Just curious if anyone is running an open downpipe on their turbo setup? Also are there any benefits or negative effect a I doing this? Noise isn't an issue, I like being loud and obnoxious when I drive her only a few times a month.

 

I think Joey is, SN Joeyballs. Probably help spooltime some and free up some hp. Besides noise, you'll smell fumes more, especially at a stop.

 

I ran my previous hatch for 3-4 seasons open 3" DP


IF sound isn't an issue, it can't do anything but help you. Turbo cars beg for it!

 

Just a word to the wise, it is super Fawking loud if it dumps under your car due to echo. It is much more reasonable if if exits somewhere not directly under the car. Like behind your wheel or under a door ect ect

 

I had a cutout on my Si back in the day, essentially an open downpipe when I wanted it. On the dyno one tuning session I did a back/back comparison, I gained 5 ft lbs of tq from it being open.

This was on a b16a2, making 450whp. Not sure spool was in issue, it was all 3", no cat, flow through muffler. I'm guessing that if you see a spool increase, you have a restriction in your exhaust downstream.

Wasn't worth the hassle/noise/attention imo.

 

I have a 2.5" open DP. I am sure it did help with some extra HP...but it is pretty loud especially going WOT.

 

I have a direct pipe in my Lotus 7 s2000, when I cruise in town...I put it in 3rd gear.....less noisy. Cops magnet

 

Zero negatives!

 

If and I mean IF its too loud with just a downpipe, one of these will take the edge off of the loudness of the exhaust. It won't make it quiet by no means and it won't change tone or loudness over time because theres nothing to burn out that will let the exhaust change its tone. Its a race muffler so little to no back pressure. Moroso Spiral Flow Racing Mufflers in 3" or 3 1/2"

http://www.moroso.com/catalog/catego...?catcode=35054

ROD

 

I run full 3" open exhaust out the fender, and dump out the hood, its a bit noisy, on my last setup with full exhaust no cat the car made 535. changed to open 3" and changed nothing else it made 591.