Optimal exhaust diameter for 1.6

15611 Views 23 Replies 5 Participants Last post by ram0042, Jul 13, 2014

ram0042

Discussion Starter · Jul 4, 2014

Ive been searching this forum for some advice on exhaust width.

Ive heard from 2 to 3 inches.

There's a Nismo exhaust for the 1.6 Juke at 75mm(2.9~ inches)
Is that what's optimal for a Versa HR16DE?

1 - 20 of 24 Posts

07Versa6MT

· #2 · Jul 4, 2014

But that's a turbo motor... turbos build alot of backpressure, especially with internal wastegates and depending on manifold design, they need all the breathability they can get to make up for the backpressure at the manifold, and cats too.

You want something that will not be a restriction at high end, but not lose exhaust velocity at low end. Loss of backpressure isn't what causes you to lose torque, it's the exhaust gas velocity and scavenging you get from it that causes it. That's why in most cases having the exhaust come straight out the engine with no real exhaust path is bad for any street car. It will feel like a dog at low RPM (lots of noise, no go). I think 2.5" on a stock 1.8 is fine. I was running 2.5" straight pipe from cat back and i didn't lose any low end driveability yet can feel the gains up top. 2" should be fine for the 1.6. Initially i was straight pipe, too loud, put a cherry bomb on, better, but still too obnoxiously loud. Then i got a Dynomax muffler off a Corvette for free one day. Thought hmm, that would quiet it down enough and still not change driveability, so i put that on. Yes i have a set of stock LT1 Corvette tips coming out of my Versa... haha. It actually sounds good, and you can have a conversation or listen to music in the cabin now.

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ram0042

Discussion Starter · #3 · Jul 5, 2014

Didnt consider the turbo.

so 2"-2.5" is what ill go with. Ill have borla muffler at the end. maybe itll clean up sound from straight pipe.

ram0042

Discussion Starter · #4 · Jul 6, 2014

i got a 2.25" pipe with borla 3".

sounds crazy. Mechanic made hole for sensor to at least fit and ive been driving all day waiting for my CEL to show up. hasnt yet. will come.

Next up coilovers or whatever suspension.

But im pretty paranoid with it now being pulled over because it's obviously straight piped with the sound.

07Versa6MT

· #5 · Jul 7, 2014

So you eliminated the cats too? That will add some noise as well since the cats kind of act like baffling/resonators. You must have a shitload of drone. How's the powerband? Feel any low end loss?

ram0042

Discussion Starter · #6 · Jul 7, 2014

07Versa6MT said:
So you eliminated the cats too? That will add some noise as well since the cats kind of act like baffling/resonators. You must have a shitload of drone. How's the powerband? Feel any low end loss?

Yes straight from the headers to the muffler. Im going to have the same guy weld a resonator, since pep boys doesnt carry smaller than 2.5".

Yea too much drone. I have a headache driving around all day. So many saves today switching to neutral to avoid attention.

To be honest, the acceleration seems slower. it probably is. but at high rpms, it walks like all the cars are still. I used to feel like the car had good acceleration until 5k rpm @ 100mph. today i went at 120 at 5K and I couldve gone further.

It also could just be that its an illusion being that im not used to driving something loud at low speeds.

but anyways, sounds gotta go.

07Versa6MT

· #7 · Jul 7, 2014

Yeah straight pipe draws too much attention. It would be fine if the car is fast, but it just makes it sound like a ricer unfortunately.

JoshG

· #8 · Jul 7, 2014

I hear you. I have a 1.6 with 2.25in. custom pipping. I had an eBay muffler on it and it was way too loud for my taste. At first it was fun but got very boring after a while, got a ticket for it as well so I had a resonator added and replaced the muffler. :thumbsup:

rstolz

· #9 · Jul 7, 2014

I'd go 2" on the 1.6 non-turbo. I run 2.5" on my Audi 1.8T, more than that and you can really start to feel the low end loss.

I have the DC Sports system on my V, which is a 2" with canister muffler. nice setup, no real low end loss, definite bonus on the high end. It was cheap, looks nice, and works. There is a bit of drone, but nothing too bad unless you're running the A/C and cruising at 80mph. VersaSpeed also offers a silencer that fits into the exhaust tip, and really quiets the system down. You lose some benefit from the open exhaust, but you get a much quieter ride and nice deep tone.

There is a serious restriction on the header. At the collector, where the 4 goes into 1, the pipe diameter is severely choked, before opening back up for the flange. So any gain you get from opening the exhaust is going to be tempered by the restrictive header.

ram0042

Discussion Starter · #10 · Jul 7, 2014

07Versa6MT said:
Yeah straight pipe draws too much attention. It would be fine if the car is fast, but it just makes it sound like a ricer unfortunately.

