gti gadge 0 Posted February 23, 2011 Looking to do this mod and either vent it to atmosphere or to BOV. Right, after some opinions from guys who have done this mod. My thoughts are to leave the main pipe on from the TB to the charger but disconnect the pipe from the TB, leaving the crank breather and ISV to go back to (breath into) the charger as they would normally and lube the charger still with oil mist. Is this a viable option? I have searched and most blank off the charger and use PTFE spray which I don't want to rely on. Prefer the idea of the above but just not 100% swung on it. Thoughts please Quote Share this post Link to post Share on other sites
JMC 0 Posted February 23, 2011 I have done the boost return before, but I blanked off the charger and then used a cut down boost return pipe, feeding in the ISV and crank breather to it, to reduce the general and continual background whistle on part throttle. I went back to normal in the end but it was a good mod while it lasted. I also :ahem: have my old blanking plate and silencer kit for sale at the moment if you're interested. Shameless plug.... http://www.the-corrado.net/showthread.php?53776-G60-boost-return-silencer-and-charger-blanking-plate Not sure how many have done it the way you suggested though... Quote Share this post Link to post Share on other sites
domwells27 0 Posted February 23, 2011 From the sounds of it, you'll leave one end of the main pipe open to atmosphere? Wouldn't recommend that as your charger will be sucking on anything that goes into the pipe. I originally removed the main pipe completely, stuck a breather filter on the ISV, blanked the 2nd charger inlet and ran a pipe from the crankcase breather out the bottom of the engine bay. Now I've got the crankcase breather hooked back up to the charger so I'm not venting oil vapour to atmosphere. My throttle body just vents to atmosphere, but this does cause whistling at part throttle, putting a short run of silicone tubing from the TB is supposed to stop this. Regarding lubing the charger, there's plenty of debate about it. If you've had your charger ported then the PTFE spray can eventually clog around the outlet and undo all of your expensive porting work. Can't think why the charger needs to be lubed anyway as the bearings are supplied with oil and the apex strips are self-lubricating. Quote Share this post Link to post Share on other sites
gti gadge 0 Posted February 23, 2011 I have done the boost return before, but I blanked off the charger and then used a cut down boost return pipe, feeding in the ISV and crank breather to it, to reduce the general and continual background whistle on part throttle. I went back to normal in the end but it was a good mod while it lasted. I also :ahem: have my old blanking plate and silencer kit for sale at the moment if you're interested. Shameless plug.... http://www.the-corrado.net/showthread.php?53776-G60-boost-return-silencer-and-charger-blanking-plate Not sure how many have done it the way you suggested though... Nothing wrong with blatant plugs mate, appreciate your input at the end of the day. I have a plate and a spare boost return pipe but I want to make the most of it. Don't really like the way the oli mist off the breather is just left to cock up the bay, even if its ported to ground level. This was the main reason I thought about returning the crank and ISV to the charger and basically just unpluging the return at the TB. From the sounds of it, you'll leave one end of the main pipe open to atmosphere? Wouldn't recommend that as your charger will be sucking on anything that goes into the pipe. I originally removed the main pipe completely, stuck a breather filter on the ISV, blanked the 2nd charger inlet and ran a pipe from the crankcase breather out the bottom of the engine bay. Now I've got the crankcase breather hooked back up to the charger so I'm not venting oil vapour to atmosphere. My throttle body just vents to atmosphere, but this does cause whistling at part throttle, putting a short run of silicone tubing from the TB is supposed to stop this. Regarding lubing the charger, there's plenty of debate about it. If you've had your charger ported then the PTFE spray can eventually clog around the outlet and undo all of your expensive porting work. Can't think why the charger needs to be lubed anyway as the bearings are supplied with oil and the apex strips are self-lubricating. Yep, I meant to say that I'd unhook the pipe returning from the TB and put a breather filter (small KN type of affair) on the end where the TB U-bend has been removed. That make sense now? Not looking to get any crap into the charger at all. Its stage 4 and I'm glad you mentioned the possible clogging, thats not something I've heard of before. Thoughts on BOV? Looking at this as it is supposed to improve throttle response. Thanks Quote Share this post Link to post Share on other sites
