G60 ISV reroute (can you vent to air)

[brookescourt 0]

Can anyone give me some advice?

I had a BBM ISV reroute kit fitted untill my Samcos arrived but didn't refit it as I didn't want to cut the hose.

What I have done instead is use a crankcase breather to vent the ISV to air.

When I change gear at high revs I know get a really nice whistle, but am I doing any damage to the engine/charger etc?

I have seen this done on lots of European cars and just thought I would try it out.

Any advice gratefully recieved.

Cheers,

Rob.

[Dubcharged 0]

So have you removed the bypass pipe to the charger? In which case your breather is venting to air also?

[brookescourt 0]

All the boost return pipes are still in place, I have just dissconected the pipe from the ISV that goes into the boost return pipe, capped it off and fitted a crankcase breather to the ISV.

[Dubcharged 0]

oh, so where are getting the whistle on gear change from then? you might have a leak where you've capped off the tube.

[G60 0]

thats the blow-off.. is it not??

 

it always does that, but you don't hear it because it gets routed back into the charger normally.. unles you bunged something up and have a leak like dubcharged said.

 

but..sounds like you just acquired the blow-off *ching!* that i miss so much from driving my XR!

[brookescourt 0]

I was sometimes getting it anyway, just not as loud. It started when I had my chip and pulley fitted.

I thought it was quite common for them to whistle.

[Dubcharged 0]

Check your blocked off aperature just in case.

 

I've removed the complete bypass system, the oil vapours from the breather dilute the octane in the petrol while mixing. Also, the oil coats the insides of your intercooler and boost tubes. Its debatable whether or not the oil vapours are needed for the charger (it has its own oil feed line). But spray some PTFE spray into the charger every now and again just in case. 8)

 

Secondly the recirculated air is pre-heated and so you're adding to the heat of the charger and heat soaking your intercooler. :cry:

 

Just my two cents/pence

[brookescourt 0]

So you think the whistle is coming from the pipe which carries excess/unused boost back to the charger? (the one with the capped off hole)

Is it a big job to remove all the bypass system? I have thought about it in the past but was worried about not lubricating the charger.

How do you go about capping off the charger, or have you fitted anothe air filter instead?

[Dubcharged 0]

Another filter on the other side but i've rerouted it so that its away from engine heat.

 

Just use a PTFE spray to lube the charger every now and then.

[Jon TDI 0]

I always thought that the whistle is the excess boost going thro' the bypass system & it was perfectly normal.

Mine's always done it since I put the smaller pulley on, especially at between 4000 & 5000rpm. Most G60's I've seen (and heard) with smaller pulleys do it.

[GazzaG60 0]

mine does it up to 4th n its standard still.

 

All i thought about it was that the blow off back thru the charger and out of the filter would obstruct incoming air. whether or not i dont know ..just a thought

[Jon TDI 0]

I've removed the complete bypass system, the oil vapours from the breather dilute the octane in the petrol while mixing. Also, the oil coats the insides of your intercooler and boost tubes. Its debatable whether or not the oil vapours are needed for the charger (it has its own oil feed line). But spray some PTFE spray into the charger every now and again just in case.

 

Dubcharged, What sort of BOV have you fitted then.

[Dubcharged 0]

None, the throttle body has its own bypass butterfly which does the job!

 

I've taken out the plastic bypass hose to the charger which the ISV and breather connect to. The small rubber u-bend is still on the underside of the throttle body, i've just turned it away from pointing to the engine bay.

[Jon TDI 0]

Ah, I see.

Is it noisy at all. The reason I'm asking, is that I'm thinking of ditching the bypass hose & ISV altogether. I don't want it to be noisy on part throttle.

Cheers,

 

Jon

[Banana Man 0]

The only time the bypass system is noisy is when it is venting boost which only occurs when the supercharger is runnig positive boost around 4000rpm if you are only running on vacuum then it wont be noisy just a slight whistle from the charger!

When you say you want to ditch the ISV altogether what do you mean as if you remove the ISV it wont idle!!!!

[Jon TDI 0]

http://corrado.atx-hosting.co.uk/viewtopic.php?t=955 :) :wink:

[Dubcharged 0]

If you reroute the bypass to under the car so it vents into atmosphere without obsruction then it wont be noisy. You'll get a nice blow off sound on gear change when booting it!

[Banana Man 0]

Its alright jon just spotted that thread I had never heard of removing the ISV thats all!!! I am a little wiser now!! :D

[Jon TDI 0]

OK, my next questions are:-

If I ditch the bypass return line, do I need to fit an oil breather pot, or will just a filter on the crankcase breather be enough?

 

And where the bypass line fits onto the G-lader I don't want to fit a second intake, so where can I get a blanking plate to fit?

[G60Jet 1]

i would fit a second intake!!!

[Jon TDI 0]

Nah, I don't want to do that.

I running a K&N panel filter in the standard airbox.

I've heard Cone filters etc, and they are too loud for me (maybe I'm getting old!). I drive an average of 300 miles each week and couldn't live with the constant induction noise.

Plus it would mean routing the filter somewhere for cold air, but I'm trying to free the engine bay of excessive pipe work!

[G60 0]

get a second air box with the same setup as you currently run. move your battery to the trunk.. sit the air box where the battery was, run a pipe to it and run cold air from below. :D

 

..or blank it.. but it kind of defeats the purpose of freeing up that second inlet..other than reducing heat by not recycling hot air.

[Banana Man 0]

If you want a blanking plate have a word with darren (8vg60) he'll machine you up one!! If your gonna remove the isv jon you can just fit a breather filter on top of the crankcase!

[Jon TDI 0]

Thanks G60 & Banana man.

I'll have a little think about what I'm gonna do & I'll let ya know. :)