Custom exhaust

[g0lds]

A good friend of mine designed and fabricated an exhaust system for me today.

Pictured below are the 5 setups he drew up. He said we could do any of the 5 setups either dual or single exit.


Option 2 would have utilized a resonator then a Y pipe off the res to the mufflers. Option 3 used a 1 inlet-2 outlet muffler back to two more mufflers

We both chose option 3. He used 3 sticks of 2.5" mild steel piping, two U bends, a Magnaflow 1 inlet-2 outlet muffler, two Vibrant mufflers, and two Silverline tips.

Stock junk removed


Front pipe section and magnaflow mocked up


A stick on each outlet to get past the diff


Welding


Vibrants mocked up


Silverlines mocked up and my buddy posing


Love the angle of the exhaust from the side


Nice under carriage shot of the assembly completely mocked up


The assembly mocked up and tack welded was then removed to complete the welds


Welding photos




We coated it with a satin grey VHT exhaust paint to help prevent rust. Overall I'm VERY pleased with both the sound and the appearance!

As far as sound: on a scale of 1-10 with a 1 being a bone stock Ford Focus and a 10 being a cammed C7 vette with 3 inch straight pipes I would rate this as a 4.5 on the aggressiveness scale. Stock BRZ exhaust would be a 2.

Idle: sounds exactly like a stock BRZ. Cruise: There was a very slight increase in noise - barely noticeable in the cabin with the window closed. WOT: obviously the most noticeable difference. Louder but not weed whacker sounding, very throaty and nice. When I come off the throttle there is a very nice deep pop sound that I absolutely love.

Performance wise: seems to have gained some mid-range power. Also seems that the horsepower doesn't taper off and the engine pulls nicely from 3.5k to the limiter.

Very pleased with the setup. Cannot wait to get a hold of an OFT to really reap the full benefit of the exhaust.

Video:

[austin_ellas]

Looks awesome man! Which magnaflow muffler did you use in the mid pipe? Can you post up a part number? I'm looking at building a similar setup but I'm concerned about space and ground clearance.

[g0lds]

Originally Posted by austin_ellas

Looks awesome man! Which magnaflow muffler did you use in the mid pipe? Can you post up a part number? I'm looking at building a similar setup but I'm concerned about space and ground clearance.

I've attached the parts list that we used. All parts sourced from Summit. My buddy had a two winged flange laying around that we used between the header and our assembly.

Note: we bought three U bends but only used 2. We bought two sticks but needed 3.

[Wayno]

So, you managed to:
- Create a big sail area under the rear bumper.
- Require everything after the overpipe to be removed to change diff or tailshaft.
- Remove the cat in the front pipe for no performance gain at all.
- Reduce ground clearance behind the rear wheels. I guess Detroit is enough of a ghost town now that you never need to reverse in to parking spots anywhere.

GG. Slow clap.

I guess you managed to do something on the cheap. Oh wait, the stock cat back comes with the car, so if not wasting money was a goal, then that can hardly be considered a win.

It's a bit late to be crapping on about OFT now, if you'd spent 5 minutes to read any of the 4 years worth of content you'd know that any gains on stock tune are a fluke. The car would pull equally hard to redline with a half decent tune on stock catback.

[RichardJ]

Originally Posted by Wayno

So, you managed to:
- Create a big sail area under the rear bumper.
- Require everything after the overpipe to be removed to change diff or tailshaft.
- Remove the cat in the front pipe for no performance gain at all.
- Reduce ground clearance behind the rear wheels. I guess Detroit is enough of a ghost town now that you never need to reverse in to parking spots anywhere.

GG. Slow clap.

I guess you managed to do something on the cheap. Oh wait, the stock cat back comes with the car, so if not wasting money was a goal, then that can hardly be considered a win.

It's a bit late to be crapping on about OFT now, if you'd spent 5 minutes to read any of the 4 years worth of content you'd know that any gains on stock tune are a fluke. The car would pull equally hard to redline with a half decent tune on stock catback.

Lmao Wayno you're a savage, at least acknowledge the difference in sound. It seems to have pleased the OP.

[humfrz]

Originally Posted by g0lds

A good friend of mine designed and fabricated an exhaust system for me today. ..............

Well, g0lds , it sure did look like you and your buddy had a good time designing, building and installing your car's exhaust system ......

