I am getting down to my final decisions on exhaust systems, and I am down to Apexi N1 and HKS Carbon-Ti. I have read a lot of threads comparing the n1 and the evo, but not to much talk on the HKS. The N1 has a bit bigger piping(5mm) but otherwise thats about it. I read about the N1 bottle necking down to 2.5 inches and since i am lookinf for a 3" turbo back no cat(no emission laws in IA ) the bottle necking kinda turns me away from the n1. I do liike the look of the angled exhaust that the n1 has and it appears in most pictures that the HKS does come out at a slight angle, but sometimes it doesnt look like there is any angle at all.
Basically i am asking for anyones input on the matter, especially people with either system. Thanks

I've had an opportunity to compare both. I personally own the N1 and my friend (97 GST AT) has the HKS. His (without cat) sounded much quieter than mine. I don't know if this is because of the AT or not.

HKS Pros
* Quieter (unsure if this is because of AT)
* Better Flow
* Looks Good
HKS Cons
*Expensive

Apexi N1 Pros
* Looks Good
* Cheaper
Apexi N1 Cons
* Loud

Ya thats one of the main reasons i haven't just gone with the HKS, it being quite a bit more expensive. Do you know if his exhaust exits at an angle like your N1?

It exits an an angle, yes, though mine is frightfully loud.

It was also expensive, but I thought it was dead sexy.

According to Nopi, the N-1 is 80-85mm, or over 3 inches, for the GSX.
HKS is 75mm all the way through or 2.95.

The neckdown you speak of for the N-1 is the adapter to go to the stock cat and can be removed. I have an N-1 for my GS-T, but the piping is different and not as big. Its over 3" back towards the muffler, but under 3 up front. So for GSX's I'd say go with the N-1. I like the N-1 on my car, but I think I'll try the Espelir next time.

leet said:

It exits an an angle, yes, though mine is frightfully loud.

It was also expensive, but I thought it was dead sexy.

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I would pay for it! It's damn sexy!!

jmadison said:

Do you know if his exhaust exits at an angle like your N1?

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Meaning does the HKS exit at an angle?? Thanks for the posts too guys helps in my decision making.

The Apex and HKS are designed to bolt up to the stock cat. So both will neck down to 2 1/2". The Apex has an removeable adapter so it will let you use their downpipes or RRE's downpipes so that its almost a full 3" from the o2 sensor flange back. I believe to make The hks exhaust a full 3" exhaust youll need to cut out the flange and weld on a 3" flange

Yes, it did angle out a bit. To be honest, if sound isn't an issue, get the N1.

SlowSpyder said:

The Apex and HKS are designed to bolt up to the stock cat. So both will neck down to 2 1/2". The Apex has an removeable adapter so it will let you use their downpipes or RRE's downpipes so that its almost a full 3" from the o2 sensor flange back. I believe to make The hks exhaust a full 3" exhaust youll need to cut out the flange and weld on a 3" flange

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You are correct. You can cut out the resonators as well if noise is not an issue.

My only issue was I wanted to get the best perfoming exhaust, but I also didn't want it to sound like a damn dumbpstruck driving down the highway( i have to take some trips with it). I suppose if the N1 is louder, but better performing, then I could see if that silencer helped at all on the highway.
I think I am going to find a turbo back o2 eliminating system. No cat. Is the o2 eliminating part a good idea?

I myself have been debating the whole issue - and i've chosen the Espelir JGT 500, recommended by RRE and im picking it up next week (the 605 was shut down the other day temporarily so i couldnt go ) But yeah its supposed to be Super loud (has optional silencer) but its full SS (unlike N1) and its under $500 (490, unlike the HKS C/Ti). Plus not very many people have it (i think only like 2 that i've seen actual pictures of) and it does exit at an angle too.

I'm sick of the "normal" exhaust. Get the HKS....that or find an RS*R. Love mine.

jmadison said:

My only issue was I wanted to get the best perfoming exhaust, but I also didn't want it to sound like a damn dumbpstruck driving down the highway( i have to take some trips with it). I suppose if the N1 is louder, but better performing, then I could see if that silencer helped at all on the highway.
I think I am going to find a turbo back o2 eliminating system. No cat. Is the o2 eliminating part a good idea?

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It's a good idea, unless you are removing and installing your Downpipe often. Hence the reason I opted for a normal style DP.

Yeah, im stuck with those 2 exhausts too. So your saying..
HKS Ti= expensive, quieter, and a little less angled exit
and the Apex N-1= Cheaper, louder, and more angled exit?
Does anyone have sound clips of these 2 exhausts?
-thanks

Yes, the bottle neck in the N1 exhaust is just the adapter that you use to connect to the stock cat, this is why it is smaller in diameter compared to the rest of the exhaust. If your using a larger aftermarket cat or a straight downpipe, you don't use this adapter, so don't worry about that. I have the N1 and think its great, looks amazing and mine isn't very loud, I'm not sure why others say theirs is? Mine is defently louder then stock, under cruise its barely noticeable under throttle is louder & its loudest under deceleration, but still not near as loud as most other NA cars with aftermarket exhausts plus this has a much deeper tone and doesn't sound like a lawn mower.

Apeximprt2nr said:

Does anyone have sound clips of these 2 exhausts?

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I am having trouble locating the N1 in a video or anything, but here is the HKS - http://www.hksusa.com/info/media.asp?id=1764

No, I've heard that exhaust. That's the Hi-Power, I'm looking for the HKS carbon Ti, but thanks anyway man

Apeximprt2nr said:

No, I've heard that exhaust. That's the Hi-Power, I'm looking for the HKS carbon Ti, but thanks anyway man

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The carbon-ti is the highpower. It is a special addition version, that has a carbonfiber-titanium muffler. So that is the same exhaust system with a different "wrapper".

jmadison said:

The carbon-ti is the highpower. It is a special addition version, that has a carbonfiber-titanium muffler. So that is the same exhaust system with a different "wrapper".

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Yes!

Wow..I really feel like a dumbass right about now . Ok thanks guys well then, whats the differences between Hi-Power and Ti? (Performance, looks, diameter, etc.)
-Thanks

GPTourer said:

The neckdown you speak of for the N-1 is the adapter to go to the stock cat and can be removed. I have an N-1 for my GS-T, but the piping is different and not as big. Its over 3" back towards the muffler, but under 3 up front. .

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Unless things have changed in the N1's design the flange is not the only neck down or bottleneck!
On the GSX toward the rear of the car, it does expand to 3.5" all the way to the can.
The problem is, it necks down inside the can to 2.5 then expands back out.
Look at your silencer. The small section is just about 2.5". It appears that the reason for the 2.5" neckdown, inside the can is for sound and so the silencer fits better.
I posted pics of this and a drawing a long time ago. I may still have them on my computer though.
I still like my N1 but I'll be making a new exhaust tomorrow.
Good luck

Wow, that HKS sounds awesome on the Evo. I remember seeing a post about the N1 bottle necking down twice, but I don't remember the exacts from it.