Right been working on / off on a fix for the dreaded goose honk that occurs when fitting induction kits when the standard recircs are still been used.
I know that fitting bovs cures the fault but why spend out on bovs if you have an auto box as they do very little then and anyhow not all owners have the spare cash.
Right, having looked at why the noise occures and at what throttle opening etc, it appears to be that crucial opening angles of the throttles the recircs operation flutters, this gives a degree of recirc operation that should NOT be occurring, the noise is a direct result of this.
So the recirc work ok, bUT the control of the recirc is the problem, they are operated by vacuum and the pick up points are either side of the plenum after the throttles where the vacuum levels are greatest when the throttles are closed, however here lies the problem even with the throttles slightly open as can be the case around the zero boost mark there is enough vacuum to operate the recircs and hence the noise occurs, this slight throttle opening relates to 30mph to 40mph in gear and is very annoying.
Ok hope you still with me on this, so by fitting solenoids in the vaccum lines that are operated by a throttle switch the recircs will only operate when the throttle is absolutely shut! and this kills the problem once and for all.
Total cost for this is around £20 by using some used solenoids, pipe and a micro switch from maplins.
If enough peeps are interested I will sketch it out and post it up so it can be copied.
Right been working on / off on a fix for the dreaded goose honk that occurs when fitting induction kits when the standard recircs are still been used.
I know that fitting bovs cures the fault but why spend out on bovs if you have an auto box as they do very little then and anyhow not all owners have the spare cash.
Right, having looked at why the noise occures and at what throttle opening etc, it appears to be that crucial opening angles of the throttles the recircs operation flutters, this gives a degree of recirc operation that should NOT be occurring, the noise is a direct result of this.
So the recirc work ok, bUT the control of the recirc is the problem, they are operated by vacuum and the pick up points are either side of the plenum after the throttles where the vacuum levels are greatest when the throttles are closed, however here lies the problem even with the throttles slightly open as can be the case around the zero boost mark there is enough vacuum to operate the recircs and hence the noise occurs, this slight throttle opening relates to 30mph to 40mph in gear and is very annoying.
Ok hope you still with me on this, so by fitting solenoids in the vaccum lines that are operated by a throttle switch the recircs will only operate when the throttle is absolutely shut! and this kills the problem once and for all.
Total cost for this is around £20 by using some used solenoids, pipe and a micro switch from maplins.
If enough peeps are interested I will sketch it out and post it up so it can be copied.
Jeff TT