gti gadge 0 Posted February 23, 2011 Whilst checking this out I came across some info suggesting the ISV should go back into the intake as on boost with a ported charger/ smaller wheel some passing will take place through the ISV losing psi and ultimately power. Thoughts? Quote Share this post Link to post Share on other sites
JMC 0 Posted February 23, 2011 I currently pass the output of the isv into the intake pipe, and I saw perhaps 1/2 psi increase in boost pressure. The only problem with do this, is if for any reason the ECU needs to vent boost pressure it now can't do it. So say the throttle jams open it now can't vent any excess air. On my setup the boost pressure is quite low (11psi at WOT) as I have quite a heavily flowed head, so it should never fingers crossed be a problem. It seems to be a popular thing to do in the US (loads of people on the Vortex have done it) but much less so here. Having tried various different arrangements I have gone back to boost return on and stayed with ISV into the intake. Like you I hated the oil mist floating round the engine bay. Do you have a bigger FMIC - if so there is no real need for the boost return anyway as the larger surface of the FMIC will be more than enough to cool any intake charge, which has beeen heated by passing through the boost pipework system already. I'd be worried about the BOV giving too quick a chnage in boost pressure and being a shock to the charger. Only ever seen one on BBM's corrado with a lysholm charger, but that was because there there was no boost return system AFAIK. Of course the big question is do you just want to do it to try it, or are you expecting more of a performance benefit from it? Quote Share this post Link to post Share on other sites
gti gadge 0 Posted February 24, 2011 I currently pass the output of the isv into the intake pipe, and I saw perhaps 1/2 psi increase in boost pressure. The only problem with do this, is if for any reason the ECU needs to vent boost pressure it now can't do it. So say the throttle jams open it now can't vent any excess air. On my setup the boost pressure is quite low (11psi at WOT) as I have quite a heavily flowed head, so it should never fingers crossed be a problem. It seems to be a popular thing to do in the US (loads of people on the Vortex have done it) but much less so here. Having tried various different arrangements I have gone back to boost return on and stayed with ISV into the intake. Like you I hated the oil mist floating round the engine bay. Do you have a bigger FMIC - if so there is no real need for the boost return anyway as the larger surface of the FMIC will be more than enough to cool any intake charge, which has beeen heated by passing through the boost pipework system already. I'd be worried about the BOV giving too quick a chnage in boost pressure and being a shock to the charger. Only ever seen one on BBM's corrado with a lysholm charger, but that was because there there was no boost return system AFAIK. Of course the big question is do you just want to do it to try it, or are you expecting more of a performance benefit from it? Thanks for this input mate, this is the type of stuff I was hoping for. I've only just gotten the G in the newyear after putting it off for years (have three golfs, so enough problems already lol) but when a nugget came up I just had to get it somehow! Sad I know but I love it. Car has a stage 4 charger and P&P head on it and using the maf function is boosting around 1 bar. The car is tidy, not immaculate, hence why I could afford it lol but the engine has been looked after. Its had work done to it but under the hood is a real mess. I do what I always do, read too much and want it to be as good as it can be. I want the bay tidied up, wiring sorted and engine optimised. I like the car and have it as my daily whilst I strip my mk2 down. I wanted the G for its smooth delivery of power and the twiney charger sound. Shoot, rambling again. Back on track. Not looking for or expecting extra power, just optimisation of whats already there. I want to upgrade the cooler to a FMIC, probs return to a standard airbox with cool air feed and re-earth the lot. Il,ike the boost delete as a way to stop any boost leakage through the ISV, returning it into the boost intake tract instead. Crank breather back to charger. Stumbled across the BOV topics whilst searching and the experiences lean towards better throttle response rather than anything else. Maybe its a suck it and see type of deal with that but any input is greatly received. Brain is in overload after staying up and reading threads all night about this and other stuff like MAP sensor changes etc. Argh...why o why can't I just leave anything well alone?? I'm interested in why you returned to running a boost return pipe again rather than breather to charger and just dumping the excess? The head porting and boost pressures is something I need to understand more aswell. It looks like I am running around 14-15 psi with the stage 4, headwork and 68 pulley. So many variables involved to gauge output against anyone else. Suppose this is the joy of owning something new, working all this **** out. Loving the G and whole Corrado experience in general Quote Share this post Link to post Share on other sites
