TTT

CC - Unless you get a video image of the bov opening and closing and the sound comming from the bov, I still stand by my opinion that the sound is that of reverberation. I just assume it sounds different to mods due to number of things I listed in a previous post. cooler piping material, intake pipe material, turbo choice... lots of things can change the pitch of the sound or the speed of each sound (call it chu chu chu or whatever) Not sure if you've had or had friends with VL turbos. in standard setup using all stock parts plus a pod filter and more boost, the fluttering sound is a normal chu chu chu. once FMIC is installed and nothing else changed, the sound goes deeper. Once the turbo is changed to something large and new (BB turbo rfom the GT range) the sound is totally different. but still, it is caused by the air back through the turbo. I used to have an 88 TX3 turbo ex rally car. hi flowed stock turbo. 1 bar boost stock intercooler. no afm aluminium intake pipe with UNIFILTER foam pod. the fluttering sound from that was most usually described by others as a horse. go figure.. not the neigh sound they make but the other one where it sounds like they are just snorting out air. my naighbour (across the road from my parents place) runs a completely sotck FJ20T engine in a gemini. using stock turbo NO INTERCOOLER no intake pipe. microtech computer. he has a k&n pod filter on the front of the stock turbo. 18 psi boost. when he changes gears, you can hear it from 4 blocks away. the wierdest sound I have ever heard.. because the pipe goes straight from turbo to plenum (about 60cm in length) the fluttering sound is not even fluttering. it is like a prrrrrrrrrrrrrrr sound. and at 18psi it is really high pitched. my brother had a liberty RS turbo. they have a top mounted water to air intercooler. and the turbo on the subaru's are just to the side. he removed the stock plumback bov and blocked up the holes and vacuum line. now the turbo to inter pipe is about 30 cm (if that). the intercooler sits ON the throttle body basically so say about 15 cm of pipe there. with a pod filter ont eh end of the intake pipe, and 15psi going through it, on gear shifts, it made a totally different sound again. still some sort of prrrrrr sound, but different to the gemini, my laser or 200sx's and gtrs with no bovs. supra's make a different sound once again. my point?? different type of fluttering sound. same reason. no bov, tight bov. the sound variation is because of the differences in setup.

what do you mean by 2 x the exhaust disharge area? 2 turbos?

if capacity had anything to do with it, RB30's would sound tougher.. but they don't. but the lifters, throttles and port shape... not too informed on these.. anyone care to go into more detail? SK? mmmmgtir?

I'm not going to go in to wether it is bad or not. I have my own opinions and that is all. I can tell you however, that it does not make the compressor spin "BACKWARDS" it will slow it down, but not stop it or spin it backwards. the reason I said to search was so that you can find out that wastegates don't flutter either. wastegates regulate boost. they are help shut by a spring. if the spring is only good for 10 psi, then once it gets there, the wastegate will be wide open to make sure that no more boost is made. it sits on the side of the turbo's exhaust wheel and is simply a flap that opens to regulate boost. if you've ever had a chance to hear an external wastegate you'll understand what I mean. to give you a rough description, the sound would be the same as a turbo, boosting at lets say 15 psi, and the exhaust comming off it is only 30 cm long with no mufflers. it is pretty much a really loud SCREAMING sound. that's why alot of the times people refer to screamer pipes in exhaust systems. which just means the wastegate pipe is open to atmo rather than back in to the exhaust.

dear god. please go to "how stuff works" website and reasearch wastegate then come back and edit your post

CC - I didn't say the S14 or S15 bov can't handle the boost. I stated that the PLUMBACK PIPE is not big enough in the stock setup and can't plumback all that air being released. so this CAUSES the 200sx's to make fluttering noises. If you replace the stock return lines with a larger diameter pipe, then you will hear a whoosh of some sort just like you do. my example about the rally cars. I was trying to get the point across that they probably DON'T have bovs. but with the antilag set up, the fluttering sound is different in between throttle jabs as it would be if a person bought an EVO or sti from the shop and removed the bov. the truth is that there is no BOV that MAKES a fluttering sound. however, alot of bovs CAUSE the fluttering sound by being too tight or not being able to flow enough. all these people going on about HKS SSQV bovs making a fluttering noise. you think this because it says "SEQUENTIAL" in the name don't you? and you associate the word "SEQUENTIAL" with "one after the other" and then think this means that it will make some sort of sound "One after the other" like chu chu chu or whatever you want to ***ing call it. the fact is that the "SEQUENTIAL" is refering to the design. those bovs actually have 2 pistons/flaps.. apparently to hold more boost. Same goes for APEXI TWIN CHAMBER BOV. it has 2 chambers, 2 pistons/flaps and still makes a normal psshhhh sound. what most people do is have the bov too tight and then the bov doesn't open and it CAUSES a fluttering sound between gears. I don't understand why this is so hard for you all to understand. boost, throttle shut, air goes bang against throttle body and needs to go somewhere. if there is a bov, it will open and vent through there to atmo or back to intake if it is plumback. if there is no bov or the bov is too tight, the air goes back out the way it came. through the turbo, but since it is spinning, it makes a fluttering sound.... just like the sound you hear if you were to blow air on to the BACK of a fan while it is spinning. if you have an HKS SSQV bov, and it is installed and set up correctly, the sound in between gears or when you back off the throttle, should be a high pitch squeekish type sound. if after all this, you people still think that BOV's "MAKE" fluttering sounds of some sort, then you really help. BOV's can "CAUSE" flutter by not oppening. BOV's can't "MAKE" a fluttering noise if they vent properly. they either open and release one gasp of air or they don't.

