hello all! this is my first post here but i've been reading this forum for quite a while

i'm about to fit ITBs to my car (206 XSi, TU5JP4) and i'm facing a dilemma.
I have Hayabusa TBs with a Jenvey manifold and 2 sets of trumpets - a 40mm set and an 80mm set.
so here is my dilemma, should i:

a) use the long 80mm trumpets with individual filters
b) use the short 40mm trumpets with a Pipercross airbox (already got the airbox) and connect it to the original airbox/air supply system.

i tend to go with the second option as i want my engine bay to look as original as possible and it will also lower the induction sound (i'm trying to avoid unnecessary attention).

so what do you think?
is the 40mm difference in induction length gonna make a huge difference in power?
will the colder air from the second option gonna make up for the shorter induction length?

tnx

only way to really see any perfomance difference is to do some back to back testing.

here are a couple of pics with the 80mm trumpets attached:

boni - yeah i know, but that means i'll have to map it twice...

i was wondering if maybe someone already tested a setup with two different trumpets lengths? did the longer trumpets made a noticeable power gain?

it depends on other aspects of the engine, cam profiles, cam timing, exhaust spec etc.....

but there is no definative answer. the map will only need small tweaks by changing trumpet lengths.

What are the overal induction lengths?

haven't measured it yet, still need to make adapters from the TBs to the manifold.

gues i'm gonna wait and see then

Given your priorities you describe, the airbox seems the best idea, but it breaks my heart!

i don't wanna break anybodies heart

my top priority is power, that's why i'm doing this in the first place!
and of course i want the sound! only dimmed if possible - 'cos the cops won't like it (tuning is illegal in my ignorant country).

if the power diffrence is minimal, i prefer to loose 2-3 HP for a "stealthier" setup.

I would never go for individual socks. If the over length is long enough I would at least fit a sausage style filter.

what's that? got a pic?

Something like this

Power wise, I think you will need the extra length, with 40mm trumpets (guess scaling from the pictures), it looks like the overall tract length will be about 300mm, which will be too short to work well generally speaking. 340mm is more likely to work well over a wide rpm range. You have to experiment with tract length to get the best results though, there are too many variables involved to make hard predictions about what will or won't work.

the 206 should allow a long inlet system ,i would experiment with even longer trumpets ,but with knowing cam spec rpm range ,ex manifold ,etc,etc its a guessing game.
how ever what ever you decide on ,you live an a country hotter than uk with more dust and grit in atmosphere ,so a plenim chamber with remote filter should be your goal ,for both good power by maximising cold air input along with good fitlration for engine life

problem with the long trumpets is that they won't fit inside the piper box/plenum, so it's either short trumpets with the box or long ones without it.
so i'm guessing there is no rule of thumb on this matter and i'll just have to do both and see what gives better results.

George - you reckon a sausage filter will give a better airflow than individual K&N ones?