Changed Muffler.. again..

[FordFasteRR]

I went to the store and picked up a new DynoMax 3 chamber high flow muffler..

it has 2 1/2 inch diameter pipes and I went to the local shop and had the swap it out for my magnaflow straight through... Hopefully this will yield a bit more torque than the straight design..

I will be heading to the Dyno tomorrow and take some new horesepower / torque measurements to see what the difference is :)

Wish me luck !


The muffler is one of these: http://www.dynomax.com/images/SuperTurbo_cutaway.gif

[CTele02]

So refresh my memory... a straight thru does give "maximum" flow but the engine needs at least some back pressure to make torque?

[FordFasteRR]

So refresh my memory... a straight thru does give "maximum" flow but the engine needs at least some back pressure to make torque?


I think that is the case...

When i dynoed last year, i had like 133 or 136 wtq...

now i'm dynoing 121 wtq ?

Something isnt right there... I think that it was the muffler that killed the torque....... because when i dynoed the 136 wtq i had a 3 chamber turbo muffler from thrush which is the cheepest turbo muffler they make...

lol... afterwards I installed a magnaflow straight through muffler and then dynoed a year later... now i'm down like 15 wtq ! ? ??? thats messed up !


I guess we'll find out if it was the muffler tomorrow. :)

[oregun]

Dude-

I thought you were going to start welding your own exhaust stuff.
Also, you might want to consider that the Magnaflow would be better once you get that SC

[FordFasteRR]

well, I still plan to mess with the muffler setup in the future.. however for now I'm just working with what i've got..


now, to reply to your suggestion.. After speaking with Alpine regarding the exhaust system, they suggested that I install a multi-chamber muffler to help bring up the backpressure ...

Their reasoning being that the slight gain in backpressure helps to retain more boost in the intake manifold during the overlap phase...

Also, my 2nd reason for changing it is the tremendous loss of mid range torque that the recent dyno shows.

:)

UPDATE:

I just made an appointment @ the dyno... I'll be there this afternoon @ 4:30 pm.

Wish me luck and may the gods of power bring me luck !

[GTSTISL]

Good luck, hope you pull in at leasy 500 wtq with that new exaust, lol

[oregun]

Well, I'll put in another two cents - while you're at the dyno. Alpine is real big on creating backpressure via the exhaust system. In fact, they don't even recommend using headers with their system. Back when SR was still alive, Random and Yam took a handful of headers to John Conchie to look at. His response was that they were all too free flowing. WTF?

Yes, with a free flowing exhaust, you will have a lower boost pressure (and consequently a bit less torque), but your horse power will increase. Ask NEXTGEN over at NewTib. He recommends headers, then increases the boost.

Personally, I don't subscribe to the "backpressure" argument. It makes no sense, whatsoever, that you would somehow improve performance by restricting airflow (either in or out). While there are performance gains to be had by improving air speed/scavanging with smaller diameter tubing in certain instances, this is not the same as causing back pressure.

You're best bet would be to call Dave at RPW and have him grind a billet intake cam for a super charger. I discussed this with him - you increase total lift, and close the valves a bit early. That keeps the boost inside the cylindar, instead of allowing the overlap to let the boost creap out of the exhaust valves.

Ford-
Engine to tailpipe: What makes up your exhaust

[only1db]

i was watching two guys garage....they said that the exhaust doestn really give any power but just lets the engine flow to it normal capacity...and thus the increase of power....so "creating" back pressure doesnt make any sense.....

[FordFasteRR]

.............

Ford-
Engine to tailpipe: What makes up your exhaust


simple..

A.1.8L 4-2-1 Elantra header slightly ported at all flanges & collectors.
B. Stock flex-pipe & mid section.
C. Hollow rear cat.
D. 2 1/4 custom crush-bent-exhaust all the way to the muffler.
E. 2 1/2 inch dynomax super turbo 3 chamber muffler.
F. 2 1/2 inch turn-down tip (stock look).

Thats it.


Dyno is here... see a new thread in the NA section to see the images and info....

:)