BigJHouse

So I'm in the market and working on the exhaust side of things. I've been doing alot of research and been thinking about the different j pipes and they're designs. I wanna get some feed back on why the aftermarket j pipes are better than the acura engineered oem pipe. The guys designing our cars are pretty smart and know what their doing. Thanks ahead of time.

Also is there any difference between the years such as 04-06 vs 07-08 or base vs type s

FamilyGuy

I thought you've "been doing a lot of research"? Simply put, OEM engineers have to design for noise, emissions and warranty, and this isn't exactly a corvette.

"Better" is subjective - aftermarket j pipes offer better performance, power wise. Which is better in terms of longest life / corrosion resistance etc. who knows, but usually OEM exhaust components outlast the life of the car, though typically because they are made of robust heavy materials. Aftermarket are usually designed for lightweight and performance, while retaining as much robustness (is that a word?) and long lasting life as possible, at a certain price point.

I don't believe so, not on the j pipe.

BigJHouse

I like the sarcastic beginning lol,
either way Im wondering why the oem pipe is considered restrictive? I see the bend on the rear bank is pretty aggressive so there's power to be made there but on the front bank there is a nice gradual increase to the collector which I think is a great design.
I over looked the weight savings so good point there.

ExcelerateRep

Well said, Ivo. My opinion in terms of longest life/corrosion, you can't beat T304 Stainless Steel! OEM exhausts are usually made of regular old steel, and after a couple decades can start to rot out. That won't happen with T304

In terms of fitment, all 04-08 TL J-pipes are the same. They vary for the 4G TLs.

http://hoa.excelerateperformance.com...i-1804833.aspx

FamilyGuy

If I recall, the factory pipes do not have mandrel bends, and I *think* are smaller diameter vs aftermarket (check specs here, been a while for me). Aftermarket gains also come from eliminating the 3rd catalytic converter, which we don't need.

BigJHouse

this is an oem j pipe and seems to have manderel bends but im not 100% and i measured mine yesterday and came out to 2.5 outer diameter. I did not check what the primaries were though. I would be putting a race pipe after the j pipe to remove the cat. if i remember correctly the third cat is where the exhaust becomes 2.25.

justnspace

iTrader: (1)

flip it over. you'll see a crushed bend

justnspace

iTrader: (1)

FamilyGuy

As shown in justnspace's photo, the aftermarket options also play with different primary lengths, which can affect where you feel it most on the RPM band (low, mid or top end). The j pipe is also a good chunk of the whole exhaust system, so if you're looking to open the car up, you should ditch the factory one, or at least ditch the 3rd cat.

Scottwax

XLR8 v2 top, OEM bottom. Any questions?

Sonnick

OEM Jpipe is made for sound suppression and scavenging for a STOCK car. Once you start modding, that throws off exhaust scavenging because you are either sucking more air into the motor, or pushing more air out. Each aftermarket Jpipe has larger primaries than stock, utilize better pipe bends than stock & also have a larger and better collector than stock.

There is no 'best' Jpipe. Everyone does different mods to their car. Someone with just an AEM CAI only will have a different experience with 'X Jpipe' vs 'Y Jpipe' than a car with full bolt ons. It's hard to say which Jpipe will perform the best on a specific setup, but you can't go wrong with any of them.

Doing research should also include searching the forums for threads similar to this one. I will say that this is the 1st thread I've seen directed specifically at why the aftermarket Jpipes are 'better designed for power' than the OEM ones, but you can read that in each manufacturers part description With that said, happy buying.

BigJHouse

Sonnick has put the nail in the coffin I wanted to have a discussion on why they are better (for performance) not which one or anything like that. I've read every one of the manufacturers descriptions but I've also worked in sales before. Haha. Thanks for the responses didn't mean for this to be another j pipe thread like all the rest. This all being said I'll be Going with a atlp v2 and a race pipe for my next set up. (Third cat already deleted). the main reason I'm going atlp v2 is because it keeps alot of the same aspects of the oem but improved upon them.

I still don't mind having more of a discussion about them but alot of points have been hit.

BigJHouse

What about skipping the race pipe all together and putting a longer more gradual pipe "increaser" to keep the exhaust gasses slightly hotter when it switches into the 3 inch exhaust? Thoughts on this?

FamilyGuy

You can just wrap the pipes.

BigJHouse

Agreed. (It's the plan anyway) I was looking to save the money and space. and I feel it's again a better design to have a gradual change in pipe diameter rather than a quick change. Even if it's a small change.

FamilyGuy

Well, you can also skip it altogether and get a true dual exhaust with an X merge. That's what some of us did, myself included. The problem with a single pipe once you start to go over 3" is clearance, esp with a resonator of that size.

BigJHouse

are you rv6 true dual? Or custom? I didn't really think about clearance. I'm not lowered and if I do I will not be slammed. being in Buffalo we see to much snow.

How do you like the dual setup?
Doesn't that diminish your point about weight?

FamilyGuy

I have RV6 with X merge, basically a true dual. I don't have the weight for the factory exhaust, but if heavier, it's not by much. The factory system is a bit hefty with its 3 mufflers and one resonator. I've already shaved off ~140lbs from the car so to me the dual was worth it.

I'm not that low either, ~2" tops, and you'd be surprised how low the flex joint on the j pipe is up front. I know a 3" inlet resonator can get pretty fat too.

The aftermarket j pipes are a lot lighter than the factory one, like around 6-8lbs or so, I forget the exact number but if you search around I'm sure you'll find it. Google "TL diet Acurazine".