JMC 0 Posted February 24, 2011 Don't worry about rambling, we all do it, lol. I returned to having the boost return attached because of 2 things really. 1st, I hated the constant whislte on part throttle. 2nd I hated the mist of oil over everything. With mine I hae rertouted the ISV into the inlet pipe and blanked of the ISV input to the boost return pipe. But as I say I have only done this becuase I have relatively low boost pressure on full boost. Some people love the sound though, and that's cool for them. Boost pressure is really a measure of unused air. If the charger is pushing a certain amount of air, and you are measuring pressure, then a system with less restrictions in it will have a lower pressure measured. So for example if your head is flowed well, and your cam is setup well, then there would be less restrictions in your inlet system and the measured pressure would be lower. Also you get pressure drop over larger intercoolers, so adding an FMIC will lower your measured pressure. But there should be better cooling which should make the charge denser, and therefore up your pressure a bit. It is complicated, but the key to making a G60 work better is to get it to breathe better. How are you measuring boost pressure? If you are using the MFA one don't bother, and get a proper boost gauge (preferably a boost and vacuum gauge). Plumb it in to the line going to the back of the clocks. Standard air box and paper filter are fine (with a bit of opening up the air box on the wing side). Quote Share this post Link to post Share on other sites
gti gadge 0 Posted February 24, 2011 How are you measuring boost pressure? If you are using the MFA one don't bother, and get a proper boost gauge (preferably a boost and vacuum gauge). Plumb it in to the line going to the back of the clocks. Standard air box and paper filter are fine (with a bit of opening up the air box on the wing side). How are you measuring boost pressure? If you are using the MFA one don't bother, and get a proper boost gauge (preferably a boost and vacuum gauge). Plumb it in to the line going to the back of the clocks. Standard air box and paper filter are fine (with a bit of opening up the air box on the wing side). Boost gauge is on its way, just can't decide on where to mount it? Any advantages other than run length on using vac pipe into the MFA rather than the pipe on the FPR which is the one I would have gone for? Will a golf airbox fit as finding a decent rado one seems to be quite hard? Any advantage with the twintake system or just overkill? FMIC will defo be on my to-do list as the standard one is minute. Then its just down to surface area and pipe runs for pressure loss. Quote Share this post Link to post Share on other sites
JMC 0 Posted February 24, 2011 Boost gauge is on its way, just can't decide on where to mount it? Any advantages other than run length on using vac pipe into the MFA rather than the pipe on the FPR which is the one I would have gone for? Will a golf airbox fit as finding a decent rado one seems to be quite hard? Any advantage with the twintake system or just overkill? FMIC will defo be on my to-do list as the standard one is minute. Then its just down to surface area and pipe runs for pressure loss. My boost gauge is up on the right hand side of the dash near the a pillar. There'll be a pic in my build thread somewhere near the beginning. It's one of those gauges you really want to be in your line of sight. I took mine off the pipe behind the clocks as it was one less pipe in the engine bay and one less pipe to feed through the firewall. AFAIK the airboxes are G60 corrado specific, though I must admit I have never looked at a Golf G60 or Rallye one before so am not 100% on that. Unless you have a very heavily modified engine the twin intake is overkill from a performance point of view. I also remember an instance of the plastic on the intake box of one of those twin intakes coming loose and being sucked through a charger. Not good. Mines running just under 250bhp and is perfectly happy with a standard(ish, bar a few holes) air box and normal paper filter. Best thing to do initially is save for a FMIC (and a decent ECU map if you haven't got one already). The next best thing to get is a separate oil cooler system. Personally I would worry about boost returns yet. Quote Share this post Link to post Share on other sites
gti gadge 0 Posted February 24, 2011 Thanks for that. I'll have a look in your thread at gauge pod etc. Yep, oil cooler is also on the cards and I'll just keep looking for an airbox, cheers Quote Share this post Link to post Share on other sites