Author Topic: Exhaust bypass/ Electronic dump  (Read 4635 times)

guest6255

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Exhaust bypass/ Electronic dump
« on: April 30, 2017, 05:06:52 PM »
hi guys im planning on getting a electric exhaust bypass, just every where ive looked its quite hard to find one what is the same size as the jazz exhaust anyone know of anything what fits? from what im aware the exhaust is 48mm diameter, i've got a 09 ge6

ps dont comment if you dont like the idea of it on a jazz, it's not your car :)

matty vapor

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Re: Exhaust bypass/ Electronic dump
« Reply #1 on: April 30, 2017, 05:16:32 PM »
what is a electric exhaust bypass? and what does it do?

Ahhhh after a google, its a noise maker and an MOT fail I would think.
« Last Edit: April 30, 2017, 05:22:19 PM by matty vapor »

guest6255

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Re: Exhaust bypass/ Electronic dump
« Reply #2 on: April 30, 2017, 05:25:55 PM »
wont fail the mot cause you just keep the side exhaust closed until you need it, i want to use the jazz on the track so having the choice of a more open exhaust but also keeping it street legal is ideal

matty vapor

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Re: Exhaust bypass/ Electronic dump
« Reply #3 on: April 30, 2017, 05:36:36 PM »
I would imagine just having it fitted will be a failure on its own, and a jazz track car? bit under powered I would say for that. alothough it will make all the right noises with it fitted.

guest6425

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Re: Exhaust bypass/ Electronic dump
« Reply #4 on: May 01, 2017, 09:56:20 AM »
I'm trying to work out just what they do, is it just so your car sounds 'kewl'  like it's exhaust has well.... fallen off ?

Or is there some kind of performance benefit?

Call me old fashioned, but there must be like... oh I don't know.. engine mods? for performance? in preference to brmm BRMMMMM noises.

Jocko

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Re: Exhaust bypass/ Electronic dump
« Reply #5 on: May 01, 2017, 03:11:50 PM »
Ever wonder why a Formula One car has no silencer. An exhaust bypass, placed in the right position, allows the exhaust to vent for maximum efficiency and performance. Added to other performance mods it allows a race car to be converted back to a road legal machine at the flip of a switch.

VicW

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Re: Exhaust bypass/ Electronic dump
« Reply #6 on: May 01, 2017, 06:37:29 PM »
It is unlikely that an exhaust modification that makes the car noisier is going to make it perform better.
A free flow exhaust should be accompanied by corresponding changes to the fuel mixture induction side.
More mixture in means providing more exhaust efficiency out.

It should be remembered that most race classes and circuits have noise limits applied which are tested on the day.

Vic.

Jocko

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Re: Exhaust bypass/ Electronic dump
« Reply #7 on: May 01, 2017, 07:29:31 PM »
Agreed. An exhaust bypass by itself would offer very little performance enhancement but with suitable other mods it has its place. They are very popular in the States for drag racing. I studied exhaust system design, back in the 60s, and it is a fascinating subject.

matty vapor

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Re: Exhaust bypass/ Electronic dump
« Reply #8 on: May 01, 2017, 10:56:49 PM »
normally aspirated engine performance comes at a cost, an exhaust by pass valve will not produce any gains apart from noise, might be good for street cred but on a track day they have noise limits and that will get thrown out.

if serious about track days you would be better remembering the golden rule. BHP per Ton

remove all the seats, carpets, and any extra weight and that will make more difference than any exhaust by pass valve.

if not the list starts to get expensive

big valve gas flowed head.
forged crank
H rods
light weight fly wheel with competition clutch
light weight HC pistons
High lift cam
full flow ex manifold and exhaust system
re worked inlet manifold
high flow injectors and fuel pump, with swirl tank to stop fuel starvation
and then a remap to get the best out of the 5k you just spent.

you might see 30+ bhp extra a lot to spend for 30bhp

and then of course you have to be able to stop the thing.

AP 6 pot callipers and rotors, braided brake lines.

handling, some coil overs required, Olin's being tops but at 5 to 6K a set OTT even so something half decent will be 1k min.

much cheaper to buy a golf Mk4 gti. remap it with the K03s turbo for 200BHP the 20v engine is solid, AGU being the strongest of all in the early MK4 golfs 19mm wrist pins engine code AGU unlike later ones with 17mm wrist pins.

there you have the basis of a track day car. a Jazz just isn't track day material with out spending a fortune on it.

an exhaust by pass valve might have a fun side on street cred look fast cars for noise only effect, but that's about all.


the best performance gain is ditch the weight! simple's


« Last Edit: May 01, 2017, 11:04:38 PM by matty vapor »

guest1372

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Re: Exhaust bypass/ Electronic dump
« Reply #9 on: May 01, 2017, 11:32:33 PM »
We had a manual exhaust bypass on a racing MG-TC, it was critical to tune the length of the free flow pipe; if you just disconnect everything at the manifold you would not have much success.  It really made little difference and we could not use it on tracks back in the UK.

.... just every where ive looked its quite hard to find one what is the same size as the jazz exhaust ...
As this is not Honda specific - more of a generic aftermarket part, you might find better luck asking in Pistonheads.  You may even be better off replacing your exhaust for a custom cat back system of a suitable diameter.

Even better would be running a car to a hot hatch rule such as run by 750 Motor Club
I had a colleague who gave up his highly tweaked Subaru for a boring daily driver with a trailer and racecar instead; go along to a 750mc event and become enthralled.
--
TG

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JohnAlways

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Re: Exhaust bypass/ Electronic dump
« Reply #10 on: May 05, 2017, 11:02:23 AM »
From my motorcycle days knocking the baffles out of Dunstall decibel silencers for the noise effect from my CB72 (as it could be heard miles away), the chap that used to tune it said the first step is to buy new silencers. You've ruined these!!!
Intake is balanced to exhaust, for simplicity so I could understand (I was only 16) "More noise = less speed". He was right actually but then the timing chain was noisier than the exhaust. To me dump valves are a street cred thing with no performance gain. I see some very low mean looking civics around (other makes as well) but they have a job to get over the speed bumps so have to drive in places at 10mph. I can space my jazz nicely over them and keep to 20.
However I remember my youth and the horror from the oldies as I came howling along the road. Now I'm an oldie I chuckle to myself and think of my youth.

d2d4j

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Re: Exhaust bypass/ Electronic dump
« Reply #11 on: May 05, 2017, 12:36:40 PM »
Hi

Spoon do it for racing, plenty of YouTube videos but I don't think I'll be modifying our jazz

Many thanks

John


olduser1

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Re: Exhaust bypass/ Electronic dump
« Reply #12 on: May 07, 2017, 07:32:38 AM »
Quickest improvement less weight, then improve driving technique if serious invest in tyre dept .
On air cooled Beetles we used to fit boom tubes £10.00 v the stock pea shooter pipes £5.00 for 2. - result louder no improvement but customer happy.

Jocko

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Re: Exhaust bypass/ Electronic dump
« Reply #13 on: May 07, 2017, 09:39:34 AM »
Driving technique makes a huge difference. I did a single seater training course and it made a huge difference to my lap times. Also helps with safety under normal road driving. All the basic training was done on a standard road car (SEAT Cupra), and that was great fun.

rogbro

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Re: Exhaust bypass/ Electronic dump
« Reply #14 on: October 05, 2017, 11:39:10 AM »
Hi x6jeopardy6x.  As usual with this site. No one will actually answer your question.
But everyone will give their opinions on everything else you should do.

Ask a silly question , like what's the side light wattage, you might be in luck.
Anything technical, like camshaft timing, forget it.

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