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2007 2.5i with Cams, Exhaust, Intake, etc...


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Thanks -- are you being sarcastic or serious? :lol:

 

In all seriousness, that is an actual log -- the exhaust did that much!

 

 

NO serious LOL you broke got a 2.5i to 150 at the wheels that is probably a first :) Nice exhaust btw.

 

Just watch the video that odd noise is from the 40 series themselves mated to a 4 cyl. You should try 60 series Delta Flow instead of 40 series or even Super 44's the 40 is just to harsh (tone wise) for a N/A H4. The 60 Series will cut out that rasp and they come in 2.5" offest/center exit

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NO serious LOL you broke got a 2.5i to 150 at the wheels that is probably a first :) Nice exhaust btw.

 

Thanks! I'm very happy with the results from all of the modding! It's nice to know I'm not the only one who cares about modding the 2.5i!

 

Just watch the video that odd noise is from the 40 series themselves mated to a 4 cyl. You should try 60 series Delta Flow instead of 40 series or even Super 44's the 40 is just to harsh (tone wise) for a N/A H4. The 60 Series will cut out that rasp and they come in 2.5" offest/center exit

 

See, the only thing that is keeping me from getting the 60 series mufflers is their size. I only have about 17" of room back there and the piping going up from the y-pipe to the mufflers is already at a really odd angle...

 

I just don't want to spend the money on the three chamber ones and have them not fit in there and have to deal with returning them (not to mention my co-worker that welded the whole thing would kill me for making him do it again :lol:)

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definately post more pics (closer) of the exhaust.

 

Will do.

 

After a little bit of Calculus with some Tactrix 2.0 logs, I calculated that our drivetrain loss (at least on the '07 2.5i) is approximately 32.6% (I know, this seems like a lot, but I got the same number from many different logs).

 

Applied to the 151.12/145.48, it is possible to make 200.40hp and 192.93ft-lb's of torque on our little N/A EJ253!

 

 

This is 26.59hp and 24.0716ft-lb's to the crank less than a stock '03 WRX!

 

Assuming that our cars don't lose power through the drivetrain, I came up with the following (the first numbers are not a direct comparison, per-se, as I used my acceleration AFTER drivetrain loss and the WRX's before, so in essence, the following is an overestimate)

 

The following assumes that the driver weighs 120lb and the extra weight doesn't lower the power....WHEW!

 

Translated into acceleration, at max power at 6200 RPM in my 2.5i, I'm accelerating at 2.43mi/hr/sec, and a stock '03 is accelerating at 5.41mi/hr/sec.

 

Honestly, this is equivalent to an additional force equivalent to balancing a 3.695lb weight on your head -- try it; that's not very much of a difference!

 

This assumes, of course, that my physics are correct -- I know the math is...I just applied the simple standard kinetic formulas (F*v=Power, F=ma) and manipulated a little bit...

 

And after a bit more math (and comparing apples with apples), I came up with the following:

 

After drivetrain loss with the WRX, we get an acceleration of 3.8mph/s

 

That's only a 2.62lb weight on your head!

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Stock Crappy Exhaust (slightly modified to remove a useless cat)

 

http://i238.photobucket.com/albums/ff279/laplacexformofs/R1-01058-0031.jpg

 

 

New exhaust out of the car being TIG welded...

 

 

http://i238.photobucket.com/albums/ff279/laplacexformofs/R1-01075-011A.jpg

 

On the car:

 

http://i238.photobucket.com/albums/ff279/laplacexformofs/R1-01075-014A.jpg

 

 

Mike putting on the muffler section...

 

http://i238.photobucket.com/albums/ff279/laplacexformofs/R1-01075-028A.jpg

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How was it when you took out the stock resonator? (the big blimp in the Y pipe)

 

 

I have a sound clip of that too if you want to hear it -- my exhaust endeavors have been well-documented.

 

There was a LOT of rasp when I took off the resonator out of the stock exhaust with the Subaru mufflers. I would not recommend doing any kind of exhaust on the 2.5i without a resonator unless you don't mind a screaming exhaust :lol:.

