Quiet Exhaust ???

[Fazz]

Hi All,

Unfortunately after a recent appearance in court for the 2nd time... I have now got to make my Mongoose purr instead of growl...

Gave as much evidence as is humanly possible, and stated very good case but fact is the judge take's cops word for it and thats all that is required for our lovely legal system

Anyway, I have to say it is a tad bit on the loud side and nothing likeit around, so for more reasons than 1 it needs to be quietened.

Can anyone point me in the right direction please?

I.e. - would a scorpion backbox do the job for me? Can I get a baffle for the goose? think the goose doesn't even have a backbox hence its so loud.. just straight pipe iirc.

I have a full mongoose with 5" tail.

Should i look at changing full system...? Or jsut cat back?

Still have Cat fitted afaik...

Help as it is too loud, don't wanna lose much power but only exhasut so shouldn't make too much difference.. aslo i need to be quieter for my own sake and not make announcements that I am coming at high rpms!

Solutions:

Fit Full scorpion? - are these much quieter?
Fit scorpion backbox? would this be enough?
Any way to baffle the goose??


And no, I really don't think I want to go standard....!

 

[macphegf]

I have a back box you could have mate, but I might need it back if I get pulled by the cops for my 'goose .

I don't know what it is but it's cat back and mucho quieter than the goose, but still sounds good on full chat.

PM me if you're interested, and you could pick it up from same place you dropped off the seatbeat stalk.

EDIT: sorry confusing you with someone else on here!

Could still let you have it for a small fee if interested. Let me know and I could give you photos.

 

[gtir bean]

the scorpion on mine is nice and quiet and sounds like a stock exhaust almost.

 

[PaulB]

Il second that, I've just fitted a full Scorpion with a de-cat and it is very quiet, spot on in fact. It is still a performance system tho, and the turbo spools up quicker because of it, ......BUT.......

I dont think there available brand new anymore, i got mine 2nd hand

I think the magnex system has a backbox, so get one of them, 250quid on fleabay.

 

[Odin]

I plan to get a rear 3" section made up for mine to replace the mongoose cat back system, But I plan to get a big box fitted at the rear running at an angle across the rear where the old standard box would of sat, But on mine it would be exiting out the other side of the car.

I feel that this should do a nice job of making it nice and quiet and making long journey's more bearable lol.

Rob

 

[jpward]

Fazz why dont you try the 3" tail first mate as this should help and if you got a small box made up to replace the cat with a mesh type tube and some sound deadening fill it should be enough to bring it below the roar factor

 

[CruiseGTi-R]

I had a tanabe back box. It was nice and quiet but with a good burble. It also rusted to pieces in time for the mot

Go to Blueflame - they should be able to add a fatter silencer box inline to your goose.

The blueflame 'goose' i just fitted isn't actually too bad noise wise, you can just about it tick the car along without it being too offensive. It has a quite a wide de-cat box and an attempt at an in line silenecer too.

 

[Fazz]

Thanks for replies.

Think I might try play with the goose and silence if possible, but suspect it will still be too loud so keeping eye out for scorpion me thinks!

Don't think the 3"tail would make whole lot of difference to be honest... must enquire about the silencing stuff i can pack in to the existing cat etc...?

Hey, price from my local Nissan dealer on standard exhasut = €1100 inc VAT!!! That's with an hours labour to fit!

Crazy Dealers!!! Not very strange then that there hasn't been one imported to Ireland ever! And there still won't be! Ha!

 

[youngsyp]

Getting something along the lines of what Rob (Thunder God) will have is the way forward. The way exhaust systems work, the further along you have a silencer, the more effective it is. One right at the end, near the tail pipe will be much more effective than Mongoose's effort with the silencer in the stock cat position.
Aslong as you keep the pipe work as straight as possible, with mandrel bends, you should be ok on the power loss front too.
You could also try one of the Apexi exhaust valves. When driving around fuzz patrolled areas, you could have it closed/semi closed. Then when you get out in the country, open it up and away you go. It'll also be good for longer journeys too !

 

[mattygti-r]

just put an apexi evc on it

then you have it noisy when you want it and non noisy when you dont by the flick of a switch

job done

 

[Fazz]

Thanks for that.

Found the evc you mentioend. Seems like it will solve my problem but only available in 67mm or 80mm it seems. So I must measure to ensure this is right size I guess. And flange or pipe type?

Anyone know anyone using this and if it definately does the job??

http://www.autocarparts.com/part/list/1663/

 

[Fazz]

Found another link that states the EVC only lowers noise by a maximum of 10db.... don't think that will be enough unfortunately...

Anyone any evidence to the contrary?

 

[mattygti-r]

you will have to have it "made to fit" for the pulsar

buy one from newera if you want, they do them quite cheaply

seen a pulsar owned by a guy who used to be on here which ran one , it went from loud to basically silent using that evc

 

[Fazz]

Thanks Matty.

Ps, some serious machinery you are seeing in the flesh over there... them GTR specials are unreal... are you just on hols or actually moved there? And are youa GTR owner now is it?

 

[youngsyp]

Found another link that states the EVC only lowers noise by a maximum of 10db.... don't think that will be enough unfortunately...

Anyone any evidence to the contrary?

Decibel (dB) measurment is logarithmic, not linear. So, for every 3dB increase, the sound/noise will be twice as loud. So, if a sound level increases by 6dB, it will be 4 times as loud as the original sound/noise. By 9dB, 8 times as loud as the original sound etc... So, if the Apexi EVC decreases the sound level of the exhaust by 10dB, it will be more than 8 times as quiet as it was without the EVC !

 

[Fazz]

Decibel (dB) measurment is logarithmic, not linear. So, for every 3dB increase, the sound/noise will be twice as loud. So, if a sound level increases by 6dB, it will be 4 times as loud as the original sound/noise. By 9dB, 8 times as loud as the original sound etc... So, if the Apexi EVC decreases the sound level of the exhaust by 10dB, it will be more than 8 times as quiet as it was without the EVC !

My aren't you the smart Sound Technician!!!

Cheers, Point taken thanks for the knowledge..

Think I'm off to shop for an EVC so and that should solve my law trouble!

Cheers to all.

 

[mattygti-r]

i will speak to miguel tomorrow night as we are out drifting and see how much a evc is for you

i am on holiday out here, just meeting up with some people out here, seeing the sights, seeing what tokyos like,

went out last night to collect an ae86, then some spiriting driving in the rx-7 knightsports

yep i own a gt-r

 

[Jim_1979]

I got pulled and fined for having the goose with a 5" tail on it. I'm also looking at changing the exhaust at some point in the future!