[Relic]

As one or two of you know I had some work done on the exhaust a couple of weeks ago at powerflow.

£400 lighter pockets later...
I have a 2.5" s/s single box, single exit on the drivers side form the flex back.
None of these actually sound much like real life unfortunately.
The camera has noise reduction and it kills the real sound.
High pitch gets really loud and low pitch get silenced.

Anyway, I was asked on the performance gains and are they worth it.
Resulting charts attached.

3 datalogs were done using the honda map and honda intercooler.
31 jan - +2c / 1000 mbar ambient ...honda exhaust (black dots)
02 feb - -1c / 1040 mbar ambient ...powerflow exhaust (blue dots)
04 feb - -3c / 1050 mbar ambient ...powerflow exhaust + airbox mods (red dots).

Each of these datalogs comprise 6x 3rd gear WOT runs which are combined.

Of note should be the 2 VE tables and the two VAF tables.
This will tell you if there are gains or not and at what %.

 

[coste1l]

as someone will ask this has the 2nd cat removed! need a drive by vid mick but it sounds good and most importantly gives a gain :-D

sent from my phone

 

[phil739]

cant watch the vids or open file as at work

was it worth the 400 quid

cheers phil

 

[Scotty182]

How come you opted for driver side exit ??
( i can see vids/pics in work )

Where's the box ??
180' turn?

Just trying to picture it

 

[regan1985]

39mpg :facepalm: that impressive on its own

 

[Relic]

cant watch the vids or open file as at work

was it worth the 400 quid

cheers phil

Free flowing exhaust work better with more airflow.
Im only running 140hp....well OK 150+ now..point is.
I was surprised to see any gain as the current exhaust should not really be plugging the system at this airflow.
I do expect the improvement to make the difference beteen 220+ or not.


It is noticably more responsive at part throttle.
The torque limiter is cutting in much more violently.
So the signs look good for when airflow increases substantially.

Worth 400 ?....if I can hit 220+ yes.
Noise...it does drone on the motorway at 1800rpm but its not quite loud enough to be annoying. This is good.
When the pedal hits the floor it does indeed sound a lot like the subaru.

 

[coste1l]

220+ is the aim :-D

sent from my phone

 

[Relic]

How come you opted for driver side exit ??
( i can see vids/pics in work )

Where's the box ??
180' turn?

Just trying to picture it

new midbox is now the rear box ?!?!?!
2nd CAT removed.

The engine has to push the exhaust through all that pipework.
The greater the air volume of the piping, the harder the engine has to work at any rpm.
Result is exhaust acts like its plugged until gas flow intertia is fast enough to bias airflow through the cylinders.
Exhaust goes back in the engine instead of out the exhaust at low rpm when the inertoa isnt enough.
Power suffers at low rpm as a result.

Not the same as pulse tuning.....but is desinged to help the engine breathe easier.
And the engine does indeed breathe easier at all rpm.

 

[Scotty182]

new midbox is now the rear box ?!?!?!

Thats the info i was after!

Very nice, it's a good idea matey

I imagine that would make it more audible over a box furthur back
(look forward to watch the vids at home)

 

[coste1l]

so the only silencer is one at drivers side door?

sent from my phone

 

[Relic]

yes

 

[coste1l]

get under there mick and take pics!

sent from my phone

 

[Relic]

....
..got to rip the bumper off and strap up the FMIC today.
(run out of ties and thought I could make do without :facepalm: :worms
Have to wait a while for those.
I will do it though

 

[coste1l]

ok do a drive by soundclip then :thumbup:

sent from my phone

 

[corasdad]

are there any downsides to removing the second cat apart from poss mot issues???

 

[coste1l]

none and no mot issues either!

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[corasdad]

then why are they there (sorry for being stupid)

 

[Scotty182]

Bit of a space filler ? It's the DPF in Europe
So over here they swapped the DPF for another cat lol

 

[JohnnyBoy]

Want.

 

[coste1l]

i imagine it has an impact on emissions but its still within limits without both cats

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