Topplayer

anyone other than sillyboy install the single yet?

Gernby

The STR pipe is at least partly to blame for the noise. If it's particularly annoying, then you might see if you could buy a non-STR expansion pipe (just the front piece), so you could swap back and forth. My guess is that you could run the non-STR pipe for 95% of the autocrosses you attend, and just swap in the STR version for the important events. They perform the same, so it's really just about avoiding a challenge.

I really hope that SCCA will open up the rule, so that the STR version can just go away...

sillyboybmxer

Is there an actual exterior visual difference between the two versions??

Urge

Yes STR does not have the 5" expansion with 4" perforated cone due to clearance issues.

URGE STR top
Original Gernby Middle
URGE Regular Bottom

[attachment=86554:STR vs Original vs URGE Gernpipes.jpg]

michaelnyden

WAs there ever db rating taken on these setups? I want to know if it's quieter than my t1r-em 70mm single and by how much.

Gernby

We talked about doing some sort of dB test, but we couldn't come up with an objective approach. There really isn't a standardized testing method that I'm aware of. The SCCA test method gives extremely inconsistent measurements, so it seems they haven't really come up with a good method either.

Topplayer

I have a meter and can do the test, just let me know the specs of the test I.E. how far away you want the microphone from the drive by

every track I've been too takes a different approach. from different angles, and different parts of the track( different rpm, and load)

s2kaok

Sorry if this has been answered to death but I just want to be absolutely sure the STR version performs identically to the non-STR version. Looking at the pictures, it looks to me like the STR version expands less than the regular version which, to my understanding of engine acoustics, could effect the intensity and timing of the sound wave coming back to the engine to shove more air into the cylinder. Gernby, could you please explain why the difference in dimensions between the two mid pipes would not adversely affect performance? Also, could you please tell me, and perhaps show me with plots, that the HP and Torque increase is the same across the entire rpm range for the STR and the regular midpipe? Again, sorry if this has been asked to death but I just want to understand and be certain that I wont be losing out on performance going with an STR super-legal midpipe.

Also is there a consensus on which header is best for this to bolt on to the back of? Was thinking of going with a PLM header (sorry URGE), so I am wondering whether header choice affects performance significantly.

Thanks.

afzan

Just curious why you went that route, any pictures of your completed setup?

a couple of people mentioned this, is there a hanger missing on the single?

sillyboybmxer

I wouldnt say its "missing" but URGE supplied us with a differential mount and extra hanger "in case".
I was reading through Gernbys original thread and he mentioned he choose not use the center hanger because it would interfere with adjustment and it just wasnt needed because the midpipe is so light compared to the oem cat/center setion, it would also pull the pipe closer to tunnel which is the opposite of what we want at that area.

I thought the single system was just fine and sturdy without extra hangers, until I got a vibration. Putting the differential mount on and temporarily mounting something (wire/metal clamp) around the exhaust to pull it away from where it randomly touched was enough to fix the problem.
If you're like me and dont have any idea who to take it to get welded, something like this might be a more permanent solution although i can see some people not needing anything depending on their hangers used.
http://www.summitracing.com/nv/parts...h11s/overview/

Edit: i just clicked the link and it didnt go anywhere so if for some reason that link doesnt work, search "pypes exhaust hanger" . Its basically a bolt on hanger.