I can't believe the sound this thing makes. Its too deep. With a 98 civic I slapped a aem intake kit with k&n and one time someone at the end of the freeway said they thought they heard a lambo. Lol, everything else was stock.

but that's the same sound my versa has now. As I'm writing this the resonator is being installed. So I'm just waiting what for what type of change this is going to do.

ram0042

Discussion Starter · #11 · Jul 7, 2014

JoshG said:
I hear you. I have a 1.6 with 2.25in. custom pipping. I had an eBay muffler on it and it was way too loud for my taste. At first it was fun but got very boring after a while, got a ticket for it as well so I had a resonator added and replaced the muffler. :thumbsup:

It is obnoxious. Like I said before, I start very slow around cops and they know I'm trying to hide it. Haven't gotten a ticket this weekend.

I like the general sound the system makes. 10 minutes from now I should be heading to work so I'll just post the result later for those who want to just get an idea of the system.

ram0042

Discussion Starter · #12 · Jul 7, 2014

rstolz said:
I'd go 2" on the 1.6 non-turbo. I run 2.5" on my Audi 1.8T, more than that and you can really start to feel the low end loss.

I have the DC Sports system on my V, which is a 2" with canister muffler. nice setup, no real low end loss, definite bonus on the high end. It was cheap, looks nice, and works. There is a bit of drone, but nothing too bad unless you're running the A/C and cruising at 80mph. VersaSpeed also offers a silencer that fits into the exhaust tip, and really quiets the system down. You lose some benefit from the open exhaust, but you get a much quieter ride and nice deep tone.

There is a serious restriction on the header. At the collector, where the 4 goes into 1, the pipe diameter is severely choked, before opening back up for the flange. So any gain you get from opening the exhaust is going to be tempered by the restrictive header.

seems right(what you're saying). I just went with some head math with other setups and other advice and decided on 2.25". The resonator was added earlier today. I started up the car and you can still quickly know its modified. But not extremely loud as it used to be. I'm glad its been added.

as far as I know for my engine there aren't much performance parts for it like headers.

07Versa6MT

· #13 · Jul 8, 2014

I have an HR16 OBX 4-2-1 header i may let go...

rstolz

· #14 · Jul 8, 2014

I think any header that fits the 1.8 also fits the 1.6... could be wrong there though.

robj80

· #15 · Jul 8, 2014

rstolz said:
I think any header that fits the 1.8 also fits the 1.6... could be wrong there though.

They have a different bolt pattern on the manifold. The center stud hole is offset on the 1.6.

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07Versa6MT

· #16 · Jul 8, 2014

Which is why i'm going to sell it... i bought it for my MR18 and just by rough looks the bolt patterns looked the same, and they pretty much are except the top center hole is offset, plus the port spacing is actually different too. The pipes on the HR16 don't line up with the ports at all, you'd have to weld a new flange, and at the same time bend the pipes to fit the spacing of the MR motor. It's stupid little stuff they do to make things not cross compatible like this, like they should be.

I bought it because i like the better 4-2-1 design of it, but then i thought realistically any scavenging gains are going to be negated by cams that can't take full advantage of that. In fact i think that's a major limiting factory in why we don't seem to feel much gain on bolt ons like intake and exhaust, the cams are the bottleneck. Didn't the DC sports header get dyno gains of only like 3HP?? Now i know the scale for HP increases as displacement goes up and vice versa, but 3HP is still pretty low gain for a header, granted it isn't a good design, but at least gets rid of that choke point at the collector.

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ram0042

Discussion Starter · #17 · Jul 9, 2014

07Versa6MT said:
I have an HR16 OBX 4-2-1 header i may let go...

I have 2014 1.6l just to check

rstolz

· #18 · Jul 10, 2014

yea it's only a few ponies, but with 120 stock for the 1.8, and less for the 1.6, a 5% gain is just 6, which is generally in-line for a small displacement NA engine.

It won't make a rip roaring difference, but it will help smooth out the flow and influence the torque curve.

Header design affects torque more than HP; and not only how much, but when. pipe length and collector design (diameter, geometry, length) affect when the torque peak occurs.

OBX and DC 4-1 units have very short pipes and collectors, pushing the torque gains higher in the RPM range. Stretch out the collector and you can push the torque curve lower, while still seeing improved top end.

07Versa6MT

· #19 · Jul 10, 2014

That's why i'd like to get the HR16 header working on my MR... there is a fabricating shop around here that could probably make me up an MR18 flange with the proper spacing, then heat and bend the primaries to where they're supposed to be. The primaries are the same diameter as the MR18 header so there won't be a restriction there.

Reactions: 1

ram0042

Discussion Starter · #20 · Jul 10, 2014

07Versa6MT said:
That's why i'd like to get the HR16 header working on my MR... there is a fabricating shop around here that could probably make me up an MR18 flange with the proper spacing, then heat and bend the primaries to where they're supposed to be. The primaries are the same diameter as the MR18 header so there won't be a restriction there.

is there a link so I can get a performance header for hr16de?

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