BLT4SPD

I recently acquired these muffler by-passes just to see what the sound/performance ratio is like without mufflers. I went looking for some Fabspeed units, but no one is selling, so I just assumed that everyone that has them, loves them....right?

Anyway, picked these up not know anything about them and I was curious if anyone had seen anything like them before. They have no markings of any kind on them, but they appear to ber VERY high quality. Welds look beautiful and the tubing appears to be very heavy walled stainless. I have yet to fit them, but if they fit like they look, all should be good.

DiegoR

How does exactly work a muffler by pass? I mean, there is any photo "before & after" to get a better idea? This isn't have to do anything with the exhaust heat exchangers right?

Basal Skull

Cool are those rufs? Don't see many with central tips like those

Basal Skull

And require bumper mods?

budge96

If I didn't know any better I'd think those are for NA ,just saying Bert

911PERVY

They arent centre exit on the bumper, the left had one is on the right and the right hand one is on the left!

Look almost home made but as you say, great quality and give the wide oval look when fitted

bbs993tt

A muffler bypass does exactly that - it bypasses the muffler by going straight from the cats to the tailpipe. Mufflers, and their 40lbs, are removed from the car.

Before flow: cats to mufflers to tailpipe
After flow: cats to tailpipe

Nothing to do with the heat exchangers.

Ridin Dirty

At first glance they look like maybe for an n/a, maybe a coveted Ruf but I think it's the orientation in the pic. I think they would fit a TT the loops are simply bigger than that of the fabs. Wonder why? Not necessary so it must be for a resonance potential benefit.

These are interesting, must be custom. These will be loud. But the bypasses do sound good. Never run these cat-less u will wake the dead. I believe no real hp gain but significant weight loss.

As long as they don't drone and sound good at idol they will actually get more quiet at WOT when the turbos spool -they will act as natural muffler.

DiegoR

Thanks. Now is totally clear for me. Do you think would exist any benefit (power gain) if is installed a by pass muffler in a 993tt that is equipped with the stock exhaust except it doesn't have CAT inside the bottles and no 02 sensors (150 option from factory = no CAT /02 sensors) besides the increment in noise?

Quadcammer

nah. they are for sound and weight. my sport cats didn't add any power either.

Basal Skull

ahh! I see it now, but don't quite see how they would fit, the open end after the cats are medial to the tip exit opening on the bumper, but these look like the inlet is lateral to the tips? if that makes sense.

BLT4SPD

Thanks for all the feedback so far! Honestly, I know so little about them, that it's impossible for me to say if they are going to fit or not. It was an eBay win and a complete roll of the dice. Seller had a one sentence description, answered zero questions before the auction and has answered zero questions I have asked since winning. Price was right and if they indeed fit a N/A, I'll just sell to some else and pass the good deal along.

I didn't have a chance to fit them this weekend but I'll try for this weekend and see if I can "wake the dead"!

Ridin Dirty

@ Diego, Diego if u truely have nothing in those cat cans then your options are nil. The great fisters as well as fabs will be too loud. And muffler by-passes with no cats are essentially straight pipes. Our cars are disproportionately loud at idol and low rpm. Straight open pipes on our cars belong on the track only (my humble opinion).
I'll quantify it: With open pipes sitting in the car talking to someone u will have to speak up, standing behind it at idol u will nearly have to yell.
Your beautiful from factory s look alike probably sounds awesome now with stock cans and no cats. But it leaves u little options. Again even fisters in my opinion the best mufflers u can buy will not work "well" without cats. I think they will be a bit too loud; u can email Darin Fister he may warn u of that too. There are other off the rack mufflers out there like Dansk (best quality), and Car Graphic. But they will sound the same as the stock mufflers u already have I guarantee it. The stock mufflers r a but restrictive but they are quality. If u go with bypasses, have no cats, and have close neighbors they will scowl at u-ha!

Felix

Standard fabspeed muffler bypasses are here - https://www.fabspeed.com/993TT_19.html.

Not sure how what you have could possible fit a 993tt.

Looks much more like https://www.fabspeed.com/993_21.html for an NA 993.

bbs993tt

No benefit except for losing about 40lbs out of the back end.