I have an inkling that the 500 engine designer knew a thing or two about his craft. I can't think of many other cars with such a distinctive and desirable natural exhaust burble than a 500. How fast do you lot want to go? Anyone got a video of their car at speed on the road?

Peter actually I am not expecting to go faster and I don8t think that I can gain more than half or one up. It's more about the sound and the cooler apearence.

I fitted the Styer Puch engine and enlarged to 750cc
The exhaust is a quad Monza system ?

gordinir8 said:

Peter actually I am not expecting to go faster and I don8t think that I can gain more than half or one up. It's more about the sound and the cooler apearence.

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I know Thomas..... I'm just being cheeky because I'm in the minority, on this thread, in preferring the original exhaust and the sound of it....... I should just butt out.

fiat500 said:

I know Thomas..... I'm just being cheeky because I'm in the minority, on this thread, in preferring the original exhaust and the sound of it....... I should just butt out.

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I’ll join you in the minority! Don’t worry you aren’t alone!

Even calling it a sports exhaust is maybe stretching the imagination a little too far for me!

fiat500 said:

I know Thomas..... I'm just being cheeky because I'm in the minority, on this thread, in preferring the original exhaust and the sound of it....... I should just butt out.

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In the end of the day who is the coolest guy here, the one with the most exotic and powerful 500 with super loud racing sound or the guy that says.. Oh you know i just had today 300 miles with my car, Yes my usual walk in the park, not really a big thing for me... Id say the second guy so please don't ''butt out'' Peter

fiat500 said:

I know Thomas..... I'm just being cheeky because I'm in the minority, on this thread, in preferring the original exhaust and the sound of it....... I should just butt out.

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Shouldn't that be putt out?

As in putt, putting around

AL.

fiat500 said:

Anyone got a video of their car at speed on the road?

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Ho, Ho, Ho.

AL. D)

Bigvtwin996 said:

the exhaust is the first thing that gets dumped if tuning a VW aircooled engine...
As mentioned there really is so much science in exhaust design, volumes and the resonance within the system also affect the sound produced as the pulses from the exhaust port need be in harmony with the system and make so much difference, bends and elbows are killers to flow...
Whilst you can simply "knock up" and exhaust from off the shelf bends and boxes, it may mean the engine many not perform to it's optimum.

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I wasn't suggesting anyone fit a VW exhaust to their 500, rather to have a look at what VW enthusiasts do to upgrade, given similar space restrictions.
There might be a silencer that could be used and fabricate the pipes oneself.

Ever read the book - "The Scientific Design of Exhaust and Intake Systems" by Philip H. Smith and John C. Morrison. Very interesting but a bit too much for my limited brain power.

I wonder how much testing is done on 'Sports' exhausts, especially before i.e. standard exhaust, and after, on the same engine.. I mentioned comparing the 850 standard exhaust with the 850 coupe 'sports' exhaust.
There wasn't any real difference inside the silencers, just 4-1 pipes which were quite short and reduced down very abruptly to enter the silencer. So not a great design imho. Which is why I suggested fabricating one's own system. You're not likely to do worse and possibly will do better. How much better? As others have suggested, given the small power output, you'll probably only see maybe 1 or 2 hp. I suspect most people fitting a 'sports' exhaust just want a 'sporty' sound. This is fine when showing-off a little in the car park or pulling away from a gathering of fellow enthusiasts but a noisy/droney exhaust will likely become a right pain in the ... head, on a long run. As others have alluded to above.

I'd agree that elbows are not good but you have to have bends to fit on a road car, unless you want to emulate some of the early race/speed record cars which had straight pipes exiting the bonnet....Methinks the police etc. might have something to say if you did this...

I modified an exhaust box on a Fiat 600, back in the day. Tail pipe fell off due to rust. I opened out the hole and welded a larger tail-pipe on in it's place. Gave a deeper, slightly sporty sound but wasn't loud or annoying. I doubt there was any power increase as the rest of the system was the original but I was happy. . Some people thought the car was tuned due to the sound and way it went, or maybe it was because of the aluminium Fiat 782 badge (in the same style as the Fiat 600 one) on the engine lid.....
(I must look to see if I still have the badge...)

AL.

Another good book for exhaust design (as well as a host of information on tuning engines) is the book:---"Four-stroke Performance Tuning" by A. Graham Bell. (Haynes are the publishers) The trouble with the 500 is that the 2 exhausts are at opposite ends of the engine, which presents problems, vis-a-vie an 'inline' engine where all the exhaust ports are next to each other. In the early days of tuning my engine I had a custom stainless-steel exhaust made for it. The 'cunning plan' was (and still is) to eventually use it on my '695' engine. It was used initially for a particular show/run, taken off and put aside, and replaced with the MBG sourced exhaust--which is what is on my engine at the moment and was on in the u-tube film. If you want to see what my stainless exhaust looks like, look on the web-site of "Demand Engineering, Stonham"---the rear of my car is in their 'gallery'. They have taken both pipes to the front of the silencer.
The reason that the 'racing' exhaust is so convoluted is because they are trying to get about a primary-pipe length of about 34ins (depending on cam and revs) into the system--not easy within the confines of a 500 rear-end!
On the 'Abarth 1000tcr' saloon racers (based on the 600 body), the exhaust IS led across the back of the car in order to gain the length required.

