Variable Exhaust Butterfly Valve in an RB25 Z

[stevo_gj]

Hey guys,

 

One of my mates recently bought an R33 and he has a valve which he can open or close to change the volume of the exhaust. I am aware that when closed they reduce the power.

 

I think this is a pretty sweet idea, as I would like to have a fairly loud exhaust when I'm cruising around but in the mornings when I'm leaving for Uni I don't want to annoy parents and neighbours. I plan to put an RB25 into my 260z in the near future and thought I might get one of these valves installed in my exhaust.

 

I've tried googling them but I don't really know what I'm looking for and can't find any hard facts.

 

I've got a few questions

• Can a 260z with an RB25 be fitted with one?
  
• Do they damage the engine at all?
  
• Will it limit my exhaust options getting one installed? IE can I only get one of those ridiculously large 4" pipes?
  

 

Thanks guys,

 

Steve

[DevilZ]

I know Performance Exhaust in Ringwood used to sell mufflers with a butterfly in them.

They wer a particular brand that made them.

Also the Mitsubishi GTO's came factory with them fitted to some models. Used to have

an electronic control in cabin to change settings.

 

[redrbzed]

I have been thinking of doing the same with my car, found this site check it out.

 

http://www.nengun.com/apexi/exhaust-control-valve

[mtopxsecret6]

Steve, there is acompany in australia who produce cannon mufflers with remote control butterfly setup. Ie.. you  have a remote in the cabin.. and increase or decrease volume.. works very effectivly.

Otherwise.. hks or apexi etc make them, but there usually for 3inch and up exhaust sizes.

[620Z]

Nice site Sinisha and cheap. Would be good if your car was a bit loud for around town or some tracks. 

[stevo_gj]

Cool, so I take it that:

 

• Yes an RB25Z can be fitted with one
  
• No one has heard of them damaging the engine in any way
  
• It will limit my exhaust options to large if I get one from HKS or Apexi. But if I get a cannon muffler with a remote control one installed then it won't?
   
  

Wait, aren't cannon mufflers the massive ones?

[redrbzed]

Also available on ebay see link.

 

http://cgi.ebay.com.au/Apexi-Exhaust-Control-Valve-ECV-80mm-R32-R33-R34-S13_W0QQitemZ220343482519QQcmdZViewItemQQptZAU_Car_Parts_Accessories?hash=item220343482519&_trksid=p3286.c0.m14&_trkparms=66%3A2|65%3A1|39%3A1|240%3A1

 

cheers,

Sinisha

[stevo_gj]

I can't use ebay unfortunately, I'm at work. it would be awesome if you could post a picture and copy over the description from ebay?

[C.A.R.]

It's the Apexi one, Steve.

$330.

 

[stevo_gj]

Thanks mate, appreciate it.

[nizm0zed]

also available from Drift, through any autobarn store, $199 retail.

only available in 3" size

[Zedman240®]

Seems to me anything not needed in the exhaust system is just a restriction.... to rob some kw's! A good well thought out system should be free flowing and pretty quiet; I've done it!

[jasonb]

hey mate, i plan on running a 3" straight through turbo back exhaust on my 260 with rb25det that im building atm, so i dont wake my girlfriends parents wen i leave there house ill be running a Varex muffler which is the remote control muffler mentioned above, seem to work well... fully free flowing when open, when closed the exhaust gasses are diverted through the muffler something like three times then out to give her a nice quiet note:)

 

around about $360 off ebay or i think about $399 RRP from the dealers

 

Jason

[jasonb]

haha just realised this is a 3 month old thread but hey hope it helps:)

[stevo_gj]

haha just realised this is a 3 month old thread but hey hope it helps:)

 

Hey Jason I must have missed your post, I'd be really keen to hear how the Varex muffler works out for you. You should post a youtube video when it's all together.

