Custom built to my design.

 

1.75" unequal length headers into a 2" system.

 

Sounds awesome and makes power !

Nice looking header! You weld that up yourself?

Nope. Unfortunately my welding skills are nowhere near as good as that. Found a small exhaust shop that builds custom stuff and gave them a picture I drew the week before.

 

I knew I was in the right place as soon as I walked into the shop. They had a wrx on the hoist and 3 harleys parked in there.

 

These guys:

 

Rutherford Muffler & Suspension & CV's

 

35 John St

Rutherford, NSW, 2320

Phone No:

0249324775

Uneven length headers don't make more power than equal length, they are less efficient.

Unequal don't make more outright power true. However every dyno print I've seen says they drop 3 or 4hp up top and gain a fatter midrange TQ (where I do most of my driving).

Added bonus is they sound wayyyyy better.

... Added bonus is they sound wayyyyy better.

 

That's True. Share a video with us, so we can hear it   

 

That is one of the Cleanest exhaust jobs I've seen.

 

Kind Regards.

Unequal don't make more outright power true. However every dyno print I've seen says they drop 3 or 4hp up top and gain a fatter midrange TQ (where I do most of my driving).

Added bonus is they sound wayyyyy better.

Different benefits and drawbacks, usually decided by space constraints.  In a nutshell, would the extra routing and twists needed to fit equal length headers end up less efficient than unequal length for a specific application.  It's usually not an issue but there are still plenty of examples if you go looking for them.

 

Mercedes has done some unequal length headers in their cars in the past.  Talking outright power, their 2015 F1 cars had unequal length headers and dominated that season.  Mercedes also did some strange stuff with them way back in the day on airplane engines like having slightly different compression ratios on the left/right cylinder banks to account for the different exhaust efficiency on each side.  You can also find them on high end sport bikes like some years of the Aprillia RV series.  Of course you can't ignore the obvious example of how well they have worked on Subaru's for so many years.

 

Bottom line is companies with huge R&D staffs full of brilliant engineers have proven that unequal length headers can be a better and more efficient choice in certain applications.  Equal length certainly have more power potential but that is not always true when considered as part of an entire chassis design.  Besides, as you pointed out they always sound better on 4 cylinder engines and that counts for something too.  Glad to hear you are happy with your result.

I'll try and shoot a vid in the next couple of days (its flogging rain here at the moment).

 

I reckon it sounds awesome, especially around 2000 rpm... gets this real fat throb to it..(no the exhaust not my pants haha).

I give you credit for chasing torque!

 

Who drives around on the HP max mark anyway?

 

Just look at the Aus Ford 4.0 litre I6 with flat torque line between 2000 and 4000 rpm was it?

Sorry for the offtopicness, but regarding this:

 

... Just look at the Aus Ford 4.0 litre I6 with flat torque line between 2000 and 4000 rpm was it?

 

Are you writing about the same in-line six cylinder Ford engine, that you have one, and also I have another one? ... If so, it is a 4.1 (250 cui) litre, not a 4.0 litre, and I didn't know, nor ever noticed that.

 

By the way, the one I have, came from factory with an unequal exhaust manifold, that fooled people, making them believe that it was a V8 somehow... sadly that unequal exhaust manifold is long gone, as it developed a Hole in front of the cylinder #1 which never got welded in a long lasting way, every welding only lasted around a week, so my dad changed it with a straight exhaust manifold from a 300, that makes the car to sound -and feel- way softer...

Kind Regards.

Sadly no longer have the beast. And reference is to the ohc 4.0 that started production about 1989 and just continued to evolve.

Heres the vid !!

 

Heres the vid !!

That growl is incredible!

And if you wanna get rid of that racket under the bonnet and get some refined revness - a tidy EA82 and a five speed youll be amazed - the cabin gets so quiet it is worth switching on the sounds in the dash

Nice, shame about the 32/36 Weber.

Jono.. Just going with the 81 for now mate. If I was gonna do a conversion at some point it would be a sohc ej20 150hp job (don't need an engineers report for that one).

 

Sapper157... thanks man ! I get a grin every time I open it up now.

Still refining the jetting on the weber btw.. came too lean from redline.

 

At the moment its running a 150 primary main and a 155 secondary main. Still getting a slight ping at 1/8th throttle in 3rd and 4th and still have a (now tiny) lean flat spot just as the secondary opens.

 

Fitting a 55 secondary idle jet today - should eliminate the flat spot, I'll let you know how it goes. Also ordering a 60 primary idle today to rid the pingy spot.

I've also tried a 155/175 mains combo in the car but that was too rich, ran "fluffy", made good power but drank fuel like a thirsty camel.

your primary jets are way too big for an EA81, unless it has a worked cam. I would suggest a 135 -140 primary and  a 150 -165 secondary and go to a 50 idle on the primary and a 55 on the secondary. If you can get them got to 3.0 or  3.5 venturis as well, as the standard 4.0 or 4.5 venturis the webers ship with are too big for the EA81 as well. Given that the CFM of a 32/36 is  between 290 to 350 (depending on the model) and EA81 Hitachis are between 130 to 190 CFM (depending on the model) you are always going to overfuel.

 

Remember as well US fuel has a different RON rating to Australian camel piss

 

Good luck with it

 

TOONGA

Great info cheers !

 

The 55 secondary idle jet cured my flat spot too.

Jono.. Just going with the 81 for now mate. If I was gonna do a conversion at some point it would be a sohc ej20 150hp job (don't need an engineers report for that one).

 

Sapper157... thanks man ! I get a grin every time I open it up now.

I must have been asking the wrong tech standards guys 1300 137 302, or asking the wrong way to get that interpretation of no need for engineers report...besides, dunno if you seen my latest signature ........                                                                                                                 

Edited December 21, 20178 yr by jono

Nice, shame about the 32/36 Weber.

Oh Willy, until YOU offer an exchange Hitachi tuned to perfection people are gonna fit Webers !

Oh Willy, until YOU offer an exchange Hitachi tuned to perfection people are gonna fit Webers !

Jono you have a severe grammatical error in your post... you used the words “hitachi” and “tuned” in the same sentence, which we all know makes no sense at all.

Well, I have been in of Willy's tuned Hitachi Subes....and he didn't even touch me Inappropriately either! You seen his videos with sound? He knows how believe me. And don't think I am getting in a car with him again though