boost return question

[wippy 0]

Hi this may have been talked about before but when you delete the boost return why do people not just route the breather outlet back to the supercharger blanking plate, surly this would solve having to spray lube in every now and again. I am new to the g60 so if im just being dumb please just humour me :)

[Yandards 0]

You can do that if you want.

 

The reason for better driveability with the boost return deleted is 2 fold, 1st of all the stock intercooler is rubbish so pumping charged air back through it just raises the charge temps even furthur resulting in lost power (not sure of actual numbers but a good guide is around 3% bhp for every 10 degrees IIRC)

 

2nd, oily vapours do not make for a good clean burn, oil vapour contained within the charge air will rob power as oil is not designed to be burnt, unlike petrol. This impacts on the quality of the burn within the cylinder and again reduces power output (although this has much less impact than rising engine temps)

[dirtytorque 0]

You can do that if you want.

 

The reason for better driveability with the boost return deleted is 2 fold, 1st of all the stock intercooler is rubbish so pumping charged air back through it just raises the charge temps even furthur resulting in lost power (not sure of actual numbers but a good guide is around 3% bhp for every 10 degrees IIRC)

 

2nd, oily vapours do not make for a good clean burn, oil vapour contained within the charge air will rob power as oil is not designed to be burnt, unlike petrol. This impacts on the quality of the burn within the cylinder and again reduces power output (although this has much less impact than rising engine temps)

 

So why did they put it on there Yan?

Not being funny.I genuinely want to know as I am about to fab a boost return for my new engine.

There must be a positive9s)?!?

Your effectively bleeding off boost without it.Ok it's warm boost but it's boost all the same.

[Henny 0]

The positives are that you don't dump hot oily gas into the atmosphere which the manufacturers want to avoid so they can get their car through the environmental tests and limits they have to, and that it lubricates the charger, although this is more of a helpful after-thought than a planned design....

 

The G60 engine ALWAYS bleeds off boost unless you've got your throttle nailed down to the floor... however, venting boost to atmosphere is frowned upon (if not illegal) on a new vehicle, hence the boost return pipe...

[dirtytorque 0]

 

The G60 engine ALWAYS bleeds off boost unless you've got your throttle nailed down to the floor... however, venting boost to atmosphere is frowned upon (if not illegal) on a new vehicle, hence the boost return pipe...

 

granted but it is effectively recirculated back into the intake system so it's on tap.

Anyway,thnks for the reply.

:salute:

[Yandards 0]

What Henny said :)

[CTWG60 0]

I think any performance increase by deleting the boost return is minimal. :D I can't back that statement up, it's just what I think. Rob buy some cheap air temp monitors and plumb them up to find out how hot the returned boosted air is compared to ambient air. I reckon sufficiently cooled boost only gets cooler as it is recycled.

 

I've jumped out my car and popped the bonnet on a number of occasions and TB is very cold to the touch and the inlet is also nice and cool as is the charger so... :shrug:

[Henny 0]

 

The G60 engine ALWAYS bleeds off boost unless you've got your throttle nailed down to the floor... however, venting boost to atmosphere is frowned upon (if not illegal) on a new vehicle, hence the boost return pipe...

 

granted but it is effectively recirculated back into the intake system so it's on tap.

Anyway,thnks for the reply.

:salute:

 

I see your point about it being on tap, but with it being a supercharger, you won't actually gain anything by slinging the boost back around into the charger again, it just ends up pressurising the boost return pipe slightly as most of the restriction will be there... with a Turbo setup, yes, I could see it would be an advantage as you'd have pressurised boost pipes to get over the turbos lag, but with a supercharger, the difference is going to be as near as damn it negligible...

 

I still run with a boost return fitted... I played with the idea of a second inlet and having the boost return fed into a catch tank and then into the bottom of a second airbox to silence it a bit, as I seem to remember John Mitchell did this on his 16VG60 Corrado waaaayyyy back when (only one airbox, but had the boost return fed into the bottom of it), but I decided that I'm not on the hunt for every last BHP I can get out of the engine, I'd rather it lasted a little longer... :)

[wippy 0]

You can do that if you want.