I wasn't suggesting fitting a WV or similar exhaust, simply that the design is bad hence first thing to be changed the replacements that suffer from 180degree bends to tuck them under one side... or end up sticking out the back
As Tom says, it is about the correct lengths etc and the lack of space in a 500 engine bay and the rear engine mount causes a host of problems...
There was one system I looked at and basically it arrives almost in pieces, you fit it and tack it together whilst in place then remove it and weld it up...
but it does look like a couple of tin snakes in the engine bay, plus you are not able to fit the tin over the exhaust, so probably best suited to cars that run open rears...

the hobbler said:

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-------------------They have taken both pipes to the front of the silencer.
The reason that the 'racing' exhaust is so convoluted is because they are trying to get about a primary-pipe length of about 34ins (depending on cam and revs) into the system--not easy within the confines of a 500 rear-end!
On the 'Abarth 1000tcr' saloon racers (based on the 600 body), the exhaust IS led across the back of the car in order to gain the length required.

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Which is what I was trying to convey (in my usual long-winded way )

Both pipes to one end of the silencer.
Longer primary pipes.
Exhaust across the rear of the car in order to fit with the longer primary pipes.

AL.

Given the similarity (air-cooled, ohv, not high revving, older design) between the Fiat 500 engine and that of the Triumph 500/650 motorcycle, maybe one could use some of the tuning techniques employed on the Triumph for tuning the Fiat.. Of course, the siamesed inlet ports on the 500 head is a limiting factor....

As regards a suitable silencer? How about a pair of chromed Triumph Goldstar?
silencers or a Dunstall Megaphone (plus ear-plugs!)

(some here won't know what i'm talking about )

Al.

the hobbler said:

Another good book for exhaust design (as well as a host of information on tuning engines) is the book:---"Four-stroke Performance Tuning" by A. Graham Bell. (Haynes are the publishers) ---------------------
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That's a great book.

I think he also invented the Telephone.

Another good book is "Motor cycle Tuning (Four-Stroke)" by John Robinson ( A Heinemann Newnes Book). There's a very good chapter on exhaust systems, explains what the different parts of the system do, plus the different types of silencer - absorbtion, capacitive, plus one of the end-can types designed by Dr. Geoff Roe which uses Helmholtz chambers to take out particular noise frequencies with no physical obstruction to the gas flow.
(which is why I suggested considering using a modern motorcycle end-can)

AL.

the hobbler said:

---------------------
--------------------------- I have a 'sport' exhaust from MBG, which seems to be very well made, sounds good and has given me no problems at all. It retains the original cast-iron exhaust 'elbows', but as I spent some time and effort on porting the head, they also got modified internally.----------------------
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I did a bit of porting in my youth (a long time ago!).
Used to take inspiration from great guys like David Vizard.
(Anyone remember the articles in "Cars and Car Conversions" magazine etc?)

One thing I discovered a few years back was not to blend the transition from the exhaust port to the manifold. Apparently you need to leave a sharp step, the manifold/primary pipe bore should be slightly larger than the exhaust port to prevent backflow of exhaust gases.

AL.

Not only do I remember 'Car and Car Perversions' (oops! Conversions), the lads from the magazine used to regularly pop into the Radbourne workshop for a chat and a coffee.
Technically, not only should there be a 'lip' between the exhaust manifold and the primary pipe (with, as Al mentioned, the port being slightly SMALLER than the primary pipe, but the inlet port should also be slightly LARGER than the inlet manifold for the same reason---to prevent REVERSION.
Be warned though---a 'cherry-bomb' silencer is noisy enough that the MOT man may so "non"--what the 'boy in blue ' will say I will leave to your imagination!

the hobbler said:

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Be warned though---a 'cherry-bomb' silencer is noisy enough --what the 'boy in blue ' will say I will leave to your imagination!

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Do you think they might invite me back to 'their place' for a chat and a cuppa?

AL.

Every chance of that Al--although the 'cuppa' might be passed through a small hatch in a door--with a 'bickie' added for 'good behaviour!

I came across a nice exhaust system fitted to a 500, it has decent length primary pipes with gentle curves entering the rear of a silencer box then flowing forward, exiting the front of the box with a pipe then running back alongside the box to exit the car in the normal location at the rear.

It's on Youtube under - "Fiat500Engine 750cc Over 7,000rpm" (by HARA0500)

AL.

F123C said:

I came across a nice exhaust system fitted to a 500, it has decent length primary pipes with gentle curves entering the rear of a silencer box then flowing forward, exiting the front of the box with a pipe then running back alongside the box to exit the car in the normal location at the rear.

It's on Youtube under - "Fiat500Engine 750cc Over 7,000rpm" (by HARA0500)

AL.

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I just watched that video and the soundtrack seems really alien to a 500, hearing it sing to those high revs, it sounds just like we’re all used too but when he hits the throttle! Nice looking exhaust on that car, and it obviously works well.