I finally found one in a local salvage yard and had it put on. Back to back dyno showed that power band and numbers did not change at all. Max hp with stock was 253, 249 with the HR pipe. Stock torque was 218, HR came in at 217. HR of course went in second, no ECU reset. Driving home I noticed all the throttle response and noise making changes everyone else has experienced, so it's not psychological. After resetting the ECU, I took my car up to Great Smoky Mountains National Park and ended by slaying the Dragon (highway 129) and arrived home yesterday. I took it back to the dyno today and ended up with 248 hp 215 tq max on the best of 3 run. The sound and driving changes are noticible but not dramatic to me, so I have decided to simply keep it on the car. I also took the chance to cut open a coupe muffler and a 2005 model sedan muffler to answer my own question (and hopefully someone else was wondering the same thing). The sedan muffler on my model year is straight through. A valve inside near the passenger side gives it the variable capacity feature. The coupe's muffler is not straight through, and has chambers. I also have to take this chance to give the guys at UpRev a thank you. I drove my car hard through the mountains using the economy tune and ended up at 26 mpg, 31 mpg on the way back to flat Texas highways. I think I'll keep my car in this map for a while.

 

Nice work, I know a lot of people were wondering.

 

pics of the coupe muffler chopped up?

 

so the hr y pipe actually lost power...

 

x2:jamin:

 

I wouldn't say it definitely lost power. It could be due to dyno variances and such. On one run my original y-pipe put out lower hp and tq compared to the HR pipe so it's probably about the same. My conclusion is more you won't gain much power if any but you'll probably like the new feel of the car enough to keep it on there. Plus it does sound good, like a Porsche idling. As for pics of the coupe muffler I'll see if I can borrow a camera. I don't have one believe it or not, which is why I end up scanning everything to post it here.

 

Can you post the dyno plot with the before / after curves overlayed on each other. Although the peak hp/torque numbers are interesting and I don't see why it would lose power, it's not all about peak numbers. I would like to see how the HR pipe performed thoughout the hp/torque curves vs stock

 

+1^ for dyno plot

 

+1 ^ what he said

 

Any updates?

 

interesting results. What year G do you have, any other mods? If you are dynoing 253WHP stock I assume you have the 6MT rev-up engine, which from what I understand has a different y-pipe than the DE engine? I could be wrong.

+1 for pics on the inside of the mufflers...wish Nissan put the coupe's harmonic chambers in the sedan muffler!!

 

So the dynos were done on seperate days? If so, what was the date of the "stock" runs? It looks to me like the HR y-pipe is a wash like I thought. It's simply a sound and throttle response mod. I never expected it to really gain any power. I'm still considering the MD y-pipe. Please post the dyno plots if you can.

Nice job on cutting open the OEM mufflers too. I knew the sedan muffler was a straight-thru variable design and the coupe/z a chambered "cross-flow" style muffler.

 

So basically the HR y pipe provides a slightly deeper sound with slightly better throttle response.
Am I right on this?
Just not sure if I should bother to install the hr ypipe I have.

I need some convincing.

 

Yes. Install it and see how you like it. It's easy to take on and off.

 

dyno plot would be awesome!!!