, and stop+go traffic.


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## jetta09black (Mar 12, 2009)

*Re: FV-QR (independent77)*

I wonder if upgrading to bigger injectors and doing this mod would make it better for driving.. and smooth out the idle?


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## Minor_Threat (May 12, 2009)

*Re: FV-QR (jetta09black)*

I swaped in a VR6 Throttle body haven't tried it yet though


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## vdubxcrew (Jul 25, 2004)

*Re: FV-QR (jetta09black)*

it has nothing to do with injectors. Larger injectors rarely solve any idle issues. It has to do with the TB communicating with the ECU.


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## jetta09black (Mar 12, 2009)

*Re: FV-QR (vdubxcrew)*

communicating what? Air flow?


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## MecE2.0 (Dec 20, 2005)

*Re: FV-QR (jetta09black)*

when they're deramped and ported the airflow at a given throttle position is different and sometimes the ECU doesn't like it. its not that its actually measure the airflow (thats what the MAF is for) but lets it know if its at idle/part-throttle/WOT so it can optimize.


_Modified by MecE2.0 at 10:44 AM 6-18-2009_


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## jetta09black (Mar 12, 2009)

*Re: FV-QR (MecE2.0)*


_Quote, originally posted by *MecE2.0* »_when they're deramped and ported the airflow at a given throttle position is different and sometimes the ECU doesn't like it. its not that its actually measure the airflow (thats what the MAF is for) but lets it know if its at idle/part-throttle/WOT so it can optimize.

_Modified by MecE2.0 at 10:44 AM 6-18-2009_

Right! So bigger injectors could even out the mix and smooth out the idle...? Since the the same air flow is measured at the MAF but it is flowing in the intake faster and at a greater volume? Because it is a after the MAF factor...


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## vdubxcrew (Jul 25, 2004)

*Re: FV-QR (jetta09black)*

I'm telling you man, your just going to run pig rich with larger injectors. Even at WOT, stock injectors aren't at maximum capacity on a well tuned N/A car. The only time you will need larger injectors is when you tend to lean out ie: turbo or SC kit. Smoothing out the idle is something to be worked out through VAG-COM or special software. Maybe a piggyback fuel controller.


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## jetta09black (Mar 12, 2009)

*Re: FV-QR (vdubxcrew)*

its cool man... just trying understand this mod and see if there are any possible ways to actually use it with out sacrificing the idle..


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## vdubxcrew (Jul 25, 2004)

*Re: FV-QR (jetta09black)*

If it's ported the right way, you shouldn't have a problem with the idle being jumpy or crazy. Maybe slightly elevated but holding a steady rpm. Fully bored TB's are what you want to stay away from, unless your strictly drag racing and continuously holding WOT. Even then, I've heard of people having problems.


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## jetta09black (Mar 12, 2009)

*Re: FV-QR (vdubxcrew)*

cool thanks.. you have any pics of it done right, like before and after?


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## MecE2.0 (Dec 20, 2005)

*Re: FV-QR (jetta09black)*

my idle increased by about 100 rpm, but it was low and lopey before so the bump was appreciated.


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## Minor_Threat (May 12, 2009)

*Re: FV-QR (vdubxcrew)*


_Quote, originally posted by *vdubxcrew* »_If it's ported the right way, you shouldn't have a problem with the idle being jumpy or crazy. Maybe slightly elevated but holding a steady rpm. Fully bored TB's are what you want to stay away from, unless your strictly drag racing and continuously holding WOT. Even then, I've heard of people having problems.

exactly why I didn't port my throttle body, just the manifold to match the VR6 throttle body


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