Exhaust decisions
Alright everyone, I'm fairly new to modding and customizing cars. I've recently bought an '07 350z and have been looking into after market exhaust. Two particular brands have caught my eye: Borla and Magnaflow. The Borla offers a 2 1/4" pipe while the Magnaflow is 3". Which, in your opinion, is a better performing set?
By reading your post,it appears that LOOKS is your number one priority.I'd expand and look at others.And,as has been mentioned,listen to some sound clips or,better yet,in person Listening.On performance,if you are talking about a cat back system,don't expect any major increases in HP.Most brands advertise results that are on the "high side".

Also, if you want people's opinions on exhausts I would start with this thread:
https://my350z.com/forum/intake-exha...aders-etc.html
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Get the Borla, 2 1/4 piping is fine it well help keep your low end torque (which the HR slightly lacks). Magnaflow is a good exhaust too but why have a Y pipe to merge the exhaust and then split it gain and run 2 mufflers? If you want a single 3" pipe I would go with one with a single exit as well like the AAM 3" single or Agency Power Ti, paired with quality Y pipe it will cost about the same as a cat back system.
tons of threads on it, auth HKS..no point.. or buy one used on the site ( ones for sale now btw) ...or just buy the replica from ebay and pay a shop to make it fit well, then get the x pipe..
to the other guy above.. ???
If you were running a ypipe, you wouldnt ever use the magnaflow.. its for dual exh cars .
OP... there a million threads on exhaust and looks etc.. they all gain minimal top end power, and nearly ALL lose low end power until you HAVE A TUNE.
Again, politely......please search, please read the threads.. theres no need for this one man. Theres a million others just like it.
to the other guy above.. ???
If you were running a ypipe, you wouldnt ever use the magnaflow.. its for dual exh cars .
OP... there a million threads on exhaust and looks etc.. they all gain minimal top end power, and nearly ALL lose low end power until you HAVE A TUNE.
Again, politely......please search, please read the threads.. theres no need for this one man. Theres a million others just like it.
Last edited by bmccann101; Jan 6, 2012 at 07:36 AM.
I believe it was proven that the HR actually makes more power throughout the entire powerband, and does not have less "low end torque". Keep in mind that the vq35de and vq35hr engines had their power figures rated under different systems. So while on paper, the HR makes 268lb-ft @ 4800 vs 274lb-ft @ 4800 for the DE, a dyno might (and has) shown that the HR doesn't really make less in the real world. If anything, they're so close that the difference falls within margin of error, or is a spike that only lasts for like 200 rpms.
Can anybody find this post/dyno? I believe it was from Motordyne or UpRev?
IIRC, while on paper the difference between the DE and Rev-Up is 13hp, and between the Rev-Up and HR was merely 6HP, on the dyno, the HR put down substantially more power throughout the entire power band.
The SAE (Society of Automotive Engineers) released a new ratings system in 2005 to level the playing field. The existing system was too easy for manufacturers to "cheat" and inflate their power ratings. The Japanese were among the worst (and I'm part Jap, so don't call me a racist). Adoption of the new system really took up in 2006-2007, which just happened to be when the vq35hr debuted!
CLIFF'S NOTES: You can't directly compare manufacturer "claimed" power figures from cars manufactured prior to ~2006/2007 to those manufactured after 2006/2007. Unless you know for a fact which SAE rating system the engine was rated (or re-rated) under.
For the record:
vq35de: 274 @ 4800
vq35hr: 268 @ 4800
vq37vhr: 269 @ 5200
Can anybody find this post/dyno? I believe it was from Motordyne or UpRev?
IIRC, while on paper the difference between the DE and Rev-Up is 13hp, and between the Rev-Up and HR was merely 6HP, on the dyno, the HR put down substantially more power throughout the entire power band.
The SAE (Society of Automotive Engineers) released a new ratings system in 2005 to level the playing field. The existing system was too easy for manufacturers to "cheat" and inflate their power ratings. The Japanese were among the worst (and I'm part Jap, so don't call me a racist). Adoption of the new system really took up in 2006-2007, which just happened to be when the vq35hr debuted!
CLIFF'S NOTES: You can't directly compare manufacturer "claimed" power figures from cars manufactured prior to ~2006/2007 to those manufactured after 2006/2007. Unless you know for a fact which SAE rating system the engine was rated (or re-rated) under.
For the record:
vq35de: 274 @ 4800
vq35hr: 268 @ 4800
vq37vhr: 269 @ 5200
OP: fwiw, I can't comment on the Magnaflow, but I do have the Borla and it is barely louder than stock. It does have more of a rumble/burble than stock, but is about the same volume under about 5000 rpms. Slightly louder than stock above that.
With a larger 3" exhaust, you're going to be losing velocity, which is going to hurt scavenging. That's why some people are saying you'll lose low-end power. When the exhaust valves open on each cylinder, the very hot & compressed gases rapidly fill the exhaust system (taking the path of least resistance) and a vacuum will form in their wake if the velocity & volume is sufficient enough. That vacuum is important because it (1) can help suck out additional exhaust gases, and (2) can help pull additional fresh air into the cylinder from the intake side. This is called scavenging. If the exhaust is of too large of a diameter, the gases will spread out & dissipate, and lose much of their velocity, which will impact vacuum/scavenging.
With a larger 3" exhaust, you're going to be losing velocity, which is going to hurt scavenging. That's why some people are saying you'll lose low-end power. When the exhaust valves open on each cylinder, the very hot & compressed gases rapidly fill the exhaust system (taking the path of least resistance) and a vacuum will form in their wake if the velocity & volume is sufficient enough. That vacuum is important because it (1) can help suck out additional exhaust gases, and (2) can help pull additional fresh air into the cylinder from the intake side. This is called scavenging. If the exhaust is of too large of a diameter, the gases will spread out & dissipate, and lose much of their velocity, which will impact vacuum/scavenging.
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