Mr_Meaty

um...I"m just going to ignore the last 3 posts and say that my dyno was on june 12th in Arizona, so super hot and slightly higher elevation.

but speaking of pully's on turbos...did you guys see the ATI twincharge tC at ScionVIP? I didn't even know it was there:

http://www.scionvip.com/gallery/gall...54&whichpage=3

lower right

hunterUnknown

iTrader: (1)

yup! that things been around for a while. thats the next project. it'll be problem-free for sure :D:D

see im not familiar with how the two setups react with temp and elevation change. maybe turbos are more adaptable to these changes and superchargers arent?

aen

yup

turbo won't change, engine will turbo won't

supercharger will.

missReni

"my book is in my car
we went over turbos today in class
it runs off of exhaust gas
therefore not changing because of elevation and heat"

I demanded a source to credit the quoted statement. It actually makes sense, really.

hunterUnknown

iTrader: (1)

yeah thats just how a turbo works. i think the temp would still have an effect, just as it would on a supercharger. i mean the higher temp the molecules of air are, the more they spread out, and thus... less to suck into a turbine and compress to begin with. the logic, to me, works on both super and turbochargers. further proof of this... intercooling.

unless im just somehow very wrong about that.

aen

no, turbos run purely on hte energy of flowing exhaust fumes which is hte same regardless of where you are.

unless you are like in space or something...then nothing moves anywhere. but lemme find hte exact quote

missReni

But then wouldn't less molecules (haha I feel so scientific) equal less energy?

aen

we are talking about turbos, not engines though. true in a higher altitude and cooler place you will be making more HP but that's because at a higher altitude and cooler place the mixture would ignite more efficiantly.

those conditions would not affect the amount of air compressed using the turbo as it is spun off of waste.

hunterUnknown

iTrader: (1)

i understand it will spin at the same speed due to exhaust gas driving it. but again, if it reaches x speed in high temp air wouldnt it make less power ultimately than spinning at x speed again in low temp air? same exhaust gas. same turbine speed.

hunterUnknown

iTrader: (1)

ok i think i get it. since the wastegate only lets off pressure at a certain amount, the turbo will just spin up more until it reaches that amount assuming there is a higher temp or higher altitude situation.

aen

"a normally aspirated engine will lose 3% of its hp with every 1000 foot increase in altitude. a turbocharged car will not lose power as it is driven into higher altitude."

haha

the only thing that is affected by tempurature and elevation is the air that is being compressed. but on a turbo, it's being compressed by waste, and that isn't dependent on the output of the engine as that is the same at all elevations and tempuratures.

like say if you were going to take an exhaust and cut it right at the downpipe you wouldn't MAKE power because it's faster at leaving, you're just FREEING power because it's leaving faster. get it? at different conditions such as tempurature and elevation the power is made the same for a turbo.

now for a supercharger, it is driven off of a belt on the engine if hte mixture is too hot then it won't move as fast yes?

aen

that makes sense.

hold on lemme read. i could have been TOTALLY wrong. hahah

aen

hmm. i don't think that's true now that i think about it.

vacuum sources are the same no matter what altitude the car is in and that's what a wastegate is dependent on.

hunterUnknown

iTrader: (1)

not sure what you mean by vacuum sources? the engine? the turbo?

aen

vac lines control the wastegate, when your engine/turbo builds enough pressure it releases

which would be hte same regardless

hunterUnknown

iTrader: (1)

exactly what i mean too. the wastegate will simply hold until the pressure is reached, thus making temp/density not matter so much. on the s/c, the turbine wont spin any faster than the engine will allow so it cant compensate the way the turbo setup will. i think we're talkin about the same thing haha

aen

not really, you're saying the turbo works harder to get somewhere when it's in less than ideal situations.

but what i'm saying is that regardless of the situation, the exhaust(waste) will be the same, propelling the impeller at hte same rate as if it were somewhere else.

missReni

And that's why temperature and elevation don't affect a turbo's numbers, right? Wasn't that what we were originally trying to figure out? This sounds like you just answered your own question, unless I'm reading it wrong..?

aen

yea but i don't think that's how it works cuz then that would decrease the efficiancy of the turbo,. also that would mean that boost would react differently, but 5 pounds is 5 pounds regardless of where you are.

aen

again i THINK i'm right but yours sounds pretty viable.