J30 Dual Exhaust : Cat-back!

Post by **willisbr** » Mon Sep 15, 2003 4:16 pm

For those that adore the J generation...I just had dual exhaust ran on my J30. Check it out on car-domain.com.

http://www.cardomain.com/id/willisbr

Post by **Jeff Williams** » Mon Sep 15, 2003 4:16 pm

Very nice. Is that aluminized steel, or stainless?

Post by **1qckser** » Mon Sep 15, 2003 4:16 pm

The car looks great, awesome job.

Post by **Omar** » Mon Sep 15, 2003 4:16 pm

Looks real nice. I like it.

Is it loud? I wonder how it sounds. Oh yeah, does your J really do 0-60 in 5.9 sec?

Where did you get exahust from? How much did it run you?

Later....

Post by **Eswift** » Mon Sep 15, 2003 4:16 pm

1/4 mile in 14.9 too?

engine swap? bore increase?

is the exhaust cat-back or right up to the exhaust manifolds? - since you claim both on your site.

Post by **VimyJ** » Mon Sep 15, 2003 4:16 pm

Those numbers like "est. 263 hp". Really? I don't see a turbo in those engine shots. Under 6 seconds 0-60? Looks like you added a lot of extra weight. Hard to fool the informed members of this site.

Post by **Eswift** » Mon Sep 15, 2003 4:16 pm

no kidding, vimy... i am hoping those specs are representative of major future goals, because in light of such exaggeration there is no telling what is accurate.

Post by **keystone** » Mon Sep 15, 2003 4:16 pm

Nice J ob

Post by **willisbr** » Mon Sep 15, 2003 4:16 pm

Thanks for the light guys...I didn't realize that the specs were off so much. The HP and 1/4 mile specs were taken off a 300ZX site because it's been hard to find a J30 that's been to the dyno. I'll be sure to tone it down. Also...the ehxaust is a very deep sound...sexy if you will. I get comps all the time when i'm at the red light. To go true cat I was going to gut or cut out the converters but I was told that the car wouldn't run at all without them. Can anyone confirm that? maybe I'm using the wrong terms. I'm learning as much as I can so if it seems that something is BS it's probably just because I'm not saying it right. Thanks for all of your help though!!

Brian

Post by **R4v3n** » Mon Sep 15, 2003 4:16 pm

I took my car to a dyno and it turned up 175 hp to the wheels. All I have done is JWT Intake, JWT ECU, and Unorthodox Racing Pulleys. My car NEEDS a tune-up though, and I'll be doing that soon, as well as flushing out the trans, rear-end, and fuel system. As far as the term cat-back goes, a cat-back exhaust means that you have pipes running from the catalyic converters to those 2 mufflers you got, what we are asking is if you have taken off the catalyic conerters (which apparently you did not), and ran piping from the manifold back. It says on the domain that you ran cat-back from the manifold back, but thats kind of a double negative. You either are running cats with new pipes out to the those mufflers you got, or you completely pulled the cats off and are running pipes from the exhaust manifold back to the mufflers. of course, you COULD run high-flow cats to get the best flow thats legal because you will automatically fail emissions without cats. The car should run though, but that I am not sure of.

Post by **Eswift** » Mon Sep 15, 2003 4:16 pm

you can cut the cats out, just that it is VERY illegal, and you most likely wont pass your emissions test.

in simple terms - the fuction of the cat is to burn unburned fuel and clear up your emissions.

car should run fine with the cats removed, or gutted.

on 300zx's you will see both gutted cats and "test pipes" that bolt in where the cats usually are.

good to hear that the sound matches the looks

Post by **robmcole** » Mon Sep 15, 2003 4:16 pm

I can testify to the fact that the J30 runs fine without cat's. Just get ready to wash the car weekly because black sut will start building on the bumper. BUT you can get up to 5 more mpg without them. Again, it is illegal, and my one gripe with Infiniti is that it is not a design that allows "test pipes" like other cars I have owned. Since it is a true dual exaust back to the muffler, there are 2 cat's, and it is a slips on design on 1 side, and a slip on/flange on the other. If you vehicle is a 94+, then it will be OBDII emmisions, which is where they place an O2 after the cat's to test for the catylitic's effeciency. You might run into computer problems with that. If you are 93, all is good.

-Rob

Post by **Eswift** » Mon Sep 15, 2003 4:16 pm

i believe only its 96+ with the OBDII. Ive got a 94 with a 94 manufacturing date, OBDI.

Post by **AZhitman** » Mon Sep 15, 2003 4:16 pm

VERY nice J, willis!

Absolutely beautiful... I like what you've done.

