breather filter g60 plus why ditch giro valve? new Question!

[TomD 0]

sorry, meant to reply to your PM but just keep forgetting... :oops:

 

The gyro valve is designed to stop boost from "leaking" through the ISV at hight boost levels... unfortunately Dr Bosch designed the ECU to VENT excess (ie, over 1bar of boost) through the ISV as anything over 1Bar, the ECU can't measure and so doesn't know how to fuel correctly. By sticking in a gyro valve, you're making the ECU think that it's successfully vented the excess boost where infact it's still getting into the cylinder where it will make the car run lean, pink and (thanks to the knock sensor) cause the ECU to knock back the timing causing you to lose power just as you would when the ECU vented some boost... only difference is that the way the ECU is designed to overcome the 1bar limit means that the engine DOES NOT run lean, where using a gyro valve means it WILL run lean while at high throttle which is where expensive damage can happen VERY quickly...

 

The net result in using a Gyro valve is that you gain NO real power increase (unless your ISV is utterly knackered) and you run the risk of melting you pistons...

 

Removing it's a bit of a no-brainer when you realise how the ECU is supposed to work... ;)

 

On that note, does anyone want to buy my Giro Valve?? :wink:

 

Cheers for the info Henny!

[goodridge 0]

sorry, meant to reply to your PM but just keep forgetting... :oops:

 

The gyro valve is designed to stop boost from "leaking" through the ISV at hight boost levels... unfortunately Dr Bosch designed the ECU to VENT excess (ie, over 1bar of boost) through the ISV as anything over 1Bar, the ECU can't measure and so doesn't know how to fuel correctly. By sticking in a gyro valve, you're making the ECU think that it's successfully vented the excess boost where infact it's still getting into the cylinder where it will make the car run lean, pink and (thanks to the knock sensor) cause the ECU to knock back the timing causing you to lose power just as you would when the ECU vented some boost... only difference is that the way the ECU is designed to overcome the 1bar limit means that the engine DOES NOT run lean, where using a gyro valve means it WILL run lean while at high throttle which is where expensive damage can happen VERY quickly...

 

The net result in using a Gyro valve is that you gain NO real power increase (unless your ISV is utterly knackered) and you run the risk of melting you pistons...

 

Removing it's a bit of a no-brainer when you realise how the ECU is supposed to work... ;)

 

Another G60 bone of contention..... No different to some of the forum members running an ISV re-route now via the BBM pipework as I saw in another post

[Henny 0]

goodridge, yup, same sh!t, different pipework... ;) :lol:

 

NOT to be confused with a boost return modification/deletion kit which doesn't mess with the ISV's bleed ability... 8)

[iow_corrado_g60 0]

henny im confused now! so would you say fit a boost return kit or not?

[Henny 0]

define boost return kit....

 

That's the problem, there's 2 different kits that people call "boost return kits"

 

BBM sell one which re-routes the ISV feed so that it attaches back to the pipe which feeds the throttle body rather than the one that takes unused boost back to the supercharger... this is the one which does a similar job to the gyro valve and should be avoided if you like your engine not running lean.

 

G-werks (amongst others) sells a boost return deletion kit which simply removes the pipe which takes the unused boost from the bottom of the throttle back to the superchargers right inlet. This kit includes an air filter for the ISV so that it can vent to atmosphere, or suck in air from the atmosphere when it's acting as an idle stabilisation valve, a long pipe for the oil breather, and a blanking plate for the side of the supercharger. This kit stops hot boost and oil vapours being fed back into the supercharger and is DEFINATELY worth fitting if you can put up with the extra noise it allows the engine to make... 8)

[goodridge 0]

define boost return kit....

 

That's the problem, there's 2 different kits that people call "boost return kits"

 

BBM sell one which re-routes the ISV feed so that it attaches back to the pipe which feeds the throttle body rather than the one that takes unused boost back to the supercharger... this is the one which does a similar job to the gyro valve and should be avoided if you like your engine not running lean.

