Power gain options

[danimicra8]

Ok, I have been reading through some of the threads on exhaust options and tbh im confused. I was thinking of a setup like this, Janspeed manifold, decat and exhaust system.
I put the links in at the end for people to have a closer look.

I have a few questions if people wouldnt mind answering:

Is this set-up the best for better power, anyone any better suggestions and what can i expect to happen to fuel intake

what does the decat actually do, is it MOT legal and is it worth the money for any gains in power

Is the janspeed exhaust system alright or is the OMP or Ashley better?

I dont want something too loud, i want it to have a nice sound and give good power gains mostly to be good build.

Link for Manifold
http://rallynuts.com/motorsport/K11...ce_Exhaust_Manifold_Nissan_Micra_K11_3165.asp
Link for Exhaust
http://rallynuts.com/motorsport/K11...ance_Exhaust_System_Nissan_Micra_K11_3167.asp
Link for decat
http://rallynuts.com/media/products/micra_decat2.jpg

 

[hoodedreeper]

only question i can answer is:

Yes a de-cat pipe WILL fail your MOT,i believe the cat just bolts out and the de-cat pipe bolts straight in.So not much work to swap things back over.

 

[danimicra8]

Well thanks thats one less question to answer :grinning:

 

[squarepants]

the best set up for good gians is, a janspeed 4branch manifold (mild steel only so wont last for ever) std cat still in the system, and 2" cat back system.

the janspeed exhaust system, OMP and Ashley are all the same bar the name..altough stainless exhaust systems have a life time garentte where as mild steel doesnt iirc ashly and omp are not stianless where as janspeed can come in stainless aswell as mild.

it wont be too loud, it will have a nice sound! but if your fitting a janspeed manifold to a cat back system it will be loud! you could quiten it down with a silancer in the system bar the back box (dont know if the exhaust mensioned above come with a silancer in the centre section)

 

[frank]

dani

the manifold will give the biggest gain, but will remove the 1st cat (the one that guarantee,s an emissions pass)

 

[danimicra8]

thanks squarepants, is that the system I showed in the links? or is the 2" cat back something else? I might just get the manifold and the exhaust system and skip the catback it depends on gains with/without the catback.

 

[squarepants]

if you fit the manifold then not the rest of the system it will loosem you power as its gone from a free flowing maniold to a std restrictive exhaust sytem i.e (diagram lol)

manifold cat back
========[]----------

goes from big diameter 2" manifold to a 1" exhaust...you would need the cat back coupled with the manifold to give you gians.

the second link is a cat back system yes...and stianless

 

[danimicra8]

got you squarepants thanks for the diagram! is it possible to just use the manifold and exhaust and still get gains without the catback?

 

[squarepants]

if you mean manifold then just a back box (the rear box at the end of the system that comes out your rear bumper) it will still be the same (loseing power) the centre section is after the cat....the 3rd link is a DE-CAT that doesnt really do anything performance wise, you will be ok useing the std cat.
erm i will draw a pic on paint for ya

hope this helps...all colour coded writing aswell so you dont get confused lol.

 

[danimicra8]

i think I get you.. so manifold - catback - exhaust

this and this on the cards then

 

[squarepants]

the full sytem is an exhaust even the manifold is an exhaust... top one is centre centre inc back box (janspeed) and bottem pic is a (4branch perofmance) janspeed manifold

 

[danimicra8]

right so thats all i need and the standard cat?

What will happen to fuel consumption? thats the only other question

 

[Paul Smith]

If you drive calmly the you shouldn't really notice much of a difference in fuel. Rally her and she will drink.

The other thought for around £200 janspeed will make you a sports cat.

 

[danimicra8]

i think 400 is a lot to be spending as it is on the manifold and exhaust so Ill leave the cat I think. Thanks for the heads up on the fuel though.

 

[squarepants]

the std cat wont effect performance, will be fine. de-cats give 1bhp dyno proven on an sr20! its near usless de-cating a micra it would change the sound and sound crap lol and make no bhp gians. and fial your MOT.

 

[Anto Modded]

the ashley cat back system is only 166 which doesnt seem to bad, just leaves manifold and 2nd cat then

 

[ollie240585]

If you are only using the secondary CAT, this will not guarantee an emissions pass, you will need to get your the secondary CAT quite hot before the MOT, so I suggest taking it for a bit of a run before hand.

Some people have passed no problems, with just the secondary CAT, others have failed.

I was running mine complete DE-CAT, Janspeed Exhaust, Janspeed CAT BY Pass, and Maniflow 4-2-1 Manifold, and it was funning like a dream. I just had sweet FA chance of passing an emissions test, so put the standard Manifold with CAT back on, still runs quite nicely, although not as nice as the RS hehe.

 

[Retepetsir]

if you mean manifold then just a back box (the rear box at the end of the system that comes out your rear bumper) it will still be the same (loseing power) the centre section is after the cat....the 3rd link is a DE-CAT that doesnt really do anything performance wise, you will be ok useing the std cat.
erm i will draw a pic on paint for ya

hope this helps...all colour coded writing aswell so you dont get confused lol.

The decat gained 3bhp for me, compared on a dyno with and without