Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: rx7-mark on March 11, 2006, 09:25:10 PM

Title: Hks dump valve problem
Post by: rx7-mark on March 11, 2006, 09:25:10 PM
Hi
I have the twin apexi induction kit fitted with the standard waste gate on one pipe and a hks dump valve fitted to the other.

The problem i have got is it doesnt dump very loud and i was wondering if i could remove the standard waste gate and have all of the air returning to the hks to make it sound better.  :Giggle
I was worried about just blocking the pipe up as im guessing that would just blow the turbo up as the air wouldnt have anywhere to go.   :wave

When i bought the car they were already on so i dont know if it is all fitted properly.

I will post pics if that will help

The hks is set to its loudest with the adjuster so i know its not just a simple job of twiddling a screw.

Any ideas would be appreciated.
Title: Hks dump valve problem
Post by: G@NDY on March 11, 2006, 09:40:53 PM
Hello Mark, hows tricks :) Not sure what you mean about the wastegate, are you still running the twins, i thought the wastegate was internal. Could you be reffering to the \'denso\' charge relief valve. Post up some piccys and we shall have a better idea, what colour is the insert on the BOV i think that could be a factor, its either the gold or the purple that is slightly quieter :WaveBye
  Cheers Andy
Title: Hks dump valve problem
Post by: SCOOMER on March 11, 2006, 09:52:08 PM
Quote from: G@NDYHello Mark, hows tricks :) Not sure what you mean about the wastegate, are you still running the twins, i thought the wastegate was internal. Could you be reffering to the \'denso\' charge relief valve. Post up some piccys and we shall have a better idea, what colour is the insert on the BOV i think that could be a factor, its either the gold or the purple that is slightly quieter :WaveBye
  Cheers Andy

Yes your rite Andy, if Mark has this purple one fitted it\'ll be alot quieter than the standard insert. Maybe this is the case????

Scott
Title: Hks dump valve problem
Post by: rx7-mark on March 11, 2006, 10:12:40 PM
Thanks for the info.
Im gonna have a quick guess tonight without going out to look at the engine and say that i have the quieter one and im gonna be buying a new one but i will post some pics up tomorrow lunchtime and see if that helps.

I did mean the denso charge relief valve, I dont know what it does though and if i remove that will it help or do i have to keep it.

Thanks again for your help.
Title: Hks dump valve problem
Post by: rx7veilside on March 12, 2006, 06:47:53 AM
the coulered inserts will make little or no difference to the sound..the hks dump valve has and alllways will be a chirp rather then woosh noise..people will say theirs is loud but most have induction kits and the noise comes more from the open air filters than the dump valve..a hks will never be loud..i have a bailey and that is loud..u only have to look at the design differences to see why the bailey is louder
Title: Hks dump valve problem
Post by: SCOOMER on March 12, 2006, 07:00:13 AM
Quote from: rx7veilsidethe coulered inserts will make little or no difference to the sound..the hks dump valve has and alllways will be a chirp rather then woosh noise..people will say theirs is loud but most have induction kits and the noise comes more from the open air filters than the dump valve..a hks will never be loud..i have a bailey and that is loud..u only have to look at the design differences to see why the bailey is louder

Sorry but your Wrong the purple insert does make a difference, it quietens the WHOOOSH (NOT A CHIRP) down alot. I know this first hand as ive got the super SQ BOV.

Scott
Title: Hks dump valve problem
Post by: peterwolds on March 12, 2006, 07:28:30 AM
if you want loud the blitz supersound is awesome
Title: Hks dump valve problem
Post by: rx7-mark on March 12, 2006, 08:14:12 AM
Yes ive been told bailey are good even tho there name isnt as big and hks, greddy, and so on..... give me a hour or so and i\'m goona take some pics of the engine and the pipe thats been capped, and i\'m hoping one of you will know if (big if) i can get louder....
I do get a woosh but only 2nd,3rd,4th,and 5th, never in first.....sounds like i need a new BOV.....

