I want it LOUD!- but not too loud....
Discussion
Just wanted a second opinion on this, after the advice given by a national custom exhaust maker goes against everything I have ever read or heard.
I wanted to know the best way to increase the volume from my exhaust on the Fiat, so i was enquiring into running it sans rear box- just leaving the middle box to do the hard work & have a pipe routed through to the rear of the car.
Obviously this is only an idea & I have no idea if it will sound s
t- so I will make that descision when I hear it on the ramp.
The main thing that bothers me was, I was enquiring about a loss of back pressure, so wanted to know a way around it- i.e. maybe fitting a restriction in the pipe to keep the pressure in the pipe up.
The chap said:
'running the car with a loss of back pressure will be fine for the turbo'
'the main reason turbo oil seals fail when running a freer flowing system is the fact the turbo spools up alot quicker & is not used to working 'that way''
The car already runs a drain pipe style exhaust & I don't really rate it- it's too boomy & not very loud/raspy.
So, if what this chap is true, since the car already has an oversized system fitted- would it be relitivly safe to run it minus one silencer?
Thanks in advance.
ETA- sensible answers only please
I refrained from posting this in the GG- I can't be bothered with YouTube style answers innit
I wanted to know the best way to increase the volume from my exhaust on the Fiat, so i was enquiring into running it sans rear box- just leaving the middle box to do the hard work & have a pipe routed through to the rear of the car.
Obviously this is only an idea & I have no idea if it will sound s
t- so I will make that descision when I hear it on the ramp.The main thing that bothers me was, I was enquiring about a loss of back pressure, so wanted to know a way around it- i.e. maybe fitting a restriction in the pipe to keep the pressure in the pipe up.
The chap said:
'running the car with a loss of back pressure will be fine for the turbo'
'the main reason turbo oil seals fail when running a freer flowing system is the fact the turbo spools up alot quicker & is not used to working 'that way''
The car already runs a drain pipe style exhaust & I don't really rate it- it's too boomy & not very loud/raspy.
So, if what this chap is true, since the car already has an oversized system fitted- would it be relitivly safe to run it minus one silencer?
Thanks in advance.
ETA- sensible answers only please
I refrained from posting this in the GG- I can't be bothered with YouTube style answers innit
Edited by ol' dirty on Thursday 26th March 12:23
Best thing to do is have a nose about of forums for the actual car you have. People will prob give you better advice on them.
I can tell you that if you remove the rear silencer the car will probably have less power and use more fuel. I removed mine when id first passed my test and didnt have any cash to replace. I just made a pipe to the rear of the car. When i did get it fixed the car performed miles better although sounded phoo again. ( this was a non turbo car tho)
I can tell you that if you remove the rear silencer the car will probably have less power and use more fuel. I removed mine when id first passed my test and didnt have any cash to replace. I just made a pipe to the rear of the car. When i did get it fixed the car performed miles better although sounded phoo again. ( this was a non turbo car tho)
The turbo is a massive restriction in the exhaust system which spins the turbine by virtue of the pressure difference before and after it. When the gases come out of the turbine they want to leave and leave fast!. Hence why race turbo cars have virtually no exhaust system at all.
Hang on, I'll go find a picture of The Hunchback for you to demonstrate....
Hang on, I'll go find a picture of The Hunchback for you to demonstrate....
Edited by BB-Q on Thursday 26th March 23:51
All the pics seem to be in Flash player format, but here's a Youtube of the car. You can see the turbo sticking out of the bonnet and the exhaust right next to it.
the hunchback
Ok, a 1000hp 2.2l car is bit extreme, but it demonstrates the point.
the hunchback
Ok, a 1000hp 2.2l car is bit extreme, but it demonstrates the point.
the exhaust system on a turbo car has very different requirements to a NASP car. Downstream of the turbo exhaust turbine there is no tuning to be done as there are no pulses to speak of, thats why they are usually quieter than a highly tuned non turbo engine. The efficiency of the turbo is defined mainly by the pressure difference between the exhaust inlet and exhaust outlet so "back pressure" is absolutely not a good think. Turbo exhaust design is very simple, bigger and straighter is better. Mine making 500BHP from a 2L and a proejected 900BHP from a 4.5 V8 both turbocharged have only 1 small silencer right at the back of the car and 3" systems from the turbos onwards. Even with no silencers and straight pipes which I tested on the 2l engine they are not very noisy at all. My Cerbera with a standardish road exhaust is way louder than either.
