RV6 2012+ Civic Si Bellmouth Downpipe

spdandpwr

spdandpwr

Well-Known Member
839
148
NY / CT
Just saw this post on the Acura forums and wanted to share because its more after-market parts for our cars. The dyno shows the before and after with just a stock cat-back. The part also comes in cheaper than current competitive offerings and has a high-flow cat version.





Order link: http://rv6-p.com/civic-si.html

Includes a before and after video on a stock cat-back:

View: http://www.youtube.com/watch?feature=player_embedded&v=XwVUVd0NRh4
 
NthTier

NthTier

Well-Known Member
133
55
Chicagoland
Vehicle Model
Civic Si
Body Style
Sedan
Here goes on my impressions of the downpipe (I ran the cat-less for a couple weeks and now have the high-flow cat version).

Applies to both versions:
- The car is more responsive and it is even easier to chirp the tires into 2nd. :)
- I have seen 1-2mpg improvement.

Cat-less:
- At low revs there is little to no difference in exhaust note (I was surprised by this).
- At higher revs, there is a some rasp and it is louder, but only slightly. It sounds free flowing (I know not real helpful, but I don't know any better way to describe it).
- As with any cat-less setup it stinks (the exhaust gases).

Catted version:
- Across entire rpm range there is no rasp and is very close to stock in terms of sound.
- not stinky

We ran the tests on my car completely stock and I was shocked by the low dyno numbers. The person running the dyno indicated that it was the type of dyno in use that caused it to read low. Something about Dyno Dynamics brand of dynos being heart-breakers.

I am personally going to stick with the version with the cat as the cat-less didn't pass the wife test with the odor.
 
NthTier

NthTier

Well-Known Member
133
55
Chicagoland
Vehicle Model
Civic Si
Body Style
Sedan
Cat-less and catted versions. Dyno Dynamics dynos tend to read low, but the deltas would apply to any dyno.

rv6-civicsi-bellmouth-800.jpgcivicHPTQfinal.jpg
 
spdandpwr

spdandpwr

Well-Known Member
839
148
NY / CT
I'm getting this. I'm not getting a 3" exhaust so I don't need a 3" downpipe. Plus it's cheaper and the welds and overall build quality look fabulous. 376 shipped to my door is such a great price too! Oh, and it comes with a defouler and a gasket.
 
spdandpwr

spdandpwr

Well-Known Member
839
148
NY / CT
Michael Kelley said:
Looks ok but im more pumped about the 3" UR Catless downpipe =)
Click to expand...

Remember, a 3" exhaust may invariably affect your down-low torque. Sure, you'll make more peak numbers, but the slower exhaust velocity from the larger tubing will, like I said, result in lower gains in the low and mid RPM ranges where you do most of your daily driving.
 
Michael Kelley

Michael Kelley

Well-Known Member
105
46
Hickam AFB, HI
Vehicle Model
Honda Civic Si
Body Style
Sedan
spdandpwr said:
Remember, a 3" exhaust may invariably affect your down-low torque. Sure, you'll make more peak numbers, but the slower exhaust velocity from the larger tubing will, like I said, result in lower gains in the low and mid RPM ranges where you do most of your daily driving.
Click to expand...

Odd...UR got gains over the entire RPM range....I think I'll be fine.... ;)
 
spdandpwr

spdandpwr

Well-Known Member
839
148
NY / CT
Actually, no...



The UR loses quite a bit of torque to the stock car below 2700 rpm...that's something you CAN feel in daily driving (I know I shift before 2700 rpm). Also, UR made the 11 lbft of torque gain with the addition of a 3" exhaust. These guys made it with the stock exhaust. Imagine how much more torque you'd get with the addition of an exhaust?
 
Michael Kelley

Michael Kelley

Well-Known Member
105
46
Hickam AFB, HI
Vehicle Model
Honda Civic Si
Body Style
Sedan
Either way, I'm in prep for the big picture. My plan is to supercharge the K24 next summer/fall. So, for me, I'm more pumped for the 3" catless downpipe.
 
Michael Kelley

Michael Kelley

Well-Known Member
105
46
Hickam AFB, HI
Vehicle Model
Honda Civic Si
Body Style
Sedan
spdandpwr said:
Actually, no...



The UR loses quite a bit of torque to the stock car below 2700 rpm...that's something you CAN feel in daily driving (I know I shift before 2700 rpm). Also, UR made the 11 lbft of torque gain with the addition of a 3" exhaust. These guys made it with the stock exhaust. Imagine how much more torque you'd get with the addition of an exhaust?
Click to expand...


lol, ok, I'm not trying to argue with you. If you must have the last word, that's fine. Like I said...I'm prep'ing for MY build...
 
spdandpwr

spdandpwr

Well-Known Member
839
148
NY / CT
Sorry, if I came off mean or too hard...definitely wasn't trying to do that! I was trying to let you know that there's definitely a give and a take with respect to piecing the right components together. I respect your decision on your build -- there is definitely no wrong way to go. Good luck on your build!
 
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