All RB's sound slightly different to one another yet still sound similar. Like most of the time, you can tell the sound of an RB25 exhaust note to an RB20. however, the RB26 sounds different to all of them. my question is what is it that makes it different? It just sounds alot tougher than the other RB's. so what is the reason for this? At idle, or cruising on WOT. they just sound ALOT tougher than the other RB's. is it the fact that there are 2 turbos? is it the individual throttle? is it cams? I understand that the exhaust system has a lot to do with it, but no other RB sounds quite like an RB26. I don't want replies like "because teh GTR can neva lose" or something equally stupid. This is a serious question on what gives the RB26 an angrier note.

my god.. The total IQ of this forum dropped 200% with this thread. 1.) bov's don't make fluttering noises. 2.) SARD R2D2 makes a single psshh release sound. 3.) if the car on the vid had a bov and made a flutter sound, chances are the bov was set really tight and wasn't opening. 4.) The standard VL sound is what you are hearing on all thse cars going woop woop or chi chi or whatever the **** you want to call it. it just sounds different on different cars. the pitch of the sound, the length that it goes for, the speed of the flutter all depends on many variables.. eg.. turbo, ball bearing, non ball bearing, number of blades on the turbo's inlet wheel, their angle, the speed at which it is spinning when you release the throttle. the intercooler pipes, diameter, length, material it is made from. intake pipe, material it is made of, the length. the WRC car's would make the same noise as a road driven W or EVO with the bov removed and plugged up, except with anti lag, it makes the sound different again due to the amount of boost. and lets not forget the 32mm inlet resrictors on their turbo's... all these add up to making weird and wonderful noises. The sound from S14's and S15 with stock bovs is another one. the reason they make it once you increase boost is that the plumback return line is too small and it can't vent enough back to the inlet.. this causes fluttering. onec again. THERE IS NO BOV THAT VENTS MAKING A FLUTTERING SOUND

I think the backfire you are talking about is actually a MISS FIRE. since you are now running so much more boost than standard, you're probably blowing out the spark. change your spark plugs with some copper NGK items. Either buy them with a 0.8mm gap or Gap them yourself to 0.8 or even 0.7 this should fix the MISS FIRE high in the rev range. and I'd say that holding 1.09 Bar is pretty good when set to 1.1 and probably on a cold night, it will hit the 1.1Bar.. I'd also liek to know what turbo you are using.

dude. buy rb20 turbo use rb20 actuator buy boost controller of some sort to get the other 2 or 3 psi you want over 10 psi.

all turbo cars need to have an actuator. this is base boost level. it has nothing to do with the EBC. if you are using the Jaycar doobie, read the thread Sydneykid has started in the stagea section. that kit needs you to have a SOLENOID much like the one in the R33's. that kit controls how much the solenoid opens and so forth. if you are using an RB20 actuator, you will always have a base boost level of MINIMUM 10psi.

putting a T28 from a S14-S15 on a RB20 would be useless exercise. it will cost more to fabricate a new flange for your manifold and I'm not so sure if would actually be called an UPGRADE. actuator. the RB20's don't have a boost controler at all. the factory boost setting of 10psi is set that way due to the spring that is in the actuators diaphram (that round part at the front) that spring is hard enough to keep the wastegate closed enough to provide the engine with 10psi of boost. The Rb25's have a solenoid that controls boost. this solenoid is controlled by the ECU. so the actuator diaphram has a spring in it that is weaker than the RB20 one. the spring alone can only hold 7psi.. and the ecu/solenoid combo work together to provide more if needed. so when people upgrade their RB20 turbo to an RB25 turbo, because their stock engine doesn't have a boost controller, they use the RB20 actuator. this means that they can still get 10psi with no other boost mods on the new bigger RB25 turbo. as Sydney kid said earlier, the RB25 turbo will flow (meaning produce) 10% more at stock 7 psi than the RB20 turbo does at 10 psi. so even if you use the Rb25 turbo and it's own actuator, at 7psi you will have more power than with the rb20 turbo at 10psi. but use the rb20 actuator on the Rb25 turbo so you have 10 psi on that as well and you end up with a 25% increase in power/flow at same boost on the new turbo. does that help?

there is no specific amount. just stick below 14 psi to be safe. people have broken turbo's at stock boost levels and some have had them on about 16psi for over 2 years without a problem. it's your $500 turbo.. you decide what you want to risk.

no.. stock boost is actually 10psi.

rb20 block? 4agze pistons? to make an RB31?

