"i" throttle body differences

[Mike]

I converted my car to manual, and the current throttle body is running two vaccuum ports with that double port check valve. I want to switch over to the single vaccuum line to the brake booster, and see if I get any slight difference in my brake pedal feel, idle, etc.

Would I need to get a throttle body specifically that uses the single vaccuum setup, or are all the "i" throttles the same, with just a cap inserted in the extra hole (for single vaccuum line).

[Mike]

BTW, realoem is kinda useless on this topic, I've tried comparing...

[asubimmer]

not all of the I's had a single. Ex, the 87' 325is has the dual.

[Mike]

Yeah, it does seem to vary alot between the models. Anybody that is running a single vaccuum line to the booster, could they please confirm that the extra hole on the throttle body has a cap inserted in it?

[nando]

you actually get more vaccum to the booster with the dual lines and check valve.

leaving it alone would be the best choice.

[vr2jetta]

Mine has a cap inserted in it but that is how I bought it. It had the timing belt break and the head crack and I am now trying to get it running. It is all together but will not start, actually, it started last night but now wont start at all. I would assume that is how it was running when the PO had it, but the intake book was all tore to hell and the distributor cap looked like it need to be changed 3x over. I dont know if this will help but I would "assume" that it ran like that before I got it.