DiegoR

Mike I got a question. Did you feel a increase in response/performance? Are you able to tell if the boost has increased a bit? Usually the stock exhaust system as we know it's quite restrictive in every factory car (or almost every car) and when we remove the CAT or just free up the exhaust in a turbocharged engine, usually the boost increase a bit. Just curious....and sounds very nice, I bet in person must be awesome!!

Mike J

I think the car is more responsive - I also recently put in a RS clutch as well, so that also helps the engine spool faster. A lot of the feeling can be via my ears, you know it plays with your mind when you hear a nicer exhaust note and then the car feels quicker!

I did not take any measurements, and perhaps I should have even done some rough measurements like time the 30mph to 90mph to see if that changed. Standing starts are hard because it depends on how much you want to abuse the driveline and that nice twisting transmission main shaft.

So yes I would say if feels like it breathes better - you figure it would. I did run the system with Fabspeed bypasses, it was way to LOUD but it revved really well, so I think I am still restricting the system with the 3" to 2.5" reduction and the smaller pipes through the muffler. that would be the next logical step.

Cheers,

Mike

Mike J

I get exactly what you mean, and you are bang on - it has that very throaty return to idle and you can at times catch the turbo noise of them winding down. I like that quite a bit, and am very happy that, after screwing around for months, finally got a sound I like. Its more like a Cummins diesel .. This stuff is definitely an artform.

The spacers in the rear are In total 42mm ( a 38 and a 7 RUF Spacer), that makes up 1.65 inches. I can go out and measure it if you want.

Cheers,

Mike

Ridin Dirty

You mean like this?? sound familiar?

Mike J

Close - I think you get more of the turbo winding down sound than I get. Nice!

tacker

Nice work, the eexhaust sounds great. I need to rework mine to reduce the drone at low RPM

ronnie993tt

Beautiful looking and sounds great Mike. It'd be really interesting to dyno it against a stock system. Jake R. says he dyno's everything and has not found an after market exhaust that yields more power - and most result in significant losses, soooo, if your unit results in stock or better power, you might have struck gold!

OverBoosted28

^^^^ this is what I spoken with Mike about, in the past couple of years. Was looking at trying to make a "cross-over" that would actually enhance the car other than just esthetics (idle). Mike has done an incredible job and like the (what appears to be) huge amount of room in the X-pipe. If they let each bank pulse past/mix efficiently, then yes he's done exactly what I'd love to have on my car. I'm gonna ask first dibs on his original work, if he decides to make another. :-)

P.S. Not just test against a stock, but any currently available systems

Ridin Dirty

Another thing I don't think we addressed is that this system does not drone (I think Mike would agree). It's absolutely loud as "_uck" on the outside but zero resonance in the cabin.
IMHO that's the RSR muffler doing that though; old school muffler style...but it works.

....and the response is night and day. "Insta-spool".

Mike J

Yah, the mufflers make a huge difference. I tried this system with Fabspeed bypasses, Fister's, Stock and RSR's (or at least I think they are). For me, and this is my personal opinion of course, so not everyone might agree, on this setup:

- Bypasses are way too loud - it's like a straight exhaust.
- Fister's - not a bad tone, but again too loud, it's almost like a straight exhaust. I suspect internally its pretty well straight pipes, it sounds that way.
- Stock mufflers - the tone is not too bad but too quiet
- RSR's (or I think they are) - definitely impact the tone, loud but not too loud

If I build some 3" mufflers as the next phase, I will try to model them after the RSR' sound, or put in a switchable bypass on the stock mufflers so I can vary the sound.

Cheers,

Mike

dbf73

To make this more complex, there is more than one version RSR turbo muffler and IIRC, no way to tell them apart without cutting them open.

The cats, even sport cats, will quiet things some so your post above will need revisiting when you add cats.

ps - much admiration for this project

Mike J

That assumes I ever put in the cats ... and I do get the muting impact. i have placed sport cats in stream as a bit of a test, and even 200cell HJS cats mute the flow. :-). I might cut one of the mufflers apart anyways just to see what was done, I have modified Turbo mufflers before so I know what they look like stock.

Cheers,

Mike

Ridin Dirty

Well I too installed cats with this system

(headers, cat bypass, x pipe, and RSR's) and it did mute the sound just a little bit. I removed them again because of only one reason...The performance decreased....so much so that I could not stand driving....decreased turbo spooling and perceived decreased power. This was all just in my personal experience. It was a noticeable difference with the cats back on.

And I shared this with Mike sometime ago but I guess it's OK to disclose what's in the RSR's (at least mine) I don't think Robin will mind that much as anyone could find this out by doing what I did. I placed a diagnostic scope camera in the RSR's. And discovered there is absolutely nothing in them. No pipes no matting nothing. Just a big void hollow space. I believe it is that hollow space that eliminates drone. I arrive at this conclusion because actually all of the modified OEMs (fister, rsr) or the OEM copies (dansk, billy boat) do not drone. The radical replacement types (fab super cups) do drone; although the fabs do sound good on the exterior. This is all in my first-hand experience/opinion