Originally Posted by laid67

I say 2.5 not because I don't want to sacrifice sound, but because I don't want to add extra weight, that and every well written tech article I've seen recommends a 2.5 in exhaust for the power levels I will be making.

The fact that of all the exhaust manufacturers for our cars, ATLP, Comptech, tanabe and magniflow and whoever else. I've never seen a 3 inch exhaust, and some of them are even smaller than 2.5 inch, is a pretty good indication that 3 inch is unnecessary at best, and could possibly result in a loss of low end torque at worse.

Also all bends will be mandril bent. all 2 of them, haha!

Originally Posted by Inaccurate

UPDATE

I GOT ANOTHER 98 POUNDS OFF OF THE CAR !!!!!
..........(this includes dynamic loss)

:gheywave::gheywave:




Weight Reduction Since Last Update
-----------------------------------------------
23.7 Lbs - Single 3" Exhaust System
12.0 Lbs - Shaved tires (2/32" thread depth)
10.3 Lbs - BC Racing Coilovers
1.9 Lbs - Rear diffuser plastic panel
1.8 Lbs - EGR Delete
0.6 Lbs - Plastic trim around tail pipes
--------------------------------------------
50.3 Lbs NET TOTAL REMOVED













CUSTOM 3" SINGLE EXHAUST






























The oem exhaust system (minus oem third cat and mid muffler) weighs 43.60 Lbs.

My custom 3" single exhaust system weighs 19.90 Lbs.

The weight reduction from the custom 3" single exhaust is 23.7 Lbs. Before attempting this mod, I had estimated that I could shed 25 pounds. So, I reached my goal for the most part.

The reason that I picked the exhaust as my next diet mod was because it hopefully offered a slight power increase along with the weight reduction. Plus with my previous exhaust, I was getting tired of the intense rasp at 3500-4500 rpm.

My new exhaust sounds identical to Sonnick's Open-Y videos (click here). Although, I don't have the cool popping and the mini backfires..... wish mine did. So if you wish to hear mine, please watch Sonnick's videos (except I have no cool popping). The reason that mine sounds identical is because it is the same engine and the same exhaust.... 3" tube with just one Magnaflow muffler. The difference is that his is the 30" version and mine is the 18" version of the same identical muffler. But this difference is probably balanced out by him having no tail pipe and I do.

I designed and built this system myself. I did not drive to a muffler shop, have them throw my car on a lift, and have them crush some bends and weld-up some spaghetti using their cheap and heavy pipes. No muffler shops for me.... I did all the work myself except for the actual welding (MIG/TIG). I cut the tubing myself and measured the angles (or created a makeshift jig) to position the pieces together for the welder. When I arrived at the welder shop, I assembled the pieces (and held them myself) while he welded it. It took three trips (one per day) to finish the system.

I had spent many, many days googling the 3" single exhaust. I was looking for people that had done 3" single exhaust in general and for the J engine in particular. I wish to thank Sonnick for sharing his experiences with his 3" single exhaust. Sonnick's post about his "open Y" experiment was very helpful to me because it was, in essence, what I had in mind for my new exhaust. Sonnick's videos were very helpful because the vids allowed me to hear how my new system would sound before I committed to it. And, obviously, I liked the sound of his open-y exhaust.

To me, my exhaust has no drone and no rasp. But, I am not sensitive to rasp. While maintaining a constant MPH (below 80 mph), it is not really any louder than my oem catback. But obviously the volume increases a lot as the throttle is opened. But at no time does my exhaust have drone or rasp (at least to me).

My exhaust was not cheap. It was actually very expensive.... so much so that I don't want to say. The thin walled 3" tubing was very, very expensive. It was my insisting on using 20 GA tubing that caused the new exhaust system to be so expensive. If I was willing to compromise and use 18 GA tubing, the cost would had been one half of the 20 GA system. But, if I had used the 18 GA tubing, the new exhaust system would had weighed 5 pounds more. The thin walled mandrel bends were super expensive too. The thin tubing is difficult to weld, requiring the welder to go slow. Thus, the welder got $300 for his services too. But, I am extremely happy with how it turned out. The final weight and exhaust sound was on target with my hopes. I would do it again if I had too.













As a side note, I originally had intended to use the larger (and it is LARGE...see pics above) 30" Magnaflow muffler #12641 (click here). I had purchased the 30" already. But, at the last minute, I decided to use the 18" size. The 30" is just too massive and heavy. I decided that I would rather risk being too loud than risk being too heavy.








PART NUMBERS (items pictured above)
Magnaflow Muffler PN #12649 (quantity = 1) (click here)
Burns Stainless Steel Mandrel Bend 90 Degrees (quantity = 2) (click here)
Burns Stainless Steel 3" Tubing (quantity = 10 ft.) (click here)
Burns Stainless Steel Transition (quantity = 1) (click here)




Below are some related links -

1) single exhaust (click here)
2) Diary of an EXHAUST Addict (click here)
3) DUAL Exhaust VS SINGLE Exhaust (click here)
4) Picked up 15 hp...find out how (click here)
5) thinking about single exhaust (click here)
6) 70mm (2.75") piping on J series? (click here)
7) 3 inch piping (click here)
8) 3 INCHES!?!?! (That's what she said) (click here)
9) custom 3" magnaflow exhaust installed (click here)
10) single vs. dual exhaust (click here)
11) Single-Exit HKS Exhaust Writeup (click here)
12) Video Clips! 6MT NA (click here)


For the links below, copy and paste these links into your browser. Remove the red X before submitting. Acurazine blocks these links. So, this is why I must disguise them with a red X.

1) www.v6Xperformance.net/forums/7g-performance-discussion/210172-3-inch-2-5-inch.html

2) www.v6Xperformance.net/forums/7th-generation-honda-accord-2003-2007/210729-magnaflow-exhaust-gurus-opinions-needed.html

3) www.v6Xperformance.net/forums/7g-performance-discussion/209692-best-single-exhaust-setup.html

4) www.v6Xperformance.net/forums/7g-performance-discussion/196600-my-dyno-vid-7th-gen-v6-6-speed-manual-245whp-211wtq-exhaust-no-cats.html

5) www.v6Xperformance.net/forums/7g-performance-discussion/201030-opinions-custom-exhaust-idea.html

6) www.v6Xperformance.net/forums/6g-performance-discussion/209376-straight-pipes.html

7) www.v6Xperformance.net/forums/7g-performance-discussion/209232-v6-accord-tsudo-76mm-single-exhaust.html

Originally Posted by fsttyms1

I ran twin 2.25 all the way back and could notice a huge difference in power, especially after 4k

Originally Posted by laid67

Well. I forgot to post but I went through with the exhaust build. 3 inch from the j pipe back with no cats. I ran strait pipe for a month or so. It was badass. But eventually got old. I ordered a magniflow muffler. The one innacurate was originally going to use. It ended up hanging too low (I have a really low car on 205/55/16's so ground clearance was really an issue. And the muffler only got rid of the raspiness that I kinda like. And it kept the drone I hate. So I'm back to stock for now. Going to build a 2.5" so I can keep ground clearance, and I'm going to try another brand's muffler that focuses more on sound cancelation for low frequencies, as opposed to magniflow's sound absorption.

Originally Posted by HairyMonkey019

ground clearance???

You're wasting time and money, you do realize you can lift the whole piping.... as in tuck it in more to a point where your frame hits before piping. It's what many people here in So Cal do and what I should have done.