Rally Car Exhaust Options

[Mac Crash 78 1 Cars]

Looking for advice on what exhaust system to use on stage car... will be mating to 4-1 Magnex manifold.

 

Have seen these parts from Special Tuning.

 

http://www.specialtuninguk.co.uk/acatalog/info_7056A.html

http://www.specialtuninguk.co.uk/acatalog/info_7056B.html

I have a spare Magnex twin box system but don't think this is suitable for rallying... I presume most cars will be running

with just one silencer, have welder so was considering using just the middle silencer (which is already skidded) as the rear
and welding some pipe work up to suit?

Any proper group A or N stuff on the market or do most folk just make up their own? Interested to know what others
are using... or what should be done.

[welshpug 1,621]

why would your magnex not be suitable? its probably the only one worth using off the shelf.

[Ryan 99]

The Special Tuning exhausts aren't great. They're designed for the original 105hp 1.6, so they're nothing amazing even on a standard 115hp engine. They don't even fit all that well.

[Mac Crash 78 1 Cars]

why would your magnex not be suitable? its probably the only one worth using off the shelf.

Have one on the road car and wouldn't use anything else... I've trial fitted the spare one to the rally car, as said the middle box has been skidded but the rear silencer just seems a bit large and bulky... and wasn't sure if it would be best just running a single silencer system... I'd like to save weight wherever possible.

 

I have the standard Peugeot rear silencer laying about, very heavy but they fit so well and I like the discreet way they look... was toying with the idea of cutting it open, removing the pipe arrangement inside and welding in a straight through perforated pipe... no harm in having a look to see... but if you think the Magnex will be suitable though...

 

The Special Tuning exhausts aren't great. They're designed for the original 105hp 1.6, so they're nothing amazing even on a standard 115hp engine. They don't even fit all that well.

 

Good to know then.... it's all I could find searching.

[Chris H 10]

If you run a magnex with just the middle silencer you are unlikely to pass noise tests!

 

The magnex systems are well made and have a good sound. They made reasonable power when there was a back to back test of exhaust systems done on a RR years ago. In fact it was the magnex and piper that were the only ones to make more power than standard if i remember. All the others lost power and the ashley system was the worst.

 

I have a few sportex systems, cheap and cheerful and not too noisy but i'm not sure how good they are power wise!

 

OMP systems are generally too noisy from my experience. I had a piper system on my old 309 gti stage car and that was quiet enough and fitted well.

 

I had a custom made system for my mi16 rally car and that was the best £300 i've spent. Really well made, quiet and doing the job after 10 years.

[welshpug 1,621]

there are many a tuned 8v and gti6 engines running on the two box magnex without any problems, they're skidded as standard too.

[Mac Crash 78 1 Cars]

I'll go with the Magnex then for now then...

 

If it's of any interest, then this is what is inside a standard rear silencer (Walker type)

 

Looks restrictive but probably isn't... normal design to keep noise down? explains the weight though...

Both Magnex silencer flows straight through, can see it with light shone down it.

[brumster 135 1 Cars]

Gravel or tarmac?

 

A single-box (rear only) system will require a very large, quality rear silencer to make the noise limits. It's possible - I use one - but you are talking a Simpson oval silencer, and it's big. So the easier and cheaper option is something along the lines of the twin-box system.

 

And don't forget to skid it, yes, this is critical, particularly if we're talking gravel or bumpy. There's a stainless twin-box system sitting in a hedge somewhere on the Isle of Man thanks to muggins here ripping it off

[Miles 331 1 Cars]

1 of the stage car's I run use's a single box system, it did have some chav make Stainless back box on it before that failed so I stuck a mile steel rear box of similar size to a std one, noise is fine and pass's all test's, the engine's a Std Group N spec 1600,

For stage I'd say a single box at back is best, saves anything getting in the way under the car, Single venue isn;t quite so important

[And 15 1 Cars]

The OMP systems mentioned are no longer available for the 205 I was looking for the group A system to replace mine but had to just repackaged it, it had only just got up to 105db after 10yr ok it's on a TU3 tho if that makes a difference? as it never was much above 95db for a long time, there is a copy version available tho from orica France but I couldn't get them to respond to emails on shipping costs another company that goes through them did but although the system cost wise is not bad the shipping wasn't far off the system price..

Edited February 16, 2017 by And

[petert 549]

I recently built a new exhaust for my 205. It has just one muffler, in the space behind the hand brake. The muffler is a Redback F727MN. ie 2.5" centre offset, 10x4" oval, 14" long. The exhaust finishes at the beam, ready for entry into a diffuser. I was very concerned about the noise. However, it has passed a 95dB test @ 30m. Since running in and being coated with carbon, it has become significantly quieter.

Edited February 17, 2017 by petert

[welshpug 1,621]

I suspect that will be significantly louder on the typical FIA/MSA noise test of 0.5m at 45 degrees from the tailpipe at between 0.5 and 1m from the ground.

 

Also exhausts must end within 150mm of the bodywork and in plain sight, and not protrude more than 150mm to the rear, or if a side exit not any further than the wheels.

[Biggles 65]

95dB test @ 30m

 

Just checking there isn't a typo here - 95db at 30m - that would be nowhere near passing an MSA noise test. They're obviously a bit more relaxed about noise down under.

[petert 549]

Just in its infancy more like it. It's like a speed camera, in that it takes a picture of the offending car.

[And 15 1 Cars]

It sounds like the Irish spec systems louder the better just fit empty boxes, they go through the noise test motions but never stop any one starting!!,..

[welshpug 1,621]

Belgium is like that, kind of, they dont bother with noise tests at all for rallying