J2 Engineering Catback Dual Exhaust system, dyno?
 

Hi all,

Tried my best to find a dyno chart for this exhaust but to no avail none was found. I googled and searched the forum, so I decided to just ask.

Kind of interested in this exhaust since it's so cheap and word is that, it produces an amazing sound compared to many others currently on the market. Seriously thinking about biting the bullet and just placing the order. But I really want to see what the dyno says first if anyone has that available.

Reading a lot of good things about the quad tip version here though: http://www.ft86club.com/forums/showthread.php?t=50474

if all you're doing is putting a catback exhaust on a naturally aspirated car, any difference from one to the other is going to be immaterial. buy what looks/sounds right to you.

Yes, I am planning to keep my car NA. I was debating between the J2 Dual tip, vs Greddy EVO3. They both look and sound good to me, just that the Greddy has the dyno to back it up.

I would most definitely snag the J2 only if I knew for sure I wouldn't be losing any power. You never know, the price is just too awesome, one would think there's a catch.

i have a j2 front pipe and it's great. it's 2.75", which was why i got it (no 3" available at the time).

That is exactly the reason why I wanted it as well. Wanted something a bit bigger than 2.5" but sticking with an NA setup and not going FI.

I figured the car's 12.5 compression would actually benefit more with a 2.75" which is why I was considering this or the Greddy. Not really sure if that is valid though...

dont get the dual tip, it flows like crap. if ur gona go j2 id get the quad tip, and square bumper cut outs. but to be honest, if i had to do it again id get something else for a littler more. but at the time the j2 was the only quad tip out and i already had the trd rear bumper. i realy wanted the evo 3. over all im happy with it for the price you realy cant complain.

Hey thanks for your advice, yea maybe I'll end up settling on the J2 frontpipe and the EVO 3. Gonna wait another week or so to finalize my decision.

If I were to get the J2 Quad would it still be able to fit on the stock bumper or do I HAVE to get the square bumper cutouts. Also, was the fitment okay?

You're going to kill yourself with drone by doing this. Just a heads up.

Its hard to say without some dyno sheets. It very well could but I have a hard time believing anything over 2.5 would offer any benefits on an NA motor. Even a full 3" on a supercharged I can see being less beneficial depending on the tuning. Have they been able to control the variable valve timing on the FA20? I know on the VQ37 we see better HP number on stock cats because the back pressure keeps the boost in the cylinders at higher rpm. Tuners haven't been able to control the VVEL on the car so there is a lot of blow through at high RPM with the Supercharger. Curious if that is an issue on these cars as well.

It's not. Ecutek and Hydra have full valve timing control, afaik. Not sure about other options, though.

There's seriously no tuner accessible timing control on the VQs???

For some reason the tuners haven't been able to/don't want to put the work in to crack it. I know people who have the Motec and HKS systems that have done it, but the cost of that is higher than most people are willing to pay.

it's not an issue as all of the available tuning solutions offer full control of the cam timing.

3" does make more power than a 2.5" on this car, it's been demonstrated and dyno tested and is no surprise. most modern high performance 4 cylinders make better power on 3" than 2.5". it's still not much of course, but it is generally more power.

Don't forget we are talking about as cat back here, having a larger rear section won't make nearly the same difference as a whole system.

I doubt you'll see any real differences between different cat back systems.

it will fit, but it just looks better with a square cut out. if the drone bothers you i spent like 50 bucks on some sound deadening for the back seat/rear shelf and it was a night and day difference. same awesome exhaust noise, just more tolerable on cruises.

Do anyone dyno this exhaust yet?
Less concerned about gains and more interested in maintaining a good flow while losing weight.

i have a j2 dual tip. low end there is no difference in power. 5k rpm and up there is an increase in power, more so at the top end.

doesnt flow good? i believe it flows very well. its 2.75 with straight through mufflers. theres nothing choking the flow. if anything the quad tip would choke the flow what that big stock looking muffler.

but.......... its loud as ****. it doesnt just add a little tone like others. if you dont like rasp or drone then this exhaust is not for you. it makes it sound like a race car.

is this loud even with the stock front pipe? I'm want to get the J2 dual tip with a catless fron't pipe. Will that be too loud or should I get a resonated FP? Pls let me know before I buy this setup thanks

I have a j2 dual exit catback. Sounds nice, wont fit up to the stock front pipe. I placed it with a AP front pipe and overpipe combo. Ended up going with a local deal so I got overpipe back exhaust for $400... cant complain!

Exactly. You probably won't gain anything with a cat back. My local dyno shop put an intake, and cat back on an FRS and it gained ZERO horsepower (it may have gained 2 hp... they did 3 runs before and 3 runs after so if you looked at the lowest of the first 3 and the highest of the final 3 it gained 2.1 hp).


After tuning the car with the intake and exhaust picked up just over 12whp over the lowest baseline. They also tuned another FRS on another day ...tune only with a drop in filter and gained just under 10whp (9.6).... so this kinda backs up the 0-2hp gain from a cat back....