I am using MINES straight through test pipes. Experience some rasp at certain rpm not sure how to get rid of it .

 

It's just part of having test pipes man. Try art pipes if you hate the rasp enough. They're expensive though and I'm not even sure how well they minimize the rasp.

 

Manufacturers put resonators and mufflers to reduce the sound of an engine. Cat's reduce sound also. Get rid of any of those and the car will get louder.

 

So why do I keep hearing tp's are so hard to install on the hr?

What are the issues for you diy'ers.

 

Dan,

I just did it myself last weekend. They are a pain, but not so bad if you've done it before. Rob and some people make it seem like it's impossible. It's just a matter of figuring out how to get to each bolt. For example, for one of the screws on each cat pipe I had to use about 3 feet of extensions and go from the engine bay near the radiator, all the way to the bolt rofl.

Then on top of that, the main pain in the butt is that the bolts seize up. I broke the top bolt for EACH side that goes from the manifold to the cat. Also one of the studs stripped out of the passenger side cat. And on top of that, one of my O2 sensors was seized so now I have to replace it. GRRRR fawking Nissan!

So in other words, use a lot of PB Blaster, but still prepare to have some messed up bolts and studs once you're done. And make sure to get a 7/8" open ended wrench to get the O2 sensors out. Do not bother trying an "O2 Sensor Tool" because that's what I had and it just started to round off the O2 sensor bolt.. sigh.

 

Also, I'd like to add..

OMG THESE THINGS ARE SO LOUD.

I've had test pipes on a 240SX before.. this is nothing like that.

I was on the fence on these for a long time.. I always thought "why bother, I love how my car sounds now." Wow, I wish I had just stuck with that plan. Finally the power addition bug got the best of me, and I installed some Berk test pipes on my TurboXS cat-back exhaust.

I literally cannot believe how loud they are. It's like I don't even have exhaust on the car. Seriously, I've driven open Y-Pipe before (when I still had stock cats) and this is just as loud. On top of that they are very hissy and raspy, and just generally don't sound very good IMO. To each his own.

I don't even think that resonated test pipes would be quiet and refined enough for my tastes so I'm going to give HFC's a shot next.

Again, I must stress, these aren't loud like "oh that's a loud car" loud. These are like NASCAR loud.. like why "would anyone ever drive on the public streets with a car that loud" loud..

I have a feeling that how loud and raspy/hissy they are depends on your cat-back exhaust.. so I can only speak for sure for those with TurboXS exhaust.

 

Stillen HFCs - going on about 600 miles so far and no CELs - but i did replace my O2s and get the osiris tune.

mods: stillen intakes, stillen, headers, stillen HFCS, and nismo exhaust

initially there was a bit of rasp until about 300 - 400 miles in and it went away. i like that its a quiet ride when running warm and at cruising speeds - and gets a very clean aggressive sound when punchin it hard.

overall - very happy. dyno showed roughly +27whp (with all mods) but more importantly i love the way she purrs.

 

I have GTM test pipes, but do throw a cell and motordynes straight pipe.

I am needing to change my setup to pass emissions. Is there a way to mod the GTM test pipes to not throw a cell and buy motordynes HFC?

Can someone point me in the right direction?

Thank you,

 

Nismo catback exhaust with Berk HFCs. Not the best video

http://www.youtube.com/watch?v=eB_4KnjlY4E

 

http://vibrantperformance.com/catalo...sort=2a&page=2

 

Just bought and installed my GTM resonated test pipes on Saturday. The install went pretty smooth as I have access to a lift and soaked everything in PB Blaster. They sound awesome with my HKS true dual. Put 92.6 miles on them before the SES light was thrown. So I guess I won't be waiting long to get my tune done.

 

Those are test pipes??? They look like HFC's. BTW - are your power numbers at the wheels or at the crank. Just curious.

 

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The test pipes are resonated. My power numbers are at the wheels but on a dynapack so they are a bit high. I'm running TPs, motordyne Y-pipe, Motordyne 3pm single, Nismo R-tune intakes, and Uprev tuned. May be going back to stock intakes with K&N's and HPS silicone connectors.

 

Those that have test pipes installed, how strong is the smell? I'm a little concerned about the smell getting noticed by the highway patrol and getting pulled over just for that. Is that something I should be worried about?

 

sometimes I can smell it when i come to a complete stop, like it catches up with the car kinda. I wouldnt be at all worried about the cops smelling it while you are crusing on the highway. nothing to worry about there.

 

I see you're from So Cal..did ya dyno at CHURCH?
I just got my 08Z..UpRev (Osirus)..Nismo intakes (on car when I got it)...and just added Invidia exhaust. Stock Cats. Got me 266Torque and 306 HP on that Dynapack (VS your 317 HP/ 278 TQ?)
Looks like the test pipes are worth another 10 HP/Lbs Ft??
This dyno after adding Invidia Dual Cat Back (BLUE). Car was already tuned with Nismo Intakes (RED).
scan0003-3.jpg?t=1314321120

 

Yep sounds about right.

 

Nice looking test pipes..Berk? I'm gonna stay stock though.
BTW, mine is RED too.

 

Just installed GTM non res. about a week ago. I have them on a Bassani exhaust and it sounds loud but not overbearing. Rasp from 3-4k. The cats coming off were a huge pita. Soaked in PB and still snapped two sockets in half trying to break the bolts. Two of the studs wound up staying in the header flanges and it was just as much trouble getting the bassani to line up with the pipes. Drove about 150 miles and got through a dyno tune before it threw a cel, cleared it with cipher and have put maybe 200 more since then and it hasnt popped up again...yet.