Back in a hour with pics
Title: Hks dump valve problem
Post by: rx7veilside on March 12, 2006, 10:08:24 AM
scott i have had a hks on my old p1 and the inserts are more cosmetic..they will ever so slightly alter the sound but look at the design of the hks and how the air escapes and then look at the bailey and that is what determines what noise it makes..hks with a standard airbox will chirp on lift off but will sound like a whoosh with cone filters as the air is coming back thru the filters as well.i got rid of the hks on my old p1 as it was too quiet and put a forge valve on and the sound was totally different..the inserts are like putting a different mouthpiece on a instrument but is is how the air is released that determines the sound.if people are happy with a hks fine but at nearly three times the price of a bailey i dont see the point as people only put vta dump valves on for the whoosh noise as a recirc does exactly the same job but without the noise..do u happen to have cone filters on urs or a enclosed airbox
Title: Hks dump valve problem
Post by: rx7-mark on March 12, 2006, 10:21:52 AM
I have just been out in the snow to take these pics

(http://i28.photobucket.com/albums/c248/rx7tt/43600001.jpg)


(http://i28.photobucket.com/albums/c248/rx7tt/43600002.jpg)


(http://i28.photobucket.com/albums/c248/rx7tt/43600003.jpg)

I hope this helps. Thanks guys.
Title: Hks dump valve problem
Post by: rx7veilside on March 12, 2006, 12:09:37 PM
that wld seem to be quite a old hks valve i would def see if u could fit a bailey
Title: Hks dump valve problem
Post by: rx7-mark on March 12, 2006, 12:34:20 PM
I knew it was old. It was on the car when i got it last october so i dont klnow exactly how long it has been on. I would say years.

I think im gonna look at getting a bailey.
Thanks for your help.
Title: Hks dump valve problem
Post by: rx7-mark on March 12, 2006, 02:55:20 PM
Has anyone got the apexi induction kit and a baileys dump valve so i can see how it should be fitted?
Title: Hks dump valve problem
Post by: dj_dee99 on March 12, 2006, 03:33:56 PM
Same HKS dump valve as I have at the mo. Mine isn\'t loud but it\'s not really quiet either. There\'s an adjuster on the back. It looks like yours is fully screwed in, although can\'t tell properly from those pics. Mine is pretty much unscrewed as much as possible.

I will probably change mine in a couple of months, though. Got a few other bits & pieces I wanna get sorted first, though. I heard that Blitz do some decent DVs? Anyone using one of those?
Title: Hks dump valve problem
Post by: peterwolds on March 12, 2006, 05:05:45 PM
I will probably change mine in a couple of months, though. Got a few other bits & pieces I wanna get sorted first, though. I heard that Blitz do some decent DVs? Anyone using one of those?[/QUOTE]
blitz supersound is LOUD had 1 on my EVO V
Title: Hks dump valve problem
Post by: ftorex on March 12, 2006, 05:40:19 PM
I have a Blitz SS dv on mine and its loud but in a good way.. :D
Looks good too..
Title: Hks dump valve problem
Post by: dj_dee99 on March 12, 2006, 07:09:59 PM
Cool! Looks like I\'ll be going for one of those, then, :chat
Title: Hks dump valve problem
Post by: SCOOMER on March 12, 2006, 07:38:41 PM
Quote from: rx7veilsidescott i have had a hks on my old p1 and the inserts are more cosmetic..they will ever so slightly alter the sound but look at the design of the hks and how the air escapes and then look at the bailey and that is what determines what noise it makes..hks with a standard airbox will chirp on lift off but will sound like a whoosh with cone filters as the air is coming back thru the filters as well.i got rid of the hks on my old p1 as it was too quiet and put a forge valve on and the sound was totally different..the inserts are like putting a different mouthpiece on a instrument but is is how the air is released that determines the sound.if people are happy with a hks fine but at nearly three times the price of a bailey i dont see the point as people only put vta dump valves on for the whoosh noise as a recirc does exactly the same job but without the noise..do u happen to have cone filters on urs or a enclosed airbox

I\'ve had the DV on both the twin hks cones filters and im currently running it on a single turbo. I bought the purple insert to see if it made much difference to the sound. So from my personal experience the purple insert lowered the whoosh, so much so i couldnt hear it inside the car so i reverted back to the standard one. From what i can remember the hks one has sounded the same on the twin filter (apart from the COW sound i used to get LOL) and on the single.

Im sure your baileys BOV does just as good a job as the HKS one but it wouldnt be very exciting if everyone was running the same engine set up, its good to have abit of variety.  :yes

Scott
Title: Hks dump valve problem
Post by: rx7veilside on March 12, 2006, 09:10:32 PM
i agree when running open air filters a lot of people think the dump valve is making a lot of noise.for a while i had a recirc on the p1 and cone airfilter and on lift off i still got the whoosh sound.i went for the bailey because it is very simple single piston on boost closed of boost big hole to let the air out and best of all about 80.00 quid..my fave though is the ones done by spec-r