UEL Header Development
 

I'm about to start on development of UEL headers and thought I'd get people's opinions.
This is not a debate about UEL vs EL (I'll be making those also) or about hp (I plan to dyno against EL to get a direct comparison). It's purely about the sound.

Which make the better off-beat rumble?
4-1
http://www.importimageracing.com/med...sheaderwrx.jpg

or

4-2-1 (single cross pipe)
http://i689.photobucket.com/albums/v...rossover_0.jpg

UEL = Better sound as a general concensus

Not overly biased as a there is a lot that goes into getting 'the best' exhaust noise. in the end it is purely personal preference.

Will want to see hp gains and hear good quality audio/video of it to make my mind up before commiting

Planning for it to be street legal in Aus?

I will do a street legal version.

Would be good to hear from anyone from the Subaru world that has experience with UEL headers and which headers make the most noticeable Subaru rumble.

The oem USDM wrx/STi have a 4-1 which produces a mean rumble...

Actually curious to know as well if a 4-1 UEL sounds any different than a 4-2-1. I suspect the main cause of the "off-beat" rumble is due to the difference in length of the primaries. The larger the difference in length, the more "off-beat rumble" there is

From a fluid dynamics perspective, the 'most rumble' would come from manifold-style designs where both cylinders on a head dump into a single tube. So something like a really short Y-configuration on each side.

See http://www.ft86club.com/forums/showthread.php?&p=308426

Of the two, definitely this one since each bank's cylinders are combining prior to 'final mixing'.

Thanks guys. The header work will start tomorrow.

I'll post video of the sound when I get something sorted.
Also dyno results, as no one will want to loose power.

well the stock headers are UEL. But the angle and design is different than the traditional EJ headers... so I am guessing the shape/angle is what is causing the rumble sound. So I'd try to make it look like the stock EJ headers as much as possible, more 90 degree bends instead of 180 degree bends.

will this be for stock exhaust application or for a 3" pipe ?

Super sick! Can't wait to see if we can have our boxer sound back!

Can you direct me to pictures of the EJ Headers? All Google wants to give me is pictures of aftermarket headers :search:

This will be a bolt-in to match the stock exhaust.

I know it's not the stock header, but this is pretty much it:

http://farm6.staticflickr.com/5042/5...96d90caa_b.jpg

The stock header is on the bottom. From an WRX.
http://www.streetsports.com/photo/ve...er_for_WRX.jpg