New 240SX and GT-R

[AWDSR20]

i like my 240 "Sr20 powerd"... 5 speed yay!

[AWDSR20]

Originally Posted by NiSmO_zt

i believe the efficiency they give for these types of turbines/compressors are thermal efficiencies. that would be the ratio of work out of the comp. and work into the comp. These work terms aren't just temperature related, they are based on enthalpys and mass flow. given that mass flow is constant, it cancels out, so the efficiency is a ratio of the specific enthalpys at the exit and the inlet of the compressor. These enthalpys are not solely temperature based, they're pressure based, and pressure is obviously not a constant, so i dont think you can make the direct temperature relations as said because i think there's more to it, but i guess you're just trying to make a point.

and i could be wrong.... its been a while since ive taken thermodynamics

btw, whats your edu?

P = Force X Area
W= Force/Distance
efficiency is based on Tangent Velocity in/out of the turbine (direction of velocity exit)

Cool?

[nissanfanatic]

Originally Posted by NiSmO_zt

is this your calculation, or did you find it somewhere?

i think these calculations are only good for an isobaric process.

i believe the efficiency they give for these types of turbines/compressors are thermal efficiencies. that would be the ratio of work out of the comp. and work into the comp. These work terms aren't just temperature related, they are based on enthalpys and mass flow. given that mass flow is constant, it cancels out, so the efficiency is a ratio of the specific enthalpys at the exit and the inlet of the compressor. These enthalpys are not solely temperature based, they're pressure based, and pressure is obviously not a constant, so i dont think you can make the direct temperature relations as said because i think there's more to it, but i guess you're just trying to make a point.

and i could be wrong.... its been a while since ive taken thermodynamics

btw, whats your edu?

They are calculations from Turbochargers by Hugh Macinnes. I plugged in the numbers, but I found the basic formula in the book. This is just one of many of the calculations used in sizing turbochargers in his book. They are really just based on heat created by compressing air, and nothing else. I'm not quite sure mass flow is the same though. As PSIG increases, so does the flow of the compressor until efficiency drops off. Thats where only the pressure ratio increases but no more air is flowing. Which is where IAT becomes a huge concern. IIRC some heat is passed over by exhaust heat but I'm not too sure if that is a large factor. You can factor in barometric pressure with the entire formula using the pressure ratio you have to find which is (PSIA+PSIG)/PSIA. So yes you could say the part I used is isobaric, but no the enitre formula is not isobaric. Yes it is just a ratio of the enthalpies. You are just using a simple forumla to figure out how much energy will be released when you compress air. I've never taken thermodynamics but if I see it on the list of courses given, I'll be sure and take it.

Originally Posted by AWDSR20

P = Force X Area
W= Force/Distance
efficiency is based on Tangent Velocity in/out of the turbine (direction of velocity exit)

Nice... I'll have to read up on that sometime. Freshen up on the ol' math skillz.

If you want an explanation in how the compressor actually increases the velocity of the incoming air(or whatever liquid or solid you're compressing), then http://mathworld.wolfram.com/VelocityVector.html should help you out a little.

My education is only a high school level education, on paper anyways. But I guess thats what counts huh?

[dpsayz]

im sure some one probably brought this since im only going to read to the 2nd page right now .. but i read in a later issue or SCC that they are going to get rid of most manuals. So them making the new GTR an auto isn't too big of a surprise.

I also hate that they change the cars the way they do. I mean look at the new BMWs. Yeah they look pretty nice but i mean they don't hold any resemblence to the older models. Same with the newer generations of the eclipse and stuffs .. doesn't really hold any good traits. I also red that like .. toyota will be discontinuing the MR-2 and the Celica .. to be replaced by the Scions. Even though the Scions are nice .. i still liked the mr2 lol

To make sure no one will think im being off topic .. what im trying to say is that alot of companies are changing in ways that maybe we ( or you guys since i don't really know a whole lot .. yet haha ) wont like .. kinda sux sometimes though

[phoenix_fire180SX]

Originally Posted by nissanfanatic

Like you were saying about the GT28, using a turbocharger with lighter materials, properly sized housings and wheel trims according to where you want to make power, and the advanced balancing and bearings of today can be much better than using a twin(sequential or parallel) setup. The larger GT series compressors are fully capable of supporting high HP levels as well as having little lag. Very efficient as well. If you are tuning a engine for power, you can't think you're going to make power everywhere in the rpm range. That kinda gets smaller with the higher amount of power you make. You were correct about twins in the upper HP areas though

You are absoulutely correct about air flow and matching the turbo to your engine. I know, I did it. That is what determines how efficient the turbocharger is going to be for your setup. You can go through and do all the math, but usually you can just "eyeball" it and say every 1lb/min=10hp.

Theres plenty more to read here:
http://www.automotiveforums.com/vbul...d.php?t=201348

That's cool then. I'll take a look at that link. I still think a parallel twin turbo setup would be better, especially with modern turbos such as the GT28RS. But yeah, I see your point, and you seem to see mine, so it's cool.

[logik23]

Originally Posted by Ace$nyper

wanta be a real man then try all your driving on chapman sturts then tell me how gay all this is

yea good tech sucks lets also just stop using chemo too right cause its not as hardcore as just dying

there tons or REAL drivers cars out there stilll hell one of the nicest most fun cars i've driven EVER was the 05GT handled nice as hell fucking live axle w00T thats OG for you.

you sound like you also wanta kill ppl who say the earth is round come on man just think before you talk yours being silly really.

