You are paying for the HKS brand name and trust you have in that brand. Exhausts are exhausts. If there are mandrel bends and hangers in the right spot with a free flowing muffler, the diameter pipe will mostly determine the gain. It's not a header and so far removed from the engine that the effects are minimized. Personally, paying $1400 to make your G gain a lot of noise and 5 hp is a waste. If this exhaust can do the same for $400, it's winner winner chicken dinner. Exhaust snobs always have the slowest cars because they are to broke to address the other areas of the car.

 

Lol, slowest car? Is that a challenge? J/K.

Again, my argument is in build quality over anything else. Also, even though the exhaust isn't near the engine, it still plays a role in power production. ESPECIALLY with a turbo car over any other type of FI or N/A. If the build quality sucks (like top speed), you will have imperfections around any welded or mating joint in the exhaust. These will cause turbulence in the exhaust flow, which will make you lose power. While were talking maybe a couple HP here, it's still a variable in the design of the exhaust.

Overall though, I'd rather pay $1200 once than have to pay $400 three or more times over the life of ownership, due to the exhaust falling apart.


BTW, forgot to snap a pic, I'll try to when I get home from work tonight...

 

Just never had a cat back fall apart. Most options for G's seem overpriced.

 

Actually you are quite wrong on that.

On a turbo car, any pipe (or none) makes no difference at all. In a naturally aspirated application an exhaust will require flow calculations to maintain a certain amount of back pressure in the exhaust, which aids in the modulation of torque in the powerband.

That being said, an exhaust is for the most part, a sound aesthetic item. Also, last time I checked its 2012 not 1998. Today's welding and bending equipment, even by chinese standards, rarely has flow issues.

At this point its all a matter of material quality, SS vs Aluminized Steel, quality of welding material. For $405 shipped for this exhaust, you can buy 3 for the price of one "Invidia" or "HKS", so if you like the sound, and the quality of materials is even half of the said products (which I doubt), you can replace it 3 times, or spend your money on other stuff. (Like sway bars )

 

Lol, you have it all wrong actually. I'll have to go into detail later about it, I'm curently working on a fluid flow system for a helicopter at work (yes, I deal with fluid flow on a daily basis as an aerospace engineer)... so I'm a bit occupied, lol.

 

Ok, I'm off work now, lol. Be forewarned, I've never been good at explaining engineering principles or topics, so if I sound like I'm rambling or whatever, I apologize...

First off, the topic of back pressure and how wrong most people get it. I don't feel like writing an article, so here is a good link (with a couple more in-depth links inside this article), explaining why back-pressure is a bad thing.

http://www.motoiq.com/magazine_artic...ask-sarah.aspx

Secondly, I will explain (as basically as I can) the difference between turbo cars and the rest of the various aspirated engines. We all know that exhaust flows in pulses straight out of the motor. And when there is nothing in the way between the header and the exhaust, it stays this way. Having mandrel bends is not as important here, because the exhaust pulses are minimally effected by the smoothness of the exhaust wall. Supercharged, Nitrous, and N/A all fallow this type of exhaust flow. Think of it as waves or bursts of exhaust going through a tube.

Turbo cars however, convert exhaust pulses into a flow similar to a toilet flushing. The flow exiting the turbine housing spins around the outer edges of the pipe at the highest velocity and slower near the center. Now when that flow sees a jagged welded joint or a diameter change in a bend, it will lose velocity (which in turn weakens the venturi affect = less power). Also, the more bends an exhaust has, the slower the exhaust will flow; also sapping power (for all types of aspiration). Typically with turbo cars, you want as large exhaust as you can, because you are producing WAY more exhaust flow a N/A car could ever produce and also at a higher velocity... HOWEVER, fluid flow still follows the basic laws of fluid dynamics. To put it simply, when exhaust of said size flows into a larger pipe, the pressure will go up and the velocity will go down. If said exhaust pipe gets smaller, velocity goes up and pressure goes down. Also keep in mind, that the larger a pipe is, the more mass flow rate it can handle. So, you want to go as large as you can WITHOUT sacrificing higher exhaust velocity, because that is what scavenges the waste out of the combustion chamber.

These principles explain why catalytic converters work. The exhaust enters a CAT (which is larger in diameter than the exhaust), and it slows down but gains pressure. The slow velocity goes through the cells in the CAT burning off contaminants, and picks up velocity as it exits. Since the pressure is lower at the exit of the CAT than it was in the middle of the CAT, it creates a vacuum (venturi affect) which pulls the high pressure zone exhaust away from the center.

Hopefully that clears things up a bit for you guys.

 

And the promised pictures of the "high quality stainless Top Speed exhaust product" with high quality included o2 sensor hardware, lol.

 

weird. I am going to say that is just regular carbon steel. I know stainless can "rust" but I have never seen anything like that. Anyway, Sux that you had that problem but, If you know so much about this stuff why did you buy the top speed pro parts to begin with?

 

It's cheap 400 series stainless, which corrodes. The more expensive 300 series does not. I bought the downpipe because at the time, I couldn't find any other part that was a reasonable price for my car (and I didn't realize you could use an MR2 DP... this was right after I bought the car). This is for a Celica Alltrac, which is a fairly rare car (2500 made in the US), so aftermarket parts aren't readily available like a 240SX, G/Z platform, etc. Also, this was before I started my current job, so I didn't have a lot of disposable income. I know now that I should have just waited to purchase a DP when I not only had more funds, but also a broader understanding of what was available for my car. Now I have to buy another DP to replace it... which sucks... and is what I'm trying to help other people avoid by letting them know how crappy Top Speed's and other chinese companies' products are.

Here is a pic of when I bought the DP to show the difference over two years of limited driving (car was also parked in a garage for a good amount of that time).

 

The pictures with the rust shows an 02 sensor bung with 2 bolts, but the picture you show below does not.. Care to explain?

I had a topspeed catback for 4 years on my previous car (civic si) in canadian winter with no issues.

 

Umm... yeah... the two bolt o2 sensor port is near the bell mouth. Care to look harder? In the picture I posted it's on the right facing the right. The two ports on the lower section of the DP are for a wideband and exhaust temp sensor.

 

My friend imports sinks from china, and all the time he has to send them back, they literally start rusting on the way here on the cargo container sometimes.. he said they say he's getting a certain grade of stainless, but they cheap out and don't put enough nickel in and hope the customer doesn't notice. Sounds like the same kind of deal on that exhaust.

 

My mistake, it wasnt clear on the pic.

Anyways, im just letting people know I had a good experience with my topspeed exhaust, no fitment or rust issues like u. And I wouldnt hesitate to buy one for my g35 if they were willing to ship via USPS Stupid UPS/Fedex brokerage fees!

 

No problem man

 

What a piece of crap......sounds like a phart can Honda.



Oh wait.......that's my car.

This exhaust is a very good deal for the money. Good quality materials.

They have the welding jig adjusted and fiittment is spot on. Zero cabin drone. I paintred the end caps black and the cans disappeared.

I am very happy.