*puts on "I'm with stupids" Tshirt and stands between R31Nismoid and GunmetalR33*

yes there is. you will need to get a one way valve. read here.. http://www.geocities.com/kilruf/bov.html Don;t worry that it was done on a bosc valve.. basically the same thing as a stock skyline bov. not really worth it but if you feel the need to waste a few dollars and some time, then go right ahead.

almost right. the only change to your post is that ATMO bovs are good for nothing. Aftermarket plumback bovs are good for the sticker they come with. This brotec device sounds interesting. I'll take 12

^^^ I belive that is the SECRET herbs so to speak in the redline stuff..

I've used motul on my R32 gearbox and it crunched. even after 100km (not in the one day) it crunched. changed it to Redline shockproof lightweight stuff and it stopped. maybe your fancy pants isn't so fancy after all.

most commonly a vacuum leak. the rubber hoses in the engine bay are old. start looking at the obvious. the BOV vacuum line. the boost gauge vacuum line. I know that after taking mine off and on about 5 times, the line split. cost's less than $2 for a replacement so don't be too worried.

there is no restrictor on a stock bov. I assume he meant he PLUGGED UP the bleed hole in the base of the bov (you have to take it off to see it) When I did this to my one, I got about 0.5 psi extra and the sound changed slightly.. oh and boost came on a little quicker as well. as for best bov.. what you should do is get the one with the biggest trumpets and attach duck call horns in front of them trumpets.. so every gearchange goes.. psshhwwhhaaaaaa

just had a look at that video... the way you come on boost.. that's just not right man.... I hear engine, engine, engine.. then SNAP, boost comes on crazy like. at about 48 seconds on the video..

well since the car's been pinched, I doubt I'm ever going to nee to bring the car back to stock so I have some bits for sale. 1 x stock S14 intercooler and some pipes. 1 x stock S14 air box with air filter. I also have a set of 17x9 and 17x8 wheels with barely legal tyres to suit 200sx and skyline gtst's... make offers on the stock parts. wheels = $700 In sydney.

A LITTLE OFF TOPIC... However, I thought you guys on this thread would enjoy this.. This is a question that was asked of the AUTOSPEED Crew. There are so many errors in the reply that I'm starting to think they are getting their answers from their asses... Question: Hi guys - I own a R33 Skyline GTS25T automatic and have decided to go for a RB25/RB30 hybrid engine. I have recently met someone who did most of the work by himself on a similar car and managed to squeeze out 345kW at the rears. He uses a massive KKK turbo, custom plenum, and all the rest of the usual goodies. The car underwent an auto to manual conversion and uses a R32 gearbox with fabricated bell housing. My concerns are, if I go this way, should I use the standard R33 gearbox or go for a S15 6-speed? Would it be better to stick with auto and get a tricked torque converter (like the Trimatic trans used in the SubZero car)? What about a bigger LSD replacing the viscous factory one? And how about plenum design - GReddy v Subzero v Nizpro one? Lastly, I have a mate in Japan who will try to get most of the parts for me - should I consider a RB26DETT head instead? Any suggestions? Amrit Ram New Zealand ANSWER: The optimal driveline depends on the torque characteristic of the engine you build and your intended application. If you're planning on coming near 345kW at the back wheels you're invariably talking about a massive single turbo and lots of lag; in this case, an auto with a high rpm converter has its advantages. An auto will allow you to stall the engine up for fast launches (it's difficult to launch a big turbo'd engine with a manual 'box without either massive wheelspin or bogging down) and it will also kick-down by itself, making the car feel livelier in traffic. The biggest problems are noise and fuel consumption (lots of revs everywhere you go). Oh, but your standard R33 trans won't be able to hack such huge power - something like the beefed up Trimatic should capably handle the grunt. We're not sure about the limits of the Nissan manual gearboxes, but we'd imagine they'd be pretty marginal at that power level. A drag-oriented auto is likely to be the more trouble-free approach. With this amount of power you'll need to find the most possible traction using, of course, sticky rear tyres and probably a locker type diff centre. See how you go durability wise using the standard type diff - a tougher unit may be required depending how hard it's treated. No idea which intake plenum is better - you'd need to compare side by side on a dyno to judge. Any parts from a Skyline GT-R engine are ultra expensive - see how you go bolting all the good gear to your standard RB25 head. If you're not satisfied with the power, you should look into a GT-R head as a final phase.