Exhaust Poll

Sh0velMan

Wow.

Okay guy.

Having a "vacuum" chamber hanging off your exhaust will improve scavenging, but also cause a flow inversion, so it's great for low to middle RPM range but does nothing positive for high rpm operation, which is all i care about.

Of course a vendor is going to say that their expensive new product is great in every way.

I can tell you right now, you don't make more power, but it doesn't matter. Bring your money down here and we'll set up on a mustang dyno back to back if you really want to 'bet' otherwise lets leave size out of this.

Fact is, you've bought one of the least engineered and cheapest produced exhausts, then butchered it up with extra tubing, then paired it with the lowest-flowing longtube headers available, and now are preaching to someone who has spent far longer in the search for power in this platform. I'm done with the subject, do what you want, I'll keep doing what I'm doing.

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chii370

so you proved my point. this is beneficial for you. but most of the Z community doesnt have their car at 7500 rpm all day long every day. im sure you would be very interested in race cams too "if it wasnt for vvel" as they completely destroy every day usefulness of a car in benefit to one very specific scenario, racing. the whole point of the argument was showing the science behind it for what is better OVERALL, not just for you you you.

and just to toss this out there, price doesnt matter. my ark was 1700. is it 1000 better than some of the cheaper exhausts? no. is the amuse 3000 better than my ark? no. it doesnt work that way. its not a ******* scale. yes their are engineering differences, but aside from build material, quality, pipe diameter, shape, bends, welds and so on they are all functionally the same. and no ones to say a MORE expensive model couldnt in fact be out performed by a less expensive one. thats a rich douchbags way of looking at things. just move your slider from one side of the bar to the next. lemme just buy all the most expensive parts and that = im the fastest best mechanic in the world. durp. I can see you do EXACTLY that, as you bought the nismo R tune intakes "twice the price means better". guess what, the stillins gen 3s are cheaper and they perform much better. so shut up. according to your logic they are not engineered as well. due to price.

Sh0velMan

Actually I have those intakes because they were sponsored to me by Nissan Motorsports North America, I paid well under what G3's run. (Less than half, actually) If I were buying intakes today, I'd be getting G3's.

Try again?

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synolimit

No ones in high rpm operation. Coming out of turns, down shifting etc you're in low and middle range where you need all the power you can get.

Actually I didn't read anything from a vender. and tony refuses to post his own testing. It's only customer dyno's and magazines that were curious about new and interesting looking projects so they tested also. Tony is some rocket scientist or something so I tend to believe a guy that knows what he's doing and then refuses to post results and tells buyers, "you post results so people believe you and don't think I'm lying or changing dyno graphs."

If I had a second car I'd totally ship my CBE to you!! You do 3 runs with yours, do 3 with mine with zero rasp and ill bet. I'm not trying to compare size, I'm simply trying to tell you about physics.

Lol and yeah that's all true about my products. Cause an exact copy of some one else's stuff is going to be so much worse than the original since it's an exact copy. You know what? Going to the dyno right now to show you a before and after eBay LTH with my CBE.

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13 370z-

kfull

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Sh0velMan

And if EITHER of you think for half a ******* second that you have any ground to lecture me on tuning principles as they relate to this car, you need to go think about what you're saying.

I have over a hundred dyno pulls across a dozen iterations of build on my car with tons and tons and tons of data collected. I'm not some ******* idiot buying random parts based upon brochure stats.

I would hazard a guess that I am probably in the top 20 or 30 people in the ******* world when it comes to knowledge on what makes THIS CAR'S engine tick and where to get power N/A. Just wait, here before too long I'll post some **** that will really blow your mind.

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synolimit

Something just came to me I think will explain better.

Imagine a vein in your arm with a syringe of blood stuck in. Your rasp is a gap of blood flow. When there is a gap the syringe (Helmholtz resonators with stored air pressure) will automatically inject blood to fill the gap and in a car will take away the rasp as it injects air back in. This helps with scavenging because the flow is kept up with no gaps. In fact the air doesn't inject in because it acts as vacuum and the air is sucked into the gap of flow. That's why art pipes make more than just straight test pipes.

This also would work with a garden hose as an example which we all can see everyday. When you first turn it on the water spits and sputter out the end because in between the water (in a car it would be exhaust gas) is air gaps. These gaps of air slow the flow and the water pressure sucks. Now if you had syringes of water stuck in the hose to inject water every time a air gap was seen, the flow would be 100% out the end of the nozzle from then second you turned on the faucet. If you have rasp, you have power loss.

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13 370z-

frost

This discussion is absolutely painful. Go to bed, you're all cranky.

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370z OG

chii370

found this. learned a lot. supports pretty much what I already said, but did it in less of a stubborn ******* way. Exhaust noises and defining rasp. - MY350Z.COM Forums

chose the next closest thing to a 370 thats not a 370, its little bro 350. and dont say G...... in my mind those dont exist.

synolimit

Boom!!!!

As promised. stock header and cats with a muffler that bends into the mufflers then bends out to the tips vs garage line LTH (looks like a eBay obx header), my Helmholtz welded in at the x pipe and straight pipes.

No tune, still running rich! 13hp, 17tq peak, 18-19hp, 11-17tq mid range.

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13 370z-

Chuck33079

Not bad gains. How much do you think you picked up with it being 20 degrees cooler on the second run? Also, what's with the dip at 5200rpm or so? it wasn't there on the stock run.

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chii370

jeez, thats not half bad. I would have never called THAT much. I have absolutely NO IDEA if I gained anything with my ark dts or not. never had the 13 dyno'd and havent tuned it since install. to be honest, i HOPE it does but i really dont give a ****. when its TT it wont matter anyway.

luigi90210

i would say 10-15whp at most if thats your only mod

either way, ark does make a really sick sounding exhaust for a good price

when you do go twin turbo, you could get 3in test pipes and have a electric cutout welded on to the test pipe this way you can keep your exhaust do when driving around town, you have a streetable car but when you are at the track, you can open them up for a optimum spool and power(heck i have seen evos gain 40whp with an electric cutout open)

thats the route im gonna take when i twin turbo my Z, get a nice tame exhaust for daily driving while having a button to make my car scream at will

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Sh0velMan

I'm really not trying to be a ****, but gaining 13whp from ditching the stock headers and cats for Longtubes is really not that impressive. Plenty of folks get that from test pipes. (Not to mention the 20 degree difference, which absolutely matters. WC or not, you will make more power when it's cooler.)

Also, there's nothing about that data that indicates your resonators had anything to do with the gains at all. I would venture a guess that the cats (and temperature) is the main thing that netted you that gain, given that the gains are uniform throughout the power band.

Anyway, glad you like it, that's all that really matters anyway.

Also, that's not really rich... most guys find maximum N/A power between 12.5 and 12.8. Before my tune, I was pegged at 10.5, now THAT was rich.

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synolimit

13 was peak. Mid range is much more impressive and important for the almost 20 it gained! And since its untuned the full gains can't be seen since its so rich. The stock map can't do everything.

You're 100% wrong about the temp. The SAE correction targets 75 degrees for both. So if both would have been run at 75* that's the power you'd see. If you want uncorrected, fine, I'll get it showing you what 20* really does.

Since another 370 dyno'd at 91* with TS I'm going to again say you're wrong. He only put down 280 which was the same as me with cats. Guess what?? He's raspy as hell.

The sniffer in the tall pipe is 1.0 AFR off. The cars wide bands were much richer from the logs.

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13 370z-