JBAKER1121'S FX50 EXHAUST thread

Dam you are getting old!

What was the total bill labor/parts?

I got a big discount, since it was a friend of a friend that ran the shop and did all the work, we helped work on it, etc. I'm not sure if it would cost the same somewhere else for the same job. Let's just say for the work involved and the mufflers itself I paid less than a new quality setup made for the FX50. :)

Also: I complained to the vendor on eBay and they refunded me 20% of the price of the mufflers.
 
So after the dyno tune and seeing the (little) amount of power that was added (without tuning ignition timing at all btw…5hp, 9tq) I've decided to get either resonated test pipes or high flow catalytic converters, and will most likely add an X pipe to the exhaust (RTP and HFC will raise the volume, and may add rasp - X pipe will take car of rasp)

TP/RTP/HFC from the 3.7 models should fit fine (besides the motor dyne ART pipes since the resonator on those will not fit on AWD models)

I'm doing so for the power gains, and to get a little more sound because although I like how it sounds now, it is still a bit "too" quiet after I thought it would have broken in more.

I've been trying to find a set of Used Resonated Test Pipes on the g/x forums but have also contacted Gordon for Invidia HFC/TP pricing.

Looking at a set of GTM resonated test pipes, found a barely used set for a decent price. I wish Invidia made RTP because I would rather buy new and from a fellow member but we shall see.

Stay tuned.

edit: Purchased a set of used GTM RTP with ~100 miles on them, essentially brand new. 30% MSRP. (not too bad)

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They come with the needed extended Jpipe for o2 sensors, bungs for wideband, and are 'quieter' than standard test pipes due to resonating chambers.

Should be to my house before I am, but they'll be on in about two weeks. If they're too loud, I'll just sell them to thenext guy in like from the thread I bought them on, and go HFC.
 

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So, The test pipe project is complete, and… it was a lot more complicated than I thought.

To start, the flange where the cats meet the header are 2-bolt on the FX50, not 3bolt like the RTP themselves. So I had to buy new flanges (vibrant)

Then, it turns out that the test pipes for the z/g, which may bolt straight up to an FX35, do not bolt in to an FX50… so we had to cut and weld.

So a "quick" swap turned into an ~8 hour fitment job including cutting, welding, a broken stud that had to be drilled out and rewelded, and heat paint treatment.
For this reason, It turned out to be a lot more work than I expected, leading it to cost a lot more than I expected.

However, I am happy with the result (and I haven't even gotten it tuned with these in….hopefully I see similar gains of 12-16hp that g/z guys got)

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^ As you can see, we had to cut out the resonator, cut the piping, and were lucky the distance needed to the flange was exactly that of the resonator itself, without needed to cut out the extra bungs for wide band

We were also able to reuse the factory brackets that bolt in to where the catalytic converters meet the headers (really where the primary cats meet the secondary cats, I replaced the secondary cats with these RTP)

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^driver's side done
V passenger side done
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Compare the shape and size of the pipes to the pic when I bought them…..

After we made sure they were a perfect fit, we blasted them with heat-resistant paint..black for stealth.

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(yeah it's salty under there)


as for sound, it did not really change drastically due to the resonator on the test pipes. The exhaust note from the back is a bit throatier now, but no drone nor much bass was added to the exhaust note. When I'm at WOT, however, the engine really opens up compared to how it sounded before. It seems to be enjoying the missing cats….

I'll try and have a vid together soon. I'm in the process of packing to drive back to buffalo for the semester so things are a bit hectic

The BUTT DYNO is telling me that it pulls a bit harder (or revs more freely) hopefully after a tune the actual dyno shows me i've improved on my power.

To be honest, It will be cool to make the extra 15hp and to have pioneered test pipes on the FX50 (as far as I know)
but for what I paid to have these then alter them, it was bit much out of my pocket.

For what I paid to have these RTP tailored to fit, and to have the HKS replica muffler tailored to fit, I could have simply bought a Borla catback from the start and had enough change left over to tune it… but again this is the price of going custom (pun intended) plus I wouldn't have test pipes with the borla
 

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Looking good. True with the Borla catback you would still have the cats, but by going the route you took, I think you will be more happier with performance gains overall. Especially with test pipes.
 
Looking good. True with the Borla catback you would still have the cats, but by going the route you took, I think you will be more happier with performance gains overall. Especially with test pipes.

