Exhaust

[sammyboi]

If i were to run a whole janspeed system (421 mani, decat, cat back system), would it be road legal? As i know if you run a decat pipe it makes it illegal due to emissions, but was reading somewhere that the janspeed decat isnt like this?

"Janspeed's sports catalysts are free flowing yet MOT legal (UK)"

Is ths true?

 

[frank]

sammyboi

the 421 + decat + catback is catless, so no.
if you fit a 421 + sportscat etc it "may" pass, if you can get the cat hot enough

 

[imy2008]

going on from that because ive got janspeed exhaust going to being getting janspeed manifold soon so if i use a janspeed cat from rallynuts its not mot legal like it says on the site.

 

[squarepants]

no would be illegal on the road and too loud for tracks unless your dragging...also has no back presurre and struggles up hills!

did you not see raceworxs k11? straight through no box exhaust? it was janspeed 4branch, de-cat and 2" to a 4" tip! was crazy loud.

k11 1.3 fails MOT with one decat never mind two lol. iam only running a de-cat & back box and mines fails. its miles off on emissions.

 

[jowley]

mine went through with one cat

 

[frank]

mine went through with one cat

mine too, 0.003 % CO (with a ga16 t/b + injectors)

 

[squarepants]

some do and some dont :S could be many reasons...like if the cat is hot, or the cat is cold when they do emissions... altough for all you know they couldve seen it was going to fail and hooked the emmsions mechine upto another petrol car so it would pass! lol ive heard of it beeing done!

whilst we are on the subject of emissons i was led to belive cg10's run rich with janspeeds and pass the MOT on emmsions! not 100% on this tho.

 

[jowley]

the first cat does most of the work jus depends on how efficiant it is dont think they run rich but not sure

 

[sammyboi]

ok then guys, cheers for the feedback!

Only asked as ive got to get a new cat as mines rattling when at 3500+rpm so thought id "upgrade" from standard as they are similar prices, but dont fancy failing mot/roadside test so will just replace it.

Thanks All!

 

[joesouthgate]

also has no back presurre and struggles up hills!

I swear i remember Ed saying backpressure was a myth...

 

[Optispart]

so i should pass my mot with janspeed manifold standard CAT and ashley bacbox?

 

[Retepetsir]

Mine isn't loud with a janspeed, decat and then a 2" system, but I do have a mid silencer as well as the rear one

Edit: and yes you should, I've passed my 2 previous mot's with a similar setup (only one cat), just get it nice and hot!

 

[ronin_kid]

I swear i remember Ed saying backpressure was a myth...

back-pressure on a turbo car = bad, but on an n/a car it can be benificial, something to do with valves opening/closing iirc...

 

[mihtymicra]

hi where can a get a de cat pipe

 

[Antony]

Mine isn't loud with a janspeed, decat and then a 2" system, but I do have a mid silencer as well as the rear one

Edit: and yes you should, I've passed my 2 previous mot's with a similar setup (only one cat), just get it nice and hot!

my car just failed its mot on emissions with both cats, clean filter, and brand new lambda sensor...... so its all about the car.

 

[Swiper]

my car just failed its mot on emissions with both cats, clean filter, and brand new lambda sensor...... so its all about the car.

or the engine builder. sorry ant, only joking lol.