hello all,

Should be picking up my vRS next week Saturday. It comes with a BOV i think ( get a shhhhhhhhhh noise on lift off ) and a cone filter. It didnt seem to pick up as quick as the SEAT Leon Cupra i drove (01' plate). Is this due to the extra weight or could it be the mods? It could be that it does pull as quick just that its a bigger quieter car maybe. Anything i need to be wary of with regards to the bov as this is the first time i have had one. Sounds great and not too chav but does it serve any beneficial function? I couldnt tell you the brand as i didnt see it for myself. Seller claims its Forge.

Cheers,

Paul

Edited 29 April, 201115 yr by Obrut

sounds like a recirc valve which is best and required. a vent to atmosphere valve is no go.

was the cone filter under the bonnet or under the car on a pipe going down by the battery?

it could be that the Leon was remapped as well.

the vrs is a great car and you won't regret getting it!

Leon was standard.

Filter was where the airbox was i belive, certainly didnt notice any aftermarket pipe work from the intake. It has a cold air feed pipe leading to it.

What benefit is the recirc or bov supposed to provide? I guess I cant tell you if it is definitely a bov or recirc till i get the keys again

Edited 29 April, 201115 yr by Obrut

from my horrible 200sx ownership experience i recall posts on the forums saying BOV cause the engine to run rich, foul the cat but the upside is they allow the turbo to keep the rpms up when shifting? I cant remember :p

If you have a BOV (vent to atmosphere), the ECU gets upset because air is 'counted' by the MAF sensor, but then gets let out of the valve, but the ECU doens't know about it, making the engine run rich, increasing fuel conumption and lowering power. If it is bad, the engine management light will come on, as the ECU thinks there's an air leak.

A recirc valve (The OEM one is recirc) puts the vented air back into the intake, so no air is lost and the original MAF reading is correct.

You can tell a recirc valve, as it will have 3 pipes. One goes to the turbo charge pipe (silver one at back of engine), the other goes to the rubber intake hose, and the other (tiny) one goes from the top down into the depths of the engine (to the front of the engine).

Obrut, using a recirc valve actaully keeps the turbo speed up better than a BOV valve does, as it lowers the pressure differential acrosss the turbo compressor inlet and outlet.

I didnt think a recirc produced sound. So the one i drove has a BOV then?

Dunno. Best you check. Bin that cone filter too and get the original airbox on.

A recirc does produce sound, just no where near as loud as a BOV does.

If it sounds chavvy, chances are it has a BOV installed, which you should swap for a recirc valve.

achh cant wait till next weekend then I will find out for sure. If I got a heat shield for the cone filter that'll be a keeper right? Or do i need some pipe work to move it away from the engine. I do rate aftermarket panel filters I have used them in the past.

You guys heard of a pigeon mod? If so do you know of any vRS owner currently doing it? Youtube sr20det pigeon mod for those that are curious. Its where you remove the ricirc and bung up the pipes. Some say it will destroy your turbo others say they have been running it like that for years with no problems. This info is on the 200sx engine tho so I dont know what VAG users think?

We've seen it before. I can't see it damaging the turbo drastically, but it does promote turbo stall, as you're forcing compressed air back through the compressor, which will slow the turbo down, almost until it stops. You will notcie this, as every time you cahneg gear, the turbo will ahve to speed up again, whereas with a recirc valve, it will still have a lot of speed from before the gear change, making it quicker to get back on boost.

Just did a bit of youtube'ing on recirc and BOV and they sound the same...

Well I will be getting the standard recirc and airbox with the car so i guess I can always revert it back to standard should I find out its a BOV. What is the point of a BOV if all they do is make noise and perform worse than a recirc?

BOV's are usually a lot louder, that's why people buy them.

People tend to get BOV valves and recirc (bypass) valves confused.

I would have thought the 'pigeon' mod will not do the turbo any good as the turbine will be driven by the exhaust at the same time as the compressor been forced backwards, the turbo will be trying to spin both ways, I have been known to be wrong though

That's what I was thinking, can't be good for it at all, especially as the k03s turbo is so small and delicate. Might have been OK with the old ball bearing turbos, but wouldn't want to do it with an oil bearing turbo.

people don't understand so they buy what they think is

best etc, or are chavs lol.

personally when I ran previous cars without any kind of recirc/dump valve I didn't notice any dip in performance, though it isn't recommended for the same reason as not having a bov. the correct term is compressor stall as already mentioned, pigeon mod sounds very chavvy!

will it cause any issues to a k03s? depends on what condition the turbo is in etc. there are certainly turbos out there such as the roller bearing ones that you shouldn't run without done kind of recirc/dump valve, but the 270/360 degree normal bearing ones tend to fair better.

I wouldn't suggest doing it tbh.

some advice i was given about the airbox/cone filter, The audi's use the same airbox on the s4,s6 etc and they're good for upto 300bhp+ so why put a cone filter on it?

depends if you want the induction noise that comes with a CAI

i didnt notice induction roar . but I dont know what a standard vrs sounds like. Plus my current ride is a 1.8 civic vtec, no airbox resonator and 4-1 SS manifold and exhaust. That you can hear has an induction roar.

I would pic function over noise anyday. Standard airbox is looking likely

Edited 29 April, 201115 yr by Obrut

I have the car now Should I here the shhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh noise from the turbo when on boost? I can here it spooling up. I thought that with a recirc the valve would be closed so I shouldnt hear anything from it. Is this noise coming from the cone filter? My concern is that im leaking boost :/ I dont know what a stock vRS is like to drive so I couldnt say if its down on power. Its certainly no snail!

You can always here the turbo anyway. It should start to spool at just under 2000 rpm.

Does it have a recirc then?

Yer its spooling <2000rpm , can here it quite loud when going up hill in 5th as it just needed a tickle of boost to get up there . Was shhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh'ing for the entire length of that hill , little annoying :p

You will hear the turbo loud and clear with a cone filter. As above, companies put a lot of cash in R and D to find the most efficient intake system, a 20 quid cone filter aint the same. Just my 2 pence worth.

As for pigeon mod, or compressor stall, I dont run a bov on my big power 2JZ car, and know a lot of people who dont run them either. Is it bad for your turbo? Oersonally Id say no

Probably won't damage your turbo immediately, but it's not a good idea for a street car, or something with a big turbo as you WILL get compressor stall, meaning the turbo loses most of its speed between gear changes, rather than having a recirc valve keeping it spinning.

A lot of the big power jap cars don't run BOV's, but a lot of them are drag cars or dyno queens.

If it's something you were wanting to try as a mod, I wouldn't bother. As said before, the recirc is there for a reason. :yes:

hopefully catch a break in the weather tmo. Will check for bov/recirc and maybe put the original airbox on in a couple of weeks when i get over the whole " i have a turbo " thing

Its ace isn't it!

Leon was standard.

Filter was where the airbox was i belive, certainly didnt notice any aftermarket pipe work from the intake. It has a cold air feed pipe leading to it.

if it has a cold air pipe leading to it, it could just me the standard OEM bosch DV. any cold air pipe fitted makes the DV much louder