 

G-werks (amongst others) sells a boost return deletion kit which simply removes the pipe which takes the unused boost from the bottom of the throttle back to the superchargers right inlet. This kit includes an air filter for the ISV so that it can vent to atmosphere, or suck in air from the atmosphere when it's acting as an idle stabilisation valve, a long pipe for the oil breather, and a blanking plate for the side of the supercharger. This kit stops hot boost and oil vapours being fed back into the supercharger and is DEFINATELY worth fitting if you can put up with the extra noise it allows the engine to make... 8)

 

G-Werks also sells the BBM pipework with the ISV re-route though.......

[flusted 0]

so a giro valve with a rallye ecu would be ok? or a different map sensor?

[Henny 0]

NO. a Giro valve is a BAD idea FULL STOP.

 

With a Rallye ECU it would still try to vent boost after it hit 1.5 bar rather than 1 bar so you'd be in the same situation, just at higher boost. Same applies with a different map sensor. If you aren't making 1.5 bar with a rallye ECU, then the ECU won't try to vent so you don't need the giro valve. If you find that you have a leaky ISV (it does happen) it's better to repair or replace the ISV than sticking in a bodge valve which is basically what the giro valve is... ;)

 

G-Werks is the UK distributor for BBM so can supply any of their kit... I'd be interested to hear what Darren would say if you asked to buy on of their re-route kits though... ;)

[flusted 0]

but 1.5 bar is about 20psi isnt it? so would be ok with a 68mm pulley?

[Henny 0]

mine used to hit 23psi on the old head... ;)

[flusted 0]

interesting read really

[iow_corrado_g60 0]

hi all I have a new question if i had an oil catch tank obviously with 1 inlet hole for the oil breather from rocker cover with a little k&n on top of the oil catch tank as per usual

 

then as normal too the isv having the little k&n on it

 

is it possible to take a tube straight from isv run it into a seperate inlet in the catch tank and let it vent through the small breather on the top of the oil catch tank or would this be seriously wrong and you all think im a tw*t!

 

Cheers Andy

[Henny 0]

iow_corrado_g60, that'd work fine... essentially that's what you're already doing on a standard car with standard pipework...

 

the only thing you'd have to be bloody careful of is that you don't let the oil level in the catch can get too high, else it'll flow down the pipe to the ISV and stop if from working!!!

[iow_corrado_g60 0]

thanks henny im gonna try get a custom one made also then ill try get one with an oil level window might cost a bit but i think it will look quite trick with both going into oil catch tank! with a k&n on top

[Henny 0]

make sure that the ISV one is as high as possible in the tank (higher than the oil breather pipe, and see if they can put a "shield" inside the tank between that pipe and the filter so that any splashed oil doesn't get into the ISV feed as you mustn't forget that the ISV needs to be able to blow AND suck air in to work properly... ;)

[iow_corrado_g60 0]

cheers mate i think it will be a work in progress henny! can i just check that this catch tank will need a:

 

1 x catch tank

1 x oil level sight

2 x inlet pipes to take oil breather and isv!

 

is that it matey!

[Henny 0]

far as I can see... yup... personally, I'd just stick with one inlet and put a small K&N straight onto the ISV so there's no chance that it'll suck in oily air when trying to stabilise the idle, but that's just me... ;)

[iow_corrado_g60 0]

i will see if i can get a gauze henny if not thats what i will do as already have one of those!

[flusted 0]

Following on from the giro valve.

I read on vortex that sns can now adjust the chip to compensate for the added boost gained by the valve?

[Henny 0]

interesting... how does that work then? :|

 

So, the ECU dumps excess boost through the ISV as the MAP sensor can no-longer read the boost as it's gone past it's upper limit -> gyro valve stops boost leaking -> the magic sensor in the system reads the extra boost -> ECU detects the gyro valve via telepathy and adjusts fuelling accordingly???

 

The whole problem is that the MAP sensor is a 1 bar (over normal atmospheric pressure) sensor... any boost OVER that 1bar, the ECU cannot deal with so it tries to leak it out of the ISV.... The ONLY way to get around this problem is to fit an up-rated MAP sensor and change the programming on the ECU main chip to take that into account (ie remap the ECU)...