Nice presentation!


humfrz

[86 South Africa]

Originally Posted by g0lds

A good friend of mine designed and fabricated an exhaust system for me today.

Pictured below are the 5 setups he drew up. He said we could do any of the 5 setups either dual or single exit.


Performance wise: seems to have gained some mid-range power. Also seems that the horsepower doesn't taper off and the engine pulls nicely from 3.5k to the limiter.

Very pleased with the setup. Cannot wait to get a hold of an OFT to really reap the full benefit of the exhaust.

Video:

I got something like your option 4 done... pleased with it in the end, just mine is pretty damn loud.

Just out of interest - did you do headers, cos that's where I got 90% of my gain (with tune of course)... the rest added a bit more, but not the bulk of it.

[g0lds]

Originally Posted by Wayno

So, you managed to:
- Create a big sail area under the rear bumper.
- Require everything after the overpipe to be removed to change diff or tailshaft.
- Remove the cat in the front pipe for no performance gain at all.
- Reduce ground clearance behind the rear wheels. I guess Detroit is enough of a ghost town now that you never need to reverse in to parking spots anywhere.

GG. Slow clap.

I guess you managed to do something on the cheap. Oh wait, the stock cat back comes with the car, so if not wasting money was a goal, then that can hardly be considered a win.

It's a bit late to be crapping on about OFT now, if you'd spent 5 minutes to read any of the 4 years worth of content you'd know that any gains on stock tune are a fluke. The car would pull equally hard to redline with a half decent tune on stock catback.

Hey no worries, not everyone is a fan, can't please everybody and that isn't the end goal, I'm happy with it which is what matters most! I welcome all feedback - positive or negative.

Wayno, you make valid points, but:

• I'm not concerned about dropping the entire assembly to service the driveline. Takes all of 2 minutes to remove it, plus I have access to my buddy's hoist whenever so it's not like I'll be wrestling with the assembly on jackstands or anything unless in the case of an emergency.

• Not concerned with the aerodynamics of the setup. It's a straight-thru exhaust with no spaghetti twists and turns and diameter changes like the stock setup had so I think any drag under the car will have limited, if any, affect on performance or mileage. I don't plan on taking it up to speeds where it will cause trouble

• As far as ground clearance, we may have to revisit and make some adjustments because I did scrape it a couple times and scraped big time pulling out of the driveway

• Not concerned with the rear converter, no emissions testing in our state. Eventually all cats will be removed.

As I said, I personally love the appearance of the setup and the exhaust note is absolutely perfect.

PS- Detroit is an awesome city and is making a comeback and Michigan is naturally beautiful!

[g0lds]

Originally Posted by 86 South Africa

I got something like your option 4 done... pleased with it in the end, just mine is pretty damn loud.

Just out of interest - did you do headers, cos that's where I got 90% of my gain (with tune of course)... the rest added a bit more, but not the bulk of it.

Nice! Yes I am most pleased with the exhaust note. As I said a 4.5 out of 10 on the aggressiveness scale which is exactly where I wanted it to be.

I did not touch the header, I am considering cutting the cats out of the header though once I get my OFT

[ichitaka05]

Interest read. Good job on the custom exhaust!

Just wondering, if front muffler (1 to 2 pipes one) isn't too low? Or it tucks in well?

[g0lds]

Originally Posted by ichitaka05

Interest read. Good job on the custom exhaust!

Just wondering, if front muffler (1 to 2 pipes one) isn't too low? Or it tucks in well?

I will measure the clearance tonight. The rear mufflers are the lowest point on the assembly, affording only 3 or so inches of clearance. Over the winter I may see if my friend can re-visit the rears to achieve more clearance.

[ichitaka05]

Originally Posted by g0lds

I will measure the clearance tonight. The rear mufflers are the lowest point on the assembly, affording only 3 or so inches of clearance. Over the winter I may see if my friend can re-visit the rears to achieve more clearance.

I was more worry bout front muffler scraping from going through bumps. iirc several Borla catback owners have this issue.

[wally]

I myself are thinking of doing my own custom exhaust, thanks this gave me a good view on how to do it

[nico_rsx]

It looks good, but mild steel...really?!?
In detroit it's going to be rusted through in 2 years top. The paint won't protect it, it will rust from the inside.