quick question Re:boost pipe

[paulg60 0]

when i get round to removing my boost return pipe where it goes into the charger. if i make a blanking plate do i need some sort of gasket between the charger and the plate?

[brookescourt 0]

I used blue hylomar (spelling?) gasket sealant, worked fine.

HTH,

Rob.

[funky 0]

is there much to be gained from removing the boost return ?

funky

[brookescourt 0]

Just a lot of funny noises I found!

I didn't notice any performance gains so I refitted everything after about a week.

[W3RKD 0]

borrowed as cant type that quick this morning....

 

The stock ISV isn't designed to control boost, it can be modified to do so, often on the corrado the ISV leaks, and you do loose boost, this is a very common problem, and you need to do an ISV rerout, which basically means add a check valve in line with the ISV. This would not be the ideal route for a BOV. On the bottom of your throttle body (the piece that bolts onto the intake, and your throttle cable connect to to control the throttle plate) the bottom has a wastegate, which will have a return line going back to the supercharger, if you remove the return line, make a blank plate or add a second intake to your supercharger, you then have an open hole.. You can add a BOV here, inbetween shifts your wastegate opens, and all your boost is lost, not a real big deal since the charger is still spinning, and will have boost as soon as you go WOT. But... if you have long intake lines, and a large intercooler, and it is just a shift it is nice to keep some boost, when u are not on the throttle you can not have full boost, your car will run lean, and detonitation will accour. You can set your BOV at say 5psi, and this will give you a quicker return between shifts, if you are running at like 20psi for instance, and you drop to zero between shifts, it will take longer to gain to full boost under a load, then if you are starting at 5psi instead of 0.

Now on the other hand installing a filter instead of a BOV or the return line is the most efficent thing for your engine. Your supercharger is plenty capable of pulling in enough fresh air, that their is no need to recycle air, and your charger makes air hotter, so why would you want to feed in air you already heated up, when their is fresh air available, this helps keep air temps down which creates denser air, and therefore more horsepower. which I think is the main goal here..

hope this sums it up...

 

i can supply the blanking plates for this job if needed...

[brookescourt 0]

Darren,

Have you got anywhere with the kits to remove the return pipe but keep noise levels down yet?

[W3RKD 0]

not yet sorry

[choumbie 0]

Exactly how loud is this noise? Im looking for that hissing noise when you shift...Does this make somewhat the same noise as a blowoff valve? Does it make the engine sound crappy or what?

[munkay 0]

There will be two new noises:

 

One on slightly open throttle which will sound very similar to the noise when you open a radiator and the air/water hisses out. This one isn't that loud tho luckily.

 

The second much more obvious one is on gear change - especially after WOT and a fair bit of revs. It sounds a bit similar to a dump valve noise altho its more subtle. Heard it described as a sneeze - not the 'ahhh' part more the 'chooo' bit :) The loudness and clarity of this will change with the amount of boost beign dumped.

 

IMO it sounds decent and will be leaving mine off, I do sometimes miss the old whisltey/ping type noise it had before though :)

[Si B 0]

What causes the whistle/ping noise that you mention. Mine makes a noise like this (similar to a dump valve noise) when I change gear on full chat. It sounds like boost squirting out from somewhere but I have checked all the pipes for leaks and can't find any. Is it a leaky ISV?

 

The noise only started when I fiitted a 68mm pulley and thus wound the boost up.

 

I have not lost sleep over it yet as it sounds quite cool but I don't want to be losing boost when I shouldn't be.

[andycowuk 0]

Exactly how loud is this noise? Im looking for that hissing noise when you shift...Does this make somewhat the same noise as a blowoff valve? Does it make the engine sound crappy or what?

 

heres what mine sounds like....

 

it hasnt anoyed me yet!.....it still makes me happy and thats been about 3 months now.

[g-master 0]

yeah i've had this mod done and it make's sense no hot boosted air back to charger and no oily crud from breather. But saying that i really did'nt like the way the car sounded (just my opinion) so i re-connected boost return pipe but blanking breather pipe off and running it to a catch tank. I know im putting hot air back in just don't like the noise on half throttle :x im still getting a dumping noise on gear changes to,but mine started making that sort of noise when i had the induction kit fitted.