 

BTW: I knew that the blimp was the resonator lol :)

 

Edit:

 

Here's the video I mentioned earlier (the pixelation is to mask my license plate number):

 

http://i238.photobucket.com/albums/ff279/laplacexformofs/th_Exhaustwores.jpg

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I can try to get a picture of the full exhaust when it is off of the car -- I think that would be a bit more helpful than the on-the-car pics.

 

Mike (Chambo) wanted me to mention, however, that if I did this that he is not responsible for the Aluminized glasspack and its subsequent MIG welds :cool:.

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Update: I aquired some APS Split-Pulse Equal Length Headers today and will be fitting them to my car soon...

 

 

I know that they are going to sound the same, but the equal length headers boast a wider tube diameter as well as the advantage of scavenging, which does not occur with UEL headers...

 

These are not cheap eBay headers either -- these normally sell for $1205 for the kit (I just happened to be at the right place at the right time and let's just say that I saved a LOT over $1205 :lol:)...

 

I will be posting the results soon...

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Maybe a 0-30... the 0-60 takes too long! :lol:

 

Actually, 0-60 is 7.14 seconds :D...I will post it...

 

 

Enjoy (I accidentally honked my horn about halfway through...You can probably take another two seconds off of the time -- I kinda scared myself ;)) It's pretty clear that the shift from first to second was a bit tentative due to the almost-self-soiling-causing horn blow...

 

http://i238.photobucket.com/albums/ff279/laplacexformofs/th_zerotosixty.jpg

 

Edit:

 

Well, I tried again and got 7.14 seconds -- I'm not going to post the video due to the crappy quality (the camera moved too much)

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Thanks -- I think it sounds better inside as well.

 

Unfortunately, I already have two resonators on the exaust...the rasp in the first video was a consequence of shooting the video when the car was still cold (the stainless in the exaust was expanding and was probably rattling due to the hot gas inside a cold tube)...I will get another outside-the-car one with the car at full temperature...

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  • 3 weeks later...

I FINALLY got the APS headers on there.

 

Just for an FYI -- STi headers do bolt directly up to the heads on our 2.5i's and have an outlet in almost the same location as our headers do.

 

 

I took some APS Split-Pulse Equal-Length STi headers with its own flanged up-pipe and cut off the y-pipe section from the up-pipe and directly mated it up with my existing mandrel-bent 3".

 

This did take about 4-5 hours and involved a lot of welding -- it is not an easy job; expect to pay around $300-$600 depending on where it is done...

 

The only downside to doing STi headers is that you need two O2 sensor bungs welded on the header and some tuning to get rid of the rear sensor codes that will appear.

 

The results are awesome!

 

The car definitely picked up quite a bit on the butt-dyno above 3k RPM and sounds (oddly) more Subish.

 

I will be posting a video soon...

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I like it, it sounds nice up top:)

 

Got any pics of the mod ?

 

 

Thanks! I like the sound better than that of the stock header.

 

The exhaust actually got a little bit quieter after putting the headers on...I know -- weird.

 

WRT pictures:

 

Nope, but I can get some. :cool:

 

Unfortunately, MAC Autosport didn't do the headers and subsequently, there was a less-than-perfect end result...

 

I will take the picture, though!

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I was extremely lucky and got on the dyno today!

 

The headers got me a consistent 5.38ft-lbs of torque and 2.79hp down low and about 2.32ft-lbs of torque and 2.06hp up top...

 

I'm consistently putting down ~150hp/146ft-lb plus or minus two -- I had three runs today at 149hp/146 ft-lb.

 

The comparison numbers were both on the second run after an ECU reset -- my max numbers were higher, but were on like the fourth run after resetting my ECU...

 

We are trying to work out a kink in the tune -- the car seems to want to close the throttle after 6400 RPM...

 

We are working on it and think that I have another ~5hp/ft-lbs hiding above 6400.

 

I will post dyno graphs as soon as we finish tweaking the tune!

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