Bora w/R32 exhaust - flapper mod?

[Dyldo]

I've read all through the Vortex and google searches of the flapper mod, and most relate to the stock exhaust for a R32 that will have the famous blue/grey wire they all talk of.

My goal when I get my R32 exhaust fitted to my Bora (this week hopefully) is to have the flapper open. Now, my question (seeing as how this is an exhaust taken from a R32 and fitted to a non-R32) is that if i pull the vac line off the vac actuator nipple and cap it with a screw and/or silicone to seal the line and also cap the actuator nipple, then will this mean the exhaust is in the "open" position?

[type 17]

Does the standard bora exhaust have a butterfly valve? i.e, do you even have a vacuum line to block? as far as i can tell, if you have a vacuum line for your exhaust that would normally plug into the valve then yes, you only need to jam a screw in it and the flap will stay constantly open.


PS, just started fishing through your emails today mate, looking interesting, sorry ive been a bit flakey but ive been dealing with some issues recently, havent had much time to think bout cars..

[Dyldo]

nope, the Bora's don't have a flapper or butterfly, so no ECU leads or vacuum lines leading back to the engine bay.

Is there a way the butterfly valve can be actuated from either in the cabin with the exhaust this way? As in because its in a Bora now the flapper (I presume) needs to be either locked open or closed. I am still getting used to the flapper idea tbh, and its not fitted yet.

Or am I missing the way it operates? I am presuming it is like the butterfly on the Varex adjustable muffler?

[Manaz]

My understanding is that vacuum forces the flapper to close - so if you block the line off (or remove it and plug it up), the flapper stays in the open position.

Just make sure there's a bung in the attachment point - that way you'll keep dirt out of it if you should ever want to use it later (there are kits to enable it with a switch - pretty sure ECSTuning sell something along those lines...).

[type 17]

yeah if there is no vacuum line at all the flapper should be jammed open all the time, just check and if its not get a clamp on the little lever so it is open... but yeah without the correct vacuum line with computer programming you will not be able to achieve the stock open-close flap arrangement of the .:R32

[Dyldo]

thats fine man, i'd rather have it as manual. as in, forced closed if the missus/boss/fun police wants to have a whinge, and left open 95% of the rest of the time

actually bugger that, i want that puppy open all the time.

how would i get the exhaust to give me a burble as well as some crackling, popping and farting on over-run?

[type 17]

well, the r32 makes bubble, popping and fizzing noises from standard if the flap is open, i did the grey/blue wire mod and have the switch sitting in the cabin for easy adjustment, that said i usually drive with it on standard mode, unless i wanna freak someone out, or piss my parents off when i go to visit them...

[Dyldo]

nice - i'll leave it then. sure the engine pumping gases through the system is a slightly different (smaller) engine in the Bora than the R32, but surely the result will be the same?

and you say keep the centre res in?

[graeme86]

Actually...it would not be too difficult to get the flapper to work on a Bora with a manual switch.

You would need the vacuum tank and solenoid from R32 (or a vacuum tank and a solenoid - just one of those generic VW green vacuum tanks on some VWs and the solenoid is the same as the variable inlet solenoid on the Bora).

Then you would need a vacuum line from the manifold - the R32 connects at the back where the three pipes are on the manifold.

Then you just wire a fused positive to the solenoid from the 87F terminal on the relay plate to the solenoid. (same as R32...or just use 75X which is ign)

The negative from the solenoid just goes through and on/off switch to earth.

Thats how it operates on the R32 - the earth for the solenoid is actually controlled internally by the ECU, so when it earths the signal, the flap is closed.

Porsche also have a separate plug-in relay (not the ECU) to control their flappers on 996 etc Tequipment package Sports exhaust. but it also connects to GALA speed signal so that it only opertes similar to R32 system - only at "out of town " speeds

[type 17]

Nice Graeme, you truly are the man....

Dylan id keep the res, but thats me, i am the quiet achiever i guess.

[graeme86]

It will be way too loud and raspy without the centre resonator I believe.

[Dyldo]

Right, dropped her off to the zorst shop to get the new one fitted. Was (hopefully) very clear about the fact I wanted the stock Bora valance cutout replicated on the other side in the same spot (as in, the same distance in from the edge) and then also stipulated the need to have the two R32 tips centered and aligned in the middle of each valance cutouts.

2 quick ones:-
1) The flapper is spring loaded, and the nipple on the flapper "spaceship" was open so it needs to be capped, but in that position is it open or closed? As in, if the rod is pulled against the spring, compressing it, is that closing or opening the flapper? Bear in mind I want the flapper locked open.
2) I think I have asked this before, but when I pick her up do I need to disconnect the battery for 10minutes and then re-connect to force the ECU to re-learn the engine and therefore the new exhaust?

[graeme86]

I believe the vacuum pulls the flap open. You will soon know which way is open anyway.

You only need to cap the "spaceship" to keep dirt out if you want. It doesn't do anything otherwise if the vacuum hose is disconnected.

The ECU would adapt anyway after a short period.

[Dyldo]

that makes sense, the valve would be under tension and pulled back on vacuum, and then when the vacuum is gone (deceleration or low rpms) the valve closes. so maybe the easiest way to lock it open would be to tack-weld it open? as in, spring compressed?

is there a potential downside to the backbox by doing this?

[graeme86]

Just tie it up with some wire... then you can close it if you want to as well.... or addn a switch later.