411Z

you know, i dont know. in theory that sounds correct. but it seems retarded. im not so sure that these cars stock put out enough displacement to run TD stock. most times, (even on stock) TD will increase hp, but make a huge loss in torque. so it is wierd what happened to the op, but i suppose it could cause a loss in hp.

btw: i only speak from my own personal experience. if someone wants to throw a bone stock z on a dyno with 3" duals on a dyno and prove me wrong i will shut up.

Cux350z

iTrader: (162)

no. hell no.

411Z

yeah i dont think thats the right way of thinkin pal. but like i said, put it on a dyno and prove me wrong. i have never seen anything that disproves what i said. you guys all say im wrong, but you sit here perplexed on why the OP's car lost power. yes the heat had something to do with it, but its not the only reason. some people on this forum agree.

when i did my exhaust, i did a 2.25 single. i wish i had dynoed before hand, but i didnt. im gonna dyno it now and see what i get.

and what do you mean i tried to redeem myself?

Cux350z

iTrader: (162)

are you talking about the math i put in my previous post or the guys 1.5" duals comment. Either way.........................wow.

you cant ignore the math that dual 2.25 != single 4.5. Especially in terms of flow in cfm and pressure.

411Z

i was talking about the 1.5 comment. your math was way too complicated for me. im just speaking from what i have seen and i have never seen anything to prove me wrong.

i dont think a v6 needs dual exhaust unless its making high hp.

Cux350z

iTrader: (162)

im not debating the " true duals may cause power loss on a NA Z", im laughing at youre lack of mathematical reasoning that a 2.25" dual will flow the same as a 4.5" single.

Cux350z

iTrader: (162)

area and circumference of a circle is too complicated? how old? what education level do you have?

area = PI * r^2
circumference = 2* PI * r

where r = D/2
and PI = 3.14
and D = 2.25 or 4.5

haeshik

iTrader: (36)

411Z

my reasoning on the math is this, and although it doesnt add up mathematically it still makes sense: with duals you have all three cylinders flowing exhaust on their own path. but if you route both cylinders together, why would that figure not be doubled. this is thinking that when setup as duals, the exhaust is actually the correct size for the amount of exhaust flow. so if three cylinders need 2.25" of pipe to flow correctly, why route 6 cylinders down one path with a smaller diameter than what they need?


and im only 21. its not that its complicated, i just havent used that since probly 10th grade, and i dont remember the figures needed to do it. to be honest, it looks like spanish to me right now lol

ssgohan434

iTrader: (13)

^ Lol, beat to the punch! I was gonna post something similar

Basically.... A true dual 2.25" exhaust, provides slightly more flow than a 3" single exhaust.

A true dual 2.25" exhaust does not equal to a 4.5" exhaust... math doesn't work like that...

For example... area of a circle = Pi r^2.

( (3.14) 2.25"^2 ) times 2 for true dual ... does not equal (3.14) (4.5"^2)

Hope I didnt' make it more confusing...

R-TuneZ

i think you guys are making this way too complicated. most of the power loss is probably due to the large increase in ambient temperature. when you go from running dynos at 40-60 degrees to 100, you are bound to experience a significant drop in horsepower when calculated with tq/lbs and time which is what dyno hp numbers are based on. when driving a car in a cold environment you are not only allowing colder, denser air to enter the engine for combustion, you are also allowing the engine to run more efficiently due to the lower ambient temperature. furthermore, the cold air will prevent, or at least reduce, heat soak which exponentially increases the temperature of the intake charge. the diameter of the exhaust is an issue, but this will not deplete the engine of 30whp. the culprit here is probably the temperature, not the size of the exhaust. also to be considered is the volk wheels and their diameter, and weight, the person who was running the dyno, the settings and correction method (or lack thereof) used.

Cux350z

iTrader: (162)

i mentioned the air temp in my first reply. Im just lol'ing at the thought of seeing someone run a 1.5" dual........or even the fact someone suggested it.

Im not really in the Size debate issue, i was covering his lack of MATH and use of logic. Like i said, ill leave the Fluid calculations to a Mechanical Engineer.

411Z

lack of math...yes. logic no. you dont have to be a deutche bag. and for the record, i never suggested 1.5" duals.

Escobar

iTrader: (27)

the hks exhaust is 2.36 inchez.

Cux350z

iTrader: (162)

im not being a DOUCHEbag.

you didnt explicitly suggest 1.5 duals, but your math convinced another member that it was a decent idea but you did say "in theory that sounds correct."

also to this:

go ahead and explain how a TD will increase hp but loose some much tq.
You know they are mathematically linked?

hp = tq * rpm/5250

Only above 5250 rpm will hp> tq and below 5250 rpm tq > hp. When you lose torque you lose hp. When you gain torque you gain hp. NO MATTER WHAT.

The only thing that can happen for example is you lose tq in the low end and gain some in the top end. You still gain HP in the top end and lose some in the low end. So when you gain tq in the top end, your hp gain is larger then the hp lost in the low end ( given constant tq loss)

411Z

thats what i was tryin to say in shorter words, obviously it didnt turn out so well. but the loss in low end tq completely kills the car and makes it a slug. sure you could go 200mph (or not), but its gonna take you a while. that is what i was tryin to say. thank you for correcting me

banshee

iTrader: (1)

I blame the Fu**ing HEAT!!! But then again... I'm also in ATL in July... so I blame pretty much everything on the heat...

Also...
"Information's" logic is starting to make sense (the formula is 2 double Maker's w/ a splash of soda neat and 4 Sam Adam's Boston Lagers, let sit for 25 min. on a drive down I20E, then add 2 redlabels), but Chris' math is flawless...

BTW 411Z... can I get the number to the Cheetah in downtown please?

gothchick

iTrader: (12)

Anything more then teh 6 inchez = teh waste yo.

411Z

(702)384-0074... there ya go big guy.. cheetahs as asked... wack away!!

singh

iTrader: (2)

The HKS nuthuggers are in denial.