I just finished putting in my helix uppipe/ catless downpipe and helix catback exhaust, I worked on it about 2 hours tuesday, 3 on wednesday and 9 hours on thursday night, from 5pm - 3am (taking and hour break) and then got up at 5:30 for work on friday. anyway I would love to pimp slap the person who designed the egt sensor there, that thing kept it from coming out, well maybe if my engine mount bolt did not round off, so I could not jack up the motor. I had to loosen the bracket that is the reason for jacking up the motor and use a screwdriver to pry the uppipe out, but I got it and got everything back together ina bout 1 hour and half. I broke my dads torque wrench in the process (he does not know yet, he will when I take it back to his house DOH) so I just tightened up the bolts pretty tight, they were not hard to break loose since I only have 13,000 miles on my ride and it is 3 years old in november.

I took it down to Pittsburgh and picked up my wife and she thought I bought a blow off valve cause the uppipe how much you can hear it. is this helix combo really that loud or does it just seem loud inside the car?

Anyway I love the extra power, seems like it has more power in the lower rpms also.

I bought this from mpjperformance.com I think he is a vendor on this site, the whole kit for uppipe, downpipe and catback exhaust cost only 850 with free shipping, and I ordered a set of kartboy hangers (which was forgotten in th eorder) but I emailed them , they emailed me right back and they were in my mailbox the next morning, I would definately recommend them to anyone, if yo are buying an exhaust for around 500-600 spend a couple extra hundred and buy this kit you would not regret it.

 

I just recently installed a catless helix downpipe on my '05 STI. When I first installed it i heard a whistling sound which i now found out that it is the sound of the turbo spooling up. I thought from the sound that i had leaks in the pipe. I took it to Grouppe S and they said that it is a good idea to tighten down the pipe bolts after a week of running it. So i did that thinking the sound that i thought was a leak would go away. After tightening the bolts i got a better seal and could feel the difference in power but i still have that sound. I think because it is a catless downpipe more of the turbo sound can be heard. If anybody knows that this is normal please holla back! But overall i love the downpipe it definately gives me more noticable power. Thanks all.

 

I already retightened mine and still the whistling sound, I know it is the turbo because it is th esame sound I got after I removed the snorkel (silencer) only louder

 

yeah the sound is just over all loud, not just in-car. My bro got the helix catless up/dp, and i had him do a fly by on the freeway, and i could hear him coming up, and passing me. the sound kicks *** tho.

 

I agree Mike it does sound good! But I also notice when i step on it, the sound of the car accelerating is dramitaclly different from stock. More air flowing or turbo spooling or somethin'. Not really sure if the sound is normal or if i have a leak. Im going to Gruppe S again today to have them take another look. Keep you posted guys.