Post by **robmcole** » Mon Sep 15, 2003 4:16 pm

That is correct.. 96+ is OBDII. I have thought otherwise all these years. Shows I have not owned a car newer than 93 ever before

Post by **IvoryJ30t** » Mon Sep 15, 2003 4:16 pm

willisbr wrote:Thanks for the light guys...I didn't realize that the specs were off so much. The HP and 1/4 mile specs were taken off a 300ZX site because it's been hard to find a J30 that's been to the dyno. I'll be sure to tone it down. Also...the ehxaust is a very deep sound...sexy if you will. I get comps all the time when i'm at the red light. To go true cat I was going to gut or cut out the converters but I was told that the car wouldn't run at all without them. Can anyone confirm that? maybe I'm using the wrong terms. I'm learning as much as I can so if it seems that something is BS it's probably just because I'm not saying it right. Thanks for all of your help though!!

Brian

the thing about the cats is BS. the car will run, and actually run better at hi rpm [hp gain] but will lose low end power [torque]that the n/a vg30 doesnt really have in the first place, so its not a good idea for the street. removing the cats will also make the exhaust louder and raspier [not as mellow and deep] which i see as a downfall. if anything get some larger aftermarket universal cats if its a concern.

Post by **willisbr** » Mon Sep 15, 2003 4:16 pm

Thanks for all the great advise guys. The car is a 94 and it does have O2 sensors. I think for now I'll leave the cats on just in case because I can't afford to flip flop if it doesn't work. I may consider at least putting high-flows on. One question...when everything is cold, the first few revs or at least until the everything warms up...the exhaust rasps a little...sounds like a piece of paper caught in a fan when I rev a little. Any ideas? Is that an accoustic thing with the mufflers untill the heat up? Thanks!!!

Post by **Eswift** » Mon Sep 15, 2003 4:16 pm

raspy noise could be loose heat shields on cats, although that wouldnt necessarily dissipate as the engine warms up...

Post by **Mayhem_J30** » Mon Sep 15, 2003 4:16 pm

The J is very loud with gutted cats, or just high flow cats for that matter. Especially after putting on some hiflow muffs and removing the resonator.

Post by **robmcole** » Mon Sep 15, 2003 4:16 pm

I had a problem with raspy sound when the little hole in front of the beginning of the catalytic converter was blowing exaust air out of it. I put some muffler mender on the hole and it stopped. This did not stop after warmup because it was essentially a leak. I dont know what those little holes are for. You can put your hand under there when you start the car and feel for leaks... maybe the heating up of the exaust is expanding the pipes enough to cover up the leak.. Just a thought.

-Robert Cole Birmingham, AL.

Post by **TechGizmo** » Mon Sep 15, 2003 4:16 pm

That hole in the Cat is a drain hole I believe, I have seen it on another cat from a minivan. If both cats on the J30 have a hole in the same place, then it is there for a reason.

Post by **seanb7rd01** » Mon Sep 15, 2003 4:16 pm

I want to put a true dual exaust on my J30 and I'm looking for suggestions for good cats and mufflers. has anyone did a before and after dyno comparison to see what kind of HP gains are attained on a J30 with an aftermarket exaust?

Post by **elwesso** » Mon Sep 15, 2003 4:16 pm

Nice J dude..... Id like to upgrade my rear muffler for something with a little more rumble, and I already have dual exhaust!!!

Anyway, where'd you get that HUD... Thats really cool.......

Post by **NY94J30** » Mon Sep 15, 2003 4:16 pm

elwesso wrote: I already have dual exhaust!!!

If you mean dual exhaust with single outlet, the J has the same set up.

As far as performance mufflers, I emailed these guys a while back just to see their prices, and they told me the only application for them was the Q, check this out:

http://www.r-spec.com/muffler/muffler.html

I think this is prices in yen (if so they're pretty expensive)

http://www.datasystem.co.jp/ca...o.pdf

Post by **elwesso** » Mon Sep 15, 2003 4:16 pm

Their website is messed up......

Post by **maxnix** » Mon Sep 15, 2003 4:16 pm

NY94J30 wrote:If you mean dual exhaust with single outlet, the J has the same set up.

No, the Q is dual stainless steel all the way through.

Post by **elwesso** » Mon Sep 15, 2003 4:16 pm

Does anyone know how the Q sounds with just straight pipe coming from the resonators......

Post by **Jeff Williams** » Mon Sep 15, 2003 4:16 pm

elwesso wrote:Does anyone know how the Q sounds with just straight pipe coming from the resonators......

Like a Ford Dump truck. Prety cool, if you like to drive dump trucks.

I am looking at a Magnaflow dual resonator/resonator combo. I might have it put together, around Christmas. I'll let you know how it sounds.

Post by **VimyJ** » Mon Sep 15, 2003 4:16 pm

J30 is true dual and all stainless steel exhaust. Little gain in hp to be had from modding it.

Post by **elwesso** » Mon Sep 15, 2003 4:16 pm

All anticipate hearing about it!!!!!!

J30 Dual Exhaust : Cat-back!

J30 Dual Exhaust : Cat-back!

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