BMW 330ci sp/ 172Cup
Hi folks,
This might have been covered countless times before. Sorry if it has but a quick search didnt throw much up.
As our track car is off the road for a while (engine rebuild/replacement) I am trying to look at other parts that could yeild improvements to performance. We already have matched inlets, which I plan to check how well these have been done, but the throttle body hasn't been touched.
My question is, rather than smoothing the step on the body can you go further than that and increase the entire (or majority) of the bore? No measurements have been taken yet, or an attempt to strip the TB but I was thinking down the lines of 2-3mm increase of bore and new larger throttle flap to fit accordingly.
In addition to this, I remember reading (quite a few years back) David Vizards book about tuning the A-series engine. I know things have moved on leaps and bounds since then but knife edging the throttle flap was recommeded and even cutting back the flap pivot shaft to reduce restriction on WOT.
Costs for us to this would be next to nothing, and it would provide a ncie little sub-project, but I wonder if other people have tried it in the past? Comments, thoughts and previous experience welcome
Cheers,
Nick
This might have been covered countless times before. Sorry if it has but a quick search didnt throw much up.
As our track car is off the road for a while (engine rebuild/replacement) I am trying to look at other parts that could yeild improvements to performance. We already have matched inlets, which I plan to check how well these have been done, but the throttle body hasn't been touched.
My question is, rather than smoothing the step on the body can you go further than that and increase the entire (or majority) of the bore? No measurements have been taken yet, or an attempt to strip the TB but I was thinking down the lines of 2-3mm increase of bore and new larger throttle flap to fit accordingly.
In addition to this, I remember reading (quite a few years back) David Vizards book about tuning the A-series engine. I know things have moved on leaps and bounds since then but knife edging the throttle flap was recommeded and even cutting back the flap pivot shaft to reduce restriction on WOT.
Costs for us to this would be next to nothing, and it would provide a ncie little sub-project, but I wonder if other people have tried it in the past? Comments, thoughts and previous experience welcome
Cheers,
Nick