 

The reason for better driveability with the boost return deleted is 2 fold, 1st of all the stock intercooler is rubbish so pumping charged air back through it just raises the charge temps even furthur resulting in lost power (not sure of actual numbers but a good guide is around 3% bhp for every 10 degrees IIRC)

 

2nd, oily vapours do not make for a good clean burn, oil vapour contained within the charge air will rob power as oil is not designed to be burnt, unlike petrol. This impacts on the quality of the burn within the cylinder and again reduces power output (although this has much less impact than rising engine temps)

 

 

thanks mate, i am a mechanic and totally understand how a supercharger works but this is the first time i have actually looked into the g60, i literally thought about buying one and then the next day i had one lol, i see a lot of people removing the boost return so i took mine off , it just puzzled me that people were then saying that you had to buy teflon spray for the supercharger when it works fine when its just using the oil from the breather, im guessing most people just remove it for the noise :D, the worst side affect from having your engine breathing oil must be the increased risk of det but having left my breather venting to atmosphere for a couple of days the ammount of oil which has been spat out is really not worth worrying about if this goes into the charger, besides this would happen anyway if you left the boost retunt there, i have now plumbed the breather to the blanking plate :D i cannot believe how much these plates are sold for, it took me 5 mins to knock one up at work lol.

 

if i may could i ask another question, i know chargers make some noise but when mine is taken over 3000 rpm there is a noise which kind of sounds like a worn bearing which obviously gets louder as the engine is taken higher up the rev range is this normal?, the charger was rebuilt by jabba about 3000 miles ago so im sure it cant be that (but i could be wrong) is it a possability it could be the idler pullys are these something which need replacing often , my car has bone 145000 miles , i dont know whether they are the originals but they look like they have seen some action, i will take them off tomorrow and have a look at them but as i said this is the first time i have looked at this engine and was just wondering if there is anything specific i need to look out for

 

any help would be much appreciated

 

thanks

kieran

[Yandards 0]

Hallo,

 

The idler pulleys do wear out along with the damper/spring tensioner. Idler pulleys tends to make a squeaking/chirping noise so hopefully that will point you in the right direction.

 

I replaced the whole lot on mine when I did the cam belt and it made a world of difference, not cheap though as its VW only for all the parts :(

 

Boost return deletion does make a lot more noise, but if like the 'woosh' when you come off full throttle it does sound good. Blanking plates are only a bit of shaped alloy with some holes in as you said its not difficult to make one up. Be worth making up a gasket between the blanking plate and the charger though; I have used a blanking plate as an adapter to carry out a leak down check on the boost/cylinder head system before and the biggest leak was the blanking plate!!

 

Charger noise varries depending on modifications, if you have an RSR style outlet (do a quick search) instead of a black plastic silencer box you tend to get resonance from the charger compression transimitted through the engine. Another item the increases the noise is if the 'snorkel' is removed from the front of the factory airbox, drilled airboxs also increase noise levels.

 

As for the G60, dont fit a cone filter intake, they tend to suffer from heatsoak, use genuine VAG oil filters as the NRV loading is critical, regular oil changes (every 6k) and change the oil supply hose to the charger (the braided one) as these tend to be a bit of an unknown.

[dirtytorque 0]

g-larders whine...

I guess this is what your hearing?!?!??

[Riley 0]

I haven't bothered with any 'lube' for a few years now...and i wouldn't recommend it really.

 

Reason being that i spent a lot of money on a full blend charger from pitstop, real nice porting of the charger. And after using lube for a while it made all the porting absolutely pointless as it just builds up and gathers. I had to strip it out and remove all the built up gunk. :gag:

 

I don't think vw really intended for the engine to breathe heavy and do any 'lubricating' of the charger apex strips, more to just keep any mist in the system as said above.

 

My charger still gives 15psi at redline with no issue's.

 

Neil.

[wippy 0]

thank you everyone for all your help, i think i may replace the pulleys because they do seem past their best. The engine pulls really well and just seems to get stronger and stronger all the way to the red line which i guess is a good sign, the charger oil feed pipe has been replaced with a newer one,

 

is it worth replacing the standard pulley with a 68mm one and fitting a chip, does it make a big difference?

 

Would anyone recommend replacing the silencer box or is it best just to leave alone?

 

also and im really sorry for all these questions, my temp gauge does not work , i did read on here about testing the sensor and it all seems to be ok, i also earthed the plug and the temp gauge still did not move, is this likely to be a fault with the gauge?

 

ill soon get the hang on this, i just thought it was best to ask people who have experience with the g60, i have had 12 mk2 golfs 3 mk1's 3 scirocco's a mk3 and a 2ltr 16v corrado then i turned to the dark side and got into my 200sx's ,skylines and rx7's but now im back lol i could rebuild a skyline engine in my sleep but because i have never heard or driven a g60 before its hard to tell whats right and whats wrong, it seems to me from what you all have said that mine is a good one :)

 

thanks again guys for all your help

[burn-rubber-not-soul 0]

hi i just got one those blanking plates did you fit yours and what was it like

 

thanks martin