What the fuck are "chapman sturts"? If you wanna be hardcore, finish grade 2 english.

Seriously though, I'm not saying they should only have minimalist cars, I'm saying they should have them, along with new techno cars.

Oh, and yeah, because I hate automatics and stability control that means I hate all technology, yeah, I'll just come home with my manual car to my cave and light a fire and roast me some mammoth meat. Dude, you're fucking retarded.

Originally Posted by 1viadrft

I learned with MT and have had many cars with MT and all I can say is AT makes sense since the shifting is no longer open to human error. You guys mentioned WRC and F1... perfect examples of this! Sure they are not AT... but it's not traditional MT when you got computers shifting for you! The best of both worlds! They may as well be automatic transmisions!

Dude, if you take out full manual trannies to get rid of human error, you might as well not have drivers, what's the point, right? I mean let's have 100% computer controlled cars, cars that don't have drivers so that it's impossible to make a mistake, oh and let's have those car built by machines so you have 0% chance of human error......wait a minute, that's just stupid! Human error is part of auto racing, that's what makes it interesting, or else, why have drivers in the first place? Do you want racing to become like the WWE where the winner is known before the match (or race in this case) is even started?

[Hit_N_Run-player]

whats the point of having the race if we know whos gonna win?..lol.. robot driven cars would suck without humen error.

[D-Bo]

autox, drifting, drag.. all auto sports will never die cause of guys like us, all tuners, everybody who loves cars these days will still be around when everything is controlled by computers..

[NiSmO_zt]

Originally Posted by AWDSR20

P = Force X Area
W= Force/Distance
efficiency is based on Tangent Velocity in/out of the turbine (direction of velocity exit)

Cool?

alright, p is pressure. what exactly do you mean by W? work? power? work is force x distance, and power is work/time. please give definitions on the terms you use to avoid confusion. and what is cool? lol this is high school physics, its soo hard....

[Hit_N_Run-player]

yeah, where did the variables that he listed com from?? What formula is he talking bout? im confused...

[AWDSR20]

Originally Posted by NiSmO_zt

alright, p is pressure. what exactly do you mean by W? work? power? work is force x distance, and power is work/time. please give definitions on the terms you use to avoid confusion. and what is cool? lol this is high school physics, its soo hard....

OK OK

here its is (i used the / insed of X for the WORK formula)

Work = force X Distance
Pressure = force X Area

think about Tangent Velocity as

v(t) = r'(t) = d(x)/d(t) i + d(y)/d(t) j (basiclly the derivative)

where t is time

v (speed) = II v(t) II

bsiclly to calculat the V in a turbine (or anything for that matter u use data for a 2 demantional V as in the 1st example, and 3d V as in a turbine 2nd example)

1) u have a position vector at a point P given with some eq like :
r(t) = 2ti + 3t^2 j + t^3 K for 0<t<2 and u need to fined the Velocity and the Accel of P at a time t. (which is simple as taking the derevative of the eq)

2) u have a point P that is rotating about the x axis on a circle of radious K that lies in the plane z=h. (think of a yoyo that is spining in the air, P is the yoyo, K is the distance from the center of the circle formed by the yoyo to the point P) The vector W = w K directed alonge the z-axis and having magnitude w is the ANGULAR VELOCITY of P. the velocity of of v(t) of P is the cross product of W and direction vector r (t) for P.

r(t) = K cos wt i + K sin wt J + h K
using the cross product



wX r(t)=
I i J K I
I 0 0 w I
I kcos wt k sinwt h I
= - wk sin wt i + wk cos wt j = r' (t) = V(t)


ps: i don't have a way of writing Matrix i used the I as the lines...



finally, i don't know if i helped. i had a final on that stuff about 1week ago... (that stuff is so Fukn hard!)

[phoenix_fire180SX]

Originally Posted by Ace$nyper

...one of the nicest most fun cars i've driven EVER was the 05GT handled nice as hell fucking live axle w00T thats OG for you.

True, the '05 Mustang GT handles exceptionally well for a car with a live rear axle. But seriously, think about how much better the handling would be if it had a fully independant rear suspension like the 240SX has had since 1989. That's why I'm hoping Ford will come out with a Mercury version of the new Mustang, so they don't have to keep the live rear axle. Ford was seriously considering ditching the live rear axle for a modern independant rear suspension, but the Mustang enthusiasts demanded the live rear axle, so they got it.

[AWDSR20]

I i j k I
I 0 0 0 I
I (k cos wt) (K sin wt) (h) I

is that better?

[nissanfanatic]

I believe we are not using the acronym KISS(Keep It Simple Stupid). Companies that make the compressors and turbines already give us maps telling us where the turbo performs most efficiently. But I like all the techy stuff. Makes me feel at home. BTW all that stuff sounds like a more complex way of explaining centrifugal force and the fact that the outside of a wheel is spinning faster than the inside. Nice post though AWDSR20.

As for human error, if all possibility of human error was taken away, sports would not exist. More possiblilty for human error makes a sport more competitive. It mean you have to be better at what you do in all aspects, not just turning the wheel.

[AWDSR20]

tnxs!