Throttle Butterfly, how much should it open?

JregGT · August 30, 2010, 09:06:59 PM

Right folks, i want to explain this without sounding like a tool, but basically i've removed my throttle body while i'm cleaning my engine up. If I physically turn the spindle to the point of stopping, and look down the body, the butterfly is not 90 degrees from where it is when flat. But I think it may be the Boost return butterfly stopping it, as that flattens out, before the larger one! Does any of this make sense? By looking I think there may be adjustment in altering the linkage between the 2 Butterfly spindles? Would this be the correct way to correct this? Normally i would have a fiddle till i'd corrected it. But i remember reading the de-wedging article, where it says to not alter the linkage, and as i'm new to G40's i thought i'd post the question.

Cheers in advance folks Rich

cheys03 · August 30, 2010, 09:28:48 PM

The one I have on my desk (appears unaltered from factory) looks like the throttle butterfly is a few degrees off, say 82 degrees on full throttle. Difficult to tell though as the wedges obscure the view. Has your's been dewedged?

JregGT · August 30, 2010, 09:34:38 PM

It has, but pretty poorley, so i will be re doing it. I think the engine has been messed about a fair bit, so i'd like to put it back to basic setting if you know what i mean. I.e each butterfly in the correct position at each point. Looking at yours, when the larger butterfly is fully closed, i sthe BRV butterfly flat? Then when the larger butterfly opens, does teh BRV one close?

Cheers for the quick reply

Rich

cheys03 · August 30, 2010, 10:15:12 PM

Aye, as you describe is exactly how this one operates too.

JregGT · August 30, 2010, 10:35:41 PM

Thanks very much fella, i'll have a littl ebetter lookst tomorrow evening, was getting rushed to go out for tea, but was desperate to get the question posted.

Thanks very much for your quick replies.

Rich

JregGT · August 31, 2010, 08:15:44 PM

Right, i've had another looksy tonight at the TB, At what point should the BRV butterfly be fully closed? Currently i'd say the BRV buttefly is fully closed when the actual butterfly is half open, is this correct? I can see in the linkage and spindle that once small butterfly is fully closed, it does allow the larger butterfly to open more. I just wanted to check this is correct as i have read a few other threads that are giving me mixed ideas.

Cheers folks

Rich

Justin14100 · August 31, 2010, 09:06:32 PM

boost return should only close when the main butterfly is fully open.

JregGT · August 31, 2010, 10:46:04 PM

So until the main butterfly is fully open, the BRV butterfly should still be slighty open too? At only 1 point are the butterflies either fully open and fully closed, as opposites to each other?
Why does the BRV spindle allow that to be fully closed, yet still let the main buttefly open futher? I hope this all makes sense, cheers for the replies

Rich

Puncharado · August 31, 2010, 10:58:32 PM

Sounds to me like yours is working OK.

JregGT · September 01, 2010, 08:30:27 PM

Logically, I think it sounds right too, so it would re-circulate wasted gases until at around half throttle, then utilise it all uptil full throttle. But wanted to have it confirmed by a few who knew what they were talking about, before i put it all back together! As i've said in other posts, i'm new to G40's, only messed with GT's and MK1 golfs so far, so its all a learning curve!

Cheers for the replies folks, anyone else know much on this area??

Thanks again folks Rich