This post froma Garrett engineer is worth a read.
http://www.fiatforum.com/cinquecento-seicento/4481...
Jon
This post froma Garrett engineer is worth a read.
http://www.fiatforum.com/cinquecento-seicento/4481...
Jon
Guys, thanks very much for the info.
Apparently, removing the cat & silencers will probably cause the seals on the turbo to fail.
If I keep the cat in place, all is good & I can run a pipe straight out the back without any silencers if I wish.
Will just have to see how loud it goes
To be honest though, the volume is secondary to getting a nice crisp sound, any ideas on how to change an exhaust note?
Apparently, removing the cat & silencers will probably cause the seals on the turbo to fail.
If I keep the cat in place, all is good & I can run a pipe straight out the back without any silencers if I wish.
Will just have to see how loud it goes
To be honest though, the volume is secondary to getting a nice crisp sound, any ideas on how to change an exhaust note?
I'm not sure why the seals would go after reducing backpressure... I think this is one of those internet myths, probably because removing the cat etc usually means a higher level of boost. It's probably this that causes a failure, but makes people think the seals have gone purely because of the lower restriction.
Low restriction on a turbo car is good. With a drainpipe exhaust, you probably already have VERY low restriction.
Note, just taking out the cat will make it a lot louder with the current system.
Low restriction on a turbo car is good. With a drainpipe exhaust, you probably already have VERY low restriction.
Note, just taking out the cat will make it a lot louder with the current system.
Otto said:
I'm not sure why the seals would go after reducing backpressure... I think this is one of those internet myths, probably because removing the cat etc usually means a higher level of boost. It's probably this that causes a failure, but makes people think the seals have gone purely because of the lower restriction.
Low restriction on a turbo car is good. With a drainpipe exhaust, you probably already have VERY low restriction.
Note, just taking out the cat will make it a lot louder with the current system.
Bear in mind that even a race cat is still the biggest restriction apart from the turbo itself.Low restriction on a turbo car is good. With a drainpipe exhaust, you probably already have VERY low restriction.
Note, just taking out the cat will make it a lot louder with the current system.
fatjon said:
the exhaust system on a turbo car has very different requirements to a NASP car. Downstream of the turbo exhaust turbine there is no tuning to be done as there are no pulses to speak of, thats why they are usually quieter than a highly tuned non turbo engine. The efficiency of the turbo is defined mainly by the pressure difference between the exhaust inlet and exhaust outlet so "back pressure" is absolutely not a good think. Turbo exhaust design is very simple, bigger and straighter is better. Mine making 500BHP from a 2L and a proejected 900BHP from a 4.5 V8 both turbocharged have only 1 small silencer right at the back of the car and 3" systems from the turbos onwards. Even with no silencers and straight pipes which I tested on the 2l engine they are not very noisy at all. My Cerbera with a standardish road exhaust is way louder than either.
This post froma Garrett engineer is worth a read.
http://www.fiatforum.com/cinquecento-seicento/4481...
Jon
Some really nice cars there mate! intrested to see the twin turbo AJP! This post froma Garrett engineer is worth a read.
http://www.fiatforum.com/cinquecento-seicento/4481...
Jon
Chris.
fatjon said:
The turbo AJP is making good progress and may be making some track days and santa pod this summer. Next year is when it really gets fun, going to try and get it under the Cerbera bonnet, must remember to order spare boxer shorts.
there is plenty of room towards the front! ;-)Chris.
All fitted now, a little boomy but overall I like it. Now running from the Cat back, a 2.5" pipe.
It's slightly louder than the stainless system it had originally- but that was'nt exactly quiet- it was just noise.
Although this is louder, the sound has got better, it burbles alot more, pops & bangs & sounds positivly fruity at full chat- 1000 x better than the pap it originally had fitted.
Needless to say, i'm loving it at the minute
If anyones interested i'll put a video up
It's slightly louder than the stainless system it had originally- but that was'nt exactly quiet- it was just noise.
Although this is louder, the sound has got better, it burbles alot more, pops & bangs & sounds positivly fruity at full chat- 1000 x better than the pap it originally had fitted.
Needless to say, i'm loving it at the minute
If anyones interested i'll put a video up
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