I agree. Im excited to see what a dyno tune will bring
 
here's a little teaser of how the new setup is sounding... full video with accel, etc (and hopefully less "noise" from wind or whatever that is)

Reminder, this is with factory headers, factory primary cats, secondary cats are now Resonated Test Pipes, factory Ypipe, factory Midpipe + resonators, HKS Hi-Power replica dual resonated mufflers...

The video doesn't really catch how much more "V8 throatiness/choppyness" was added without adding any bass/drone..but it sounds.. more german?
I'm not sure how to explain it. Hear for yourself:

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(yes it sounds similar to my muffler delete but trust me it is quieter, less bass, and minimal drone added from the RTP)
 

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Sounds pretty good. Not a lot of raspy tone and not muscle-car-ish either. Sounds well tuned to me. Nice work!
 
Great job, I am in the same process as well (altough looking for HFCs...) and you are definitely an inspiration! :)
 
Sounds pretty good. Not a lot of raspy tone and not muscle-car-ish either. Sounds well tuned to me. Nice work!

Thanks! That's what I was going for. This is why I've changed it around a few times.. I'm trying to get that perfect tone, but also a good amount of power.

Dam that sounds real sick bro

Thanks man

Great job, I am in the same process as well (altough looking for HFCs...) and you are definitely an inspiration! :)

Thanks. You should just go the same route... buy ones for the vq37 and cut/weld to fit. It wasn't too tough a job although it was about 8hrs of work. Just make sure you get good quality CATs and use good stainless steel, and either defoulers for the sensors or a J-pipe like mine have to avoid a CEL. Good luck! If You'd like I can forward you links to some I found, or I can draw up approx where we cut for it to fit.
 
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OK, so I've read this entire thread in great detail and have come to a logical conclusion. No offence, but i'm going to take all of your swapping and changing around as my own 3rd party trial and error and simply remove the stock exhaust and install two X-Force Varex Mufflers with some nice matte black powder coated tips. The cats, resonators, mid section etc will all be left alone; no point touching it and this way my new car warranty is completely safe!

I've heard these mufflers on Holden HSV's which are Aussie V8 muscle cars, and they sound mean! So I can have quiet and loud. Closed should be quieter than stock and open should be the same as having straight pipes. I'm also going to have a physical hard wired control knob fitted in the car so that I don't have to use the cheesy hand held remote control. Not sure where i'll put it but it'll look like it was put there by the factory.

I'll finish it off with some matte black double walled tips, maybe Remus if they make one that's a similar size to the stock tips.


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What do you think?
 

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I say go for it. You won't change your power at all - it will just be for sound only since you're just replacing the mufflers with different ones. This will pretty much be the same as doing a muffler delete when you have those at 100% open, and when you have them adjusted to "muffle" it will just sound a bit different because it's just a different muffler.

if you want to change performance, that's when you need to address the cats and the overall flow of the exhaust system. It depends on your overall goals.

let's keep that topic in your exhaust thread though so mine doesn't get too cluttered ;)
 
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I'm not really that concerned about performance, the best case scenario with all of the aforementioned changes would net me maybe 15HP; which would make virtually no real world benefit. More importantly, I'll have a system that can be either quieter than stock for when i'm on the highway or completely loud and aggressive for wen i want it to sound angry; and everything in-between. That is what will make the most significant real world difference for me. In any case, my FX is brand new so I shouldn't be playing around with the cats or the resonators anyway; can't have my warranty screwed with.
 
I'm not really that concerned about performance, the best case scenario with all of the aforementioned changes would net me maybe 15HP; which would make virtually no real world benefit. More importantly, I'll have a system that can be either quieter than stock for when i'm on the highway or completely loud and aggressive for wen i want it to sound angry; and everything in-between. That is what will make the most significant real world difference for me. In any case, my FX is brand new so I shouldn't be playing around with the cats or the resonators anyway; can't have my warranty screwed with.

You're likely to see a zero hp increase simply from changing the mufflers. Even with a tune, you'll maybe get 5hp. (Note, I got 5hp and 9tq after changing to the HKS style mufflers, and with K&N intakes - everything else factory- and this was without any ignition timing work) And we can agree that is negligible.

Just changing the mufflers and not getting a tune is not going to get you anything, (and won't void anything) but let's keep your exhaust in your exhaust thread :)

As for my car,
With the test pipes in, after a proper tune with ignition timing adjustment, I should see another ~10-20hp if I don't make any other changes to the exhaust. And that's not considering that I may go 1 step colder plugs and run on a rich tune, which would be more hp. Unfortunately, I can;t get a retune now because UpRev hasn't picked up support for the FX50 since they dropped it in December...so I must wait.
 
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