The 30V throttle body prioject has begun...
06-20-2004, 06:54 AM
#1
AudiWorld Super User
Thread Starter
The 30V throttle body prioject has begun...
<center><img src="http://pictureposter.audiworld.com/711/30vtb1.jpg"></center><p>Just started work on this week before last. Very time consuming as jig fixtures have to be made to hold the throttle body parallel to the bore for machine work at both ends. I've got the outlet side fixture made which allows me to mill or turn on the lathe for the machine tasks involved.
The outlines in this pic refer to initial planned material removal areas. As I get deeper into this I'll likely find ways to enhance these initial modifications. The 12V TB's today are a far cry from those early attempts 2 years ago. Since I don't drive a 30V the results and future development will rely on feed-back and driver input rather than my own "on-car" perceptions.
Next I'll make the inlet side fixture so I can get to work on that side.
The stock 30V throttle body in this pic flows slightly less than the stock 12V TB at 294CFM vs 312CFM.
The outlines in this pic refer to initial planned material removal areas. As I get deeper into this I'll likely find ways to enhance these initial modifications. The 12V TB's today are a far cry from those early attempts 2 years ago. Since I don't drive a 30V the results and future development will rely on feed-back and driver input rather than my own "on-car" perceptions.
Next I'll make the inlet side fixture so I can get to work on that side.
The stock 30V throttle body in this pic flows slightly less than the stock 12V TB at 294CFM vs 312CFM.
06-20-2004, 07:13 AM
#2
AudiWorld Super User
Thread Starter
Pic 2: Initial outlet side machine work and "after" flow rates...
<center><img src="http://pictureposter.audiworld.com/711/30vtb2.jpg"></center><p>Here you can see the same bore-shot of the outlet side of the 30V TB. This opened up the cast-in deflection on one wall by 5.08mm and turned down the brass vac nipples opposite that wall flush with the bore I.D.
There's much more I'd like to do while in here but I need to proceed in "baby steps" initially. Next I'll make a fixture for the other side as there's a lot of CFM to be had there with a more agressive inlet wall taper. And that side I'm alot more comfy with making greater changes in. The outlet side dictates a slower, more cautious approach with driver feed-back as some of these mods "may" affect off-idle transitions. But it while it risks affecting them negatively it also risks affecting them positively as well. Won't know till it's driven.
TB now flows 350.8CFM for a just-under 20% net flow increase. But at this point I have no idea how the car would drive. My primary concern remains the off-idle transition, ie; getting the car rolling from a stop. May be better, may be worse. I just won't know till it's on a car and driven. Once under speed I'm sure it will be better and after manifold switchover to the high RPM runners even better yet.
Time will tell. I'll get on an inlet side fixture this week and hopefully have this TB back in the hands of its owner week after next so we can all get some much-anticipated feedback.
There's much more I'd like to do while in here but I need to proceed in "baby steps" initially. Next I'll make a fixture for the other side as there's a lot of CFM to be had there with a more agressive inlet wall taper. And that side I'm alot more comfy with making greater changes in. The outlet side dictates a slower, more cautious approach with driver feed-back as some of these mods "may" affect off-idle transitions. But it while it risks affecting them negatively it also risks affecting them positively as well. Won't know till it's driven.
TB now flows 350.8CFM for a just-under 20% net flow increase. But at this point I have no idea how the car would drive. My primary concern remains the off-idle transition, ie; getting the car rolling from a stop. May be better, may be worse. I just won't know till it's on a car and driven. Once under speed I'm sure it will be better and after manifold switchover to the high RPM runners even better yet.
Time will tell. I'll get on an inlet side fixture this week and hopefully have this TB back in the hands of its owner week after next so we can all get some much-anticipated feedback.
06-20-2004, 07:35 AM
#4
AudiWorld Super User
Thread Starter
No idea yet. Mechanically it should. But holding/gripping the DBW ones is tricky
after this one I'll look at the later ones if someone sends me an "expendable" spare as it's possible to easily ruin one if I crash it in the lathe. Sadly this is an omellette that could break some shells trying to get the yolks out.
Both inlet/outlet sides require some machining that turns the throttle body and other tasks require the TB be stationary while the cutting tool turns. The 12V throttle body in contrast is never turned... but rather only held firmly while the mill does all the work.
Both inlet/outlet sides require some machining that turns the throttle body and other tasks require the TB be stationary while the cutting tool turns. The 12V throttle body in contrast is never turned... but rather only held firmly while the mill does all the work.
06-20-2004, 07:40 AM
#5
AudiWorld Super User
Hmmm, I have an extra 30v TB somewhere that I was going to experiment with...
I was going to see if I could open it up and use it on my 1.8t...which i never did do.