 

Steve

[(Locky)]

ive got a varex muffler on my s14

 

its a full 3in turbo back system with a pucnched out cat (previous owner) one lil resonater, then just the varex at the end

 

when its open sounds like  normal exhaust with a cannon on the end

when its closed it sounds stock volume, ie hear the engine over the exhaust

 

I still wouldnt be thrashing it 100% with the butterfly closed, but it would definattly be alot better or the engine compared to those drift/apexi oes where it completly blocks the exhaust

 

when it used to be on my old 180, had it closed so i could quitly drive to the track, then open it up there so it would be like a normal 3in exhaust

 

 

i dont have a vid, but if you search varex on you tube theres a fair few of them

 

 

 

im actually thinking about getting it mounted further back in the system like a mid muffler then have it going to twin tips, to get rid of the big cannon look

 

[620Z]

Well I got pinned for noise in my car a few months ago. The car was only allowed 96db. At idle it was 90db and at 3,000rpm it went to 98-100db. So I thought I would be smart and shove some massive steel wool balls down the exhaust (Per Lurch's suggestion, which was a good one) and went back for a re test. The exhaust was heaps quieter at adle and even driving. The car was really restricted and nearly didn't start. At idle the was around 80-82db but reving at 3,000 rpm she was still 98db. Go figure??? I wouldn't have beleived it if I hadn't seen it with my own eyes. So I got sick of stuffing around and threw on two new 2.25" rear baffled exhausts ($440-) which took it down to 94db. Then got home and put the old ones, twin 2.5" free flowing back on. At least if those bastards get me again it will only be $31- to have the yellow sticker removed.   :-\

I guess my point here is that I don't see how the butterfly could quieten the car down that much short of strangling it and or stalling the car. Might be OK on the track to quieten it a little but to pass an EPA I think the only solution would be what I had to do.

[RB30X]

I'm just pointing this out cause no-one else has but any device electronic or manual that can effect the sound of your exhaust system is illegal in Austraila.  

 

Oh, and a loud car is not a fast car. You only really said you wanted this to make your car louder, not faster. Depending on the engine you will loose a heap of torque down low or in the lower half of the rev range with a straight through system, only really seeing the benifits at the drags, circuit or dyno.

 

Corvette's have the best systems incorporating these valves though as they have four pipes coming back from both banks of cyclinders, two which each have a muffler and a resinator but when the revs climb above 3500rpm (??) two valves gradually open with the revs allowing flow from each individual bank without any mufflers or res to come out the two inside tail pipes (they have four across the back).

 

As far as hurting your engine, I'm not sure if you mentioned it was turbo or not (big difference). You may need to have it incorporated into two different tunes if you are really serious.

 

[620Z]

I wasn't nocking the butterfly system I am sure it would work some how. I am just not sure how. But as you suggest having muliple set ups with and electronic adjustment and finely tuned to the car as it accelerates sounds perfect. But a bit too technical for my set up. Oh, my cars a V8 by the way. 

[.]

I'm surprised there hasn't been more talk about the obvious application.

 

Driving down the road with a loud Zed. BAAAAAAAAAAAAAAAA! ....Oh no here comes the boys in blue.......Flick........Prrrrrrrrrrrr... Nice day officer.......Flick BAAAAAAAAAAAAA!

[stevo_gj]

I'm surprised there hasn't been more talk about the obvious application.

 

Driving down the road with a loud Zed. BAAAAAAAAAAAAAAAA! ....Oh no here comes the boys in blue.......Flick........Prrrrrrrrrrrr... Nice day officer.......Flick BAAAAAAAAAAAAA!

 

Greg it goes without saying  ;D

[(Locky)]

that what i did with mine

 

drove past in a group of cars, loud+backfiring. see nice officer, exhaust on quite

officer pulls me over (because i had rediculuus ride height compared to the others)

my car is nice and quite

 

the whole point i see, is that if you want it to be quite for daily drive ect have the valve shut and drive normally low revs/off boost

but then when you want to give it a hit through some twisties or something you open it up and have the advantage of a normal free flowing system

 

 

it wont get you through the epa ect, but great for a street car

[stevo_gj]

epa?