pee vee

just wondering, the Focus WRC cars, (and ive only noticed it on the fords)

when they are rallying, everything is SO hot that even the inside of the exhaust tail pipe is glowing pretty much all the time...


so how do they get away with it running so hard and SO hot, even that far back in the exhaust system, and not have melted anything in the engine??

pa_sjo

Because the heat is in the exhaust, not the engine.. the ALS causes that, mainly.. the exhaust isn't made from stainless either, usually inconel or titanium, which may transfer heat better than steel alloy.

Farmer Giles

because they spend hundreds of thousands of pounds developing everything to work at those levels.

That's why high level motorsport costs so much.

richard_syko

There is a catalyst in the tail pipe, as unburn fuel goes through it burns and glows. Its not all that hot,.

http://www.rallysportmag.com.au/home...Exhaust300.jpg

Ginge !

its a rear light like in F1,,,,, they are so smart them F1 boys that they think of everything in there designs

Micky The Finn

as said above,its the catalitic converter you can see glowing,not the whole exhaust,and the exhaust is coated so that almost all the heat comes out of the tail pipe.the tunnel where it travels down is also heatshielded to protect the body.

pee vee

cool, thanks!

Glenn_

iTrader: (1)

This might sound silly but i never thought they would have catalist converters on rally cars.

Glenn_

iTrader: (1)

i love anti lag on cars too.

JHS

iTrader: (1)

Why wouldnt they? They have to be road legal...

cozzfather

iTrader: (1)

and the first catalitic rally car was ..................



































































4x4 sierra cosworth driven by a bird called aitkin walker, and she could handle a cozzie let me tell you

Micky The Finn

celica gt 4.

cozzfather

iTrader: (1)

Tim you sure ???

i remember the ads and it was the rac rally from chester in 92


how the bleeding ell do you go from your old user name to mickey the finn ??

richm

interesting that they have Cat's at the back, anyone got any links to more info on this?
I found a pic:

Micky The Finn

cats were used in 1991 though.

as for the username,your the one bloke on here i thought would click straight away,infact i thought of you as i typed it!!

Mad Matt

iTrader: (2)

The put the cat at the back because it is less restrictive for the engine than putting it at the front.

richm

I'm not sure I follow how it would be, but thats interesting if it is so..
We have to run with catalysts in our saloon race series at castle combe in 2009 so may be worth considering this

We have a 340bhp 1.8T Audi TT and for the odd trackdays are forced to run extra silencing which we do in the form of a tailpipe muffler as it is easy to fit and remove -



http://www.merlinmotorsport.co.uk/p1...duct_info.html

we have a 3" exhaust and this muffler is approx 2" clear I/D and the 8" long - this makes a distinct reduction in power delivery, so I'm interested to know how much effect a Cat would have, even a 100CSI one. If there is benefit in fitting it at the back then that's what I'll try.

Turbosystems

iTrader: (5)

the cat is as far away from the heat source to prevent it from melting

richm

Tony, further to my previous post - are we likely to run a realistic risk of melting the cat in the TT if fitted in a more conventional position, bearing in mind it's being subjected to race use with no regard to AFR that the cat wants to see obviously (11.5-11.8 afr).. ?
Damn thing is only there for the benefit of MSA lip service to the tree huggers, so need to minimise the impact it has on the engine.

pa_sjo

richm- you put a thermocouple just before the cat and map it rich enough to not melt it

richm

lol, will block it up with soot if I go much richer - 11.5afr mostly now.

doctor stavros

pa_sjo

That's pretty tame for a cat car. A lot of production cat cars run in the 10's at WOT.

richm

True - my skoda is high tens at peak rpm WOT.
OK, but I don't WANT to run much lower than 11's lol especially if it's only for the bloody CAT's benefit

Matt Evans

I never knew they put the cats so far back!

And ive wondered before why the focus exhaust was always glowing red hot. Now i know.

Steven_RW

Interesting:

So on a production car they put the cat as far forward as possible (in the down pipe on some cars?) and I believe this is to get the heat to the cat as soon as possible (as a cat needs to warm up to work) whereas on a Rally car they put it as far back as possible to stop it from melting due to their extremely high exhaust temps? Does an anti lag car really have that much higher temps in the exhaust? Would be interested to know how many extra degrees we are talking.

One last thought, I recall being told that an exhaust pipe needs to be larger, closer to the engine as the volume of the gas (due to it being at its hottest) closer to the engine is higher, and as it travels up the exhaust it cools and thus the volume of gas reduces so the bore of the exhaust doesn't necessarily need to be as big. So this would would hint towards a cat (being a restriction) being better placed towards the back of the exhaust as it will create less of a restriction at that stage?

On that note, I was never happy when I was told I had to keep cats on my M3. It reads the gas before and after the cat and goes into a limp home style mode if there is not any difference. So it is either expensive "race" cats or a new style ECU that doesn't read before and after, or some adaption to my current ECU that means it no longer cares (no one seems to be able to do that yet).

Cheers
RW

Cheers

RW

Aaroncast

WHY NOT?????

Aaroncast

---------is it from a moggy!minor-------------

cozzfather

iTrader: (1)

aww i think of you too mick er i mean mr finn


A Mickey Finn

Meaning
A sedative (or sometimes in the US a purgative) drug surreptitiously slipped into someone's drink.
Origin
A 'Mickey Finn', which is sometimes called just a 'Mickey' is supposed to be named after a character from 19th century Chicago - 'Mickey Finn', of course. Finn was the keeper of Chicago's Lone Star Saloon in the late 19th and early 20th century. He was alleged to have drugged and robbed his customers. There are a couple of US newspaper references from December 1903 that allude to this

Aaroncast

--------ive got an escort cosworth 96 plate- no cat!! Taken of when purchased----dont need it -----never will!!!!!!!!
The belief that you will fail an mot without it is crap!!!!!
The mot tester can alter the figures!!!
Climate change!! Not from the uk it aint!!-your all brain washed into believing it!!!-like bloody sheep bah-bah-we contribute f----------all to global warming-------------

Glenn_

iTrader: (1)

Well i didnt know They had to be road legal i dont follow rallying much sorry.

krypton

Mite be a stupid idea but I know on some french cars like citreon c2s when fitting a 4 branch manifold to them it does away with the cat and you can get a sleeve that goes over the 1st probe and you use the 2nd one. Your ecu will be more complicated so maybe not be able to do something like this




Subaru wrc ran with the cats at the back aswell but not as big as the focus looked just like a standard back box

Ginge !

that is the real reason i would belive, the heat of antilag would melt the bricks if on the downpipe

Micky The Finn

a 1996 car with no cat fitted will no longer be type aproved and will not pass an mot.

Nash_mr2

the red glowing tailpipe isnt heat....it's a Halfords LED Glowing Tailpipe they have to use it to keep the sponsors happy, it's wired to the fog lights.