A new exhaust system in development for Fulvias

[angelorange]

One only has to read the excellent articles by Paul Leclercq ( http://var1016.blogspot.com/ ) to appreciate the issues with Fulvia exhausts - especially the factory manifolds and so called Group 4 versions currently marketed. It is early days but a better quality than presently available exhaust system is in development westward across the channel.

The company chosen has over 40 years of experience in developing manifolds and systems including older Maserati, Ferraris, Astons and Jaguars and even the latest Bugatti Veyron.

The basis of the manifold is my own "Gp 4" steel one (originally purchased from Lancia Racing's Peter de Wit some moons ago) and we will replace the current mid mounted side exit race system to improve ground clearance and offer standard 2 box rear outlet for those who seek quieter road legal and more original look.

To bring the cost down group buys are the best option - such a scheme has been done for Citroen DS owners and Jaguar Mk1s.

The manifold will be easier to remove than my current version.

The first stage of development will be a much more discreet race side exit version that would also suit Fulvia Sport Competizione cars. After that the manifold will be removed and jigs made and mods to ease removal with better collectors produced.

Handmade, the material will be 304 grade Stainless with vehicle lifetime g-tee. The system will suit 1300 and 1600 initially with possiblities for smaller dia. manifolds later.

Those interested in one of the following please email me so we can get an idea of numbers and hence reduce individual cost (NB: this is for all interested Fulvia owners and apart from any group discount on the purchase price there is no financial benefit my end):

Manifold only
Side exit or conventional up and over rear axle mounted box(es).
Centre pipe with expansion box
Straight pipe from manifold to rear box

Existing system pictures are posted here to give an idea of current (non ideal) setup.

http://web.me.com/ekranoplan/LUKAFOTORACING/

Kind Regards

[ncundy]

I am interested, but only if it is being designed / specified such that it will work well with the standard inlet/carbs, valves and cam setup (1600). I wouldn't be interested if it is predominantly designed to cater for the gas flow from modified head, aggresive cams and larger carbs unless it is shown to benefit the standard setup.

Can you give some idea of the design critera and aims (increase in top end power / low end torque).

Thanks
Neil

[Philm]

I would be interested and as a former race car engine designer would be particularly interested n the technical background of the people designing the system.

[Zagato]

I may be intersted - dependant on price and spec.
I have a Fulvia Zagato Sport 5 speed box (believe the 4 and 5 speed versions were slighty different) - and am running twin 45 webers - and I use the car for Irish tarmac rallying

[angelorange]

We have both standard Solex set up and the car shown in pics has weber45s

Those involved at present include race engine developer, aeronautical engineer and the supplier who has plenty of experience from prewar to 21st century sportscar exhaust designs.

However any input from this forum most welcome. Within the constraints of Fulvia chassis and budget there will be compromises and one design won't benefit all by the same bhp/torque % but we have to start somewhere. Thank you for your interest.

[angelorange]

First prototype of centre pipe with expansion chamber and side exit complete.

See:  http://web.me.com/ekranoplan/LUKAFOTORACING

Now need to find a rolling road near Notts......

[DavidLaver]

Reminds me of Paul and Barry at BWE where such things were (what seemed like) a constant topic of conversation.  Quite takes me back!!

Why not "straight line" from manifold to "mid" box/chamber?  Is there something in the way?

At the back isn't there a design of box(es) that avoids the 90 left, 180, and then the jiggles on the outlet to the tip?   On a previous car we ended up with (I think) Volvo boxes that were oval with the pipe off centre which made great use of the space available.

Feel free to ignore all of this - my interest is as a specator only, and my knowledge and experiance just about nothing.  The hope is that "the fools question" might spark a sensible idea...

The REALLY silly idea...what about taking the pipe under a floor instead of down the tunnel?  That could straighten out the front AND rear, the pipe seems to hang a long way below the tunnel anyway, and perhaps with some lagging the heat wouldn't be all that much bother in a racing car?

I once had a copy of this book which I remember as fairly practical rather than hard sums.  Am sure better books available now, or more likely software.

http://www.amazon.com/Scientific-Exhaust-Systems-Engineering-Performance/dp/0837603099

http://www.amazon.co.uk/Scientific-Exhaust-Systems-Engineering-Performance/dp/0837603099

David

[angelorange]

Hi David,

Yes in an ideal world....

But ground clearance is the name of the game with such a low ride height and the rear of the subframe would need quite a bit of modifying to allow straight from manifold to expansion box.

However, next manifold will hopefully solve this.

Have a look at the side profile and this is about as close to the floor as you can get without vibration or heat issues.

Best
 

[DavidLaver]

I can see its shaped to hug the floor, and I liked the "low profile" front box - is it just an expansion box or is there stuff inside?

Looking again this (http://web.me.com/ekranoplan/FulviaSS/content/_0016388_large.html) is the photo that makes the back box look as if its tucked up very high, and that perhaps there's space for a short fat oval. 

See picture attached for what I ended up with - after a brush with the law and a VERY tight time over the next 10 days as the "get away car" for a wedding, new exhaust, MOT station say-so, and back to plod.  In fact it worked SO well I then got a "noisy set" made up.

David

[DavidLaver]

...and another photo...

Being made up from "bits and bobs" it was worth adding the skid plate infront of the front box.   

Note the non-slip jacking point under the cage leg to fit into the trolley jack cup - its fine at home where I have an almost infinate selection of wooden blocks and planks but even with floors of that "quality" I was nervous placing a jack.  As an aside I've just finished "Lotus Elite - Racing Car for the Road" and one of the many early problems was garages wrecking suspension or GRP when jacking.

David

[DavidLaver]

That last photo showed the bolted flange between the boxes - for the noisy setup I'd replace the back boxes with straight pipes.  The placement of the flange was dictated by how long an exhaust section I could carry in the car so I could drive on the quiet to the track and swap over.  In the end that was a trick I did just the once for an AutoItalia Brooklands day when Ed McDunkinDonut (terrible memory for names - anyone help me?) had a go in the car.

David

[angelorange]

Drove down to Silverstone on wet Saturday, wizzed through scrut., 30 mins practice and 40 mins race with driver change then drove home - that new exhaust is fantastic!